Multi-wavelength Observations of PKS 2142-758 during an Active Gamma-Ray State

TL;DR

This paper reports multi-wavelength observations of the quasar PKS 2142-758 during its active gamma-ray flaring state, providing a broadband spectral energy distribution and initial insights into its high-energy emission mechanisms.

Contribution

It presents the first simultaneous multi-wavelength campaign during a gamma-ray flare of PKS 2142-758, constructing a broadband SED and analyzing the emission constraints.

Findings

Detected elevated gamma-ray activity in 2010 and 2011.

Constructed broadband SED during active state.

Provided preliminary constraints on high-energy emission.

Abstract

PKS 2142-758 is a flat spectrum radio quasar which emits few, weak but significant gamma-ray flares in the MeV through GeV energy range. The first flare occured on April 4th, 2010, when the source reached a daily flux of (1.1 \pm 0.3) * 10^-6 ph cm^-2 s^-1 (ATEL #2539) in the 100 MeV to 300 GeV range. This flux represented more than an order of magnitude increase over its quiescent flux. Since the initial flare, this source has been detected in an elevated state within the same energy range from October to November of 2010 and another period ranging from July to August of 2011. During the latest flaring period in 2011 a multi wavelength observing campaign was carried out using the Ceduna radio telescope, the Australian Telescope Compact Array (ATCA), the TANAMI VLBI Array, Swift, the Rapid Eye Mount Telescope (REM), and the Large Area Telescope (LAT) on board Fermi. These quasi-simultaneous data were used to construct a broadband SED of this object in its rare active state. We present these observations and the resulting SED and some preliminary analysis of the constraints they place on the high energy emission from this object.