Discipline: Physics
Subcategory: Astronomy and Astrophysics
Quianah T. Joyce - University of the Virgin Islands
Co-Author(s): Bruce Gendre, University of the Virgin Islands, St. Thomas, VI, Etelman Observatory, St. Thomas, VI; Guilia Stratta, University of Urbino, Urbino, Italy; Jean-Luc Atteia, L'Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France; Norton Brice Orange, OrangeWave, Inc., Charleston, North Carolina, Michel Boer, ARTEMIS, CNRS/OCA, Nice, France; David Morris, University of the Virgin Islands, St. Thomas, VI
Unique progenitors and a thermal component not present in short and long gamma ray bursts have distinguished ultra-long gamma ray bursts as a new class of events. Their extensive durations can theoretically allow for pointing sensitive instruments towards the event during its prompt phase, however, this is complicated as the nature of the event is initially unclear. A burst is only deemed “ultra-long” after it has been observed for thousands of seconds and following analysis has been conducted. Consequently, the question arises: can we predict an event to be an ultra-long gamma ray burst, i.e. duration of more than 3 hours, while high-energy instruments are only observing the first tens/hundreds of seconds of the burst’s emission? We have tested the hypothesis that the early stages of the prompt phase may reveal intrinsic properties that indicate that a burst is ultra-long, using data from Swift’s Burst Alert Telescope. For this purpose, we have analyzed and compared the spectral properties in the first minutes of the prompt phases of ultra-long gamma ray bursts, as well as long gamma ray bursts of standard and extended durations. Based on our results, the spectro-temporal properties are inconclusive for discriminating between ultra-long and long gamma ray bursts. Pass a certain threshold, the probability that a burst is ultra-long is large enough so that follow up observation is worth investigating. Future work may include building a larger sample of ultra-long candidates to analyze, however, ultra-long gamma ray bursts are rare in occurrence and building a fruitful sample would take a significant amount of time. This research made use of the studies and findings by Gendre et. al. 2013, Boer et. al. 2014, and Piro et. al. 2015.
Not SubmittedFunder Acknowledgement(s): Conducting this research was made possible by NASA grants NNX13AD28A and NNX15AP95A, as well as the University of the Virgin Islands and the Etelman Observatory.
Faculty Advisor: Bruce Gendre, bruce.gendre@gmail.com
Role: For this research, I was responsible for producing the spectra and corresponding spectral properties used in our comparative analysis. This included retrieving the data for our samples from our instrument used in our study, NASA's Swift satellite, specifically data from the Burst Alert Telescope (BAT). This data had to be cleaned and sorted, and I made the required response matrices and quality maps for each event file we used to produce correct and accurate spectra. I made histograms for some of our samples and in addition, I also aided with comparing our resulting spectral properties.