Astrophysics undergraduate Victoria Weller von Ahlefeld is a co-author of a paper about Gamma-Ray Bursts that was published in the American Journal for Astrophysics this month. She undertook the work at the Max-Planck Institute for Extraterrestrial Physics after the second year of her degree here in the School.
Victoria explains the background to the paper.
Detecting Gamma-Ray Bursts
Gamma Rays are at the most energetic end of the electromagnetic spectrum, allowing them to travel into the depths of the Cosmos. Therefore, Gamma-Ray Bursts (GRBs) can reach Earth from very distant objects, allowing insight into primordial conditions of the Universe. Possible sources of such energy blasts are supernovae, hypernovae or binary neutron star systems, although there is little which is really known about them.
The space telescope Fermi has been in orbit detecting GRBs with the Gamma-ray Burst Monitor (GBM) device since June 2008 and has been triggered on over 900 occasions since. A large volume of data must be analyzed and put into a useful format: the spectral catalog. Spectra extracted from 462 GRBs in years 3 and 4 of the mission supplemented the data from the first two years.
My internship was with the High-Energy Astrophysics group at the Max-Planck Institute for Extraterrestrial Physics during the time when the peak of data analysis was carried out. I was working with David Gruber, a brilliant PhD student in charge of producing a spectral catalog.
Via the IDL (Interactive Data Language) data visualization and analysis platform, 462 GRBs underwent proper readout and visualization. The GBM on Fermi has 14 detectors, of which the best exposed must be selected. After determining the duration of all observed bursts, polynomial background needed to be fitted across a user-defined interval to all suitable detectors. Furthermore, reduced data was used to perform the spectral analysis using four different spectral models, therefore obtaining a compendium of over 3700 GRB spectra.
The Fermi GBM Gamma-Ray Burst Spectral Catalog: Four Years of Data was published in The Astrophysical Journal Supplement Series in March 2014. Following Victoria's work on the data analysis part of the production of the catalog, her name is the third of 32 authors of the paper.