Support ATel At Patreon

[ Previous | Next | ADS ]

Fermi-LAT detection of a new gamma-ray source associated with the FSRQ B3 0251+39

ATel #14923; I. Mereu (INFN Perugia) on behalf of the Fermi Large Area Telescope Collaboration
on 17 Sep 2021; 20:33 UT
Credential Certification: Isabella Mereu (mereuisabella@gmail.com)

Subjects: Gamma Ray, Request for Observations, AGN, Blazar, Quasar, Transient

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed gamma-ray emission from a source positionally consistent with the flat spectrum radio quasar B3 0251+39, also known as 5BZQ J0254+3931, with coordinates R.A. = 43.6776337 deg, Decl. = +39.5263086 deg (J2000; Beasley et al., 2002, ApJS, 141, 13), and redshift z=0.289 (Marcha et al, 1996 ,MNRAS, 281, 425). This source is not in any published LAT catalog and was not detected by AGILE or EGRET.

Preliminary analysis indicates that this source was significantly detected (>5 sigma) in a high gamma-ray state on September 13, 2021, with a daily averaged gamma-ray flux (E>100MeV) of (0.25 +/- 0.09) X 10^-6 photons cm^-2 s^-1 and a single power-law photon index of 2.1 +/- 0.2 (statistical uncertainties only).

Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact person is Isabella Mereu (mereuisabella@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.