Deep Search for and Investigations of Untriggered Gamma-Ray Transient Events Using Fermi/GBM Data

(Fermi/GBM Verileri ile Tetiklememiş Geçici Gama Işını Olaylarının Derinlemesine Araştırılması ve İncelenmesi)

A project funded by TÜBİTAK (118F344)

Fermi/GBM Transient Event Catalog


The page is still under construction, the database will be available soon. Please visit again in a few months!

This catalog lists the results of our searches for untriggered transient events using the 10-years of data collected with Gamma-ray Burst Monitors (GBM) on board the Fermi Gamma-ray Space Telescope. The searches are done using the high resolution Continuous Time-Tagged Event (CTTE) data, which became available in October 2010.   Search Methods: We used the following three independent statistical methods to identify transient events:  
Method Criteria for Event Detection
Signal to Noise Ratio (SNR) >4.5𝜎 above the background level
Poisson statistics (Poisson) Poisson probability <10−4
Bayesian Blocks (Bayesian) Any blocks above the estimated background level *
* “Event” blocks are identified based on a pre-defined duration that depends on the search Mode (see below)
For each of the method, the search was done in the following four energy-time modes:
Mode Targeted Event Types Time Resolution (ms) Energy Range (keV)
1 SGR 8 10 – 100
2 Long GRB & Short Transients (<10 s) 512 10 – 300
3 Short GRB & TGF 16 50 – 1000
4 Long Transients (>10 s) & SFL 2048 10 - 25
SGR = Soft Gamma Repeater GRB = Gamma-Ray Burst TGF = Terrestrial Gamma Flash SFL = Solar Flare
Classification Methods: For each of the transient events identified in the search, we calculated the likelihood probability for each known event class, namely, SGR, GRB, TGF, SFL, particle event (PAR), transients (TRN), and unknown (UKN), based on the properties of the GBM triggered events in each event class.

Sabancı University
Last updated on Sep 7, 2020