8 research outputs found
A Search for High-Energy Counterparts to Fast Radio Bursts
We report on a search for high-energy counterparts to fast radio bursts
(FRBs) with the Fermi Gamma-ray Burst Monitor (GBM), Fermi Large Area Telescope
(LAT), and the Neil Gehrels Swift Observatory Burst Alert Telescope (BAT). We
find no significant associations for any of the 23 FRBs in our sample, but
report upper limits to the high-energy fluence for each on timescales of 0.1,
1, 10, and 100 s. We report lower limits on the ratio of the radio to
high-energy fluence, , for timescales of 0.1 and 100
s. We discuss the implications of our non-detections on various proposed
progenitor models for FRBs, including analogs of giant pulses from the Crab
pulsar and hyperflares from magnetars. This work demonstrates the utility of
analyses of high-energy data for FRBs in tracking down the nature of these
elusive sources
The 3rd Fermi GBM Gamma-Ray Burst Catalog: The First Six Years
Since its launch in 2008, the Fermi Gamma-ray Burst Monitor (GBM) has
triggered and located on average approximately two gamma-ray bursts (GRB) every
three days. Here we present the third of a series of catalogs of GRBs detected
by GBM, extending the second catalog by two more years, through the middle of
July 2014. The resulting list includes 1405 triggers identified as GRBs. The
intention of the GBM GRB catalog is to provide information to the community on
the most important observables of the GBM detected GRBs. For each GRB the
location and main characteristics of the prompt emission, the duration, peak
flux and fluence are derived. The latter two quantities are calculated for the
50-300~keV energy band, where the maximum energy release of GRBs in the
instrument reference system is observed, and also for a broader energy band
from 10-1000 keV, exploiting the full energy range of GBM's low-energy NaI(Tl)
detectors. Using statistical methods to assess clustering, we find that the
hardness and duration of GRBs are better fitted by a two-component model with
short-hard and long-soft bursts, than by a model with three components.
Furthermore, information is provided on the settings and modifications of the
triggering criteria and exceptional operational conditions during years five
and six in the mission. This third catalog is an official product of the Fermi
GBM science team, and the data files containing the complete results are
available from the High-Energy Astrophysics Science Archive Research Center
(HEASARC).Comment: 225 pages, 13 figures and 8 tables. Accepted for publication in
Astrophysical Journal Supplement 201
Hartigan's dip test of unimodality applied on terrestrial Gamma-ray flashes
Advisor: Dr. Michael, Briggs, CSPAR; Date: 2012; Pages: 17 p