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*[Burst Advocate Guide]{.smallcaps}*

PSU-OPS-002

Version 0.8

Date: 15 July 2004

Rev: 15 July 2004

Approved by:

John Nousek, PSU Date

MOC Director

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  **REVISION                                                           
  SUMMARY**                                                            

  REV          RELEASE DATE   BRIEF DESCRIPTION/REASON FOR CHANGE      EFFECTIVE
                                                                       PAGES

  0.1          30 June 2003   Initial draft.                           All

  0.2          11 August 2003 Revision, including section by Kevin     All
                              Hurley                                   

  0.3          15 August 2003 Following review by Leisa Townsley       All

  0.4          22 August 2003 Additions to Section 4, by John Nousek   10 - 11

  0.5          12 September   Additions to Section 3.2, 4.5.3, 7 by    9-10,
               2003           Neil Gehrels                             13-14, 19

  "            "              Additions to Section 4.1.3, 4.2.3 by     
                              Pete Roming                              

  "            "              Additions to Section 4.4.2 by Padi Boyd  

  "            "              Additions to Section 5 by Kevin Hurley   

  "            "              Additions to Section 4.1.1, 4.2.1 by Ann 
                              Parsons                                  

  "            17 September   Section 3.1 by Bing Zhang                
               2003                                                    

  0.6          8 October 2003 Revisions based on comments at Burst     All
                              Advocate Workshop                        

  0.7          14 January     Inclusion of Swift Afterglow Observing   
               2004           Plan, Internal MOC interfaces by John    
                              Nousek                                   

  0.8          15 July 2004   Version to support FOR                   

                                                                       

                                                                       

                                                                       

                                                                       

                                                                       

                                                                       

                                                                       

                                                                       

                                                                       

                                                                       

                                                                       
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#  {#section .unnumbered}

[1 Scope 4](#scope)

[1.1 Burst Advocate Mission 4](#burst-advocate-mission)

[1.2 Purpose of Guide 6](#purpose-of-guide)

[2 Burst Advocate Management 7](#burst-advocate-management)

[2.1 BA Appointment 7](#ba-appointment)

[2.2 BA Succession 8](#ba-succession)

[2.3 BA Handoff 9](#ba-handoff)

[3 Burst Advocate Science Issues 9](#burst-advocate-science-issues)

[3.1 Brief GRB Science Overview 9](#brief-grb-science-overview)

[3.2 Swift Key Projects 15](#swift-key-projects)

[3.3 Recognizing 'Special' Bursts 16](#recognizing-special-bursts)

[4 Swift Operations and Data 16](#swift-operations-and-data)

[4.1 TDRSS Data 16](#tdrss-data)

[4.1.1 BAT 16](#bat)

[4.1.2 XRT 17](#xrt)

[4.1.3 UVOT 17](#uvot)

[4.1.4 Observing Scenarios 22](#observing-scenarios)

[4.2 Standard Ground Pass Data 25](#standard-ground-pass-data)

[4.2.1 BAT 25](#bat-1)

[4.2.2 XRT 26](#xrt-1)

[4.2.3 UVOT 26](#uvot-1)

[4.3 Spacecraft and Other Infrastructure Data
26](#spacecraft-and-other-infrastructure-data)

[4.3.1 Figure of Merit (FoM) 26](#figure-of-merit-fom)

[4.3.2 Spacecraft 27](#spacecraft)

[4.4 Data Paths 27](#data-paths)

[4.4.1 TDRSS Data Path 27](#tdrss-data-path)

[4.4.2 Ground Pass Data Path 28](#ground-pass-data-path)

[4.5 Rapid Response Framework 29](#rapid-response-framework)

[4.5.1 Internal Interaction Interfaces of Ops Center
29](#internal-interaction-interfaces-of-ops-center)

[4.5.2 Mission Ops Center Daily Routine
30](#mission-ops-center-daily-routine)

[4.5.3 External Interaction Interfaces of Ops Center
30](#external-interaction-interfaces-of-ops-center)

[4.5.4 Rapid Response Data Products/Publications
31](#rapid-response-data-productspublications)

[5 Follow-Up Team Communications 33](#follow-up-team-communications)

[6 Burst Summary Report 37](#burst-summary-report)

[7 Publications for Each Burst 37](#publications-for-each-burst)

[8 Appendices 38](#appendices)

[8.1 Swift Follow-Up Team Members And Associate Scientists
38](#swift-follow-up-team-members-and-associate-scientists)

[8.2 Swift GRB Afterglow Observing Plan
41](#swift-grb-afterglow-observing-plan)

[9 Abbreviations 42](#abbreviations)

[10 Burst Advocate 'To-Do' List 44](#burst-advocate-to-do-list)

#   {#section-1 .unnumbered}

# Scope

This document provides a Guide, intended to serve as a basic training
tool, and a reference manual for individuals who will participate in the
Swift Gamma-Ray Burst Explorer mission by serving as Burst Advocates.
Burst Advocates are individuals assigned by the Swift Executive
Committee to take personal responsibility for an individual burst, and
who (available on a 24 hour per day, 365 day per year basis) monitor the
Swift reaction to that burst (starting as soon as the burst report
reaches the ground) and support the Swift operations team and the
external follow-up teams to ensure that both the Observatory and the
ground follow-up are as scientifically productive as possible.

This document serves as a Guide, so it does not serve as a definitive
reference for any of the instruments, spacecraft, operations or
Observatory data or procedures. Such information provided here is to be
used for training and convenience. Please refer to the appropriate
definitive documentation within the Swift library, if needed.

##  Burst Advocate Mission

Swift is a totally unique astrophysical observatory. Its primary mission
is to rapidly respond to Gamma-Ray Bursts (GRBs), maneuvering the
spacecraft and operating the instruments to respond to new GRBs without
ground intervention. This autonomous response allows Swift to collect
important data with the XRT and UVOT within just 20-70 seconds of the
discovery of a new GRB by the BAT.

As GRBs occur randomly on the sky and without warning, Swift ground
operations must be prepared to deal with the science challenges of this
prompt data in a highly agile and efficient manner. Moreover, the GRBs
and their afterglows rapidly fade from observability, so the premium on
rapid response applies equally to the scientific response of Swift, its
instruments and the expected ground followup activities.

Most previous observatories have relied on the concept of a 'Guest
Observer', or similar term, who had the responsibility to define the
scientific requirements of an observation and provide inputs to the
observatory technical staff on how that observation should be carried
out. The random nature of the GRB phenomenon, and the rapid nature of
the swiftly changing target properties of GRBs, precludes using a Guest
Observer approach prior to the discovery of a new GRB, and the rapid
requirement for followup precludes a selection process after discovery.

Burst Advocates (BA) provide the scientific guidance normally provided
by Guest Observers, but with the immediate response and pre-planned
knowledge required by the Swift mission. The key elements of the Burst
Advocate role are:

-   **Before the burst --**

BAs are expected to be trained to understand the basic capabilities of
the Swift spacecraft, the Swift instruments, Swift ground operations and
the Follow-up Team.

BAs are expected to serve in a standby succession pattern and be on call
to respond to the next burst occurring during a one week long duty
window. During this time they must be prepared to respond on a 24 hour
per day basis.

BAs are expected to be knowledgeable about how to receive and send
information about GRBs, Swift (including spacecraft, instruments and
mission operations), and the Follow-up team planned activities. They are
expected to be aware of and be prepared to follow Swift Project policy
with regard to this information.

BAs will be available for questions and discussions concerning
pre-planning the observing strategy for bursts in concert with other,
non-Swift activity. This may include Targets of Opportunity (ToO)
activities with other spacecraft, or ground based observatories; or
coordinated observing programs.

-   **During the immediate (minutes to hours) response to a new burst
    --**

BAs are expected to acknowledge that they have assumed responsibility
for the new GRB, and to inform their successor as next-in-line to be
prepared to respond to the next GRB.

BAs are expected to promptly establish regular, direct communication
with the current Swift Observatory Duty Scientist (ODS), and inform the
ODS of any issues relating to the scientific importance (or lack
thereof) of the new burst, the activities of the Swift Follow-up team,
and the general scientific community.

BAs are expected to file GCN notices, IAU Circulars, Astronomer's
Telegrams, or other rapid scientific communication, as needed, on behalf
of the Swift team. BAs will conform to any guidelines established by the
PI on publication, authorship and content of such communications made on
behalf of the Swift team.

BAs will serve as the Swift scientific interface to the Swift Follow-up
team and the general science community to explain the Swift response to
the new burst, and to collect scientific inputs for the ODS which might
pertain to the Swift operations or Swift observing schedules.

BAs are expected to examine the newly arriving data from the recent
burst, and assess the data for science content and quality.

-   **During the longer period (tens of hours) response to a new burst
    --**

BAs will propose optimum observing strategies for their assigned bursts
to the MOC Science Planners, to facilitate the preparation of a Swift
pre-planned target list (typically the day following the discovery of a
new GRB) and update their proposal on a daily basis while the burst
remains a viable target.

BAs continue to serve as the Swift science point of contact for the
burst to which they are assigned.

BAs are expected to keep Follow-up team members and the Swift operations
team mutually informed on significant issues relating to their burst.

BAs are expected to continue to examine the newly arriving data from the
recent burst, and assess the data for science content and quality.

-   **During the later period (days or weeks) response to a new burst
    --**

BAs will monitor the continuing Swift observations of their burst, and
recommend when no further data are valuable.

BAs review the data collected from their burst and verify that all data
collected from that burst are processed and properly accessible, and
that all data have been analyzed. They will file a summary report on
their burst data, which will be archived by the MOC.

BAs continue to respond to community questions concerning their bursts.

-   **Overall --**

The essential requirement on Burst Advocates is to assure that every
burst receives the appropriate level of observation by the Swift
mission, that Swift is optimally configured to collect data, and that
the Swift mission both receives and provides to the follow-up team, and
general community, accurate and understandable information about the
Swift mission and the data for the GRB assigned to the Burst Advocate.

##  Purpose of Guide

Because the BAT is more sensitive than any previous GRB detector, we
cannot predict with certainty how many GRBs will be discovered during
the Swift era. Pre-launch predictions suggest that we might expect to
find perhaps 100 bursts per year (with an uncertainty of a factor of 2-3
in either direction). As we expect GRBs to remain visible to Swift for
periods from days to weeks, and we wish to have a unique BA for every
burst, we will need to train at least 50, to perhaps 150 BAs over the
lifetime of the mission. In addition, the assignment of BAs goes across
the entire Swift science team, which includes a mixture of
nationalities, scientific expertise and experience level. Moreover, BAs
are not expected to travel to the MOC on a routine basis, but will
operate out of their home institution or possibly a central site much
closer to their home than the MOC.

Thus we require means to assure that all Burst Advocates have levels of
knowledge and training commensurate with the tasks we expect them to
carry out. This Guide serves as the basic training tool and reference
guide for people serving as BAs. To supplement this Guide, we will
conduct training sessions and workshops at the MOC to provide 'hands-on'
training for a sub-set of the total BA pool, who will then serve as
trainers at their home institution. During pre-launch Mission
Simulations we will offer a small number of BAs actual experience with
carrying out the BA function, to test the soundness of the BA approach
and our training plan.

By providing a standard document for all BAs to study, we are creating
guidelines for reporting, communication, data analysis and documentation
that will result in a higher level of standardization and a lower level
of human errors or misunderstanding.

Finally, we plan to revise and update this document to incorporate the
lessons learned and new procedures as they are developed. Thus our
distributed and homogeneous science team will deliver the highest
quality scientific performance on a continuing basis.

# Burst Advocate Management

Management of the Burst Advocate activity is structured around the
organization of the principal institutions which carried out the
creation and development of the Swift mission. The makeup of these
institutions closely follows the composition of the Swift Executive
Committee. It is expected that top level policy considerations will be
developed and considered by the Executive Committee, and that final
decisions on all policy questions shall be the responsibility of the
Swift PI. Direction of the Burst Advocates shall be carried out by the
managers of the principal institutions, following policy set out by the
PI.

For the purposes of BA management, the Swift team is composed of five
institutions: Goddard Space Flight Center (GSFC; led by Neil Gehrels);
Penn State University (PSU; led by John Nousek); University of Leicester
(UL; led by Alan Wells until launch and Martin Ward after launch);
Mullard Space Flight Center (MSSL; led by Keith Mason); and the
Brera-ASI Italian team (OAB; led by Guido Chincarini). The leaders of
each institution shall be referred to as 'Institutional Managers' (IM),
in the rest of this document.

Institutional Managers may be replaced at the discretion of the PI. It
is expected that Alan Wells will step down as IM at Leicester when he
retires, and will be replaced by Martin Ward.

Institutions associated with Swift, which are not included in the five
principal institutions above, are included in the BA process by being
associated with one of the principal institutions as an 'Affiliated
Institution'. Examples of affiliated institutions are Los Alamos
National Lab (LANL; affiliated with GSFC), the Institute for Space and
Astronautical Sciences (ISAS; affiliated with GSFC) and Max Planck
Insitut für Extraterresiche Physik (MPE; affiliated with UL). Management
and integration of the affiliated institution BAs shall be the
responsibility of the IM of the principal institution to which they are
affiliated.

Individuals who wish to serve as Burst Advocates who are not associated
with either principal or affiliated institutions shall be attached
individually to one of the principal institutions. This attachment will
be mutually accepted by the IM and the attached scientist. Such attached
scientists agree to accept the BA management by the IM, and the IM will
be responsible for integrating the participation of the attached
scientist into the overall BA activities of that institution.

##  BA Appointment

Appointment of BAs shall be carried out on a weekly basis. Each week of
Swift BA operation is assigned to one of the principal Swift
institutions according to the following rotation: 2 weeks assigned to
GSFC; 1 week assigned to PSU; 1 week assigned to the UK; and 1 week
assigned to Italy. The week assigned to the UK will alternate between
MSSL and UL, yielding a 10 week rotation in that case. The Italian week
shall be handled by the OAB/ASI IM. The exact phasing of the initial
weekly assignments will be made by the PI, with Exec Committee consent,
prior to launch.

A succession chain, at least three positions deep, identified by name,
shall be delivered to the MOC by the IM responsible for that week at
least one week prior to the duty week. IMs may choose to sub-divide the
week, or sub-divide the day, or use a tiered responsibility as suits
their convenience, as long as the list provided to the MOC is
unambiguous and can be implemented by the MOC remote paging capability.

Handover between institutions occurs at 10 AM US time on Wednesday
(usually 3 PM UK time and 4 PM Italy time). When the week ends, the BA
succession immediately reverts to the BA succession of the new
institution. Any BAs in the old succession who do not receive bursts are
free of BA responsibilities. They may be assigned to a later week at the
discretion of their IM.

For bursts occurring close to a weekly change boundary, the burst will
be assigned according to the time of the BAT burst trigger message.
Bursts prior to 10 AM Wednesday follow the old succession; bursts on or
after 10 AM follow the new succession.

On rare occasions the PI (in consultation with the Exec Committee) may
designate a burst to have extraordinary importance, and override the
standard BA succession list. In these cases the GRB observations and
analysis will be co-organized by the PI and the assigned institution,
with participation of other members of the science team as appropriate.
Should this happen, the IM responsible for the current succession list
will revise the succession list (for any following bursts) as fits the
situation and provide the new list to the MOC as soon as possible.

It is the responsibility of the IM to determine how frequently any BA
should appear in succession lists, and to assure that BAs carry out
their duties (in both the near and longer term periods). The IM may
choose to provide assistance to a BA, to transfer responsibility for a
given burst to a new BA, or subdivide the BA duties as needed.

##  BA Succession

When a burst occurs the MOC automated paging service will send paging
messages to the BA at the top of the current institution succession. It
is the responsibility of the new BA to inform the MOC that he/she has
received the page, and that the BA is able to carry out his/her BA
duties. The MOC has an automated confirmation process using a Web-based
interface, which will log the commencement of BA responsibilities.

If the BA is unable to carry out his/her responsibilities, he/she is
expected to notify the MOC, and the MOC will initiate paging of the next
person on the current succession list. If the BA fails to respond to the
page within one hour (TBR), then the MOC paging system will
automatically initiate paging of the next person on the succession list.

If the current succession list ever becomes empty (either due to BA
disability, communication failure or an unexpectedly large number of
bursts) then the MOC will contact the IM (or designate) to request a new
succession list. If the IM is unavailable, the MOC Director (or
designate) will create a succession list.

If bursts are discovered by non-Swift sources, then the MOC will
initiate BA paging and assignment in the same way as a Swift discovered
burst, except the assignment time will be based on the ToO message time
sent to Swift. BA duties for bursts being followed by the ToO mechanism
are essentially the same as for Swift bursts.

##  BA Handoff

Upon starting duty with a new burst, the new BA shall notify the next in
line on the succession list that they are on call for the new burst. The
BA shall notify the MOC that they have assumed the BA duty for that
burst.

The BA will also consult the Follow-up team instructions to see what
actions are requested by the Follow-up team relevant to the new burst.
These actions may include contacting critical observatories or analysis
teams, perhaps based on special characteristics of the new burst. In
some cases pre-existing arrangements for coordinated observations or
triggering ToOs on other observatories may exist. The BA should be
acquainted with these arrangements and be prepared to rapidly take
action as needed.

The BA will prepare any rapid communications (such as GCN notices, IAU
Circulars, etc.) on behalf of the Swift team. The BA will follow
guidelines established by the PI on publications, and inform the ODS,
IM, PI and appropriate Key Project and Follow-up team members when a
communication is issued.

# Burst Advocate Science Issues

## Brief GRB Science Overview

Gamma-Ray Bursts (GRBs) are, by definition, electromagnetic signals in
the gamma-ray band (in the spectral domain) with short durations (in the
temporal domain). The adventure of understanding the nature of these
objects has been bumpy, mainly due to the limited information contained
in these abrupt gamma-ray episodes. Since their discovery, many big
steps were made to achieve our current understanding of the phenomenon.
Among these, two major breakthroughs were ground-breaking. The first
followed the launch of the Compton Gamma-Ray Observatory (CGRO) in 1991.
The BATSE instrument on CGRO collected over 2700 bursts during its
10-year operation and led to the dramatic results that the GRB spatial
distribution is isotropic, and that GRBs have two distinct sub-groups:
the long and short bursts. The second breakthough came from the BeppoSAX
satellite, which resulted in the discovery of GRB afterglows in the
X-ray, optical and radio bands. From these discoveries we now believe
that GRBs are cosmological events, likely associated with the deaths of
massive stars.

As GRBs are high energy phenomena which also include afterglows across a
broad band (gamma-ray to radio), and possibly non-electromagnetic
signals (such as cosmic rays, neutrinos and gravitational waves), the
GRB field is an intersection of many branches of astrophysics. The
association of long GRBs with the deaths of massive stars, makes GRB
study related to the fields of stellar structure and evolution,
supernovae, and supernova remnants. Progenitor study has simulated
stellar population work. Central engine study has promoted study of
mechanisms for extracting energy from accretion disks or spinning black
holes. GRB afterglow light curves and spectral features probe properties
of the ambient interstellar medium (ISM) and the progenitor stellar
wind. Study of the GRB host galaxies and the GRB locations within the
hosts reveals information about the global star formation history of the
Universe and the nature of GRB progenitors.

GRBs are also important objects in the cosmological context. They can be
used in the same way as AGNs to probe the low-redshift range, but they
hold the potential (if they are also formed at high redshifts) to see
much farther into the early Universe, possibly into the epoch of
re-ionization (z\~6-15). GRBs may be the source of ultra-high energy
cosmic rays (UHECRs), as well as high energy neutrinos and LIGO or LISA
detectable gravitational wave signals.

There may be no other field that could have such a broad interaction
across the branches of astrophysics. Comprehensive reviews of GRBs
include: Fishman & Meegan (Ann.Rev.A&A 33, 415 (1995) \[for GRB prompt
emission observations\]), van Paradijs, Kouvelioutou & Wijers
(Ann.Rev.A&A 38, 379 (2000) \[for afterglow observations\]), Piran
(Phys.Rep. 314, 575 (1999)) and Mészáros (Ann.Rev.A&A 40, 137 (2002))
\[for GRB theories\], Hurley, Sari & Djorgovski (astro-ph/0211620
(2002)) \[for afterglow theory and observations\], and Zhang & Mészáros
(Int.J.Mod.Phys.A in press, 2003)) \[for a general review of
GRB/afterglow theory and observations).

-   **Observational Progress**

GRB main characteristics are summarized in the following:

-   Prompt emission characteristics:

    -   Temporal properties:

> Duration (T~90~: time interval during which 90% of burst energy is
> released): 0.01 to 1000 s, typical \~20 s for long bursts, \~0.2 s for
> short bursts
>
> Lightcurves: Very irregular. Some are erratic, spiky, while others are
> smooth with only one or two components.
>
> Widths of individual pulses (δt) vary over a wide range: shortest δt
> \~ millisec.
>
> Pulse symmetry: Most are asymmetric, with sharper leading edge than
> trailing.

-   Spectral properties:

> Continuum: Non-thermal, characterized by smoothly-joined broken power
> law, known as GRB-function or Band-function (Band et al. ApJ 413, 281
> (1993)). There is usually a spectral energy peak, called E~p~.
>
> E~p~ distribution: Found to be narrow for a sample of bright BATSE
> bursts.
>
> High energy components: Some GRBs seen in GeV and TeV range.
>
> Spectral features: Absorption and emission features reported in GRB
> prompt emission prior to BATSE have not been confirmed. Only recent
> report was a 3.8 keV absorption feature in GRB990705 (Amati et al.
> Science 290, 953 (2000)).

-   Polarization properties:

> At least for GRB021206, prompt gamma-ray emission is strongly
> polarized.

-   Global properties:

> Angular distribution: Isotropic, both for entire GRB population and
> long and short bursts taken separately.
>
> Intensity distribution: Log N-Log S distribution is a power law with
> slope of -3/2 at high flux and turn over at lower fluxes; consistent
> with cosmological origin.
>
> Event rate: BATSE rate \~ 1/day. Total rate may be \~600/year. Average
> birth rate is then \~7.5 Gpc^-1^ yr ^-1^. Local GRB rate is lower due
> to drastic decrease in star formation rate at low redshift, resulting
> in local GRB birth rate of 0.5 Gpc^-1^ yr ^-1^. Beaming factor is
> estimated as 500, making 'true' GRB rate of \~1/100 seconds, or \~200
> Myr^-1^ galaxy^-1^ mean and \~12.5 Myr^-1^ galaxy^-1^ locally.

-   Taxonomy:

> Duration classification: Long burst (T~90~\>2 s) are 75% of total;
> short (T~90~\<2 s) are 25%.
>
> Temporal classification: No well defined classes have been defined
> based on light curves.
>
> Spectral hardness: "X-ray rich", and "X-ray Flashes" (XRF) have been
> used, but recently XRFs are thought to be the natural extension of
> GRBs to soft/faint regime.
>
> "Long-lag" class: Long-lag bursts (such as GRB 980425/SN 1998bw) may
> belong to a sub-type of long bursts at closer distance, and may be
> associated with the super-galactic plane.

-   Empirical laws for prompt emission:

> GRB power density spectrum: Power law with index of -5/3 over two
> decades of frequency, with a break near 1 Hz.
>
> Pulse width and pulse interval distributions: log-normal
>
> Temporal variability: Positively correlated with burst luminosity
>
> Burst pulse spectra: For asymmetric pulses, pulse peak times migrate
> to later times at lower energies and pulse widths turn wider. Spectral
> lag is found to be negatively correlated with the isotropic
> luminosity.
>
> E~p~ distribution: Positively correlated with variability parameter;
> and hence, with the luminosity.
>
> Long GRB standard energy: After correction for beaming, long GRBs seem
> to have a standard energy.

-   Afterglow emission characteristics:

    -   Global properties:

> All current data come exclusively from long bursts
>
> After glows are broad-band, with detections in X-ray, optical/IR &
> radio
>
> Light curves usually show power-law decay, but there are various
> deviations (steepenings, bumps, wiggles, etc.) in various bands.
>
> X-ray afterglows are most commonly detected. About 60% of bursts have
> optically detected afterglows. Radio afterglows are seen in about 50%
> of GRBs.
>
> Essentially every GRB with afterglow detection has been found with an
> underlying host galaxy, and the properties of host and GRB location
> within the hosts are consistent with GRBs being associated with star
> forming regions.
>
> GRBs are cosmological events, with redshifts spanning from 0.168 for
> GRB 030329 (or 0.0085 for GRB 980425) to 4.5 for GRB 000131. See
> Greiner,
> [http://www.mpe.mpg.de/\~jcg/grb.html](http://www.mpe.mpg.de/~jcg/grm.html)
> for a database of afterglow data.
>
> At least some GRBs are associated with supernova explosions. Most
> famous are GRB980425/SN1998bw and GRB030329/SN2003dh.
>
> Modeling of broadband afterglow behavior yields a consensus on the
> following parameters. The GRB immediate environment typically
> resembles a constant density, rather than a stellar wind (although a
> few GRB are consistent with a wind model). In the shock region, the
> energy fraction carried by electrons is typically \~ 0.1 or less. Most
> energy is contained in baryons (likely protons).

-   X-ray afterglows

> Continuum spectra: Power law F~x~(t,ν) = k · t^-α^ · ν^-β^; where α \~
> -0.9 and β \~ -1.4, but with a wide scatter in both.
>
> X-ray emission lines: As of August 2003, X-ray emission line features
> have been claimed in afterglows of 6 bursts at moderate significance
> (\< 5σ).

-   Optical afterglows

> Continuum spectrum: F~opt~(t,ν) = k · t^-α^ · ν^-β^; where α \~ -1 (at
> early times) and β \~ -0.7, but with wide scatter in both.
>
> In some bursts, a clear achromatic light curve steepening is seen,
> with temporal index after the break of -2 (with some scatter). This
> break is attributed to the "jet break". At later times the decay rate
> gradually slows until finally reaching a constant level due to the
> contribution from the host galaxy.
>
> Other irregular temporal features are also seen. These include a
> substantial rebrightening in GRB 970508; an achromatic bump signature
> in GRB 000301C; wiggles in GRB 021004; and step-like features in GRB
> 030329.
>
> Polarization: As of August, 2003, 8 GRB optical afterglows have been
> detected to be polarized. The detected degree of polarization is
> small, typically several per cent. Changes in polarization angle have
> been seen.
>
> Early Afterglows: In 4 GRBs, optical afterglows have been detected
> within 5 minutes after the burst trigger. These four show diverse
> behavior; GRB 990123 reached \~9 mag optically during the gamma-ray
> prompt emission.

-   Radio afterglows

> Light curves: Radio afterglows do not follow a simple power law
> decline. Sources can be followed for years, and a late-time flattening
> (in excess of standard fireball models) is observed.
>
> Flares: Prompt, short-lived radio flares have been detected in several
> GRBs.
>
> Early time variation: Radio afterglows show strong fluctuations, which
> can be interpreted as interstellar scintillation.

-   Taxonomy

> Optically dark bursts: About 40% of GRBs with precise localizations do
> not have bright enough optical afterglows to be detected.
>
> Fast-fading GRBs: Several bursts (e.g., GRB 980519, GRB 980326) follow
> a steep decay (index \~ -2) in the early phase. They do not fit the
> "standard energy reservoir" scenario, and may constitute a peculiar
> class of GRB.

-   **Theoretical Progress**

The "Fireball Shock Model" is a standard theoretical framework that has
successfully interpreted the GRB and afterglow phenomenology. As early
as 1975, a generic argument was raised for the "compactness problem".
The idea is that the observed non-thermal gamma-rays from GRBs are
incompatible with a very high luminosity (for cosmological GRBs L~γ~ \~
10^51^ to 10^54^ erg/s), since the gamma-rays are subject to strong
photon-photon pair production. The only way to avoid this problem is if
the source has relativistic bulk motion. A first cosmological model of
GRBs (Paczynski, ApJ 308, L43 (1986); Goodman, ApJ 308, L47 (1986)),
where a pure photon-pair fireball was found to expand relativistically,
leaving only a quasi-thermal photospheric emission component, in
contrast with the non-thermal spectrum observed. Later it was found that
by including a small amount of baryon contamination, the fireball
thermal energy is essentially converted to kinetic energy, not
radiation.

An essential step toward a realistic GRB model was the realization that
the kinetic energy has to be re-converted back to radiation via
dissipation shocks. This suggestion laid the foundation of the current
fireball-shock model. GRB emission could, in principle, result from two
types of shock. In the "external shock", a shock results when the
fireball is decelerated by the ambient interstellar medium. In the
"internal shocks" model, these shocks are formed via collisions among
individual shells in the fireball wind. From various combinations of
these shocks predictions can be made which agree with observations from
the X-ray to the radio. A standard afterglow model is now widely used to
interpret the broad afterglow from dozens of GRBs (Sari, Piran &
Narayan, ApJ 497, L17 (1998)).

The Fireball Shock Model is generic, regardless of the progenitor or
central engine. Paralleling its development, several major GRB
progenitor models have been developed. Leading scenarios include neutron
star-neutron star mergers, "failed" supernovae (now called the
"collapsar" model), millisecond magnetars (neutron stars with surface
magnetic fields of \~10^15^ Gauss), and a two-step collapse "supranova"
model. Accumulating evidence suggests that long GRBs are associated with
supernova explosions, and at least for several well-studied events, the
SN/GRB association is consistent with the collapsar scenario, while the
GRB-SN delay is highly constrained.

The standard model has several solid theoretical ingredients, listed
below:

-   Relativistic bulk motion:

The compactness argument suggests that the GRB fireball must be
initially relativistic.

-   Relativistic shocks:

The collision between the relativistic fireball and the ISM, and the
collisions between the individual shells in the fireball excite
relativistic shocks. For external shocks, a long-lived forward shock
propagates into the ISM and keeps decelerating the fireball, and a
short-lived reverse shock propagates into the fireball shell itself
during the initial stage of the fireball deceleration. For internal
shocks, there are both a forward and a reverse shock propagating into
both colliding shells for each collision.

-   Synchrotron radiation:

Relativistic electrons are accelerated from the shocks (both forward and
reverse), usually assumed to have a power-law distribution with a
spectral index denoted as *p*. It is believed that there are random
magnetic fields in the shocked region, and the relativistic electrons
radiate in these magnetic fields via synchrotron radiation. A typical
synchrotron spectrum is a four-segment broken power law, separated at
three characteristic electron frequencies: the self-absorption
frequency, ν~a~ (above which the emission is optically thick), the
typical injection frequency, ν~m~ (the characteristic frequency emitted
by the shock-injected electrons with the lowest energy), and the cooling
frequency, ν~c~ (the lowest frequency resulting from electrons that have
cooled). The case of ν~m~ \< ν~c~ is called "slow cooling", and the
synchrotron emission power-law indices in the four segments are \[2,
1/3, -(*p*-1)/2,-*p*/2\] respectively. The case of ν~m~ \> ν~c~ is
called "fast cooling", and the synchrotron emission power-law indices
are \[2, 1/3, -1/2, -*p*/2\] respectively.

-   Simplest afterglow model:

Minimum complications result if one assumes: a) isotropic fireball, b)
constant ambient density ISM, c) constant energy per solid angle in the
fireball, d) relativistic fireball, e) synchrotron emission by the
electrons, and f) constraints on the microphysics parameters (such as no
evolution, *p* \> 2, etc.). In this case, the fireball Lorentz factor,
Γ, evolves with radius, *r*, and the observer's time, *t*, as Γ
proportional to *r*^-3/2^ and *t*^-3/8^ for an adiabatic expansion of
the fireball. The temporal dependencies of the maximum specific flux and
the critical frequencies can then be quantified, and the light curve in
a fixed observational band can be predicted. In this model, by writing
F~ν~(t,ν) = k · t^-α^ · ν^-β^, the relations of α and β in various
regimes are well predicted. This model gives a successful first-order
interpretation of the broad-band data for most GRB afterglows.

-   Modifications to the simplest model:

In order to fully explain observations the simplest afterglow model
requires modification by relaxing some of the assumptions. In the
literature, the following generalizations have been applied:

-   

```{=html}
<!-- -->
```
-   Reverse shock emission:

-   GRB prompt emission:

##  Swift Key Projects

The Swift science team core science program is organized by Key Projects
that cover both GRB and non-GRB topics. Each Key Project has a small
number of Swift science team members assigned to it. A full list of Key
Projects and their descriptions can be found at http://swiftsc.gsfc. A
list of the GRB Key Project topics and science teams is given in Table
3.2. The name listed first is the lead for each project. Two names
listed first separated by an \"&\" indicates co-leadership.

Table 3.2 Swift Team GRB Key Projects

[Project Title Project Team]{.underline}

GRB catalog Gehrels, & Angelini, Roming, Hurley

Extended Swift observations of bright GRBs Gehrels, Swift team

Extended Swift observations of random \~30 GRBs/yr Angelini, White

Multivariate statistical analyses of GRBs Roming, Feigelson, Hunsberger,
Chester

Luminosity functions of GRBs & afterglows Antonelli, Burderi,
Chincarini, Ghisellini, Stella, Vietri.

GRB Hubble Diagram Schaefer, BAT team, Norris, Fenimore

IGM studies with the XRT and UVOT Fiore & White, Parsons

Short GRB studies with Swift Gehrels, Barthelmy, BAT team, Coletta,
Hurley

X-ray rich GRB studies with Swift Parsons, BAT team

BAT studies of GRB classifications Barthelmy, BAT team, Mason/Cropper

BAT GRB temporal studies including precursors Cline, Barthelmy, BAT team

BAT variability / luminosity studies Fenimore, Schaefer

BAT spectral lag / luminosity studies Norris, Bonnell, Schaefer

BAT filling factor analysis Fenimore

BAT searches for repeating and lensed GRBs Barthelmy, BAT team

XRT Fe line studies of GRBs Burrows & Ghisellini, Meszaros, Vietri,

White, Angelini, Gehrels

XRT absorption signatures in GRBs Tagliaferri & Nousek, Meszaros,
Marshall, Brandt

XRT search for spectral features in early afterglow Osborne, Wells,
Rees, Gehrels, Takahashi

XRT studies of the decay profile of GRBs Ghisellini, Antonelli,
Angelini/White, Cline

Mason, Takahashi

UVOT absorption signatures in GRBs Marshall, Mason, Gehrels

UVOT searches for prompt UV flashes from GRBs Meszaros, Roming, Cropper,
Hunsberger

UVOT spectral signatures of high-z GRBs Mason, Meszaros, Marshall,
Parsons, Gehrels, Covino

UVOT studies of the optical decay profile of GRBs Antonelli,
Angelini/White, Mason, Covino,

Cline, Roming, Hunsberger

UVOT arc searches for lensed GRBs Palmer

##  Recognizing 'Special' Bursts

The procedures to be followed when a 'special' burst will be developed
by the Swift Science Team, with final approval from the Principal
Investigator (Neil Gehrels). When a Burst Advocate, Observatory Duty
Scientist, or Instrument Duty Scientist recognizes a burst which has
special or unique characteristics, they should immediately contact the
PI and Mission Director in parallel, using the manual paging system as
required. The PI and Mission Director are listed in the SERS paging
system, so that contact information will always be available. When the
PI and Mission Director expect to be temporarily unavailable, they will
provide surrogates who are on-call to respond to such extraordinary
situations.

# Swift Operations and Data

## TDRSS Data

###  BAT

BAT GRB messages are transmitted via TDRSS and distributed immediately
to all interested observers by the GRB Coordinates Network (GCN):\
\
Data available within seconds, via TDRSS:

1\) GRB alert (includes trigger time and burst significance).  These
contain no position information or no guarantee that a position will be
found.\
\
2) GRB position message.   In addition to the sky location, this message
includes trigger time, burst significance, peak intensity, burst and
background fluence, and the burst and background time intervals used to
produce burst location.  This is the information that follow-up
observers will use to determine whether they can and choose to try to
observe the burst or afterglow.\
\
3) TDRSS light curves (not background subtracted).  Four channel light
curves from   24 seconds before to 186 seconds after the burst trigger. 
Available in FITS, GIF, JPEG and PS formats.\
\
4) Scaled maps.  Used to produce a background subtracted sky image for
the burst trigger interval.\
\
All of these TDRSS messages are made available through the GCN in a
variety of formats (e.g. email attachments, web access, etc.).\
\
See end of message for TDRSS FITS file headers and other info

###  XRT

### UVOT

The UVOT is a modified Ritchey-Chrétien telescope with a 30 cm aperture
and an f-number of 12.7 operating in the wavelength range of 170-600 nm.
It is mounted on the optical bench (OB) with the BAT and the XRT as
shown in Figure 1 and co-aligned with the XRT. An 11-position filter
wheel houses UV and optical grisms, a 4x magnifier, broadband UV and
optical filters, a clear "white-light" filter, and blocking filter.
Photons register on a micro-channel plate intensified charged-coupled
device (MIC). These MICs can operate in a photon counting mode and are
capable of detecting very low light levels. When flown above the
atmosphere the UVOT will possess the equivalent sensitivity of a 4 m
ground-based telescope, capable of detecting a 24^th^ magnitude B-star
in 1000s using the white-light filter. An outline of the UVOT's
characteristics can be found in Table 1.

![](media/image2.jpeg){width="3.335433070866142in"
height="2.500787401574803in"}![](media/image3.jpeg){width="2.0118110236220472in"
height="2.543700787401575in"}Figure 1. UVOT Placement on the OB

The UVOT consists of 5 units (Figure 2): a Telescope Module (TM)
containing a UV/optical telescope, a Beam Steering Mirror (BSM), two
filter wheel mechanisms[^1], two photon counting detectors, power
supplies, and electronics; two Digital Electronics Modules (DEMs), each
one containing a Data Processing Unit (DPU), an Instrument Control Unit
(ICU), and power supplies for the DPU and ICU; and two Interconnecting
Harness Units (IHUs) to connect the TM to the two DEMs.

![](media/image4.png){width="6.6625in" height="3.551388888888889in"}

Figure 2. UVOT Schematic

#### Optics

The telescope tube contains a 30 cm primary and 7.2 cm secondary mirror
which are both made from Zerodur. The telescope is a modified
Ritchey-Chrétien design. The optical train has a primary f-ratio of
f/2.0 increasing to f/12.72 after the secondary. The primary mirror is
mounted on a strong back for stability and the secondary mirror is
mounted onto spider arms. To maintain focus the mirrors are separated by
thermally stable INVAR metering rods. The boresight is near the center
of the CCDs.

For light rejection there are internal and external baffles. The
external baffles are forward of the secondary mirrors and help prevent
scattered light from reaching the detectors. The internal baffle lines
the inner walls of the telescope tube between the primary and secondary
mirrors. Secondary/primary baffles also surround the secondary mirror
and the hole at the center of the primary. Behind the primary mirror is
the Beam Steering Mirror (BSM) which directs light to one of the two
detectors.

Before the light enters the detector it passes through a filter housed
in a filter wheel. Each filter wheel contains the following elements: a
blocked position for detector safety, UV-grism, UVW2-filter, V-filter,
UVM2-filter, optical-grism, UVW1-filter, U-filter, magnifier, B-filter,
& White-light-filter. The characteristics of the UVOT lenticular filters
can be found in Table 2. The lenticular filter response (Figure 3) and
the anticipated grism profiles (Figure 4) are also provided. The grisms
supply a low spectral resolution. The magnifier offers a 4x increase in
the image scale which increases the f-ratio to f/54 in the blue and
provides diffraction-limited images. It does not operate in the UV
because of transmission limitations in this part of the spectrum.
Because the focal plane is curved, the filters are weakly figured and
the surface of the detector window is concave. The PSF of the UVOT
filters can be found in Table 3. These values were determined during the
UVOT instrument level calibration. They have not been deconvolved from
the collimator's PSF. Significant changes in PSF should be reported to
the instrument team immediately.

  ---------------------- -------------------- ---------------------------
  **Filter**             **λ~c~ (nm)**        **FWHM (nm)**

  V                      544                  75.0

  B                      439                  98.0

  U                      345                  87.5

  UVW1                   251                  70.0

  UVM2                   217                  51.0

  UVW2                   188                  76.0

  White                  385                  260.0
  ---------------------- -------------------- ---------------------------

Table 2. UVOT Lenticular Filter Characteristics

+---+-------+-------+-------+-------+-------+-------+-------+-------+
| > | >     | >     | >     | > U   | > B   | > V   | >     | >     |
|   |  UVW2 |  UVM2 |  UVW1 |       |       |       | White |  Magn |
| C |       |       |       |       |       |       |       | ifier |
| h |       |       |       |       |       |       |       |       |
| a |       |       |       |       |       |       |       |       |
| n |       |       |       |       |       |       |       |       |
| n |       |       |       |       |       |       |       |       |
| e |       |       |       |       |       |       |       |       |
| l |       |       |       |       |       |       |       |       |
+---+-------+-------+-------+-------+-------+-------+-------+-------+
| A | 1.74  | 1.63  | 1.59  | 1.28  | 1.31  | 1.24  | 1.06  | 1.04  |
+---+-------+-------+-------+-------+-------+-------+-------+-------+
| B | 1.76  | 1.76  | 1.66  | 1.52  | 1.40  | 1.17  | 1.12  | 1.00  |
+---+-------+-------+-------+-------+-------+-------+-------+-------+

Table 3. UVOT Filter PSF

![](media/image5.wmf){width="3.0243055555555554in"
height="2.0722222222222224in"}

Figure 3. UVOT Lenticular Filter Response

![](media/image6.wmf){width="3.0145833333333334in"
height="2.046527777777778in"}

Figure 4. UVOT Anticipated Grism Response

#### Detectors

Housed in the BMT are the two detector assemblies. Each detector
assembly consists of detector window, a S20 photocathode, three
Micro-Channel Plates (MCPs), a phosphor screen, tapered fiber-optics,
and a CCD (Figure 5). The CCD has 385 x 288 pixels, 256 x 256 of which
are usable for science observations. Each pixel has a size of 4 x 4
arcsec^2^ on the sky thus providing a 17 x 17 arcmin^2^ FOV. The first
MCP has pore sizes of 8 μm with a distance of 10 μm between pore
centers. The second and third MCPs have pore sizes of 10 μm with a
distance of 12 μm between pore centers. The photocathode is optimized
for the UV and blue.

Photons arriving from the BSM enter the detector window and hit the
photocathode. Electrons emitted from the photocathode are then amplified
by the three successive MCPs which in turn illuminate the phosphor
screen. The photons from the phosphor screen are then sent through the
fiber-optics to the CCD. This affords an amplification of 10^6^ of the
original signal. The detection of photons is accomplished by reading out
the CCD at a high frame rate and determining the photon splash's
position using a centroiding algorithm. The detector attains a large
format through this centroiding algorithm by sub sampling each of the
256 x 256 CCD pixels into 8 x 8 virtual pixels, thus providing an array
of 2048 x 2048 virtual pixels with a size of 0.5 x 0.5 arcsec^2^ on the
sky. Faint residuals of a pattern (referred to as Mod-8) formed by
creating the 8 x 8 virtual pixels are removed by ground processing.
Unlike most UV/optical telescopes, because UVOT's CCD is read out at a
high frame rate, the UVOT is operated in a photon-counting mode.

![](media/image7.png){width="2.113888888888889in"
height="1.9708333333333334in"}

Figure 5. UVOT Detector

As with all photon-counting devices there is a maximum count rate limit.
The frame rate of the UVOT detectors is 11.1 ms for a full 17 x 17
arcmin^2^ frame; therefore, for count rates above \~10 counts/s (for
point sources) a dead time or coincidence loss correction needs to be
applied during the data processing. Details of this dead time correcting
will be provided after launch. In addition, care must be taken when
observing bright sources as the local sensitivity of the photocathode is
permanently depressed. Autonomous operations diminish the time spent on
bright sources (see next Section). The detector's dark noise is
extremely low and can be ignored when compared to other sources of
background noise.

#### Detector Safety

The Swift mission requires the UVOT to have autonomous functionality in
order to protect itself against potentially damaging bright sources.
This is accomplished through the use of a bright source catalogue and a
real time system for monitoring the raw pixel data from the camera and
automatically reducing the detector gain when a signal above a
programmable threshold is seen.

#### Software

Both digital electronics units in the UVOT contain microprocessors
running custom flight software.  The ICU software is responsible for
controlling and managing all aspects of the UVOT\'s operations,
including:

-   autonomous instrument safing in off-nominal observatory conditions,

-   autonomous protection of the detector from fields containing bright
    stars,

-   interacting with the Figure of Merit computer to select & execute
    appropriate science observations.

Many ICU behaviors, most notably the exposure sequences used to observe
targets, can be reconfigured via simple table uploads.  ICU capabilities
are implemented via a combination of compiled Ada code and a custom
interpreted scripting language.

The DPU software is responsible for reducing and packaging the detector
event stream for transport to the ground.  Data reduction tasks include
spatial windowing of event data (to control telemetry volume),
compression of event data, binning of event data into images,
compression of images, transformation of engineering data streams into
calibration products, and construction of a Finding Chart (which
involves source detection).  The DPU contains significant data buffering
capacity to accommodate variation in the science data & telemetry
production rates.

### Observing Scenarios

There are six observing scenarios for the UVOT: slewing, settling,
finding chart, automated targets, pre-planned targets, and safe pointing
targets.

*Slewing*. As the spacecraft slews to a new target, the UVOT does not
observe in order to protect itself from bright sources slewing across
its FOV and damaging the detector.

*Settling*. After notification from the spacecraft that the intended
object is within ten arcminutes of the target the UVOT begins observing.
All UV photons in the entire 17 x 17 arcmin^2^ FOV are recorded in an
event list. During this phase pointing errors are off-nominal, i.e., the
target is moving rapidly across the FOV as the spacecraft settles. The
positional accuracy is only known to a few arcmin based on the BAT's
centroided position.

*Finding Chart*. If the intended target is a new GRB and the spacecraft
is sufficiently settled, i.e., the pointing errors are small, the UVOT
begins a 100 second exposure in the V filter to produce a finding chart.
The finding chart is telemetered to the ground in order to assist ground
based observers in pinpointing the burst. This is typically accomplished
in less than 300 seconds while the afterglow is still bright. The
positional accuracy of the finding chart will be approximately 0.3
arcsec relative to the background stars in the FOV. It is anticipated
that for most bursts the XRT will have reported a better than 5 arcsec
position for the target before the end of the finding chart observation
(see Figure 6).

![](media/image8.png){width="1.7220472440944883in"
height="1.505511811023622in"}![](media/image9.png){width="1.6818897637795276in"
height="1.508267716535433in"}![](media/image10.png){width="1.2543307086614173in"
height="1.3291338582677166in"}

Figure 6. Rapid Position Determination of GRBs

*Automated Targets (ATs)*. Once a finding chart has been produced, a
several thousand-second automated sequence of exposures, which uses a
combination of filters, is executed. The sequence is based on the
optical decay profile of the GRB afterglow and time since the initial
burst. Currently, two automated sequences will be launched: bright and
dim GRB sequences (Figures 7 & 8; BB, UU, W1, GV, M2, VV, W2, & GU in
the figures are the B, U, UVW1, Visual Grism, UVM2, V, UVW2, & UV Grism
filters respectively; gaps in the figures are due to earth occultation).
For bright bursts the filter sequence includes grisms. For fainter
targets (17.0 \< m~V~ \< 24.0), light curves are acquired by cycling
through the six broadband filters. Source variability during exposures
is monitored by collecting data in event mode.

Although only two sequences will be loaded at launch, new sequences can
be added and existing ones modified as GRB afterglows become better
understood.

![](media/image11.png){width="3.0652777777777778in"
height="2.307638888888889in"}

Figure 7. Bright GRB Sequence (Early GRB Detection)

![](media/image12.png){width="3.0381944444444446in"
height="2.286111111111111in"}

Figure 8. Dim GRB Sequence (Early GRB Detection)

*Pre-Planned Targets (PTs)*. When there are no automated targets,
observation of planned targets (which have been uploaded to the
spacecraft) begin. Follow-up of previous automated targets,
targets-of-opportunity, and survey targets are included as planned
targets. Because the UVOT filter wheels are limited life items, many of
the PTs will only use one filter in order to minimize the wear on the
filter wheel motors. Scientific justification will need to be provided
to the UVOT scientists in order to increase the number of filters used
for a PT observations.

*Safe Pointing Targets*. When observing constraints do not allow
observations of automated or pre-planned targets the spacecraft points
to predetermined locations on the sky that are observationally safe for
the UVOT.

#### Data Products

The UVOT can produce seven types of data products: event lists, images,
finding charts, intensifier characteristics, channel boundaries, and
centroid confirmation images.

*Event List.* Each photon event is reported by its position on the
detector and the associated CCD frame time-stamp.  The accuracy of
photon arrival time is dominated by the ambiguity of the CCD frame
integration period (11ms). 

*Image.* Image data consist of a 2-D histogram (image) of the event
stream, taken over the specified integration period (generally
10-1000s).  Image pixels can span 1x1, 2x2, or 4x4 detector sub-pixels. 
For large numbers of events, image data require much less telemetry than
event data, at the expense of greatly reduced time resolution.

*Finding Chart.* Finding Chart data consist of a small subset of the
pixels in an image, carefully chosen to lie under and near the brightest
point sources.  A \"sparse\" version of the full image can be
constructed on the ground, providing a coarse representation of the
detected point sources while consuming modest telemetry volume. Finding
chart data are sent immediately via TDRSS to the GCN, whereas most other
science data is stored for later downlinks via a ground station.

*Dark Burst Image*. All the data in the NxN Finding Chart pixels around
the XRT position are sent to the ground.  This image will facilitate
solving the question of "dark" GRBs. The Dark Burst Image is sent
immediately after the Finding Chart via TDRSS to the GCN.

*Intensifier Characteristics.* Intensifier Characteristics data consist
of a histogram of the \"pulse height\" of a set of events obtained with
an internal calibration lamp.  Examination of these data on the ground
assists in adjusting the gains in the detector.

*Channel Boundaries.* Channel Boundaries data consist of a set of
calibration threshold values which, when loaded into the detector
electronics, would produce the optimal sub-pixel positioning
calculation.  The detector data used in the computation of Channel
Boundaries are obtained with an internal calibration lamp.

*Centroid Confirmation Image.* Centroid Confirmation Image data consist
of a 2-D histogram which characterizes the bias of the sub-pixel
positioning calculation (which is driven by the Channel Boundaries
values) across 64 regions of the detector.  The detector data used in
the computation of a Centroid Confirmation Image are obtained with an
internal calibration lamp.

#### Data Analysis Software

The Swift Science Center (SSC) has developed FTOOLs[^2] for UVOT data
analysis which will be available for public download after launch[^3].
The tools will operate as stand-alone FTOOLs, within the processing
pipeline, or within the user meta-tool "UVOTCHAIN." Once the telemetery
has been converted into FITS format, FTOOLs will operate on the data.
Since the UVOT produces both event and image data products, two sets of
tools have been provided.

#### Telemetry volume

Because of limitations in the Spacecraft data storage capabilities and
the telemetry bandwidth between the UVOT-and-Spacecraft and the
Spacecraft-and-Malindi, the type of data generated is constrained. Full
frame event data can only be obtained for short periods of time. In
general, the smaller the window size, the longer event data can be
obtained.

##  Standard Ground Pass Data

###  BAT

Data available within hours via ground link through Malindi:

1\) Background subtracted light curves derived from the event files in
four energy channels.  These will include the time covering the S/C slew
to the burst. \
Time binning: \
    uniform 64 ms\
    uniform 1 sec\
       Bayes blocks. \
\
2) Counts spectra on various time scales during and after the burst.
Response matrix for each spectrum.  Spectral fit parameters from XSPEC.\
\
3) Burst summary parameters:\
\
- Burst durations: T50 and T90.\
- Energy fluences (10-25 keV, 25-50 keV, 50-100 keV, 100-300 keV, 2-2000
keV).\
-  Variability \*.\
-  Time lags between fiducial energy bands \*.\
\
(\* May not be calculated in the pipeline)\
\
4) Event files (\~10 minutes around the burst trigger time).\
\
5) Short time scale (\~1 minute) survey histograms until the next S/C
slew.\
\
6) Images of the burst and surrounding sky before, during and after the
burst.

Burst advocate generated products a few days later (possible examples):\
\
- Revised burst location\
- Estimate of red shift from lag-variability analysis\
- Spectral fits for additional time intervals\
- Comparisons between BAT and Swift narrow field instrument analysis.\
\
- Lists of follow-up observations and links to any publicly available
data from follow-ups\
\
- Gamma-ray burst catalog.\
\
- Longer time scale (weeks) overall summary web page for each burst.\
\
\
All BAT data (except for the hard X-ray survey) will be made publicly
available within two hours of receipt at the Swift Science Data Center
(SDC).\
\
- Available through SDC Quicklook web site for the first week.\
- Available through HEASARC after one week.\
- Hard X-ray survey available in  HEASARC after release\
- All Swift products will also be available through European mirror
sites.

###  XRT

### UVOT

## Spacecraft and Other Infrastructure Data

### Figure of Merit (FoM)

Swift utilizes a novel approach to responding to new gamma-ray bursts.
In order to eliminate the substantial delay that would be caused by
waiting for ground intervention, Swift responds to BAT discovered bursts
by autonomously superceding its pre-planned target list by substituting
an automated response.

The way this works is that when the BAT discovers a new burst, it
generates a new burst message. Internal to the BAT processor is a
software module called the Figure of Merit (FoM) process. When the BAT
burst message occurs the FoM process evaluates a numerical quantity
called the Figure of Merit. The Figure of Merit value results from a
calculation based on input parameters generated by the BAT (and possibly
the UVOT and XRT as well). The form of the calculation is an algebraic
formula, including weights for the significant of the input parameters.
The definition of the FoM calculation can be changed in flight by
uploading new weights, without making a software patch.

The FoM value is used by comparing it to the FoM value of any current
existing automated target (AT). An AT may be a recent burst, for which
Swift has not yet completed the initial sequence of observations, or a
burst or other Target of Opportunity (ToO) target which has been
uploaded from the ground via the TDRSS link as an AT. If the FoM for the
new burst exceeds the FoM value for the current AT (or if no current AT
is in the system), then the new burst becomes the current AT. When the
AT changes, Swift will no longer autonomously return to the old AT. Old
ATs can only be rescheduled by ground control.

When the AT changes, the FoM process then compares the FoM value for the
new AT, and compares it to the priority for the Pre-Programmed Target
(PPT) scheduled to be observed at that time. If the AT FoM value exceeds
the Priority value of the current PPT, then the FoM process sends a slew
request to the spacecraft. If the AT FoM value is less than the the PPT
priority, then the FoM does not request a slew and Swift continues to
observe the PPT target.

When the current target snapshot is completed (either because Swift can
no longer view the target, or because the target reaches the complete
observation time requested) then the FoM reevaluates the FoM of the AT,
and again checks whether the next PPT is observed, or to have the new AT
take precedence.

The net effect is that Swift will observe the highest FoM/PPT priority
as assigned by the formula on board the spacecraft and the ground
assigned PPT priority.

### Spacecraft

## Data Paths

Data, commands and ancillary information are up and downloaded to Swift
via complementary paths. Because of the critical science driver of rapid
response to bursts, Swift must have a continuous capability to download
information about new bursts, and to upload potential ground
instructions to point Swift at new bursts discovered by non-Swift means.
On the other hand, Swift produces large amounts of important but less
time critical data for download, and has the need to upload lengthy
observing schedules and command loads.

The Swift mission provides to both needs by complementary data paths.
High criticality, low volume data are sent to and from Swift via the
Tracking Data Relay Satellite System (TDRSS) Demand Access System (DAS).
DAS will transmit Swift messages reporting the discovery of a new burst,
and critical science results from the BAT, XRT and UVOT, down to the
ground within seconds. Similarly the TDRSS DAS allows uploading of
Target of Opportunity (ToO) targets and ground loaded FoM targets within
minutes. (The longer latency for uploads is due to the need to schedule
the TDRSS data channels.)

The TDRSS data link is available on demand on a 24 hour per day basis.
The final throughput of the Swift DAS link will be at least 1 kbps
minimum requirement, and is expected to be 3 kbps typically, depending
on link margins.

The TDRSS data path cannot carry the full volume of Swift data. Moreover
it is too slow for efficient upload of Swift command loads. For these
activities Swift employs ground stations. While Swift is in view of the
Malindi ground station, Swift is able to dump data from the on-board
solid-state recorders at 2.25 Mbps.

Swift's orbit is expected to offer approximately 13 ground passes of at
least 5 minute duration, every day. The Swift data management plan
assumes that 7 ground passes per day will be used for data download and
command loads. During these passes, Swift is in direct two-way
communication with the ground, and commands, software patches and
parameter table uploads can be verified in real-time. It is planned to
conduct all normal Swift command uploads during ground passes so that
the MOC can verify proper receipt by Swift of these critical data.

### TDRSS Data Path

### Ground Pass Data Path

#### Data Analysis and Processing Software 

Swift software tasks needed to produce scientifically useful data files
from BAT, XRT and UVOT are defined and explained. These tasks are
required for data processing performed on data that is delivered from
the MOC to the SDC, through the SDC processing pipeline. Data products
appear on the Swift Quick Look Data area until complete, after which
time they are delivered to the HEASARC for acquisition and analysis by
the Swift user community.

#### Swift Software Overview 

Each software task will run in the Swift processing pipeline in the SDC
and in the Swift FTOOLs package provided to the science user by the SSC.
The SDC can and do make modifications to the analysis scripts to
optimize the pipeline performance, though the algorithms of the tasks
themselves are unchanged. This way, Swift users can reprocess/reanalyze
data by themselves, and reproduce the pipeline processing results if
using identical input and calibration information.

All the software that operates on Level I FITS files to produce the
Level II and Level III FITS data files and products in the pipeline will
be distributed to Swift users. In particular, it is important to
distribute the software for calibration so that Swift users can quickly
re-calibrate their data when new calibration information is made
available, instead of needing to wait for eventual reprocessing. All the
distributable Swift software is included in the Swift FTOOLS package.

> **Swift Data Center (SDC)**

The SDC, located at NASA/GSFC, converts Swift Level 0 data products
received from the MOC into Flexible Imaging Transport & System (FITS)
files and standard data products using a semi-automatic processing
pipeline.  As part of this process, the SDC checks the format of the
telemetry and checks for missing data. The format of the FITS files is
consistent with Office of Guest Investigator Programs (OGIP) standards. 
The SDC generates level 1, 2, and 3 data products.  The data sets are
organized by observation to facilitate later scientific analysis. 
Quick-look data products are made on a shorter time scale using less
complete telemetry and the same processing pipeline.

The Space Science Data Operations Office, Code 630, at GSFC is
implementing the SDC.  Additional development support is provided from
the Information Systems Center (Code 580) at GSFC.

**        Swift Science Center (SSC)**

The SSC assists the science community in the scientific analysis of
Swift data.  The SSC has the lead role in developing the software tools
needed to perform scientific analysis of the Swift data.  Many of these
tools are also used in the pipeline processing in the SDC. This effort
is supported by the instrument teams and the ASDC. After launch, the SSC
updates the analysis tools as the understanding of the techniques
utilized improves with experience.  In addition, the SSC maintains
documentation of the Swift data and analysis techniques for the use of
the science community. The SSC also produces documentation in support of
the Swift GI program and provides technical support for reviewing GI
proposals.

The SSC is part of the Office of Guest Investigator Programs (OGIP),
which also contains High Energy Astrophysical Science Archive Research
Center (HEASARC) and similar support centers for other high-energy
astrophysics missions.  The Information Systems Center (ISC) (Code 580)
is supporting the software effort in the SSC.

##  {#section-2 .unnumbered}

## Rapid Response Framework

### Internal Interaction Interfaces of Ops Center

Figure 4.7.1 -- MOC Functional Schematic

The MOC is organized into two closely inter-related teams: the Flight
Operations Team (FOT) and the Science Operations Team (SOT). The primary
duty of the FOT is to assure the health and safety of the Swift
Observatory at all times. It does this by continuous monitoring of the
spacecraft telemetry through automated software, with on-demand paging
of the FOT during spacecraft or instrument anomalies. In addition, the
FOT has responsibility for uploading and verifying the Command Loads
which are sent to the spacecraft. The FOT also tracks the successful
download of data from the spacecraft.

The SOT is responsible for the scientific functioning of the Swift
observatory. They prepare Pre-Planned Science Timelines (PPST) which
direct the Swift observing program in those times when the on-board
Figure of Merit (FoM) process does not override the PPST by detecting an
Automated Target (AT) -- typically a new BAT discovered GRB.

Figure 4.7.1 shows the working interfaces between the duty elements of
the MOC. The Burst Advocate (BA), has responsibility for monitoring the
current Swift response to active GRBs. This includes being the point of
contact between Swift and the Follow-Up team and the general GRB
community interested in the assigned burst. The BA will work closely
with the Observatory Duty Scientist (ODS; who is a member of the SOT),
to keep the ODS informed of the scientific significance of the burst,
and what Swift actions might enhance the science return. The ODS also is
charged with assuring that proper data are being collected, and that the
instruments appear to be functioning as expected.

The FOT duty officer is responsible for receiving the PPST from the SOT,
and properly converting the PPST into a Command Load which is loaded and
run on the spacecraft. The FOT duty officer also monitors instrument and
satellite health and safety.

### Mission Ops Center Daily Routine

The MOC will be routinely staffed on a 8 hour per day, 5 day per week
schedule. During the initial Launch & Early Orbit (L&EO) period the MOC
will be continuously staffed. When the MOC is staffed below the
continuous 24 hour per day level, the FOT and SOT will have duty
personnel responsible for responding to paging alerts automatically
generated by the SERS software to detect spacecraft emergencies, and
newly discovered GRBs.

On a typical work day the MOC schedule is expected to work like this:

8 AM -- SOT arrives and consults logs, GCN and other records of
overnight activity and current spacecraft telemetry

9 AM -- Science Planning telecom -- SOT Lead moderates a discussion
including the on-duty Instrument Duty Specialists, all BAs with recently
active bursts, and the current Science Planner for that day. Goal is to
review all current bursts and spacecraft activity to set priority for
targets in Science Plan.

10 AM -- Science Planner generates PPST for following week.

12 AM -- PPST is passed to UVOT and BAT IDSs for review. UVOT monitors
the planned targets for UVOT bright source problems and filter wheel
rotation and changes UVOT modes as required. BAT monitors targets for
bright gamma-ray sources in BAT field of view and creates appropriate
table loads to modify trigger thresholds as required.

1 PM -- PPST is delivered to FOT

6 PM -- PPST is converted to ATS load for spacecraft, and successfully
uploaded to Observatory.

### External Interaction Interfaces of Ops Center

The Ops Center has external interfaces to the Swift science team and the
community. Inter­actions will flow in both direction for both of these
groups.

Rapid response inputs coming from the community and the science team to
the Ops Center will take the form of Targets of Opportunity (ToOs)
requests to repoint Swift. They will be submitted to the Ops Center
Director and approved by the Principal Investigator. A web form for
requesters to fill out is provided at http://xxxxxxxx. An example of a
GRB ToO would be a request to point the XRT and UVOT at the position of
a GRB detected by another observatory such as HETE-2, INTEGRAL or the
IPN.

Rapid response outputs to the science team will be through e-mails and
phone calls. The science team web site, which can be accessed through
the Swift main page at http://swift.gsfc.nasa.gov has e-mail exploders
for the full science team and various subgroups. Phone and e-mail
information for individuals can also be found there. Outputs to the
community will take the form of GCNs, IAU Circulars and ATELs discussed
in the next section. Outputs to the public, such as

press releases and interviews, will be coordinated through the Swift
Press Officer at Sonoma State University, with approval by the Principal
Investigator.

Emergency contact information is as follows:

Position Name e-mail phone cell phone

MOC Console

MOC Director John Nousek nousek@astro.psu.edn 814-865-7747

Principal Investigator Neil Gehrels gehrels@gsfc.nasa.gov 301-286-6546
301-526-9288

GCN Lead Scott Barthelmy scott@lheamail.gsfc.nasa.gov 301-286-3106

Press Officer Lynn Cominsky lynnc@charmian.sonoam.edu 707-664-2655

### Rapid Response Data Products/Publications

There are currently three principal, independent methods of distributing
time-critical data rapidly to large numbers of astronomers and other
interested scientists: Gamma-Ray Burst Coordinates Network (GCN)
circulars, International Astronomical Union (IAU) Circulars, and
Astronomer's Telegrams (ATEL's). There is some overlap in the
subscribers and subjects covered, but the bare essentials of each method
are summarized in the following table, and each method is discussed in
detail in the following paragraphs. Note that, depending on the exact
nature of a discovery, it may be appropriate to use more than one method
to distribute information. Unlike the refereed literature, it is
acceptable to circulate identical announcements via different methods.

  ---------------------- ------------------------------------------------------- ----------------------------------------------- ----------------------------------------------
                         GCN Circulars                                           IAU Circulars                                   ATEL

  Website                [gcn.gsfc.nasa.gov/gcn](http://gcn.gsfc.nasa.gov/gcn)   <http://cfa-www.harvard.edu/cfa/ps/cbat.html>   [atel.caltech.edu](http://atel.caltech.edu/)

  Approx. \# of readers  600?                                                    300 *paid* subscribers, but much wider          500
                                                                                 readership                                      

  Cost                   Free                                                    \$20/line + \$50/item                           Free

  Sign-up/registration   Yes                                                     Not required, but possible, mainly for billing  Yes
  required?                                                                      purposes                                        

  Primary data           GRB, SGR observations                                   SNe, novae, comets, satellites of planets, CV's SNe, novae, X-ray pulsars, QPOs
  distributed                                                                                                                    

  Approx. time delay     Practically instantaneous                               1 day                                           Practically instantaneous

  Filtering/Error        No                                                      Yes                                             No
  checking/Editing?                                                                                                              

  Citeable in the        Yes                                                     Yes                                             Yes
  literature?                                                                                                                    

  Approx. number         TBD                                                     260                                             30
  issued/year                                                                                                                    
  ---------------------- ------------------------------------------------------- ----------------------------------------------- ----------------------------------------------

[GCN CIRCULARS]{.underline}

(Scott to write, but I do want to emphasize one thing, from our HETE
experience. It is essential to write a GCN *circular* for each burst,
because the automatically generated GCN *notices* have no author, and
are difficult to cite.)

[IAU CIRCULARS]{.underline}

IAUC's are no longer the method of choice for circulating GRB and SGR
information (GCN circulars replaced them several years ago for this
purpose), but they may still be appropriate for announcing certain Swift
discoveries. Such discoveries might include, but not be limited to, new
X-ray sources, or the flaring or unexpected behavior of previously known
ones. In general, the purpose of issuing an IAUC is to call the
attention of the astronomical community to a phenomenon which would
benefit from rapid, but not instantaneous, multiwavelength observations.
The advantages of IAUC's are first, that they are read by a very large
audience (don't be fooled by the small number of paid subscribers --
many are large institutions, and the circulars are posted and/or passed
around), and second, that they go out to many astronomers/observers who
may not be particularly interested in GRB-type phenomena, but who *are*
actively involved in other high energy astrophysics areas. The
disadvantages are first, that they are quite expensive to send (several
hundred dollars), and second, that they do not go out instantly (they
are filtered, and often revised, and you do not always get a chance to
see the final version -- in principle, they can also be rejected).

All burst advocates are strongly encouraged to visit the IAUC website
(<http://cfa-www.harvard.edu/cfa/ps/cbat.html>) and read the
instructions carefully well in advance of their first shift as an
advocate, because the instructions are lengthy, specific, and somewhat
arcane, and non-adherence to them will delay acceptance (in some cases,
indefinitely). Also, submission of an IAUC implies that you, or your
institution, is prepared to pay for the circular; burst advocates must
be prepared to receive an invoice for their submissions.

[Astronomer's Telegrams (ATEL's)]{.underline}

ATEL's are the invention of Robert Rutledge (now at Caltech). They were
initially used on occasion for announcing GRB's, but that function is
now served almost exclusively by GCN circulars. Instead, ATEL's announce
other high energy astrophysical phenomena, such as QPO's, XTE and
INTEGRAL discoveries of new X-ray sources, and discoveries of radio and
optical counterparts to new X-ray sources. Just as for the IAUC's,
ATEL's may be appropriate for announcing Swift discoveries such as new
X-ray sources, or the flaring or unexpected behavior of previously known
ones. The advantages of ATEL's are that they are free and practically
instantaneous. The only disadvantage is that they do not seem to have
been embraced as widely by the community as GCN's and IAUC's.

ATEL's are not filtered or refereed in any way, but you must be
registered and have a password to submit them. Burst advocates are urged
to sign up at the ATEL website
([atel.caltech.edu](http://atel.caltech.edu/)) well in advance of their
first shift in order to receive a password and review the procedures for
submission. ATEL's are somewhat more structured than GCN's and IAUC's,
but are easy to write. A good rule of thumb might be to submit an ATEL
in addition to, or even in place of, an IAUC.

# Follow-Up Team Communications

As of this writing, the Swift follow-up team consists of 31 people who
have agreed to commit a significant amount of their time, or their
observing time, to GRB's discovered by Swift, or to X-ray sources which
Swift observes. They have also agreed, at least in principle, to allow
certain Swift team members, in particular the BA's, to know about their
observing plans and their preliminary results, in order to assist Swift
planning. Conversely, it is also possible that BA's will be contacted by
follow-up team members to get information on Swift observations of a
particular GRB, so that they can use their observing time more
efficiently. The principles which define the interaction between
follow-up team members and the Swift team are given in Appendix TBD.
This appendix also discusses Swift Associate Scientists, but it is
expected that there will be relatively little urgent communication
between Associate Scientists and BA's.

Table TBD lists the follow-up team members, and figure TBD shows their
geographical locations. Note that the on-line version of this manual
contains hyperlinks to the e-mail addresses of the team members, and to
the websites containing instrumentation descriptions. The
instrumentation available to follow-up team members may be roughly
sorted into four categories as follows.

1.  Automated telescopes. These instruments slew automatically to a GRB
    position to observe it whenever possible. They include AEOS,
    Faulkes, KAIT, LOTIS, REM, Super-LOTIS, TAROT, and WASP.

2.  Non-steerable facilities. These are instruments which observe a
    large fraction of the sky more or less continuously. LIGO and
    MILAGRO are in this category.

3.  Space-based telescopes. These can in principle respond to Swift GRBs
    on a ToO basis. HST and INTEGRAL are in this category.

4.  Steerable ground-based telescopes. Apache Point, CTIO, ESO, Galileo,
    HET, Isaac Newton, Keck, KPNO, LBT, McDonald, NASA IRTF, NOT,
    Palomar, SALT, SAAO, Tenerife IRTF, and VLT are in this category. It
    is expected that most, although not all, of the interactions between
    the BA and the follow-up team will take place with people using
    these instruments.

Exactly how the BA's and the follow-up team members interact remains to
be determined. An attempt has been made to provide a website for
follow-up team members to post information about their ongoing
observations. *This site is password-protected, and BA's should be aware
that all information on it is proprietary and only for their use in
managing Swift observations; it should not be given out to anyone
(including other follow-up team members) without the express permission
of the person who posted it.* That said, it is not at all certain that
the follow-up team members will actually use this site; in the trials
which have taken place to date, the reception to it has been lukewarm at
best. The url, username, and password for this website are TBD, TBD, and
TBD.

Other possible means of interaction are by telephone or e-mail. Even
though all Swift data are public, follow-up team members who are
observing, or planning to observe, may not have the time or desire to
retrieve and analyze data, and may want to get an "instant analysis" of
Swift data from the BA, or may want to know how long Swift will continue
to observe a particular event. Conversely, the BA may want to contact
follow-up team members to inquire about their observing plans in order
to make decisions. Table TBD gives the phone numbers of those team
members who have agreed to be contacted, and the local times when they
will take calls. No entry means that the member has not agreed to be
contacted by phone; in these cases, e-mail should be used. The names of
the team members are hyperlinked to their e-mail addresses. *All
information given to a BA by a follow-up team member should be
considered proprietary unless otherwise stated; this information should
not be passed along to anyone else.*

BA's should keep in mind that they may be contacted not only by
follow-up team members, but also by associate scientists and
institutional scientists, and by "outside" observers.

  ------------------------------------------------------- ------------------ ------------------------------------------------------------------------------------------ --------------------
  NAME                                                    INSTITUTE          INSTRUMENTS                                                                                PHONE; LOCAL TIME
                                                                                                                                                                        (ALL TBD AT THIS
                                                                                                                                                                        STAGE)

  [Angelo Antonelli](mailto:angelo@coma.mporzio.astro.it) Rome Observatory   [ESO](http://www.eso.org/), [REM](http://golem.merate.mi.astro.it/projects/rem/),          
                                                                             [FAME](http://grb.mporzio.astro.it/)                                                       

  [Michel Boer](mailto:boer@cesr.fr)                      CESR, France       [TAROT](http://www.cesr.fr/~boer/tarot/)                                                   

  [David Buckley](mailto:dibnob@saao.ac.za)               SAAO, S. Africa    9 m [SALT](http://www.salt.ac.za/default.htm) telescope                                    

  [Michael Busby](mailto:busby@coe.tsuniv.edu)            Tennessee State U. [Misc. automated telescopes (24 - 81")](http://schwab.tsuniv.edu/)                         

  [Andrea Cimatti](mailto:cimatti@arcetri.astro.it)       Arcetri, Italy     [LBT](http://medusa.as.arizona.edu/lbtwww/lbt.html)                                        

  [Malcolm Coe](mailto:M.J.Coe@soton.ac.uk)               Southampton, UK    [Tenerife IRTF](http://www.iac.es/gabinete/oteide/carlos/carlos.html),                     
                                                                             [SAAO](http://www.saao.ac.za/)                                                             

  [Stefano Covino](mailto:covino@merate.mi.astro.it)      Brera, Italy       [ESO](http://www.eso.org/), [REM](http://golem.merate.mi.astro.it/projects/rem/)           

  [Thierry                                                ISDC, Switzerland  [INTEGRAL](http://astro.estec.esa.nl/SA-general/Projects/Integral/integral.html)           
  Courvoisier](mailto:thierry.courvoisier@obs.unige.ch)                                                                                                                 

  [Massimo Della Valle](mailto:massimo@arcetri.astro.it)  Arcetri, Italy     [VLT](http://www.eso.org/paranal/), [LBT](http://medusa.as.arizona.edu/lbtwww/lbt.html),   
                                                                             [Galileo](http://www.tng.iac.es/)                                                          

  [Brenda Dingus](mailto:dingus@lanl.gov)                 LANL, USA          [Milagro](http://www.lanl.gov/milagro/)                                                    

  [Alex                                                   UC Berkeley, USA   [KAIT](http://astron.berkeley.edu/~bait/kait_lwd.html),                                    
  Filippenko](mailto:afilippenko@astro.berkeley.edu)                         [Keck](http://www2.keck.hawaii.edu/)                                                       

  [Sam Finn](mailto:LSFinn@psu.edu)                       Penn. State U.,    [LIGO](http://www.ligo.caltech.edu/)                                                       
                                                          USA                                                                                                           

  [Fabrizio Fiore](mailto:fiore@mporzio.astro.it)         Rome Observatory,  [VLT](http://www.eso.org/paranal/)                                                         
                                                          Italy                                                                                                         

  [Andy Fruchter](mailto:fruchter@stsci.edu)              STScI, USA         [HST](http://hubble.stsci.edu/)                                                            

  [Gabriele                                               Brera, Italy       [VLT](http://www.eso.org/paranal), [LBT](http://medusa.as.arizona.edu/lbtwww/lbt.html),    
  Ghisellini](mailto:gabriele@merate.mi.astro.it)                            [Galileo](http://www.tng.iac.es/)                                                          

  [Roberto Gilmozzi](mailto:rgilmozz@eso.org)             VLT, Chile         [VLT](http://www.eso.org/paranal)                                                          

  [Shri Kulkarni](mailto:srk@astro.caltech.edu)           Caltech, USA       [Keck](http://www2.keck.hawaii.edu/),                                                      
                                                                             [Palomar](http://www.astro.caltech.edu/observatories/palomar/)                             

  [Bruce Margon](mailto:margon@stsci.edu)                 STScI, USA         [ARC, Apache Point](http://www.apo.nmsu.edu/)                                              

  [Hye-Sook Park](mailto:park1@llnl.gov)                  LLNL, USA          [LOTIS,                                                                                    
                                                                             Super-LOTIS](http://search.msn.com/http:/slotis.noao.kpno.edu/~ggwilli/LOTIS/index.html)   

  [Holger Pedersen](mailto:holger@astro.ku.dk)            Copenhagen U.      [NOT La Palma](http://www.not.iac.es/), [ESO](http://www.eso.org/)                         
                                                          Observatory,                                                                                                  
                                                          Denmark                                                                                                       

  [James Rhoads](mailto:rhoads@stsci.edu)                 STScI, USA         [KPNO](http://www.noao.edu/kpno/), [CTIO](http://www.ctio.noao.edu/), [NASA                
                                                                             IRTF](http://irtfweb.ifa.hawaii.edu/)                                                      

  [Brad Schaefer](mailto:schaefer@astro.as.utexas.edu)    UT Austin, USA     [McDonald](http://www.as.utexas.edu/mcdonald/mcdonald.html),                               
                                                                             [HET](http://www.as.utexas.edu/mcdonald/het/het.html)                                      

  [Don Schneider](mailto:dps@astro.psu.edu)               Penn. State U.,    [HET](http://www.as.utexas.edu/mcdonald/het/het.html)                                      
                                                          USA                                                                                                           

  [Mark Skinner](mailto:mark.skinner@maui.afmc.af.mil)    Maui Air Force     [AEOS](http://www.fas.org/spp/military/program/track/aeos.htm)                             
                                                          Site, USA                                                                                                     

  [Ian Smith](mailto:ian@spacsun.rice.edu)                Rice U., USA       [AEOS](http://www.fas.org/spp/military/program/track/aeos.htm), Misc. IR, sub-mm           

  [Chris Stubbs](mailto:stubbs@astro.washington.edu)      U. Washington, USA [ARC, Apache Point](http://www.apo.nmsu.edu/)                                              

  [Chris Thompson](mailto:thompson@cita.utoronto.ca)      CITA, Canada       ????                                                                                       

  [Fred Vrba](mailto:fjv@nofs.navy.mil)                   USNO, USA          [1 m, 1.3 m telescopes](http://www.usno.navy.mil/)                                         

  [Nic Walton](mailto:naw@ast.cam.ac.uk)                  Cambridge, UK      [Isaac Newton Telescopes](http://www.ing.iac.es/Astronomy/astronomy.html)                  

  [Peter Wheatley](mailto:pjw@star.le.ac.uk)              Leicester, UK      [WASP](http://www.star.le.ac.uk/~pjw/wasp/wasp_escience.html),                             
                                                                             [Faulkes](http://www.faulkes-telescope.com/)                                               

  [Filippo Zerbi](mailto:zerbi@merate.mi.astro.it)        Brera, Italy       [REM](http://golem.merate.mi.astro.it/projects/rem)                                        
  ------------------------------------------------------- ------------------ ------------------------------------------------------------------------------------------ --------------------

![](media/image13.png){width="6.5in" height="3.3375in"}

Figure TBD. The geographical locations of the radio and optical
telescopes available to the follow-up team.

It is possible that the BA's will encounter conflicts of interest, and
situations which require difficult choices. Some examples follow.

-one follow-up team member requests that Swift continue to observe a GRB
to complete or enhance his or her dataset; another follow-up team member
requests that Swift slew to a new burst because his or her instrument is
prepared to take data on it.

-a follow-up team member makes one request, while an observer who is not
on the follow-up team makes a conflicting request, e.g., "slew to the
position of this amazing INTEGRAL/IPN/HETE burst that LIGO just observed
gravitational radiation from!".

-an associate scientist or an institutional scientist requests a slew to
an X-ray source position, because the source is exhibiting interesting
behavior; but a GRB observation is in progress.

-a BA's friend/colleague/close collaborator/spouse requests something
which conflicts with another request which has already been granted.

-   Rapid Response Data Products

Some follow-up team members may require \"instant data analysis\" in
order to trigger or conduct their observations.  Even though all Swift
data are made public, such analysis can, in some cases, be done faster
and better by the BA.  Some examples follow.

-notify me when you have a burst with an XRT position which is good to 2
arcseconds, but which has no detectable optical counterpart

-notify me when you have an optical transient which appears to be
decaying with a power law index greater than -2

-notify me when the X-ray counterpart flux for a GRB is greater than
10\^-13 erg/cm2 s in the 2-10 keV band two hours after the burst

These examples are all hypothetical.  In fact, no follow-up team member
has yet requested such analysis.  But in principle, the team members are
entitled to make such requests, if they entail a reasonable amount of
work from the Swift team and the BA.

Prior to the start of Swift operations, the follow-up team leader will
notify the members of the follow-up team that requests for data analysis
must be submitted TBD days in advance.  These requests will then be
circulated to the appropriate personnel, such as instrument team members
and software engineers, for consideration and implementation.  It will
be the responsibility of the BA to ensure that the analyses are carried
out, and that the follow-up team members are notified.

# Burst Summary Report

For each burst the responsible Burst Advocate shall provide entries and
review a Burst Summary Report. The form for this report is being
developed by the HEASARC, under the direction of Lorella Angellini. The
report form is available as a Web page. It contains quick results and
standardized data pertaining to that burst. Details are available from
Dr. Angellini.

# Publications for Each Burst

The general publication philosophy of the Swift team is to have
scientists who contribute to a project be co-authors on the publications
from that work. Recognition will be given to people who developed the
hardware or specific software that enabled that project either in
authorship or acknowledgement. It is expected that some major results
from the mission, particularly obtained in the early phases of the
mission, will have longer lists of authors, The question of first
authorship and order of authors will be decided by the team working on
that project following the basic principle that recognition is given to
members who contribute the most.

To ensure the quality of team publications, the Swift PI will be
notified of all pending papers written by Swift team members using Swift
data and will implement a rapid internal review of the paper.
Opportunities will be provided for Swift team members to contribute to
and thereby join any paper in progress. A sentence will be put in the
acknowledgement of the paper to the effect that it is a Swift team
paper. Swift team publications will be listed in a web-based publication
list.

For GRBs, there will be GCNs for each burst. Early in the mission, first
authorship on the GCNs will be given to Swift team members who have
contributed most to the development of the mission. It is expected at
later stages of the mission that the Burst Advocates will be the first
authors on GCNs.

Questions or disputes concerning publications and authorship will be
addressed by the Swift PI.

# Appendices

## Swift Follow-Up Team Members And Associate Scientists

The Swift team recognizes two categories of collaborators, in addition
to co-investigators: follow-up team members and associate scientists.
This document explains their roles and responsibilities in the project.

FOLLOW-UP TEAM MEMBERS

Follow-up team members are individuals who have a particular interest or
expertise in observing the multi-wavelength or non-electromagnetic
counterparts to GRBs. In general they must have access to ground- or
space-based observing facilities or experiments to carry out these
observations. Such access may either be through proposals to guest
investigator programs, or through fixed blocks of observing time
reserved for members of a particular institution. In many, but not all,
cases, their main contributions to the project will be made after Swift
has been launched.

Their roles will be:

a\. to observe Swift GRB positions, and/or

b\. to observe Swift SGR positions, and/or

c\. to observe sources detected in the all-sky survey or pointed
observations.

Their responsibilities will be:

a\. To request observing time at the appropriate facilities for

Swift follow-up studies as needed,

b\. To inform the Swift project in a timely manner about their observing
plans;

such information may be posted on the Swift website in an area whose
access is

restricted to Swift co-investigators and other follow-up team members,

c\. To collaborate as needed with Swift co-investigators in the analysis
and public

dissemination of their results.

Follow-up team members are also strongly encouraged to attend Swift
science team meetings, both prior to and after launch, and present their
projects.

Since much of the basic Swift data on GRBs must be made public, the
Swift team\'s responsibility to follow-up team members will be

a\. to perform any supplementary analysis of Swift data which is
required to enhance the results of the follow-up observations. In case
of a conflict between observers who are not members of the follow-up
team and observers who are members, such analysis will be carried out
preferentially for follow-up team members.

b\. To consult with follow-up observers in planning pointed observations
of GRBs in a way which will maximize the scientific output and minimize
any redundancy in the observations.

c\. As far as possible, to minimize competition between follow-up
members for any particular observatory or experiment by limiting the
number of follow-up team members who have access to that particular
facility.

Currently there are 31 members of the follow-up team, selected to assure
good multi-wavelength coverage of GRBs, multiple observing sites, a wide
geographical distribution, and access to the most appropriate facilities
for following up Swift GRBs.

Members may be added or deleted to the team according to the following
rules.

> a\. An individual wishing to join the follow-up team must be nominated
> by a member of the Swift Science Working Group (SWG)
>
> b\. Upon nomination, the individual must write a short (\~1 page)
> statement of his or her research interests, access to any relevant
> instruments, experiments, or facilities, and potential contributions
> to the Swift project. This statement must be submitted to the
> follow-up team leader.
>
> c\. The SWG will consider the application at its following semiannual
> meeting and vote on it; the applicant will be informed of the decision
> following the meeting. This letter

should be received no later than one month prior to the SWG meeting in
question.

An individual who is a follow-up team member, who changes his or her
institutional affiliation, must write a short note (\~1 page or less) to
the follow-up team leader, re-affirming his or her intent to continue
participating in the project. If, as a result of such a change of
institution, the individual loses access to an instrument, experiment,
or facility, and/or gains access to a different instrument, experiment,
or facility, this must be explained.

Such changes of institution will be considered by the SWG in one of its
semiannual meetings and the individual will be notified thereafter.

An individual who wishes to resign from the follow-up team for any
reason is requested to write a short note of explanation to the
follow-up team leader.

ASSOCIATE SCIENTISTS

Associate scientists are individuals who have a particular expertise in
an area of use to the project. Areas of expertise include, but are not
limited to,

a\. theory

b\. data reduction and/or analysis

c\. modeling of experiment performance

d\. construction of experiments

e\. verification and testing of experimental parameters

f\. organization of results into a database or other repository

g\. outreach and education

Their roles will be to enhance all aspects of the mission, its
performance, and/or the utilization of its data. Their main
contributions to the project may be made before and/or after Swift has

been launched. Currently there are 14 associate scientists.

Their responsibilities will be:

a\. To carry out specific tasks as requested by the Swift PI,

b\. To advise the project on issues related to the mission,

> c\. To inform the Swift project in a timely manner about their plans
> and progress; such information may be posted on the Swift website in
> an area whose access is restricted to Swift co-investigators and other
> associate scientists, and
>
> d\. To collaborate as needed with Swift co-investigators for the
> public dissemination of their results.

Associate scientists are also strongly encouraged to attend Swift
science team meetings, both prior to and after launch, and present their
projects.

Since much of the basic Swift data on GRBs must be made public, the
Swift team\'s responsibility to associate scientists will be to perform
any supplementary analysis of Swift data which is required to enhance
the results of their studies. In case of a conflict between individuals
who are not associate scientists and individuals who are, such analysis
will be carried out preferentially for associate scientists.

The rules for adding and deleting associate scientists are identical to
those for follow-up team members. In general, individuals who work at a
co-I institution are eligible to become associate scientists, if they
are senior scientists at their institution.

FINANCIAL SUPPORT

In general, follow-up team members and associate scientists are not
eligible for financial support from the Swift project.

Swift follow-up team members and associate scientists are eligible to
apply for financial support from the Swift Guest Investigator program,
if they apply to that program with a U.S. Principal Investigator-led
proposal, and win a competitive peer-reviewed selection process.

## Swift GRB Afterglow Observing Plan

When Swift discovers a new GRB, it will commence an automated target
(AT) set of observations which continue until 20,000 seconds of
observing (non-SAA) time on target are accumulated.  Following
completion of these automated observations, the on-duty Observatory Duty
Scientist will extend these automated observations by uploading the GRB
location as a ground loaded AT target, unless another GRB occurs
(creating a new automated AT target; either as a BAT trigger or as a
non-Swift discovered burst) or unless extending the AT observations will
prevent afterglow followup of a previous burst.  Such extensions will
continue until the Science Planners can create a new schedule, and that
new schedule takes effect through an uploaded Command Load.

Swift Science Planners will meet on every normal workday and produce a
new Science Plan which will schedule PPT targets. PPT targets are
observed according to a strict timeline which is not changed by the
occurrence of GRBs, but will be superceded by AT targets, when or if
they are visible within the Swift observing constraints.

Science Plans are created using the TAKO software, which includes
knowledge of the orbital elements, thus ensuring that the PPT targets
are visible at the scheduled times.  Science Plans will also fill all
available time.

Science Planners will create the Science Plan through the following
steps:

1)  All required, non-routine afterglow observations are inserted into
TAKO, using the required integration times.  Examples of non-routine
observations are calibrations, ToO observations, and GRB afterglow
observations which exceed the routine category.  Non-routine
observations are assigned priorities below the default AT value, but
higher than the routine priority.  (If or when a BAT hard X-ray
transient or Galactic plane survey is conducted, those pointings will
also be non-routine.)

2)  The Science Planners will determine the observation length for
routine afterglow observations.  The observation length will be the
total available time (total time minus time for non-routine
observations) divided by the number of afterglow targets.  The Science
Planners will determine the number of afterglow targets through a
telecom with the BAs of recent bursts.  Typically each afterglow will be
observed for a minimum of 10 days (TBR \[To Be Revised\], based on
experience). Afterglow targets include both Swift and non-Swift
discovered GRBs.

3)  The Science Planners will run TAKO using all the non-routine
targets, all the routine targets (inserted at 90% TBR of the routine
observation length and medium priority), and all the routine targets
again (inserted now at 20% TBR of the routine observation length and low
priority).

4)  The TAKO-produced draft Science Plan will be reviewed for gaps (i.e.
times without targets) or dropped targets (i.e. afterglow targets which
do not get scheduled).  Gaps will be filled by adding repeat
observations of routine GRBs or Fill-in targets (from the list of BAT
Survey targets).  Dropped targets will be corrected by applying time
windows to alternate days between competing targets.

5)  The TAKO scheduling process will be repeated until a Science Plan
results which has no gaps, and all available routine and non-routine
targets are observed within the run of the schedule uploaded as the new
Command Load.

# Abbreviations

  -------------- --------------------------------------------------------
  AEOS           Advanced Electro-Optical System

  ARC            Astrophysical Research Consortium

  ATEL           Astronomer's Telegram

  BA             Burst Advocate

  BAT            Burst Alert Telescope

  CESR           Centre d'Etude Spatiale des Rayonnements

  CITA           Canadian Institute for Theoretical Astrophysics

  CTIO           Cerro Tololo Interamerican Observatory

  CV             Cataclysmic Variable

  ESO            European Southern Observatory

  FAME           Fast Alert MachinE

  FoM            Figure of Merit

  GCN            Gamma-Ray Burst Coordinates Network

  GI             Guest Investigator

  GRB            Gamma-Ray Burst

  HET            Hobby-Eberly Telescope

  HST            Hubble Space Telescope

  IAUC           International Astronomical Union Circular

  IM             Institutional Manager

  INTEGRAL       International Gamma Ray Astrophysics Laboratory

  IRTF           InfraRed Telescope Facility

  ISDC           INTEGRAL Science Data Center

  KAIT           Katzman Automatic Imaging Telescope

  KPNO           Kitt Peak National Observatory

  LANL           Los Alamos National Laboratory

  LBT            Large Binocular Telescope

  LIGO           Laser Interferometer Gravitational Wave Observatory

  LLNL           Lawrence Livermore National Laboratory

  LOTIS          Livermore Optical Transient Imaging Survey

  MOC            Mission Operations Center

  NASA           National Aeronautics and Space Administration (duh)

  NOT            Nordic Optical Telescope

  ODS            Observatory Duty Scientist

  PI             Principal Investigator (Neil Gehrels of GSFC)

  PSU            The Pennsylvania State University

  QPO            Quasi-Periodic Oscillation

  REM            Rapid Eye Mount

  SAAO           South African Astronomical Observatory

  SALT           South African Large Telescope

  SNe            Supernovae

  STScI          Space Telescope Science Institute

  TAROT          Télescope à Action Rapide pour les Objets Transitoires
                 (Rapid Action Telescope for Transient Objects)

  USNO           United States Naval Observatory

  UVOT           Ultra-Violet/Optical Telescope

  VLT            Very Large Telescope

  WASP           The UK Wide-field Automated Survey Programme

  XRT            X-Ray Telescope instrument
  -------------- --------------------------------------------------------

#   {#section-3 .unnumbered}

# Burst Advocate 'To-Do' List

1.  Check automated GCNs for information on GRB (BA will be paged by
    second BAT GCN)

2.  If normal hours, contact Swift Observatory Duty Scientist to
    acknowledge assumption of BA duty and inform successor Burst
    Advocates they are on-call for next GRB.

3.  Use web-form to enter GCN circular on new burst.

4.  Initiate new chat-room for new GRB information within team.

5.  If after hours, decide if GRB is interesting enough to page duty
    scientists and assistants

6.  If GRB is interesting, contact Swift Duty Scientist to recommend
    future Swift observations

7.  Check BAT flux, T90, Epeak and hardness ratio to determine type of
    GRB

8.  Check XRT flux and spectral parameters to determine x-ray properties

9.  Check UVOT flux and finding chart to determine optical properties

10. If GRB is exceptional, contact MOC Director and PI

11. Provide UVOT counterpart (with position & magnitude) to GCN, if
    found at XRT position of counterpart, or based on rapid variation

12. Provide inputs to SDC web site

13. Monitor community GCNs and Follow-up Team web site to determine what
    observations are being made

14. If appropriate, contact Follow-up Team members to alert them to
    developments or ask them for advice.

15. Monitor state of data products and contact SDC if products are late,
    or instrument teams if instrument data looks incorrect

16. Provide input to MOC for UVOT modes for this GRB during Preplanned
    Target (PT) observations

17. Collect data products for GRB and fill in HEASARC web site for GRB

18. Contact key project leads, as appropriate

19. Fill in problem/short report form at end of shift

20. Participate in publication of results, as appropriate

[^1]: In each case where two units are specified, one unit is a "cold"
    redundant unit.

[^2]: See http://heasarc.gsfc.nasa.gov/ftools/

[^3]: The home page for the SSC can be found at
    http://swiftsc.gsfc.nasa.gov.