1. The TeV Spectrum of H1426+428
- Author
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Vladimir Vassiliev, Dietrich Müller, Jamie Holder, S. M. Bradbury, Frank Krennrich, M. Kertzman, S. J. Fegan, A. M. Hillas, T. N. Nagai, John Kildea, D. J. Fegan, D. Horan, Wei Cui, M. Schroedter, J. Hall, S. Gammell, J. P. Finley, K. Kosack, J. Knapp, C. Duke, D. A. Carter-Lewis, T. C. Weekes, S. P. Swordy, R. A. Ong, Morgan T. Page, R. Sidwell, P. Moriarty, I. H. Bond, S. P. Wakely, S. LeBohec, N. Stanton, B. Power-Mooney, G. Walker, I. de la Calle Perez, D. Petry, Tony Hall, J. H. Buckley, J. A. Gaidos, David Kieda, G. H. Sembroski, R. Pallassini, M. Jordan, Abraham D. Falcone, H. J. Rose, N. W. Reay, John L. Quinn, K. G. Gibbs, and P. T. Reynolds
- Subjects
Normalization (statistics) ,Physics ,ray ,Astrophysics::High Energy Astrophysical Phenomena ,Spectrum (functional analysis) ,Flux ,Astronomy and Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Astrophysics ,Space (mathematics) ,Power law ,objects ,Crab Nebula ,Space and Planetary Science ,bl lacertae objects : individual (h1426+428) ,gamma rays : observations ,High Energy Physics::Experiment ,Blazar ,BL Lac object - Abstract
The BL Lac object H1426+428 was recently detected as a high energy gamma-ray source by the VERITAS collaboration (Horan et al. 2002). We have reanalyzed the 2001 portion of the data used in the detection in order to examine the spectrum of H1426+428 above 250 GeV. We find that the time-averaged spectrum agrees with a power law of the shape dF/dE = 10^(-7.31 +- 0.15(stat) +- 0.16(syst)) x E^(-3.50 +- 0.35(stat) +- 0.05(syst)) m^(-2)s^(-1)TeV^(-1) The statistical evidence from our data for emission above 2.5 TeV is 2.6 sigma. With 95% c.l., the integral flux of H1426+428 above 2.5 TeV is larger than 3% of the corresponding flux from the Crab Nebula. The spectrum is consistent with the (non-contemporaneous) measurement by Aharonian et al. (2002) both in shape and in normalization. Below 800 GeV, the data clearly favours a spectrum steeper than that of any other TeV Blazar observed so far indicating a difference in the processes involved either at the source or in the intervening space., Comment: LaTeX, 8 pages, 4 figures, accepted for publication in ApJ
- Published
- 2002
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