# Presentation: 442317

## VERITAS:Present/Future Plans

- Trevor Weekes
- Harvard-Smithsonian Center for Astrophysics

## Davies-Cotton f/1.0 Optics. Total area=110m2
Installed at Whipple Basecamp on Mt. Hopkins (1275m) in January 2005

- 499 PMT camera

- Steel OSS

- Control Room

- Davies-Cotton f/1.0 Optics. Total area=110m2
- Installed at Whipple Basecamp on Mt. Hopkins (1275m) in January 2005

**VERITAS Telescope-1**

## Camera

**Camera**

- 1.8 m

- 3.5o FOV

- 499 PMTs
- Photonis XP2970
- 0.15o spacing

- Hadron

- Gamma ray

- Muon Ring

- Hadron

## Timing

- Poster: “Exploiting VERITAS Timing Information” Holder et al.

## Horseshoe Canyon on Kitt Peak;anticipated site for VERITAS

- Horseshoe Canyon
-  site was ready
-  for installation
-  of Telescopes in
-  April, 2005; power,
-  pads, access,
-  communications, etc

## Legal Complications

- National Science Foundation issued Stop Work order for VERITAS activity on Kitt Peak on April 7, 2005
- (NSF leases Kitt Peak mountain as site for national observatory based on lease signed in 1958; VERITAS leases site from NSF)
- Complaint lodged by Tohono O’odham Nation
- Court Order overturned (“egregious lack of cooperation”)
- New Environmental Assessment required; still
-    in progress as of May, 2006; negotiations continue with Tohono O’odham; resolution uncertain

- Two VERITAS telescopes at temporary site at Whipple Observatory Basecamp, December 2005

## New Contingency Plan

- No light at the end of the Site Tunnel
- January 2006: Adopt Contingency Plan: install all four telescopes at Basecamp immediately giving two years of operation while Kitt Peak situation is resolved or new permanent site is approved
- Move VERITAS to permanent site at beginning of 2009
- Begin full scientific program

- Flux Sensitivity
- Effective Energy Threshold

- Contingency Plan:
- Install two more
- Telescopes at the
- Whipple Basecamp.
- Dark Site
- Elevation ~ 1.3 km
- Energy Threshold ~
- 120 GeV (20% higher
-  than Horseshoe
- Canyon).
- Can be operational by
-  end of 2006 in time
-  for GLAST overlap.
- Operate thus for two
-  years...then relocate
-  to darker, higher, less
-  restricted site.

- Aerial View of Whipple Observatory Basecamp

## ACIT TeV gamma-ray astronomy field has changed dramatically in last few years
Five major players
Explosion of astrophysical interest
HESS has brought TeV gamma-ray astronomy into the mainstream of astronomy
There is great interest now in going beyond HESS/VERITAS; a two-year hiatus gives us chance to plan for the long term
Horseshoe Canyon has become an increasingly less attractive site
Vehement Indian opposition
Mexican Spotted Owl
Restriction on future development
Higher/darker/larger site desirable in long term
Hardware, software to complete array virtually complete and in storage 

- Five major players
- Explosion of astrophysical interest
- HESS has brought TeV gamma-ray astronomy into the mainstream of astronomy
- There is great interest now in going beyond HESS/VERITAS; a two-year hiatus gives us chance to plan for the long term
- Horseshoe Canyon has become an increasingly less attractive site
- Vehement Indian opposition
- Mexican Spotted Owl
- Restriction on future development
- Higher/darker/larger site desirable in long term
- Hardware, software to complete array virtually complete and in storage

- Drivers

## Telescope-3

- First light: September 12, 2006

## Telescope-4

- First Light: November 6, 2006

## Costs/Schedule

- Forest Service, DOE, NSF, SAO has approved three year plan
- Four telescopes can be operational by end of calendar year (2006)
- Two full years (2007 and 2008) of full scientific program
- Extra Cost of installing Telescope-3  and -4 is not large
- New funding will needed for relocation to higher, more remote, more flexible, site
- Darker, higher site desirable in long term; expanded array?.

## Basecamp then HC (2)

## Meanwhile back at theWhipple 10 m telescope2005-6 Continuous monitoring of five TeV AGN

- Markarian 421 has been
-  active since Dec., 2005
- (almost always detectable)

## Whipple Multiwavelength Campaign (D.Horan)

- Whipple 1.2 m Optical (R band)
- Whipple 1.3 m Infrared (H,K,L)
- RXTE (keV)
- Whipple 10 m (TeV)

- Stereo Observations also by VERITAS:1-2 in April-May, 2006

## VERITAS:1-2Stereo Observations of Mrk 421April-May , 2006Wobble mode: ~10 sigma/30 minutes

## TeV2032 Recent Analysis of 10 m data by Finley, Konopelko, Syson....

|  | S/N | ON-OFF | Rate [/min] | Rate [Crab] |
| --- | --- | --- | --- | --- |
| S1 | 4.68 | 624 | 0.18 | 0.086 |
| S2 | 4.98 | 589 | 0.17 | 0.081 |

- T = 65.6 hrs

**ON-OFF counts**

**Total significance: 6.8**

**S1**

**S2**

**HEGRA**

- Standard 2d analysis:
- ‘canalyse’ at Purdue

-  Two robust excesses in the field of view
-  S1 is likely a point like source
-  S1 is 0.14o  away from the HEGRA source
-  S2 could be extended and variable

**50 hrs with VERITAS will allow detailed study of a signal morphology and spectral shape!**

## Summary: VERITAS  status

- Temporary Solution: two years of operation at Basecamp while better permanent site is chosen, funds acquired, and infrastructure built
- Sensitivity at Basecamp
- Configuration not important
- Site is as dark as Whipple Observatory
- Elevation effect not large <15% in energy (175 GeV ->200 GeV)
- No downtime; observations continue throughout
- Best use made of available resources
- Have control of our destiny
- Come on-line with plenty of time before GLAST launch
- Meanwhile continue operation with 10 m (VERITAS-0)