Fermi-LAT Detection of Gamma-ray Emission from PMN J1747-5236
ATel #10721; Roopesh Ojha (NASA/GSFC/UMBC), Bryce Carpenter (CUA/NASA/GSFC) and Janeth Valverde (LLR/Ecole Polytechnique) on behalf of the Fermi Large Area Telescope Collaboration
on 8 Sep 2017; 14:39 UT
Credential Certification: Roopesh Ojha (Roopesh.Ojha@gmail.com)
Subjects: Gamma Ray, >GeV, AGN, Blazar, Quasar
Referred to by ATel #: 10748
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 radio source PMN J1747-5236
with coordinates RA: 17h47m05.68s, Dec: -52d36m32.5s, J2000, (Healey
et al. 2007, ApJS, 171, 61). This source is not in any published LAT
catalog and was not detected by AGILE or EGRET. Its redshift is unknown.
Preliminary analysis indicates that on 5 September 2017 and 6
September 2017, this source was in a high-flux state, with a daily
averaged gamma-ray flux (E>100MeV) of (0.6+/-0.1) X 10^-6 photons
cm^-2 s^-1 and (0.7+/-0.2) X 10^-6 photons cm^-2 s^-1, respectively
(statistical uncertainty only). The corresponding photon spectral
index of 2.1+/-0.2 and 2.2+/-0.2, respectively, is in the typical range
for a Fermi blazar.
We note the long-term increase in optical brightness of PMN J1747-5236 reported by Gaia
with a recent (13 August 2017) peak: http://gsaweb.ast.cam.ac.uk/alerts/alert/Gaia17cbz/
Because Fermi operates in an all-sky scanning mode, regular gamma-ray
monitoring of this source will continue. We encourage further
multifrequency observations of this source. For this source the Fermi
LAT contact person is Roopesh Ojha (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.