VERITAS Observations of the gamma-Ray Binary LS I +61 303

Abstract

LS I +61 303 is one of only a few high-mass X-ray binaries currently detected at high significance in very high energy gamma-rays. The system was observed over several orbital cycles (between September 2006 and February 2007) with the VERITAS array of imaging air-Cherenkov telescopes. A signal of gamma-rays with energies above 300 GeV is found with a statistical significance of 8.4 standard deviations. The detected flux is measured to be strongly variable; the maximum flux is found during most orbital cycles at apastron. The energy spectrum for the period of maximum emission can be characterized by a power law with a photon index of Gamma=2.40+-0.16_stat+-0.2_sys and a flux above 300 GeV corresponding to 15-20% of the flux from the Crab Nebula.

accepted for publication in The Astrophysical Journal

References in corpus (24)

• Variable Very High Energy Gamma-ray Emission from the Microquasar LS I +61 303
• Background Modelling in Very-High-Energy gamma-ray Astronomy
• VERITAS: the Very Energetic Radiation Imaging Telescope Array System
• Discovery of the Binary Pulsar PSR B1259-63 in Very-High-Energy Gamma Rays around Periastron with H.E.S.S
• Discovery of very high energy gamma-rays associated with an X-ray binary
• The First VERITAS Telescope
• Gamma-ray binaries: pulsars in disguise ?
• 3.9 day orbital modulation in the TeV gamma-ray flux and spectrum from the X-ray binary LS 5039
• Orbital Parameters of the Microquasar LSI +61 303
• Cosmic Rays from Microquasars: a Narrow Component to the CR Spectrum?
• Accretion vs colliding wind models for the gamma-ray binary LS I +61 303: an assessment
• A Systematic Search for Periodicities in RXTE/ASM Data
• Hadronic high-energy gamma-ray emission from the microquasar LS I $+61303$
• Comparison of techniques to reconstruct VHE gamma-ray showers from multiple stereoscopic Cherenkov images
• The distances to the X-ray binaries LSI +61 303 and A0535+262
• INTEGRAL and XMM-Newton observations of LSI +61 303
• Joint H-alpha and X-Ray Observations of Massive X-Ray Binaries. II. The Be X-ray Binary and Microquasar LS I +61 303
• Gamma-Hadron Separation Methods for the VERITAS Array of Four Imaging Atmospheric Cherenkov Telescopes
• XMM-Newton observation of a spectral state transition in the peculiar radio/X-ray/gamma-ray source LS I +61 303
• LSI+61303 in the context of microquasars
• Improved energy resolution for VHE gamma-ray astronomy with systems of Cherenkov telescopes
• A Time Dependent Leptonic Model for Microquasar Jets: Application to LSI 61 303
• Inverse Compton e-p pair cascade model for the gamma-ray production in massive binary LSI +61^o 303
• Muon Flux at the Geographical South Pole

Cited by in corpus (105)

• Gamma-ray binaries and related systems
• Radio Imaging of the Very-High-Energy Gamma-Ray Emission Region in the Central Engine of a Radio Galaxy
• Insights Into the High-Energy Gamma-ray Emission of Markarian 501 from Extensive Multifrequency Observations in the Fermi Era
• Detection of Pulsed Gamma Rays Above 100 GeV from the Crab Pulsar
• Discovery of TeV Gamma Ray Emission from Tycho's Supernova Remnant
• TeV and Multi-wavelength Observations of Mrk 421 in 2006-2008
• Fermi LAT Observations of LS I +61 303: First detection of an orbital modulation in GeV Gamma Rays
• HESS J0632+057 : A new gamma-ray binary?
• The June 2008 flare of Markarian 421 from optical to TeV energies
• Periodic very high energy gamma-ray emission from LS I +61 303 observed with the MAGIC telescope
• Study of the Spectral and Temporal Characteristics of X-Ray Emission of the Gamma-Ray Binary LS 5039 with Suzaku
• Spectral Energy Distribution of Markarian 501: Quiescent State vs. Extreme Outburst
• VERITAS Deep Observations of the Dwarf Spheroidal Galaxy Segue 1
• VERITAS Discovery of >200GeV Gamma-ray Emission from the Intermediate-frequency-peaked BL Lac Object W Comae
• Relativistic Doppler-boosted emission in gamma-ray binaries
• Multiwavelength observations of a TeV-Flare from W Comae
• Multi-wavelength Observations of the Flaring Gamma-ray Blazar 3C 66A in 2008 October
• A Three-Year Multi-Wavelength Study of the Very High Energy Gamma-ray Blazar 1ES 0229+200
• Long-term monitoring of the high-energy gamma-ray emission from LS I +61° 303 and LS 5039
• VERITAS Search for VHE Gamma-ray Emission from Dwarf Spheroidal Galaxies
• A magnetar-like event from LS I +61 303 and its nature as a gamma-ray binary
• Discovery of very high energy gamma rays from PKS 1424+240 and multiwavelength constraints on its redshift
• A New TeV Binary: The Discovery of an Orbital Period in HESS J0632+057
• Multiwavelength observations of Mrk 501 in 2008
• Detection of Extended VHE Gamma Ray Emission from G106.3+2.7 with VERITAS
• First NuSTAR Observations of Mrk 501 within a Radio to TeV Multi-Instrument Campaign
• A compact pulsar wind nebula model of the gamma-ray loud binary LS I +61 303
• Spatially Resolving the Very High Energy emission from MGRO J2019+37 with VERITAS
• 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
• Evidence for proton acceleration up to TeV energies based on VERITAS and Fermi-LAT observations of the Cas A SNR
• The most powerful flaring activity from the NLSy1 PMN J0948+0022
• The gamma-ray binary LS 5039: mass and orbit constraints from MOST observations
• Long-term TeV and X-ray Observations of the Gamma-ray Binary HESS J0632+057
• Evidence for long-term Gamma-ray and X-ray variability from the unidentified TeV source HESS J0632+057
• Long Term X-ray Monitoring Of The TeV Binary LS I +61 303 with RXTE
• First optical validation of a Schwarzschild Couder telescope: the ASTRI SST-2M Cherenkov telescope
• The Great Markarian 421 Flare of February 2010: Multiwavelength variability and correlation studies
• TeV Gamma-ray Astronomy: A Summary
• Fermi Gamma-ray Space Telescope: High-Energy Results from the First Year
• Discovery of TeV Gamma-ray Emission from CTA 1 by VERITAS
• Multiwavelength Observations of LS I +61 303 with VERITAS, Swift and RXTE
• Discovery of a new TeV gamma-ray source: VER J0521+211
• Multiwavelength Observations of the VHE Blazar 1ES 2344+514
• PSRs J0248+6021 and J2240+5832: Young Pulsars in the Northern Galactic Plane. Discovery, Timing, and Gamma-ray observations
• Long-term Stability of Non-thermal X-ray Modulation in the Gamma-ray Binary LS 5039
• VERITAS Observations of the TeV Binary LS I +61 303 During 2008-2010
• Production of secondary particles and nuclei in cosmic rays collisions with the interstellar gas using the FLUKA code
• Unveiling the super-orbital modulation of LS I +61 303 in X-rays
• Superorbital modulation of X-ray emission from gamma-ray binary LSI +61 303
• Direct Wind Accretion and Jet Launch in Binary Systems
• On the origin of correlated X-ray/VHE emission from LS I +61 303
• VERITAS Observations of the Nova in V407 Cygni
• INTEGRAL observation of hard X-ray variability of the TeV binary LS5039 / RX J1826.2-1450
• Long term observations of B2 1215+30 with VERITAS
• VERITAS Observations of the BL Lac Object PG 1553+113
• Super-orbital variability of LS I +61°303 at TeV energies
• Estimating the contribution of Galactic sources to the diffuse neutrino flux
• Long-term X-ray monitoring of LS I +61 303: analysis of spectral variability and flares
• Binaries with the eyes of CTA
• Probing the Nature of the unidentified TeV Gamma-ray source HESS J0632+057 with Swift
• Overview of non-transient gamma-ray binaries and prospects for the Cherenkov Telescope Array
• The throughput calibration of the VERITAS telescopes
• Exceptionally bright TeV flares from the binary LS I +61${}^{\circ }$ 303
• Gamma-ray observations of the Be/pulsar binary 1A 0535+262 during a giant X-ray outburst
• H-alpha observations of the gamma-ray-emitting Be/X-ray binary LSI+61303: orbital modulation, disk truncation, and long-term variability
• TeV Gamma-rays from accreting magnetars in massive binaries
• VERITAS Observations of the Microquasar Cygnus X-3
• A model for the two component gamma-ray spectra observed from the gamma-ray binaries
• Very-High-Energy $\gamma$-Ray Observations of the Blazar 1ES 2344+514 with VERITAS
• HESS J1943+213: An Extreme Blazar Shining Through The Galactic Plane
• The missing GeV γ-ray binary: Searching for HESS J0632+057 with Fermi-LAT
• 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
• Neutrino signal from gamma-ray loud binaries powered by high energy protons
• TeV $\gamma$-ray fluxes from the long campaigns on Mrk421 as constraints on the emission of TeV-PeV Neutrinos and UHECRs
• Searches for periodic neutrino emission from binary systems with 22 and 40 strings of IceCube
• Multiwavelength Observations of The TeV Binary LS I +61 303 with VERITAS, Fermi-LAT and Swift-XRT During a TeV Outburst
• Radio QPO in the $\gamma$-ray-loud X-ray binary LS I +61${}^{\circ }$303
• The jet and arc molecular clouds toward Westerlund 2, RCW 49, and HESS J1023-575; 12CO and 13CO (J=2-1 and J=1-0) observations with NANTEN2 and Mopra Telescope
• The Multi-wavelength Characteristics of the TeV Binary LS I +61${}^{\circ }$ 303
• Chandra Imaging of Gamma-Ray Binaries
• Numerical Modeling of Multi-wavelength Spectra of M87 Core Emission
• A Search for Very High-Energy Gamma Rays from the Missing Link Binary Pulsar J1023+0038 with VERITAS
• Broad-Band High-Energy Emission of the Gamma-ray Binary System LS 5039: Spectral and Temporal Features using NuSTAR and Fermi Observations
• VERITAS Observations of Six Bright, Hard-Spectrum Fermi-LAT Blazars
• Measurement of night sky brightness in southern Australia
• TeV Gamma Ray Astronomy
• A Search for Pulsed Very High-Energy Gamma Rays from Thirteen Young Pulsars in Archival VERITAS Data
• Probing the Properties of the Pulsar Wind in the Gamma-Ray Binary HESS J0632+057 with NuSTAR and VERITAS Observations
• Orbital and superorbital variability of LS I +61 303 at low radio frequencies with GMRT and LOFAR
• Multi-Wavelength Observation Campaign of the TeV Gamma-Ray Binary HESS J0632+057 with NuSTAR, VERITAS, MDM, and Swift
• Optimization of large homogeneous air Cherenkov arrays and application to the design of a 1TeV-100TeV gamma-ray observatory
• A precessing stellar disk model for superorbital modulations of the gamma-ray binary LS I+61${}^{\circ }$ 303
• Unveiling properties of the non-thermal X-ray production in the gamma-ray binary LS 5039 using the long-term pattern of its fast X-ray variability
• Status of Very High Energy gamma-ray Astronomy as of early 2008
• A Decade of TeV Observations of the Gamma-ray Binary HESSJ0632+057 with VERITAS
• An Archival Search for Neutron-Star Mergers in Gravitational Waves and Very-High-Energy Gamma Rays
• Gamma ray attenuation in X-ray binaries: An application to LSI +61 303
• Optical microflares in LS I +61 303 and the search for their multiwavelength counterpart
• VHE gamma-ray observations of transient and variable stellar objects with the MAGIC Telescopes
• The strange case of HESS J0632+057 and the γ-ray High Mass X-ray Binaries
• The MAGIC highlights of the gamma ray binary LS I +61 303
• Science with the ASTRI prototype
• Results from the binaries LS I +61°303 and LS 5039 after 2.5 years of Fermi monitoring
• VERITAS monitoring of LS I +61${}^{\circ }$ 303 in conjunction with X-ray, and GeV observation campaigns