Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy

Physical Sciences Publications

Binaries: general

Publication Year

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Long-Term Tev And X-Ray Observations Of The Gamma- Ray Binary Hess J0632+057, P. T. Reynolds, Veritas, Hess Jan 2014

Long-Term Tev And X-Ray Observations Of The Gamma- Ray Binary Hess J0632+057, P. T. Reynolds, Veritas, Hess

Physical Sciences Publications

HESS J0632+057 is the only gamma-ray binary known so far whose position in the sky allows observations with ground-based observatories in both the northern and southern hemispheres. Here we report on long-term observations of HESS J0632+057 conducted with the Very Energetic Radiation Imaging Telescope Array System and High Energy Stereoscopic System Cherenkov telescopes and the X-ray satellite Swift, spanning a time range from 2004 to 2012 and covering most of the system's orbit. The very-high-energy (VHE) emission is found to be variable and is correlated with that at X-ray energies. An orbital period of days is derived from the …


Veritas Observations Of The Tev Binary Ls I+61 Degrees 303 During 2008-2010, P. T. Reynolds, Et. Al. Sep 2011

Veritas Observations Of The Tev Binary Ls I+61 Degrees 303 During 2008-2010, P. T. Reynolds, Et. Al.

Physical Sciences Publications

We present the results of observations of the TeV binary LS I +61° 303 with the VERITAS telescope array between 2008 and 2010, at energies above 300 GeV. In the past, both ground-based gamma-ray telescopes VERITAS and MAGIC have reported detections of TeV emission near the apastron phases of the binary orbit. The observations presented here show no strong evidence for TeV emission during these orbital phases; however, during observations taken in late 2010, significant emission was detected from the source close to the phase of superior conjunction (much closer to periastron passage) at a 5.6 standard deviation (5.6σ) post-trials …


Multiwavelength Observations Of Ls I+61 Degrees 303 With Veritas, Swift, And Rxte, P. T. Reynolds, Et. Al. Aug 2009

Multiwavelength Observations Of Ls I+61 Degrees 303 With Veritas, Swift, And Rxte, P. T. Reynolds, Et. Al.

Physical Sciences Publications

We present results from a long-term monitoring campaign on the TeV binary LSI +61° 303 with VERITAS at energies above 500 GeV, and in the 2-10 keV hard X-ray bands with RXTE and Swift, sampling nine 26.5 day orbital cycles between 2006 September and 2008 February. The binary was observed by VERITAS to be variable, with all integrated observations resulting in a detection at the 8.8σ (2006/2007) and 7.3σ (2007/2008) significance level for emission above 500 GeV. The source was detected during active periods with flux values ranging from 5% to 20% of the Crab Nebula, varying over the course …