Veritas observations of the gamma-ray binary LS I+61 303

Download

index.pdf

Date

2008-06-01

Author

Acciari, V. A.
Beilicke, M.
Blaylock, G.
Bradbury, S. M.
Buckley, J. H.
Bugaev, V.
Butt, Y.
Byrum, K. L.
Celik, O.
Cesarini, A.
Ciupik, L.
Chow, Y. C. K.
Cogan, P.
Colin, P.
Cui, W.
Daniel, M. K.
Duke, C.
Ergin, Tülün
Falcone, A. D.
Fegan, S. J.
Finley, J. P.
Fortin, P.
Fortson, L. F.
Gall, D.
Gibbs, K.
Gillanders, G. H.
Grube, J.
Guenette, R.
Hanna, D.
Hays, E.
Holder, J.
Horan, D.
Hughes, S. B.
Hui, C. M.
Humensky, T. B.
Kaaret, P.
Kieda, D. B.
Kildea, J.
Konopelko, A.
Krawczynski, H.
Krennrich, F.
Lang, M. J.
LeBohec, S.
Lee, K.
Maier, G.
McCann, A.
McCutcheon, M.
Millis, J.
Moriarty, P.
Mukherjee, R.
Nagai, T.
Ong, R. A.
Pandel, D.
Perkins, J. S.
Pizlo, F.
Pohl, M.
Quinn, J.
Ragan, K.
Reynolds, P. T.
Rose, H. J.
Schroedter, M.
Sembroski, G. H.
Smith, A. W.
Steele, D.
Swordy, S. P.
Toner, J. A.
Valcarcel, L.
Vassiliev, V. V.
Wagner, R.
Wakely, S. P.
Ward, J. E.
Weekes, T. C.
Weinstein, A.
White, R. J.
Williams, D. A.
Wissel, S. A.
Wood, M.
Zitzer, B.

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

180
views

85
downloads

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 2006 September and 2007 February) with the VERITAS array of imaging air Cerenkov 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.

Subject Keywords

Space and Planetary Science, Astronomy and Astrophysics, Gamma rays, LS I +61 303, X-ray binary, Acceleration of particles LS I +61 303

URI

https://hdl.handle.net/11511/37624

Journal

ASTROPHYSICAL JOURNAL

DOI

https://doi.org/10.1086/587736

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

VERITAS OBSERVATIONS OF A VERY HIGH ENERGY gamma-RAY FLARE FROM THE BLAZAR 3C 66A Acciari, V. A.; et. al. (IOP Publishing, 2009-03-10) The intermediate-frequency peaked BL Lacertae (IBL) object 3C 66A is detected during 2007-2008 in VHE ( very high energy; E > 100 GeV) gamma rays with the VERITAS stereoscopic array of imaging atmospheric Cherenkov telescopes. An excess of 1791 events is detected, corresponding to a significance of 21.2 standard deviations (sigma), in these observations (32.8 hr live time). The observed integral flux above 200 GeV is 6% of the Crab Nebula's flux and shows evidence for variability on the timescale of days. T...
VERITAS discovery of > 200 GeV gamma-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae Acciari, V. A.; et. al. (IOP Publishing, 2008-09-10) We report the detection of very high energy gamma- ray emission from the intermediate- frequency- peaked BL Lacertae object W Comae (z = 0.102) by VERITAS. The source was observed between 2008 January and April. A strong outburst of gamma-ray emission was measured in the middle of March, lasting for only 4 days. The energy spectrum measured during the two highest flare nights is fit by a power law and is found to be very steep, with a differential photon spectral index of Gamma = 3.81 +/- 0.35(stat) +/- 0.3...
VERITAS OBSERVATIONS OF THE BL LAC OBJECT 1ES 1218+304 Acciari, V. A.; et. al. (IOP Publishing, 2009-04-20) The VERITAS collaboration reports the detection of very-high-energy gamma-ray emission from the high-frequency-peaked BL Lac object 1ES 1218+304 located at a redshift of z = 0.182. A gamma-ray signal was detected with a statistical significance of 10.4 standard deviations (10.4 sigma) for the observations taken during the first three months of 2007, confirming the discovery of this object made by the MAGIC collaboration. The photon spectrum between similar to 160 GeV and similar to 1.8 TeV is well described...
Very high energy gamma rays from the composite SNR G0.9+0.1 Aharonian, F; et. al. (EDP Sciences, 2005-03-01) Very high energy (> 100 GeV) gamma-ray emission has been detected for the first time from the composite supernova remnant G0.9+ 0.1 using the HESS instrument. The source is detected with a significance of approximate to 13sigma, and a photon flux above 200 GeV of ( 5.7 +/- 0.7(stat) +/- 1.2(sys)) x 10(-12) cm(-2) s(-1), making it one of the weakest sources ever detected at TeV energies. The photon spectrum is compatible with a power law ( dN/dE proportional to E-Gamma) with photon index Gamma = 2.40 +/- 0.1...
MULTIWAVELENGTH OBSERVATIONS OF LS I+61 degrees 303 WITH VERITAS, SWIFT, AND RXTE Acciari, V. A.; et. al. (IOP Publishing, 2009-08-01) We present results from a long-term monitoring campaign on the TeV binary LSI +61 degrees 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 8.8 sigma (2006/2007) and 7.3 sigma (2007/2008) significance level for emission above 500 GeV. The source was detected durin...

Citation Formats

V. A. Acciari et al., “Veritas observations of the gamma-ray binary LS I+61 303,” ASTROPHYSICAL JOURNAL, pp. 1427–1432, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/37624.