MAGIC detection of the putative gamma-ray binary HESS J0632+057

TL;DR

This paper reports the detection of gamma-ray activity from the candidate binary system HESS J0632+057 during an X-ray outburst, providing insights into its variable gamma-ray emission and spectral characteristics.

Contribution

First MAGIC detection of gamma-ray emission from HESS J0632+057 during an X-ray outburst, confirming its binary nature and variability.

Findings

Gamma-ray activity detected in February 2011 during X-ray outburst

Spectral analysis of gamma-ray emission during the outburst

Correlation between gamma-ray and X-ray variability

Abstract

The variable gamma-ray source HESS J0632+057 is an excellent candidate for a gamma-ray binary. The putative binary system was discovered as a point-like VHE gamma-ray source by HESS. Later measurements by VERITAS yielding no detection, provided evidence for variable emission in the gamma-ray domain. A variable X-ray source as well as a Be star (MWC 148) are found at the location of the gamma-ray source. Recently a periodic X-ray outburst occurring about every 320 days was reported by Swift (ATel 3152). The putative binary system was observed by the MAGIC stereo system in 2010 and 2011. Our measurements demonstrate significant activity in the gamma-ray (E > 200 GeV) band in February 2011. Our detection of the system occurred during an X-ray outburst reported by Swift. Here we present the obtained light curve and spectrum during this outburst and put them into context with the X-ray measurements.