Fermi-LAT detection of continuing gamma-ray activity from the FSRQ PKS 0346-27
ATel #13521; I. Mereu (INFN, Perugia), on behalf of the Fermi Large Area Telescope Collaboration
on 24 Feb 2020; 19:37 UT
Credential Certification: Roberto Angioni (r.angioni90@gmail.com)
Subjects: >GeV, Request for Observations, AGN, Blazar, Quasar
Referred to by ATel #: 15020
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed continuing gamma-ray flaring activity from a source positionally consistent with the flat-spectrum radio quasar PKS 0346-27, also known as 4FGL J0348.5-2749 (The Fermi-LAT collaboration 2019, arXiv:1902.10045), with coordinates RA = 57.1589354 deg, DEC = -27.8204344 deg, (J2000; Beasley et al. 2002 ApJS, 141, 13), and redshift z=0.991 (White et al. 1988 ApJ, 327, 561).
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on February 23, 2020, with a daily averaged gamma-ray flux (E>100MeV) of (2.1 +/- 0.4) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). The latter corresponds to a flux increase of a factor of ~120 relative to the average flux reported in the fourth Fermi-LAT catalog (4FGL). The flare is characterized by a hard spectrum, with a photon index 2.0 +/- 0.1 that is significantly smaller than the 4FGL value of 2.5 +/- 0.1. The faring activity of this source is also reported in in ATel #11251, ATel #11644 and ATel #12693, in which is reported the maximum reached by PKS 0346-27 on April 24, 2019. Since PKS 0346-27 is in the list of monitored sources, its light curve can be find at this link https://fermi.gsfc.nasa.gov/ssc/data/access/lat/msl_lc/source/PKS_0346-27.
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 Roberto Angioni (roberto.angioni@ssdc.asi.it) .
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.