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Fermi LAT Detection of a GeV flare from spectrally hard FSRQ TXS 1100+122

ATel #5202; Roopesh Ojha (NASA/GSFC/ORAU), B. Carpenter (Catholic U.), C. C. Cheung (NRL) on behalf of the Fermi Large Area Telescope Collaboration
on 10 Jul 2013; 17:18 UT
Credential Certification: Roopesh Ojha (Roopesh.Ojha@gmail.com)

Subjects: Gamma Ray, >GeV, AGN, Blazar, Quasar

Referred to by ATel #: 5221, 6914

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source whose preliminary location is RA:165.76 DEC:12.00 (J2000) with an error circle radius of 0.15 degrees (68% confidence level). This is positionally consistent with the flat spectrum radio quasar (FSRQ) TXS 1100+122 (also known as SDSS J110303.52+115816.5). This source does not appear in the 2FGL catalog (Nolan et al. 2012, ApJS, 199, 31). TXS 1100+122 has coordinates RA=11h03m03.5298s DEC=+11d58m16.624s, J2000, (Petrov et al. 2005, AJ, 129, 1163) and redshift z=0.913941 (Hewett & Wild, 2010, MNRAS, 405, 2302).

Preliminary analysis indicates that on July 8th, 2013, the daily averaged flux (E>100MeV) was (0.3 +/- 0.1) x 10^-6 photons cm^-2 s^-1 and that this source had a particularly hard gamma-ray spectrum with a photon index of 1.60 +/- 0.20 (errors are statistical only). Average photon indices for LAT-detected FSRQs are typically greater than 2.0 and the photon index of this source is similar to those seen during active states of J1418+3541 (ATel#4643) and GB6 B1310+4844 (ATel#2316).

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. Multiwavelength observations during the ongoing activity of this source are strongly encouraged. The Fermi LAT contact person is Roopesh Ojha (e-mail: Roopesh.Ojha@gmail.com).

The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.