MULTIWAVELENGTH OBSERVATIONS OF THE TeV BINARY LS I+61 degrees 303 WITH VERITAS, Fermi-LAT, AND Swift/XRT DURING A TeV OUTBURST

作者：Aliu E^*; Archambault S; Behera B; Berger K; Beilicke M; Benbow W; Bird R; Bouvier A; Bugaev V; Cerruti M; Chen X; Ciupik L; Connolly M P; Cui W; Dumm J; Falcone A; Federici S; Feng Q; Finley J P; Fortin P; Fortson L; Furniss A; Galante N; Gillanders G H; Griffin S; Griffiths S T; Grube J; Gyuk G; Hanna D; Holder J; Hughes G; Humensky T B; Kaaret P; Kertzman M; Khassen Y; Kieda D; Krennrich F; Lang M J; Maier G

来源：Astrophysical Journal, 2013, 779(1): UNSP 88.

DOI：10.1088/0004-637X/779/1/88

• acceleration of particles
• binaries: general
• gamma rays: stars
• relativistic processes
• X-rays: binaries

We present the results of a multiwavelength observational campaign on the TeV binary system LS I +61 degrees 303 with the VERITAS telescope array (%26gt;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 degrees 303 was detected at a statistical significance of 11.9 sigma. These TeV observations show evidence for nightly variability in the TeV regime at a post-trial significance of 3.6 sigma. The combination of the simultaneously obtained TeV and X-ray fluxes do not demonstrate any evidence for a correlation between emission in the two bands. For the first time since the launch of the Fermi satellite in 2008, this TeV detection allows the construction of a detailed MeV-TeV spectral energy distribution from LS I +61 degrees 303. This spectrum shows a distinct cutoff in emission near 4 GeV, with emission seen by the VERITAS observations following a simple power-law above 200 GeV. This feature in the spectrum of LS I +61 degrees 303, obtained from overlapping observations with Fermi-LAT and VERITAS, may indicate that there are two distinct populations of accelerated particles producing the GeV and TeV emission.

• 出版日期2013-12-10
• 单位McGill