The TeV spectrum of H1426+428

被引:56
作者
Petry, D
Bond, IH
Bradbury, SM
Buckley, JH
Carter-Lewis, DA
Cui, W
Duke, C
Perez, ID
Falcone, A
Fegan, DJ
Fegan, SJ
Finley, JP
Gaidos, JA
Gibbs, K
Gammell, S
Hall, J
Hall, TA
Hillas, AM
Holder, J
Horan, D
Jordan, M
Kertzman, M
Kieda, D
Kildea, J
Knapp, J
Kosack, K
Krennrich, F
LeBohec, S
Moriarty, P
Müller, D
Nagai, TN
Ong, R
Page, M
Pallassini, R
Power-Mooney, B
Quinn, J
Reay, NW
Reynolds, PT
Rose, HJ
Schroedter, M
Sembroski, GH
Sidwell, R
Stanton, N
Swordy, SP
Vassiliev, VV
Wakely, SP
Walker, G
Weekes, TC
机构
[1] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA
[2] Univ Leeds, Dept Phys, Leeds LS2 9JT, W Yorkshire, England
[3] Washington Univ, Dept Phys, St Louis, MO 63130 USA
[4] Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA
[5] Grinnell Coll, Dept Phys, Grinnell, IA 50112 USA
[6] Natl Univ Ireland, Dept Phys, Dublin 4, Ireland
[7] Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA
[8] Univ Arizona, Dept Phys, Tucson, AZ 85721 USA
[9] Univ Utah, High Energy Astrophys Inst, Salt Lake City, UT 84112 USA
[10] Univ Arkansas, Dept Phys & Astron, Little Rock, AR 72204 USA
[11] Depauw Univ, Dept Phys, Greencastle, IN 46135 USA
[12] Galway Mayo Inst Technol, Sch Sci, Galway, Ireland
[13] Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA
[14] Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA
[15] Kansas State Univ, Dept Phys, Manhattan, KS 66506 USA
[16] Cork Inst Technol, Dept Phys, Cork, Ireland
关键词
BL Lacertae objects : individual (H1426+428); gamma rays : observations;
D O I
10.1086/343102
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The BL Lac object H1426+428 was recently detected as a high-energy gamma-ray source by the VERITAS collaboration (Horan et al.). 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) (E)=10(-7.31+/-0.15 stat +/-0.16 syst) 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. At the 95% confidence level, 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 (noncontemporaneous) measurement by Aharonian et al. both in shape and in normalization. Below 800 GeV, the data clearly favor 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.
引用
收藏
页码:104 / 109
页数:6
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