Multiwavelength Observations of LS I +61 303 with VERITAS, Swift and RXTE

Abstract

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 September 2006 and February 2008. The binary was observed by VERITAS to be variable, with all integrated observations resulting in a detection at the 8.8 sigma (2006/2007) and 7.3 sigma (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 of a single orbital cycle. Additionally, the observations conducted in the 2007-2008 observing season show marginal evidence (at the 3.6 sigma significance level) for TeV emission outside of the apastron passage of the compact object around the Be star. Contemporaneous hard X-ray observations with RXTE and Swift show large variability with flux values typically varying between 0.5 and 3.0*10^-11 ergs cm^-2 s^-1 over a single orbital cycle. The contemporaneous X-ray and TeV data are examined and it is shown that the TeV sampling is not dense enough to detect a correlation between the two bands.

30 pages, 5 figures, 2 table, Accepted for publication in The Astrophysical Journal

References in corpus (9)

• The First VERITAS Telescope
• Gamma-ray binaries: pulsars in disguise ?
• VERITAS Observations of the gamma-Ray Binary LS I +61 303
• Accretion vs colliding wind models for the gamma-ray binary LS I +61 303: an assessment
• Periodic very high energy gamma-ray emission from LS I +61 303 observed with the MAGIC telescope
• Joint H-alpha and X-Ray Observations of Massive X-Ray Binaries. II. The Be X-ray Binary and Microquasar LS I +61 303
• XMM-Newton observation of a spectral state transition in the peculiar radio/X-ray/gamma-ray source LS I +61 303
• Chandra Observations of the Gamma-ray Binary LSI+61303: Extended X-ray Structure?
• Swift/XRT monitoring of five orbital cycles of LSI +61 303

Cited by in corpus (32)

• Gamma-ray binaries and related systems
• Relativistic Doppler-boosted emission in gamma-ray binaries
• A magnetar-like event from LS I +61 303 and its nature as a gamma-ray binary
• A New TeV Binary: The Discovery of an Orbital Period in HESS J0632+057
• Magic constraints on Gamma-ray emission from Cygnus X-3
• Correlated X-ray and Very High Energy emission in the gamma-ray binary LS I +61 303
• VERITAS Observations of the TeV Binary LS I +61 303 During 2008-2010
• Unveiling the super-orbital modulation of LS I +61 303 in X-rays
• Radio Spectral Index Analysis and Classes of Ejection in LS I +61 303
• On the origin of correlated X-ray/VHE emission from LS I +61 303
• Direct Wind Accretion and Jet Launch in Binary Systems
• Super-orbital variability of LS I +61°303 at TeV energies
• Probing the Nature of the unidentified TeV Gamma-ray source HESS J0632+057 with Swift
• Binaries with the eyes of CTA
• Long-term X-ray monitoring of LS I +61 303: analysis of spectral variability and flares
• Variability in the orbital profiles of the X-ray emission of the gamma-ray binary LS I +61 303
• Long-term monitoring of LS I+61303 with INTEGRAL
• Feasibility Study of Lense-Thirring Precession in LS I +61303
• Spectral analysis in orbital/superorbital phase space and hints of superorbital variability in the hard X-rays of LS I +61 303
• Detection of the gamma-ray binary LS I +61 303 in a low flux state at Very High Energy gamma-rays with the MAGIC Telescopes in 2009
• Search for radio pulsations in LS I +61 303
• Searches for periodic neutrino emission from binary systems with 22 and 40 strings of IceCube
• Does the gamma-ray binary LS I +61°303 harbor a magnetar?
• A search for VHE counterparts of Galactic Fermi bright sources and MeV to TeV spectral characterization
• A precessing stellar disk model for superorbital modulations of the gamma-ray binary LS I+61${}^{\circ }$ 303
• Achromatic rapid flares in hard X-rays in the $\gamma$-ray binary LS I +61-303
• VERITAS Observations of LS I +61 303 in the Fermi Era
• The Very Energetic Radiation Imaging Telescope Array System (VERITAS)
• Gamma ray attenuation in X-ray binaries: An application to LSI +61 303
• Gamma-ray emission from pulsar/massive-star binaries
• The MAGIC highlights of the gamma ray binary LS I +61 303
• VERITAS monitoring of LS I +61${}^{\circ }$ 303 in conjunction with X-ray, and GeV observation campaigns