Gamma-ray flares from the blazars TXS 2241+406, Ton 599, and 4C +01.02

ATel #8319; Roopesh Ojha (NASA/GSFC/UMBC) and Bryce Carpenter (CUA/NASA/GSFC) on behalf of the Fermi Large Area Telescope Collaboration
on 22 Nov 2015; 14:06 UT
Credential Certification: Roopesh Ojha (Roopesh.Ojha@gmail.com)

Tweet

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope has observed a gamma-ray flare from a source positionally consistent with the BL Lac object TXS 2241+406 (3FGL J2244.1+4057, Acero et al. 2015, ApJS 218, 23) with coordinates RA=22h 44m 12.7311s, Dec=40d 57m 13.62s (J2000, Beasley et al. 2002, ApJS, 141, 13) with redshift z=1.171 (Shaw et al. 2012, ApJ, 748, 49).

Preliminary analysis indicates that on 20 November 2015 this source was in a high-flux state, with a daily averaged gamma-ray flux (E>100MeV) of (1.2+/-0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only) and photon spectral index of 2.2+/-0.1 (errors are statistical only). This corresponds to a flux increase of a factor around 36 compared with the average flux reported in the third Fermi-LAT catalog. The Fermi LAT contact person for this source is S. Buson (sara.buson@gmail.com).

The LAT has also observed a hard spectrum gamma-ray flare from a source positionally consistent with the flat spectrum radio quasar Ton 599 which is also known as 4C 29.45, OM 295, S3 1156+29 and 3FGL J1159.5+2914. Its coordinates are: RA= 11h 59m 31.8339s, Dec= +29d 14m 43.827s, (J2000, Kenneth et al. 1995, AJ, 110, 880). The redshift of this source is 0.724688 (Hewett & Wild 2010, MNRAS, 405, 2302).

Preliminary analysis indicates that on 20 November 2015 this source was in a high-flux state, with a daily averaged gamma-ray flux (E>100MeV) of (1.0+/-0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only) and photon spectral index of 1.9+/-0.1 (errors are statistical only). This corresponds to a flux increase of a factor around 8 compared with the average flux reported in the third Fermi-LAT catalog. The Fermi LAT contact persons for this source are S. Ciprini (stefano.ciprini@pg.infn.it) and D. J. Thompson (David.J.Thompson@nasa.gov).

The LAT has also observed a gamma-ray flare from a source positionally consistent with the flat spectrum radio quasar 4C +01.02 which is also known as PKS 0106+01 and OC 12. Its coordinates are RA= 01h 08m 38.7719s, Dec= 01d 35m 00.317s (J2000.0, Johnston et al. 1995, AJ, 110, 880) and it is at a high redshift z=2.099 (Hewett et al. 1995, AJ, 109, 1498).

Preliminary analysis indicates that on 20 November 2015 this source was in a high-flux state, with a daily averaged gamma-ray flux (E>100MeV) of (2.1+/-0.3) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only) and photon spectral index of 2.4+/-0.1 (errors are statistical only). This corresponds to a flux increase of a factor around 17 compared with the average flux reported in the third Fermi-LAT catalog. The Fermi LAT contact person for this source is S. Buson (sara.buson@gmail.com).

Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of all of these sources will continue. We encourage further multifrequency observations of this source.

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.