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

Search Methods

Method	Criteria for Event Detection
Signal to Noise Ratio (SNR)	>4.5𝜎 above the background level in two or more detectors
Poisson statistics (Poisson)	Poisson probability <10^-4 in two or more detectors
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).

This catalog lists the results of our searches for untriggered transient events using the 11-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 of 12 NAI detectors, which became available in October 2010. 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

* “Event” blocks are identified based on a pre-defined duration that depends on the search Mode (see below).

For each of the transient events identified in the search, we calculated the likelihood probability for each known event class, namely, SGR, GRB, TGF, SFLARE, particle event (DISTPAR/LOCLPAR), transients (TRANSNT), and unknown (UNKNOWN), based on the properties of the GBM triggered events in each event class.