bluuebunny/crossref_metadata_2025 huggingface dataset:
Incidence of Tension Pneumothorax in Police Officers Feloniously Killed in the Line of Duty: A Ten-Year Retrospective Analysis
Authors: Mark Ashley C. , Wimberger Nicole , Sztajnkrycer Matthew D.
Published: April 2012

Background: According to US military data, tension pneumothorax (TPx) is the second leading cause of possibly preventable combat death after isolated extremity hemorrhage. The purpose of this study was to determine whether TPx similarly represents a significant cause of possibly preventable death in police officers.

Methods: FBI data for the years 1998 through 2007 were reviewed. Cases were included if officers were on-duty at the time of fatal injury, and died within one hour from time of wounding from penetrating torso trauma. After case identification, letters were sent to the departments of victim officers requesting autopsy reports.

Results: One hundred and eight victim officers met inclusion criteria. Four charts were excluded due to inability to re-identify officers. Departmental response rate was 83.7%. Autopsy reports were provided for 60 officers (57.7%). All officers died from gunshot wounds. No coroner specifically identified TPx as either a direct cause of death or a contributing factor (95% CI, 0.00%-5.96%).

Conclusion: In contrast to the military experience, TPx appears to be a rare cause of possibly preventable death in police officers. Further study of non-fatal “near miss” events will be required to determine the actual need for law enforcement-specific medical training in the recognition and management of TPx.
Assessing the Psychosocial Elements of Crowds at Mass Gatherings
Authors: Hutton Alison , Zeitz Kathryn , Brown Steve , Arbon Paul
Published: April 2012

Introduction: The environmental aspects of mass gatherings that can affect the health and safety of the crowd have been well described. Although it has been recognized that the nature of the crowd will directly impact the health and safety of the crowd, the majority of research focuses on crowd behavior in a negative context such as violence or conflict. Within the mass gathering literature, there is no agreement on what crowd behavior, crowd mood and crowd type actually mean. At the same time, these elements have a number of applications, including event management and mass gathering medicine. These questions are worthy of exploration.

Methods: This paper will report on a pilot project undertaken to evaluate how effective current crowd assessment tools are in understanding the psychosocial domain of a mass gathering event.

Results: The pilot project highlighted the need for a more consistent descriptive data set that focuses on crowd behavior.

Conclusions: The descriptive data collected in this study provide a beginning insight into the science of understanding crowds at a mass gathering event. This pilot has commenced a process of quantifying the psychosocial nature of an event. To maximize the value of this work, future research is required to understand the interplay among the three domains of mass gatherings (physical, environmental and psychological), along with the effects of each element within the domains on safety and health outcomes for participants at mass gatherings.
Balancing Between Closeness and Distance: Emergency Medical Services Personnel’s Experiences of Caring for Families at Out-of-Hospital Cardiac Arrest and Sudden Death
Authors: Bremer Anders , Dahlberg Karin , Sandman Lars
Published: April 2012

Introduction:Out-of-hospital cardiac arrest (OHCA) is a lethal health problem that affects between 236,000 and 325,000 people in the United States each year. As resuscitation attempts are unsuccessful in 70-98% of OHCA cases, Emergency Medical Services (EMS) personnel often face the needs of bereaved family members.

Problem:Decisions to continue or terminate resuscitation at OHCA are influenced by factors other than patient clinical characteristics, such as EMS personnel’s knowledge, attitudes, and beliefs regarding family emotional preparedness. However, there is little research exploring how EMS personnel care for bereaved family members, or how they are affected by family dynamics and the emotional contexts. The aim of this study is to analyze EMS personnel’s experiences of caring for families when patients suffer cardiac arrest and sudden death.

Methods:The study is based on a hermeneutic lifeworld approach. Qualitative interviews were conducted with 10 EMS personnel from an EMS agency in southern Sweden.

Results:The EMS personnel interviewed felt responsible for both patient care and family care, and sometimes failed to prioritize these responsibilities as a result of their own perceptions, feelings and reactions. Moving from patient care to family care implied a movement from well-structured guidance to a situational response, where the personnel were forced to balance between interpretive reasoning and a more direct emotional response, at their own discretion. With such affective responses in decision-making, the personnel risked erroneous conclusions and care relationships with elements of dishonesty, misguided benevolence and false hopes. The ability to recognize and respond to people’s existential questions and needs was essential. It was dependent on the EMS personnel’s balance between closeness and distance, and on their courage in facing the emotional expressions of the families, as well as the personnel’s own vulnerability. The presence of family members placed great demands on mobility (moving from patient care to family care) in the decision-making process, invoking a need for ethical competence.

Conclusion:Ethical caring competence is needed in the care of bereaved family members to avoid additional suffering. Opportunities to reflect on these situations within a framework of care ethics, continuous moral education, and clinical ethics training are needed. Support in dealing with personal discomfort and clear guidelines on family support could benefit EMS personnel.
The Ethics of Resuscitation: How Do Paramedics Experience Ethical Dilemmas when Faced with Cancer Patients with Cardiac Arrest?
Authors: Nordby Halvor , Nøhr Øyvind
Published: April 2012

Introduction:Research on prehospital emergency work traditionally has focused on medical issues, but paramedics often have to make ethical choices. The goal of this exploratory study was to understand how paramedics experience difficult ethical dilemmas regarding resuscitation of cancer patients.

Methods:Paramedics from ambulance services in Norway were interviewed about resuscitation of cancer patients with cardiac arrest. The qualitative study included naturalistic, semi-structured interviews and a cognitive-emotional, interpretive approach.

Results:All study participants believed that it ethically can be correct not to resuscitate if the patient is expected to survive for only a short time with a very low quality of life and severe negative illness experiences. However, this belief sometimes failed to match formal or informal guidelines and contextual factors such as expectations of relatives. When confronting these challenges, the majority of the paramedics relied heavily on the advice of medical experts, but some had to make more autonomous decisions.

Discussion:The concept of a double pressure situation can be used to analyze the ethical dilemmas regarding resuscitation of cancer patients. The pressure from “below” is grounded in individual caring frameworks, and in the belief that it can be wrong to resuscitate. The pressure from “above” is objective and system-related, related to uncertainty, and grounded in the fundamental and irreducible value of human life.

Conclusions:The findings of this qualitative, exploratory study suggest that ethical concepts and analyses of double pressure situations should have an important role in education and training designed to prepare emergency personnel for difficult life and death choices. More research is needed to shed light on how ethical dilemmas arise in prehospital work.
Optical Transient Surveys
Authors: Schmidt Brian
Published: April 2012

The last five years have seen an explosion of activity to monitor the sky at optical wavelengths. The following summarizes an overview of the range of experiments currently being, or soon to be, undertaken in both cataloguing and monitoring the sky, and suggests scientific opportunities for the short- to medium- term in the arena of optical transient astronomy. In so doing, it applies the philosophy described by Warner (page 3) to the gamut of variability studies that are now burgeoning in observational astronomy.
The Scientific Potential of LOFAR for Time Domain Astronomy
Authors: Fender Rob
Published: April 2012

LOFAR is a ground-breaking low-frequency radio telescope that is currently nearing completion across northern Europe. As a software telescope with no moving parts, enormous fields of view and multi-beaming, it has fantastic potential for the exploration of the time-variable universe. In this brief paper I outline LOFAR's capabilities, our plans to use it for a range of transient searches, and some crude estimated rates of transient detections.
Time-Domain Astronomy withSwift,FermiandLobster
Authors: Gehrels Neil , Barthelmy Scott D. , Cannizzo John K.
Published: April 2012

The dynamic transient gamma-ray sky is revealing many interesting results, largely due to findings byFermiandSwift. The list includes new twists on gamma-ray bursts (GRBs), a GeV flare from a symbiotic star, GeV flares from the Crab Nebula, high-energy emission from novae and supernovae, and, within the last year, a new type of object discovered bySwift—a jetted tidal disruption event. In this review we present highlights of these exciting discoveries. A new mission concept calledLobsteris also described; it would monitor the X-ray sky at order-of-magnitude higher sensitivity than current missions can.
Explosions on a Variety of Scales
Authors: Bildsten Lars
Published: April 2012

The theoretical community is beginning to appreciate (and predict) the potential diversity of explosive outcomes from stellar evolution, while the supernovæ surveys are finding new kinds of supernovæ. This talk described two such new supernovæ. The first are ultraluminous core collapse supernovæ with radiated energies approaching 1051 ergs. The talk went on to present our recent work that explains these events with late-time energy deposition from rapidly rotating, highly magnetized neutron stars: magnetars. It concluded with our theoretical work on helium shell detonations on accreting white dwarfs that predict a new class of supernovæ called “.Ia's”. The first such candidate may well have been found by the Palomar Transient Factory.
On the Sensitivity of Period Searches
Authors: Schwarzenberg-Czerny A.
Published: April 2012

Astronomical time series are special in that time sampling in them is uneven yet often with periodic gaps due to daytime, moon and seasons. There is therefore a need for special-purpose time-series analysis (TSA) methods. The emergence of massive CCD photometric surveys from the ground and space raises the question of an automatic period search in ≫ 105 light curves. We caution that already at the planning stage it is important to account for the effects of time sampling and analysis methods on the sensitivity of detections. We present a transparent scheme for the classification of period-search methods. We employ tools for evaluating the performance of those methods, according to the type of light curves investigated. In particular we consider sinusoidal and non-sinusoidal oscillations as well as eclipse or transit light curves. From these considerations we draw recommendations for the optimum analysis of astronomical time series. We present briefly the capability of an automatic period-search package Tatry. Finally we discuss the role of Monte Carlo simulations in the analysis of detection sensitivity. As an example, we demonstrate a practical method to account for the bandwidth (multi-trial) penalty in the statistical evaluation of detected periods.
Probing the Physics of Planets and Stars with Transit Data
Authors: Aigrain Suzanne
Published: April 2012

Virtually all exoplanet detection and characterisation methods are based on time-domain data. This invited talk gave an overview of some recent results in the field, highlighting some of the time-series-specific challenges encountered along the way. In particular it focussed on planetary transits: how to detect shallow, rare transits in noisy data, and how to model them with extreme accuracy to extract information about the transiting planet's atmosphere. Space-based transit surveys also constitute an extraordinary goldmine of information on stellar variability, and the talk touched briefly upon some recent statistical work in that field.
Variability in Active Galactic Nuclei
Authors: Bonning Erin Wells
Published: April 2012

This talk explored variability in active galactic nuclei (AGN) for a variety of scales across the time domain. From billion-year-scale intermittency to a quasi-periodic oscillation signal with a period of one hour, time-varying signals offer insights into a myriad of complex processes driven by the AGN central engine. Athough the era of time-domain observations of AGN across the spectrum has but just begun, already observations reveal the rich detail of phenomena associated with actively accreting black holes which challenge theoretical models.
Variable Red Giants
Authors: Kerschbaum Franz , Nowotny Walter
Published: April 2012

The longest-known class of pulsating variable stars, namely pulsating red giants, is also the one that involves the most complex physical processes. Pulsation, mass loss, nuclear synthesis, mixing, atmospheric and circumstellar chemistry and dust formation all interrelate with one another and make both the observational studies and the modelling efforts quite challenging. The paper outlines some of the current key questions, and recommends observational strategies.
Towards a New Generation of Multi-Dimensional Stellar Models: Can Our Models Meet the Challenges?
Authors: Baraffe I. , Viallet M. , Walder R.
Published: April 2012

The talk described the first steps of development of a new multi-dimensional time-implicit code devoted to the study of hydrodynamical processes in stellar interiors. The main motivation stemmed from the fact that our physical understanding of stellar interiors and evolution still largely relies on one-dimensional calculations. The description of complex physical processes like time-dependent turbulent convection, rotation or MHD processes mostly relies on simplified, phenomenological approaches, with a predictive power hampered by the use of several free parameters. These approaches have now reached their limits in the understanding of stellar structure and evolution. The development of multi-dimensional hydrodynamical simulations becomes crucial to progress in the field of stellar physics and to meet the enormous observational efforts aimed at producing data of unprecedented quality (COROT, Kepler GAIA). The code we are developing solves the hydrodynamical equations in spherical geometry and is based on the finite volume method. The talk presented a global simulation of turbulent convective motions in a cold giant envelope, covering 80% in radius of the stellar structure. Our first developments show that the use of an implicit scheme applied to a stellar evolution context is perfectly thinkable.
Exploring the Time Domain with Synoptic Sky Surveys
Authors: Djorgovski S. G. , Mahabal A. A. , Drake A. J. , Graham M. J. , Donalek C. , Williams R.
Published: April 2012

Synoptic sky surveys are becoming the largest data generators in astronomy, and they are opening a new research frontier that touches practically every field of astronomy. Opening the time domain to a systematic exploration will strengthen our understanding of a number of interesting known phenomena, and may lead to the discoveries of as yet unknown ones. We describe some lessons learned over the past decade, and offer some ideas that may guide strategic considerations in the planning and execution of future synoptic sky surveys.
From Hipparcos to Gaia
Authors: Eyer L. , Dubath P. , Saesen S. , Evans D.W. , Wyrzykowski L. , Hodgkin S. , Mowlavi N.
Published: April 2012

The measurement of the positions, distances, motions and luminosities of stars represents the foundations of modern astronomical knowledge. Launched at the end of the eighties, the ESA Hipparcos satellite was the first space mission dedicated to such measurements. Hipparcos improved position accuracies by a factor of 100 compared to typical ground-based results and provided astrometric and photometric multi-epoch observations of 118,000 stars over the entire sky. The impact of Hipparcos on astrophysics has been extremely valuable and diverse. Building on this important European success, the ESA Gaia cornerstone mission promises an even more impressive advance. Compared to Hipparcos, it will bring a gain of a factor 50 to 100 in position accuracy and of a factor of 10,000 in star number, collecting photometric, spectrophotometric and spectroscopic data for one billion celestial objects. During its 5-year flight, Gaia will measure objects repeatedly, up to a few hundred times, providing an unprecedented database to study the variability of all types of celestial objects. Gaia will bring outstanding contributions, directly or indirectly, to most fields of research in astrophysics, such as the study of our Galaxy and of its stellar constituents, and the search for planets outside the solar system.
Technical and Observational Challenges for Future Time-Domain Surveys
Authors: Bloom Joshua S.
Published: April 2012

By the end of the last decade, robotic telescopes were established as effective alternatives to the traditional role of astronomer in planning, conducting and reducing time-domain observations. By the end of this decade, machines will play a much more central role in the discovery and classification of time-domain events observed by such robots. While this abstraction of humans away from the real-time loop (and the nightly slog of the nominal scientific process) is inevitable, just how we will get there as a community is uncertain. I discuss the importance of machine learning in astronomy today, and project where we might consider heading in the future. I will also touch on the role of people and organisations in shaping and maximising the scientific returns of the coming data deluge.
Optical & NIR Transient Surveys
Authors: Cross Nicholas J. G. , Djorgovski S. G.
Published: April 2012

A workshop on Optical & Near Infrared Transients took place during the first afternoon of the Symposium. It ran for two sessions. The first was given over to talks about various current optical and near-infrared transient surveys, focussing on the Vista surveys, the Catalina Real-Time Transient Survey, Pan-STARRS, Gaia, TAOS and TAOS2. The second session was a panel-led discussion about coordinating multi-wavelength surveys and associated follow-ups.
The Future of X-Ray Time-Domain Surveys
Authors: Haggard Daryl , Sivakoff Gregory R.
Published: April 2012

Modern X-ray observatories yield unique insight into the astrophysical time domain. Each X-ray photon can be assigned an arrival time, an energy and a sky position, yielding sensitive, energy-dependent light curves and enabling time-resolved spectra down to millisecond time-scales. Combining those with multiple views of the same patch of sky (e.g., in the Chandra and XMM-Newton deep fields) so as to extend variability studies over longer baselines, the spectral timing capacity of X-ray observatories then stretch over 10 orders of magnitude at spatial resolutions of arcseconds, and 13 orders of magnitude at spatial resolutions of a degree. A wealth of high-energy time-domain data already exists, and indicates variability on timescales ranging from microseconds to years in a wide variety of objects, including numerous classes of AGN, high-energy phenomena at the Galactic centre, Galactic and extra-Galactic X-ray binaries, supernovæ, gamma-ray bursts, stellar flares, tidal disruption flares, and as-yet unknown X-ray variables. This workshop explored the potential of strategic X-ray surveys to probe a broad range of astrophysical sources and phenomena. Here we present the highlights, with an emphasis on the science topics and mission designs that will drive future discovery in the X-ray time domain.
Gravitational Microlensing
Authors: Wyrzykowski Ł. , Moniez M. , Horne K. , Street R.
Published: April 2012

Gravitational microlensing is a well established and unique field of time-domain astrophysics. For two decades microlensing surveys have been regularly observing millions of stars to detect elusive events that follow a characteristic Paczyński lightcurve. This workshop reviewed the current state of the field, and covered the major topics related to microlensing: searches for extrasolar planets, and studies of dark matter. There were also discussions of issues relating to the organisation of follow-up observations for microlensing, as well as serendipitous scientific outcomes resulting from extensive microlensing data.
Using the VO to Study the Time Domain
Authors: Seaman Rob , Williams Roy , Graham Matthew , Murphy Tara
Published: April 2012

Just as the astronomical “Time Domain” is a catch-phrase for a diverse group of different science objectives involving time-varying phenomena in all astrophysical régimes from the solar system to cosmological scales, so the “Virtual Observatory” is a complex set of community-wide activities from archives to astroinformatics. This workshop touched on some aspects of adapting and developing those semantic and network technologies in order to address transient and time-domain research challenges. It discussed the VOEvent format for representing alerts and reports on celestial transient events, the SkyAlert and ATELstream facilities for distributing these alerts, and the IVOA time-series protocol and time-series tools provided by the VAO. Those tools and infrastructure are available today to address the real-world needs of astronomers.
Small and Robotic Telescopes in the Era of Massive Time-Domain Surveys
Authors: Bode M. F. , Vestrand W. T.
Published: April 2012

We have entered an era in time-domain astronomy in which the detected rate of explosive transients and important ephemeral states in persistent objects threatens to overwhelm the world's supply of traditional follow-up telescopes. As new, comprehensive time-domain surveys become operational and wide-field multi-messenger observatories come on-line, that problem will become more acute. The goal of this workshop was to foster discussion about how autonomous robotic telescopes and small-aperture conventional telescopes can be employed in the most effective ways to help deal with the coming deluge of scientifically interesting follow-up opportunities. Discussion topics included the role of event brokers, automated event triage, the establishment of cooperative global telescope networks, and real-time coordination of observations at geographically diverse sites. It therefore included brief overviews of the current diverse landscape of telescopes and their interactions, and also considered planned and potential new facilities and operating models.
Historical Time-Domain: Data Archives, Processing, and Distribution
Authors: Grindlay Jonathan E. , Griffin R. Elizabeth
Published: April 2012

The workshop on Historical Time-Domain Astronomy (TDA) was attended by a near-capacity gathering of ~30 people. From information provided in turn by those present, an up-to-date overview was created of available plate archives, progress in their digitization, the extent of actual processing of those data, and plans for data distribution. Several recommendations were made for prioritising the processing and distribution of historical TDA data.
Workshop on Stellar Tidal Disruption
Authors: Farrar Glennys R.
Published: April 2012

The past year has seen major advances in the observational status of Stellar Tidal Disruption, with the discovery of two strong optical candidates in archived SDSS data and the real-time X-ray detection of Swift J1644+57, plus rapid radio and optical follow-up establishing it as a probable Tidal Disruption Flare (TDF) in “blazar mode”. These observations motivated a workshop devoted to discussion of such events and of the theory of their emission and flare rate. Observational contributions included a presentation of Swift J2058+05 (a possible second example of a TDF in blazar mode), reports on the late-time evolution and X-ray variability of the two Swift events, and a proposal that additional candidates may be evidenced by spectral signatures in SDSS. Theory presentations included models of radio emission, theory of light curves and the proposal that GRB101225A may be the Galactic tidal disruption of a neutron star, an interpretation of Swift J1644+57 as due to the disruption of a white dwarf instead of main-sequence star, calculation of the dependence of the TDF rate on the spin of the black hole, and analysis of the SDSS events, fitting their SEDs to profiles of thoretical emission from accretion disks and showing that their luminosity and rate are consistent with the proposal that TDEs can be responsible for UHECR acceleration.
Workshop on Faint and Fast Transients
Authors: Kasliwal Mansi , Bildsten Lars
Published: April 2012

In the past five years systematic searches, serendipitous discoveries and archival searches have yielded over a dozen transients that are brighter than novæ but fainter than supernovæ. The observed properties of these “gap” transients tend to place them in distinct classes, some being about 100 times brighter than novæ and durations of nearly 100 days (e.g., M85 OT, PTF10fqs), while others (such as SN2002bj and PTF10bhp) nearly reach supernovæ luminosities but fade in five days. The state of theoretical understanding varies substantially across the class of objects, and is ripe for progress.
Workshop on Algorithms for Time-Series Analysis
Authors: Protopapas Pavlos
Published: April 2012

This Workshop covered the four major subjects listed below in two 90-minute sessions. Each talk or tutorial allowed questions, and concluded with a discussion.

Classification: Automatic classification using machine-learning methods is becoming a standard in surveys that generate large datasets. Ashish Mahabal (Caltech) reviewed various methods, and presented examples of several applications.

Time-Series Modelling: Suzanne Aigrain (Oxford University) discussed autoregressive models and multivariate approaches such as Gaussian Processes.

Meta-classification/mixture of expert models: Karim Pichara (Pontificia Universidad Católica, Chile) described the substantial promise which machine-learning classification methods are now showing in automatic classification, and discussed how the various methods can be combined together.

Event Detection: Pavlos Protopapas (Harvard) addressed methods of fast identification of events with low signal-to-noise ratios, enlarging on the characterization and statistical issues of low signal-to-noise ratios and rare events.
Investigating the Sources of Flickering and Superhumps in the Dwarf Nova V4140 Sgr
Authors: Baptista R. , Borges B. , Oliveira A.
Published: April 2012

We report the results of maximum entropy eclipse-mapping analysis of an ensemble of light curves of the dwarf nova V4140 Sagitarii (V4140 Sgr) with the objective of studying the spatial distribution of its steady-light and flickering sources in quiescence, and the changing disk structure during an outburst.
The Kepler Guest Observer Programme
Authors: Barclay Thomas
Published: April 2012

The Kepler Guest Observer Office is dedicated to the service of the broad science community, with a charter to promote the exploitation of Kepler data and broaden the scientific impact of the Kepler mission. There are four routes by which to gain access to Kepler data: the Guest Observer programme annual call for proposals, the quarterly call for Director's Discretionary Targets, the Kepler Asteroseismic Science Consortium, and by accessing the Kepler public data archive. The Guest Observer Office supports all users of Kepler data no matter which route they took to access data, and to that end have developed software tools which can be used by the community in their data analyses.
Crab Pulsar: Enhanced Optical Emission During Giant Radio Pulses
Authors: Collins Susan , Shearer Andy , Stappers Ben , Barbieri Cesare , Naletto Giampiero , Zampieri Luca , Verroi Enrico , Gradari Serena
Published: April 2012

Although optical pulsar studies have been limited to a few favoured objects, the observation of pulsars at optical wavelengths provides an opportunity to derive a number of important pulsar characteristics, including the energy spectrum of the emitting electrons and the geometry of the emission zone. These parameters will be vital for a comprehensive model of pulsar emission mechanisms. Observations of the Crab pulsar with the high-time-resolution photon-tagging photometer IquEYE show an optical–radio delay of ~178 μs. Incorporating simultaneous Jodrell Bank radio observations suggested a correlation between giant radio pulses and enhanced optical pulses for this pulsar, thus offering possible evidence for the reprocessing of radio photons.
False-Alarm Probabilities in Period Searches: Can Extreme-Value Distributions be of Use?
Authors: Cuypers Jan
Published: April 2012

Results of simulating false-alarm probabilities in irregularly sampled time series are presented. Relations to well-known expressions and earlier-used criteria are shown and tested for applicability. The use of an extreme-values distribution in this context is investigated.
The VAO Transient Facility
Authors: Graham Matthew J. , Djorgovski S. G. , Drake Andrew , Mahabal Ashish , Williams Roy , Seaman Rob
Published: April 2012

The time-domain community wants robust and reliable tools to enable the production of, and subscription to, community-endorsed event notification packets (VOEvent). The Virtual Astronomical Observatory (VAO) Transient Facility (VTF) is being designed to be the premier brokering service for the community, both collecting and disseminating observations about time-critical astronomical transients but also supporting annotations and the application of intelligent machine-learning to those observations. Two types of activity associated with the facility can therefore be distinguished: core infrastructure, and user services. We review the prior art in both areas, and describe the planned capabilities of the VTF. In particular, we focus on scalability and quality-of-service issues required by the next generation of sky surveys such as LSST and SKA.
Searching for Fast Optical Transients using a Veritas Cherenkov Telescope
Authors: Griffin Sean C.
Published: April 2012

Astronomical transients are intrinsically interesting objects to study. However, fast optical transients (μs time-scales) are a largely unexplored field of optical astronomy. Most optical observations use instruments that have integration times of the order of seconds and are thus unable to resolve fast transients. Current-generation atmospheric Cherenkov gamma-ray telescopes such as Veritas, which consists of four 12-m telescopes, have huge collecting areas, much larger than those of any existing optical telescopes. This paper outlines the benefits of using a Cherenkov telescope to detect optical transients, and the implementation of the Veritas Transient Detector (TRenDy), a dedicated multi-channel photometer based on field-programmable gate arrays which can be used on Veritas for such studies without interfering with gamma-ray observations.
La Silla-QUEST Variability Survey in the Southern Hemisphere
Authors: Hadjiyska Ellie , Rabinowitz David , Baltay Charles , Ellman Nancy , Nugent Peter , Zinn Robert , Horowitz Benjamin , McKinnon Ryan , Miller Lissa R.
Published: April 2012

We describe the La Silla-QUEST (LSQ) Variability Survey. LSQ is a dedicated wide-field synoptic survey in the Southern Hemisphere, focussing on the discovery and study of transients ranging from low redshift (z < 0.1) SN Ia, Tidal Disruption events, RR Lyræ variables, CVs, Quasars, TNOs and others. The survey utilizes the 1.0-m Schmidt Telescope of the European Southern Observatory at La Silla, Chile, with the large-area QUEST camera, a mosaic of 112 CCDs with field of view of 9.6 square degrees. The LSQ Survey was commissioned in 2009, and is now regularly covering ~1000 square deg per night with a repeat cadence of hours to days. The data are currently processed on a daily basis. We present here a first look at the photometric capabilities of LSQ and we discuss some of the most interesting recent transient detections.
Proposal for Multi-Messenger Observations of Radio Transients by Nasu and Ligo-Virgo
Authors: Hayama Kazuhiro , Niinuma Kotaro , Oyama Tomoaki
Published: April 2012

The gravitational waves radiated from explosions of compact objects are expected to be accompanied by other astronomical radiation such as radio flares, neutrinos and gamma-rays. In order to improve the detection of gravitational waves, mutual follow-up observations have been proposed between gravitational wave telescopes and other astronomical telescopes, known as “multi-messenger” observations. We propose multi-messenger observations using the LIGO, Virgo and Nasu Radio Telescopes.
Variability with Wise
Authors: Hoffman Douglas , Cutri Roc , Fowler John , Masci Frank
Published: April 2012

Wise mapped the entire sky in four bands during its approximately 7-month cryogenic mission. The number of exposures for each point on the sky increased with ecliptic latitude, and ranged from ~12 on the ecliptic to over 1000 at the ecliptic poles. The observing cadence is well suited to studying variable objects with periods between ~2 hours to ~2 days on the ecliptic, with the maximum period increasing up to several weeks near the ecliptic poles. We present the method used to identify several types of variables in the Wise Preliminary Release Database, and the mid-IR light curves of several objects. Many of these objects are new, and include RR Lyr, Algol, W UMa, Mira, BL Lac and YSO-type variables, as well as some unknown objects.
Fast Transient Detection as a Prototypical “Big Data” Problem
Authors: Jones Dayton L. , Wagstaff Kiri , Thompson David , D'Addario Larry , Navarro Robert , Mattmann Chris , Majid Walid , Rebbapragada Umaa , Lazio Joseph , Preston Robert
Published: April 2012

The detection of fast (< 1 second) transient signals requires a challenging balance between the need to examine vast quantities of high time-resolution data and the impracticality of storing all the data for later analysis. This is the epitome of a “big data” issue—far more data will be produced by next generation-astronomy facilities than can be analyzed, distributed, or archived using traditional methods. JPL is developing technologies to deal with “big data” problems from initial data generation through real-time data triage algorithms to large-scale data archiving and mining. Although most current work is focused on the needs of large radio arrays, the technologies involved are widely applicable in other areas.
A Refined QSO Selection Method Using Diagnostics
Authors: Kim Dae-Won , Protopapas Pavlos , Trichas Markos , Rowan-Robinson Michael , Khardon Roni , Alcock Charles , Byun Yong-Ik
Published: April 2012

We present 663 QSO candidates in the Large Magellanic Cloud (LMC) that were selected using multiple diagnostics. We started with a set of 2,566 QSO candidates selected using the methodology presented in our previous work based on time variability of the MACHO LMC light curves. We then obtained additional information for the candidates by cross-matching them with the Spitzer SAGE, the 2MASS, the Chandra, the XMM, and an LMC UBVI catalogues. Using that information, we specified diagnostic features based on mid-IR colours, photometric redshifts using SED template fitting, and X-ray luminosities, in order to discriminate more high-confidence QSO candidates in the absence of spectral information. We then trained a one-class Support Vector Machine model using those diagnostics features. We applied the trained model to the original candidates, and finally selected 663 high-confidence QSO candidates. We cross-matched those 663 QSO candidates with 152 newly-confirmed QSOs and 275 non-QSOs in the LMC fields, and found that the false positive rate was less than 1%.
Real-Time Classification of Transient Events in Synoptic Sky Surveys
Authors: Mahabal Ashish A. , Donalek C. , Djorgovski S. G. , Drake A. J. , Graham M. J. , Williams R. , Chen Y. , Moghaddam B. , Turmon M.
Published: April 2012

An automated rapid classification of the transient events detected in modern synoptic sky surveys is essential for their scientific utility and effective follow-up when resources are scarce. This problem will grow by orders of magnitude with the next generation of surveys. We are exploring a variety of novel automated classification techniques, mostly Bayesian, to respond to those challenges, using the ongoing CRTS sky survey as a testbed. We describe briefly some of the methods used.
LOFT: Large Observatory For X-Ray Timing
Authors: Mignani R. P. , Zane S. , Walton D. , Kennedy T. , Winter B. , Smith P. , Cole R. , Kataria D. , Smith A.
Published: April 2012

High-time-resolution X-ray observations of compact objects provide direct access to strong-field gravity, black-hole masses and spins, and the equation of state of ultra-dense matter. LOFT, the Large Observatory for Xray Timing, is specifically designed to study the very rapid X-ray flux and spectral variability that directly probe the motion of matter down to distances very close to black holes and neutron stars. A 10-m2-class instrument in combination with good spectral resolution (<260 eV @ 6 keV) is required to exploit the relevant diagnostics, and has the potential of revolutionising the study of collapsed objects in our Galaxy and of the brightest supermassive black holes in active galactic nuclei. LOFT will carry two main instruments: a Large Area Detector (LAD), to be built at MSSL/UCL in collaboration with the Leicester Space Research Centre, and a Wide Field Monitor (WFM). The ground-breaking characteristic of the LAD (it will work in the energy range 2–30 keV) is a mass per unit surface in the range ~10 kg/m2, giving an effective area of ~10 m2 (@10 keV) at a reasonable weight—an improvement by ~20 over all predecessors. This will allow timing measurements of unprecedented sensitivity, providing the capability to measure the mass and radius of neutron stars with ~5% accuracy, or to reveal blobs orbiting close to the marginally stable orbit in active galactic nuclei. We summarise the characteristics of the LOFT instruments and give an overview of its expected capabilities.
Photographic Archives of Ukrainian Observatories: Digitizing a Heritage
Authors: Pakuliak Ludmila , Kazantseva Lilia , Virun Natalia , Andruk Vitaly
Published: April 2012

We describe a key project of the Ukrainian Virtual Observatory (UkrVO), namely, a collaboration to digitize the large collections of photographic plates that had been exposed during more than 100 years at Ukrainian observatories, and to combine the digitized images with CCD archives to form the UkrVO Joint Digital Archive. The application of flatbed scanners for digitizing plates is discussed.
Towards a More General Method for Filling Gaps in Time Series
Authors: Pascual-Granado J. , Garrido R. , Gutirrez-Soto J. , Martín-Ruiz S.
Published: April 2012

The need for a proper interpolation method for data coming from space missions like CoRoT is emphasized. A new gap-filling method is introduced which is based on auto-regressive moving average interpolation (ARMA) models. The method is tested on light curves from stars observed by the CoRoT satellite, filling the gaps caused by the South Atlantic Anomaly.
The International Liquid Mirror Telescope (ILMT) as a Variability Time Machine
Authors: Poels Joël , Borra Ermanno , Hickson Paul , Sagar Ram , Bartczak Przemyslaw , Delchambre Ludovic , Finet François , Habraken Serge , Swings Jean-Pierre , Surdej Jean
Published: April 2012

During the year 2012 the International Liquid Mirror Telescope (a collaboration between astronomical institutions in Belgium, Canada, India and Poland) wil see first light. The instrument will provide substantial, in-depth sky coverage and make an unprecedented number of nightly observations.
A Global Robotic Telescope Network for Time-Domain Science
Authors: Street R. A. , Lister T. A. , Tsapras Y. , Shporer A. , Bianco F. B. , Fulton B. J. , Howell D. A. , Dilday B. , Graham M. , Sand D. , Parent J. , Brown T. , Horne K. , Dominik M. , Browne P. , Snodgrass C. , Kains N. , Bramich D. , Law N. , Steele I.
Published: April 2012

Las Cumbres Observatory Global Telescope Network (LCOGT) is currently building a new kind of general-purpose astronomical facility: a fully robotic network of telescopes of 2m, 1m and 0.4m apertures and homogeneous instrumentation. A pan-network approach to scheduling (rather than per individual telescope) offers redundancy in the event of poor weather or technical failure, as well as the ability to observe a target around the clock. Here we describe the network design and instrumentation under development, together with the main science programmes already being lead by LCOGT staff.
FRATs: Searching for Fast Radio Transients in Real Time with LOFAR
Authors: ter Veen S. , Schellart P. , Falcke H.
Published: April 2012

The aim of the FRATs project is to detect single dispersed pulses from Fast Radio Transients with LOFAR in real time. The pulses can originate from pulsars, RRATS and other classes of known or unknown objects. To detect the pulses a trigger algorithm is run on an incoherent beam from the different LOFAR stations. The beam has a wide field of view and can be formed parallel to other observations. A precise localisation is achieved by storing and processing off-line the data from each dipole, giving all-sky coverage with a spatial resolution of the order of arc-seconds. The source is identified by making high-time-resolution images. The method has been tested by detecting and identifying a giant pulse from the Crab pulsar.
Period Analyses of 100+ Years of RR Lyræ Data
Authors: Walker E. N.
Published: April 2012

The GEOS data base for RR Lyr stars has been analysed to search for secondary (Blazhko) periods in several stars for which over 100 years of measurements are available. The results indicate that, even when there is a secondary period present, its behaviour can be dramatically different from star to star or even over time in the same star. In one star there is a clear correlation between the O–C diagrams for both the pulsation and Blazko periods; that has implications for the origins of the Blazhko periods.
Type II SN Light Curves from the Caltech Core Collapse Project
Authors: Arcavi Iair
Published: April 2012

We presented our analysis of a sample of type II supernova (SN) light curves measured by the Caltech Core Collapse Project (CCCP). CCCP is a large observational program which made use of the robotic 60-in and the Hale 200-in telescopes to obtain optical photometry, spectroscopy and IR photometry of 49 nearby core-collapse supernovae (SNe). It provides a fair sample of core-collapse events, with well-defined selection criteria, and uniform, high-quality optical/IR observations. Our goal is to characterize the little-studied properties of core-collapse supernovae as a population. Preliminary data indicate a diverse set of sub-populations including “standard” type IIP supernovæ, declining supernovæ (at different rates) and slowly rising peculiar supernovæ. Work is in progress to map and quantify that diversity better. It is hoped that a single tunable formula will be able to describe most light-curve shapes, thereby helping us attain a better understanding of the physical mechanisms underlying these results.
Zum Einfluss gesundheitsorientierten Krafttrainings auf psychisches Wohlbefinden
Authors: Tscharaktschiew Nadine , Rudolph Udo
Published: April 2012

Zusammenfassung. Wir untersuchten die Wirkung eines gesundheitsorientierten Krafttrainings auf verschiedene Aspekte des psychischen Wohlbefindens für einen Zeitraum von 3 (t1) und 6 Monaten (t2). N = 531 Teilnehmer führten 6 Mal monatlich ein präventives (PKT, n = 317) oder medizinisches gesundheitsorientiertes Krafttraining (MKT, n = 109) durch oder gehörten einer Warte-Kontrollgruppe (KG, n = 105) an. Nach 6 Monaten zeigten sich Verbesserungen des Körperbildes. Für beide Trainingsformen verbesserte sich die vitale Körperdynamik (PKT: d = 0.59, MKT: d = 0.40), die ablehnende Körperbewertung reduzierte sich (PKT: d = –0.44, MKT: d = –0.32). Für Selbstwirksamkeitserwartung und Lebenszufriedenheit fanden wir anhand von Strukturgleichungsmodellen und Pfadanalysen indirekte Wirkmechanismen: Das durch gesundheitsorientiertes Krafttraining verbesserte Körperbild fördert eine Zunahme der Selbstwirksamkeitserwartung, die wiederum eine höhere Lebenszufriedenheit begünstigt (χ2 = 3.35, p = .501, df = 4, NFI = .98, CFI = 1.00, RMSEA = .00). Die Ergebnisse werden im Hinblick auf das Zusammenspiel der zugrunde liegenden körperlichen und psychischen Wirkmechanismen untersucht.
Multipoint observations of dipolarization front formation by magnetotail reconnection
Authors: Runov A. , Angelopoulos V. , Zhou X.‐Z.
Published: April 2012

We present multipoint observations of magnetotail plasma sheet dynamics during an event in which magnetic reconnection and dipolarization were observed at −16 < X < −15 RE (mid‐tail) and at −10 < X < −4.8 RE (near‐Earth plasma sheet), respectively. Timing analysis of the observations shows that the near‐Earth dipolarization was a consequence of mid‐tail reconnection. Large‐amplitude magnetic field oscillations were observed in the temporal and spatial vicinity of the reconnection site. Interpreted as current sheet flapping, they enable reconstruction of a complex sheet structure with an embedded thin current sheet of ion inertial scale size. Detailed analysis of the orientation of the dipolarization front and of plasma motions around it reveals that the front of the reconnection jet was interchange unstable.
Coordinated observations of a high‐altitude auroral electrojet by UHF/VHF receivers, magnetometers and meridian scanning photometer
Authors: Gallagher H. A. , Bayne S. , Garner T. W. , Weatherwax A. T. , Secan J.
Published: April 2012

UHF/VHF beacon receivers deployed in Alaska measure the latitude profile of relative total electron content over Alaska and frequently across the auroral oval. On March 9, 2008, these receivers observed a plasma density enhancement at 147 km. These observations are supported by collocated scanning photometer measurements. A simple model current consistent with magnetic field perturbations observed by a chain of magnetometers across Alaska corresponds spatially to the enhanced density observed by the receivers. Hence, these measurements suggest that the auroral electrojet is flowing at 147 km, which is unusually high. Indeed, the ratio of the 630.0 nm and 427.8 nm emissions and the strength of the magnetic perturbation suggest the electrojet is flowing at a lower altitude. We attribute this difference to thermospheric compositional changes associated with particle and Joule heating that could result in a lower ratio of the 630.0 nm and 427.8 nm emissions and higher conductivity corresponding to observed density enhancement.