[ Previous | Next | ADS ]

Fermi-LAT detection of a GeV gamma-ray flare from the blazar PKS 0514-459

ATel #8595; Stefano Ciprini (ASI Science Data Center, Rome, & INFN Perugia, Italy), on behalf of the the Fermi Large Area Telescope
on 27 Jan 2016; 00:29 UT
Credential Certification: Stefano Ciprini (stefano.ciprini@asdc.asi.it)

Subjects: >GeV, Request for Observations, AGN, Blazar, Quasar

The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed increasing gamma-ray flux from a source positionally consistent with the flat spectrum radio quasar PKS 0514-459 (also known as RX J0515.7-4556 and 3FGL J0515.3-4557), with radio counterpart position R.A.: 78.938767 deg, Dec.: -45.945369 deg (J2000.0, Costa & Loyola 1996, A&AS, 115, 75) and with redshift z=0.194 (Stickel, Kuehr, & Fried 1993, A&AS, 97, 483). This source has a resolved host galaxy and was previously detected in the microwave band by BOOMERanG, WMAP and Planck.

Preliminary analysis indicates that on 2016 January 25, PKS 0514-459 was in a high state with a daily averaged gamma-ray flux (E>100 MeV) of (0.8+/-0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only), about 90 times greater than its four-year average flux reported in the third Fermi-LAT source catalog (3FGL, Acero et al. 2015, ApJS, 218, 23). The corresponding daily averaged spectral photon index (E>100 MeV) of 2.3+/-0.2 (statistical uncertainty only) is consistent with the 3FGL catalog value of 2.44+/-0.18.

This is the first time that Fermi LAT is announcing enhanced gamma-ray activity from PKS 0514-459. Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the ongoing activity of this source, we encourage multiwavelength observations. For this source the Fermi LAT contact person is S. Ciprini (stefano.ciprini@asdc.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.