Long-term TeV Observations of the Gamma-ray Binary HESS J0632+057 with VERITAS

TL;DR

This paper reports a decade of VERITAS observations of the gamma-ray binary HESS J0632+057, revealing flux variations over its orbit and providing new insights into its high-energy emission behavior.

Contribution

It presents the first detection of flux enhancement at orbital phase 0.75 with VERITAS and an updated analysis covering nearly the entire orbital period.

Findings

Detection of HESS J0632+057 with >20σ significance above 350 GeV.

Observation of flux enhancements at orbital phases 0.35 and 0.75.

Comprehensive coverage of the binary's orbital period with multi-wavelength context.

Abstract

The gamma-ray binary HESS J0632+057 has been observed at very-high energies for almost ten years by all major systems of imaging atmospheric Cherenkov telescopes. We present new observations taken by the VERITAS observatory and an updated analysis of the previously published observations. HESS J0632+057 has been detected by VERITAS with a total significance $>20\sigma$ at energies above 350 GeV in about 200 hours of observations. The exposure covers now almost the entire orbital period of 315 days including the flux enhancements at phases $\approx$0.35 and, for the first time, detected with VERITAS, at phases $\approx$0.75. The results are discussed along with simultaneous observations by the X-ray satellite {\em Swift} XRT.