Observation of Gamma-Ray Emission from the Galaxy M87 above 250 GeV with VERITAS
Observation of Gamma-Ray Emission from the Galaxy M87 above 250 GeV with VERITAS
复制标题
使用 VERITAS 观测 Galaxy M87 高于 250 GeV 的伽马射线发射
DOI：
10.1086/587458
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
B. Zitzer
中科院分区：
文献类型：
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作者：
V. Acciari;M. Beilicke;G. Blaylock;S. Bradbury;J. Buckley;V. Bugaev;Y. Butt;O. Celik;A. Cesarini;L. Ciupik;P. Cogan;P. Colin;W. Cui;M. Daniel;C. Duke;T. Ergin;A. Falcone;S. Fegan;J. Finley;G. Finnegan;P. Fortin;L. Fortson;K. Gibbs;G. Gillanders;J. Grube;R. Guenette;G. Gyuk;D. Hanna;E. Hays;J. Holder;D. Horan;S. Hughes;M. Hui;T. Humensky;A. Imran;P. Kaaret;M. Kertzman;D. Kieda;J. Kildea;A. Konopelko;H. Krawczynski;F. Krennrich;M. Lang;S. LeBohec;K. Lee;G. Maier;A. McCann;M. McCutcheon;J. Millis;P. Moriarty;R. Mukherjee;T. Nagai;R. Ong;D. Pandel;J. Perkins;M. Pohl;J. Quinn;K. Ragan;P. Reynolds;H. Rose;M. Schroedter;G. Sembroski;A. Smith;D. Steele;S. Swordy;A. Toner;L. Valcárcel;V. Vassiliev;S. Wakely;J. Ward;T. Weekes;A. Weinstein;R. White;D. Williams;S. Wissel;M. Wood;B. Zitzer
对附近射电星系M87的多波长观测提供了一个独特的机会，可以详细研究活动星系核中从无线电波到TeV γ射线的过程。本文报道了2007年春利用VERITAS大气切伦科夫望远镜阵列探测到的M87的250 GeV以上的γ射线辐射，并讨论了其与X射线辐射的相关性。γ射线发射是点状的，内禀源半径小于4.5′。微分能谱可以用幂律函数很好地拟合：dΦ/dE =（7.4 ± 1.3stat ± 1.5sys）（E/TeV）（− 2.31 ± 0.17stat ± 0.2sys）10−9 m−2 s−1 TeV−1。我们展示了TeV实验报告的γ射线通量与ASM RXTE天文台测量的X射线辐射之间存在年尺度相关性的强有力证据，并讨论了可能的短时间尺度变化。这些结果意味着M87的γ射线发射更可能与星系的核心有关，而不是与喷流中的其他明亮X射线特征有关。
The multiwavelength observation of the nearby radio galaxy M87 provides a unique opportunity to study in detail processes occurring in active galactic nuclei from radio waves to TeV γ-rays. Here we report the detection of γ-ray emission above 250 GeV from M87 in spring 2007 with the VERITAS atmospheric Cerenkov telescope array and discuss its correlation with the X-ray emission. The γ-ray emission is measured to be pointlike with an intrinsic source radius less than 4.5′. The differential energy spectrum is fitted well by a power-law function: dΦ/dE = (7.4 ± 1.3stat ± 1.5sys)(E/TeV)(− 2.31 ± 0.17stat ± 0.2sys) 10−9 m−2 s−1 TeV−1. We show strong evidence for a year-scale correlation between the γ-ray flux reported by TeV experiments and the X-ray emission measured by the ASM RXTE observatory, and discuss the possible short-timescale variability. These results imply that the γ-ray emission from M87 is more likely associated with the core of the galaxy than with other bright X-ray features in the jet.