VERITAS discovery of > 200 GeV gamma-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae

Download

Date

2008-09-10

Author

Acciari, V. A.
Aliu, E.
Beilicke, M.
Benbow, W.
Boettcher, M.
Bradbury, S. M.
Buckley, J. H.
Bugaev, V.
Butt, Y.
Celik, O.
Cesarini, A.
Ciupik, L.
Chow, Y. C. K.
Cogan, P.
Colin, P.
Cui, W.
Daniel, M. K.
Ergin, Tülün
Falcone, A. D.
Fegan, S. J.
Finley, J. P.
Finnegan, G.
Fortin, P.
Fortson, L. F.
Furniss, A.
Gall, D.
Gillanders, G. H.
Grube, J.
Guenette, R.
Gyuk, G.
Hanna, D.
Hays, E.
Holder, J.
Horan, D.
Hui, C. M.
Humensky, T. B.
Imran, A.
Kaaret, P.
Karlsson, N.
Kertzman, M.
Kieda, D. B.
Konopelko, A.
Krawczynski, H.
Krennrich, F.
Lang, M. J.
LeBohec, S.
Lee, K.
Maier, G.
McCann, A.
McCutcheon, M.
Moriarty, P.
Mukherjee, R.
Nagai, T.
Niemiec, J.
Ong, R. A.
Pandel, D.
Perkins, J. S.
Petry, D.
Pohl, M.
Quinn, J.
Ragan, K.
Reyes, L. C.
Reynolds, P. T.
Roache, E.
Rose, H. J.
Schroedter, M.
Sembroski, G. H.
Smith, A. W.
Steele, D.
Swordy, S. P.
Toner, J. A.
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

83
views

0
downloads

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) +/- 0.34(syst). The integral photon flux above 200 GeV during those two nights corresponds to roughly 9% of the flux from the Crab Nebula. Quasi-simultaneous Swift observations at X-ray energies were triggered by the VERITAS observations. The spectral energy distribution of the flare data can be described by synchrotron self-Compton (SSC) or external Compton (EC) leptonic jet models.

Subject Keywords

Space and Planetary Science, Astronomy and Astrophysics

URI

https://hdl.handle.net/11511/43259

Journal

ASTROPHYSICAL JOURNAL LETTERS

DOI

https://doi.org/10.1086/592244

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

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...
RXTE and Swift Observations of SWIFT J0513.4-6547 Sahiner, S.; Serim, Muhammed Miraç; Baykal, Altan; İNAM, SITKI ÇAĞDAŞ (Oxford University Press (OUP), 2016-02-11) We present timing and spectral analysis of Swift-XRT (X-ray Telescope) and RXTE-PCA (Rossi X-ray Timing Explorer-proportional Counter Array) observations of the transient Be/X-ray pulsar SWIFT J0513.4-6547 during its outburst in 2009 and its rebrightening in 2014. From 2009 observations, short-term spin-up rate of the source after the peak of the outburst is found to have about half of the value measured at the peak of the outburst by Coe et al. When the source is quiescent between 2009 and 2014, average sp...
Frequency-resolved spectroscopy of XB1323-619 using XMM-Newton data: detection of a reflection region in the disc Balman, Şölen (Oxford University Press (OUP), 2010-09-21) We present the frequency-resolved energy spectra (FRS) of the low-mass X-ray binary dipper XB1323-619 during persistent emission in four different frequency bands using an archival XMM-Newton observation. FRS method helps to probe the inner zones of an accretion disc. XB1323-619 is an Atoll source and a type-I burster. We find that the FRS is well described by a single blackbody component with kT in a range 1.0-1.4 keV responsible for the source variability in the frequency ranges of 0.002-0.04 and 0.07-0.3...
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...

Citation Formats

V. A. Acciari et al., “VERITAS discovery of > 200 GeV gamma-ray emission from the intermediate-frequency-peaked BL Lacertae object W Comae,” ASTROPHYSICAL JOURNAL LETTERS, pp. 0–0, 2008, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/43259.