VERITAS对BL Lac天体1ES 1218+304的观测
高能天体物理现象
2014-11-18 v1 宇宙学与河外天体物理
摘要
VERITAS合作组报告探测到来自高峰频BL Lac天体1ES 1218+304（红移z=0.182）的甚高能（VHE）伽马射线辐射。在2007年前三个月的观测中，伽马射线信号以10.4个标准偏差（10.4 sigma）的统计显著性被探测到，证实了MAGIC合作组对该天体的发现。在约160 GeV至约1.8 TeV之间的光子谱可以用幂律很好地描述，谱指数为Gamma = 3.08 +/- 0.34_stat +/- 0.2_sys。积分流量为Phi(E > 200 GeV) = (12.2 +/- 2.6) X 10^-12 cm^-2 s^-1，约为蟹状星云流量的6%。光变曲线未显示任何VHE流量变化的证据。利用近红外到中红外波段河外背景光密度的下限，我们能够限制1ES 1218+304的内禀能谱范围。我们表明，内禀光子谱的指数比Gamma = 2.32 +/- 0.37_stat更硬。当加入来自1ES 1101-232和1ES 0229+200谱的限制时，1ES 1218+304的谱很可能比Gamma = 1.86 +/- 0.37_stat更硬。
引用
@article{arxiv.0901.4561,
title = {VERITAS observations of the BL Lac 1ES 1218+304},
author = {VERITAS Collaboration and V. A. Acciari and E. Aliu and T. Arlen and M. Beilicke and W. Benbow and S. M. Bradbury and J. H. Buckley and V. Bugaev and Y. Butt and K. L. Byrum and O. Celik and A. Cesarini and L. Ciupik and Y. C. K. Chow and P. Cogan and P. Colin and W. Cui and M. K. Daniel and T. Ergin and A. D. Falcone and S. J. Fegan and J. P. Finley and P. Fortin and L. F. Fortson and A. Furniss and G. H. Gillanders and J. Grube and R. Guenette and G. Gyuk and D. Hanna and E. Hays and J. Holder and D. Horan and C. M. Hui and T. B. Humensky and A. Imran and P. Kaaret and N. Karlsson and M. Kertzman and D. B. Kieda and J. Kildea and A. Konopelko and H. Krawczynski and F. Krennrich and M. J. Lang and S. LeBohec and G. Maier and A. McCann and M. McCutcheon and P. Moriarty and R. Mukherjee and T. Nagai and J. Niemiec and R. A. Ong and D. Pandel and J. S. Perkins and M. Pohl and J. Quinn and K. Ragan and L. C. Reyes and P. T. Reynolds and H. J. Rose and M. Schroedter and G. H. Sembroski and A. W. Smith and D. Steele and S. P. Swordy and J. A. Toner and L. Valcarcel and V. V. Vassiliev and R. Wagner and S. P. Wakely and J. E. Ward and T. C. Weekes and A. Weinstein and R. J. White and D. A. Williams and S. A. Wissel and M. Wood and B. Zitzer},
journal= {arXiv preprint arXiv:0901.4561},
year = {2014}
}
备注
Accepted for publication in The Astrophysical Journal