Fermi-LAT detection of gamma-ray activity from the BL Lac source PKS 1519-273
ATel #16313; Chiara Bartolini (Universita di Trento, INFN Bari) on behalf of the Fermi Large Area Telescope Collaboration
on 30 Oct 2023; 19:32 UT
Credential Certification: Janeth Valverde (valverde@llr.in2p3.fr)
Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar
The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed gamma-ray activity from a source positionally consistent with the BL Lac PKS 1519-273, also known as 4FGL J1522.6-2730 (The Fermi-LAT collaboration 2020, ApJS, 247, 33), with coordinates R.A. = 230.656983 deg, Decl. = -27.502996 deg (J2000; Johnston et al. 1995, AJ, 110, 880), and redshift z=1.297 (Landoni et al. 2020, ApJS, 250, 37).
Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on October 27, 2023 , with a daily averaged gamma-ray flux (E>100MeV) of (0.8+/-0.3) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). This corresponds to a flux increase of a factor of 40 relative to the average flux reported in the fourth Fermi-LAT catalog (4FGL). The corresponding photon index is 2.4+/-0.3, and is consistent with the 4FGL value of 2.20+/-0.03 within the uncertainties.
Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. A preliminary light curve can be accessed via the Fermi-LAT Light-Curve Repository at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/LightCurveRepository/source.html?source_name=4FGL_J1522.6-2730. We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact person is Chiara Bartolini (chiara.bartolini@ba.infn.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.
