Multiwavelength observations of the TeV binary LS I +61° 303 with Veritas, Fermi-LAT, and Swift/xrt during a TeV outburst

  title={Multiwavelength observations of the TeV binary LS I +61° 303 with Veritas, Fermi-LAT, and Swift/xrt during a TeV outburst},
  author={Ester Aliu and Simon Archambault and Bagmeet Behera and Kenneth I. Berger and Matthias Beilicke and W. Benbow and R. Bird and A. Bouvier and Viatcheslav Bugaev and M. Cerruti and Xiaofei Chen and L. Ciupik and Michael P. Connolly and Wei Wei Cui and Jonathan Dumm and Abraham D. Falcone and S. Federici and Qi Feng and John Park Finley and Pascal D. Fortin and Lucy Fortson and A. Furniss and Nicola Galante and G. H. Gillanders and Sean Griffin and Scott T. Griffiths and Jeff Grube and Geza Gyuk and David Hanna and Jamie Holder and Gareth Hughes and Thomas Brian Humensky and Philip Kaaret and M. P. Kertzman and Yerbol Farkhatuly Khassen and D. Kieda and Frank Krennrich and Matthew J. Lang and Gernot Maier and P. Majumdar and Steven McArthur and A. McCann and Patrick Moriarty and Reshmi Mukherjee and Anna O'Faol{\'a}in de Bhr{\'o}ithe and R. A. Ong and A. N. Otte and Nahee Park and Jeremy S. Perkins and Martin Pohl and Alexis Popkow and Heike Prokoph and Joseph F. Quinn and K. Ragan and J. Rajotte and Gayle Ratliff and Philip T. Reynolds and Gordon T. Richards and E. Roache and Glenn H. Sembroski and Farzaneh Sheidaei and C. Skole and Andrew William Smith and David Staszak and Igor Telezhinsky and Joshua Tyler and Angelo Varlotta and Stephane Vincent and Scott Patrick Wakely and Trevor C. Weekes and Amanda J. Weinstein and Roman Welsing and Anna Zajczyk and Benjamin Zitzer},
  journal={The Astrophysical Journal},
We present the results of a multiwavelength observational campaign on the TeV binary system LS I +61° 303 with the VERITAS telescope array (>200 GeV), Fermi-LAT (0.3-300 GeV), and Swift/XRT (2-10 keV). The data were taken from 2011 December through 2012 January and show a strong detection in all three wavebands. During this period VERITAS obtained 24.9 hr of quality selected livetime data in which LS I +61° 303 was detected at a statistical significance of 11.9σ. These TeV observations show… Expand

Figures and Tables from this paper

VERITAS monitoring of LS I +61$^\circ$ 303 in conjunction with X-ray, and GeV observation campaigns
One of the most enigmatic TeV binary systems, LS I +61$^\circ$ 303 exhibits a high degree of flux modulation from radio to TeV wavelengths over a single orbit of the binary system, once everyExpand
Super-orbital variability of LS I +61 ◦ 303 at TeV energies
Context. The gamma-ray binary LS I +61o303 is a well-established source from centimeter radio up to very high energy (VHE; E > 100 GeV). The broadband emission shows a periodicity of ∼26.5 days,Expand
Characterizing the VHE Emission of LS I +61 303 using VERITAS Observations
The TeV gamma-ray binary LS I +61 303, approximately 2 kpc from Earth, consists of a low mass compact object in an eccentric orbit around a massive Be star. LS I +61 303 exhibits modulated VHEExpand
P o S ( I C R C 2 0 1 5 ) 8 1 8 VERITAS monitoring of LS I + 61 ◦ 303 in conjunction with X-ray , and GeV observation campaigns
One of the most enigmatic TeV binary systems, LS I +61◦ 303 exhibits a high degree of flux modulation from radio to TeV wavelengths over a single orbit of the binary system, once every ∼26.5 days.Expand
VERITAS observations of exceptionally bright TeV flares from LS I +61$^\circ$ 303
The very-high-energy (VHE; E > 100 GeV) gamma-ray experiment, VERITAS, detected exceptionally bright flares from the high-mass X-ray binary LS I +61$^\circ$ 303 during the period October-DecemberExpand
We study the characteristics of the TeV binary LS I+61°303 in radio, soft X-ray, hard X-ray, and gamma-ray (GeV and TeV) energies. The long-term variability characteristics are examined as a functionExpand
Superorbital Modulation at GeV Energies in the γ-Ray Binary LS I + 61°303
We report the results from our analysis of eight years of the data for the γ-ray binary LS I +61°303, obtained with the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope. We find aExpand
Observation of Markarian 421 in TeV Gamma Rays Over a 14-Year Time Span
Abstract The variability of the blazar Markarian 421 in TeV gamma rays over a 14-year time period has been explored with the Whipple 10 m telescope. It is shown that the dynamic range of its fluxExpand
The VERITAS Survey of the Cygnus Region of the Galaxy
The Cygnus region is a very active region of our Galaxy with many sources of GeV and TeV gamma-ray emission, such as supernova remnants, pulsar wind nebulae, and massive star clusters. A detailedExpand
Understanding the periodicities in radio and GeV emission from LS I +61°303
Context. One possible scenario to explain the emission from the stellar binary system LS I + 61°303 is that the observed flux is emitted by precessing jets powered by accretion. Accretion modelsExpand


VERITAS Observations of the TeV binary LS I +61 303
We present the results of observations of the TeV binary LS I +61{sup 0} 303 with the VERITAS telescope array between 2008 and 2010, at energies above 300 GeV. In the past, both ground-basedExpand
Fermi LAT Observations of LS I +61 303: First Detection of an Orbital Modulation in GeV Gamma Rays
This Letter presents the first results from the observations of LS I +61°303 using Large Area Telescope data from the Fermi Gamma-Ray Space Telescope between 2008 August and 2009 March. Our resultsExpand
VERITAS Observations of the ?-Ray Binary LS I +61 303
LS I +61 303 is one of only a few high-mass X-ray binaries currently detected at high significance in very high energy γ-rays. The system was observed over several orbital cycles (between 2006Expand
Detection of the γ-Ray Binary LS I +61°303 in a Low-flux State at Very High Energy γ-Rays with the MAGIC Telescopes in 2009
We present very high energy (E > 100 GeV) gamma-ray observations of the gamma-ray binary system LS I +61 degrees 303 obtained with the MAGIC stereo system between 2009 October and 2010 January. WeExpand
One-sided jet at milliarcsecond scales in LS I +61˚ 303
We present Very Long Baseline Interferometry (VLBI) observations of the high mass X-ray binary LS I+ 61303, carried out with the European VLBI Network (EVN). Over the 11 hour observing run, performedExpand
We report on the results of a long-term X-ray monitoring campaign of the galactic binary LS I +61 303 performed by the Rossi X-ray Timing Explorer. This data set consists of 1 ks pointings takenExpand
Swift/XRT monitoring of five orbital cycles of LS I +61° 303
Context. LS I +61° 303 is one of the most interesting high-mass X-ray binaries owing to its spatially resolved radio emission and its TeV emission, generally attributed to non-thermal particles in anExpand
The Fermi Large Area Telescope (LAT) reported the first definitive GeV detections of the binaries LS I +61°303 and LS 5039 in the first year after its launch in 2008 June. These detections wereExpand
Long‐term monitoring of LS I +61°303 with INTEGRAL
LS I +61 � 303 is one of the few high-mass X-ray binaries that have been recently observed at TeV and GeV energies. Here we investigate the hard X-ray spectral and timing properties of this sourceExpand
Search for radio pulsations in LS I +61 303
Context. LS I +61 303 is a member of the select group of gamma-ray binaries: galactic binary systems that contain a massive star and a compact object, show a changing milliarcsecond morphology and aExpand