VERITAS Reports Increased Activity of HESS J0632+057 in Very High Energy Gamma Rays
ATel #3153; Rene A. Ong, for the VERITAS Collaboration
on 8 Feb 2011; 22:54 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Rene Ong (rene@astro.ucla.edu)
Subjects: >GeV, TeV, VHE, Binary, Transient
The VERITAS collaboration reports increased activity at very high energies
(VHE; E>100 GeV) from the unidentified gamma-ray source HESS J0632+057.
The object is located in the Monoceros region
(R.A. 06:32:58.3, Dec. +05:48:20, J2000)
and is positionally associated with the B0pe-type star MWC 148 (HD 259440)
(Hinton et al. 2009, ApJ 690, L101). Its point-like nature, its variability
in the X-ray (Falcone et al. 2009, ApJ 708, L52) and gamma-ray regimes
(Acciari et al. 2009, ApJ 698, L94), and the non-blazar-like radio flux
(Skilton et al. 2009, MNRAS, 399, 317) led to the suggestion that
HESS J0632+057 is a new X-ray/TeV binary.
The observations reported here were motivated by the increase in
X-ray activity, based on Swift-XRT monitoring data, as reported by
Falcone et al. 2011 (ATel #3152). Preliminary analysis of 5.6 hours of
VERITAS observations indicates that HESS J0632+057 was in a high state on
07/08 February 2011 (MJD 55599-55600), coincident with a high state in
X-rays. Analysis of these data has resulted in the detection of the
object with a statistical significance of more than 8 standard deviations.
The estimated VHE gamma-ray flux from HESS J0632+057 is about 4% of the
flux from the Crab Nebula above 300 GeV, significantly higher than
during the previous VERITAS observations.
Multiwavelength observations of HESS J0632+057 are encouraged.
