PKS 2155-304的甚高能伽马射线辐射：光谱与时变特征
高能天体物理现象
2015-05-19 v2
摘要
对耀变体甚高能伽马射线的观测提供了有关其最内层区域加速机制的信息。研究这些天体的光变性有助于更好地理解其中的作用机制。本文旨在利用H.E.S.S.成像大气切伦科夫望远镜，在广泛的通量状态下，研究著名高频峰BL Lac天体PKS 2155-304的甚高能（>100 GeV）伽马射线的光谱与时变特征。我们分析了2005年至2007年收集的数据。在从3年到4分钟的时间尺度上导出光谱。通过倍增时标和结构函数研究光变曲线变异性，并与红噪声过程模拟进行比较。发现该源在2005年至2007年间处于低态，除了2006年7月发生的一组异常耀发。该源的宁静态特征为：200 GeV以上平均通量水平为4.32 +/-0.09 x 10^-11 cm^-2 s^-1，约为蟹状星云的15%，幂律光子指数为3.53 +/-0.06。在2006年7月的耀发期间，发现了约2分钟的倍增时标。在跨越两个数量级的通量范围内检查了光谱指数变化，揭示了在低通量和高通量下的不同行为，这是甚高能伽马射线辐射耀变体中的一个新现象。以分数均方根表征的变异性幅度强烈依赖于能量，并与E^(0.19 +/- 0.01)成正比。光变曲线均方根与通量相关。这是一个倍增过程的特征，可以解释为傅里叶指数约为2的红噪声。这个独特的数据集显示了PKS 2155-304存在低水平伽马射线辐射态的证据，其起源可能与爆发不同。光变曲线对数正态行为的发现可能是一个指标...
引用
@article{arxiv.1005.3702,
title = {VHE gamma-ray emission of PKS 2155-304: spectral and temporal variability},
author = {HESS Collaboration and A. Abramowski and F. Acero and F. Aharonian and A. G. Akhperjanian and G. Anton and U. Barres de Almeida and A. R. Bazer-Bachi and Y. Becherini and B. Behera and W. Benbow and K. Bernlohr and A. Bochow and C. Boisson and J. Bolmont and V. Borrel and J. Brucker and F. Brun and P. Brun and R. Buhler and T. Bulik and I. Busching and T. Boutelier and P. M. Chadwick and A. Charbonnier and R. C. G. Chaves and A. Cheesebrough and J. Conrad and L. -M. Chounet and A. C. Clapson and G. Coignet and L. Costamante and M. Dalton and M. K. Daniel and I. D. Davids and B. Degrange and C. Deil and H. J. Dickinson and A. Djannati-Atai and W. Domainko and L. O'C. Drury and F. Dubois and G. Dubus and J. Dyks and M. Dyrda and K. Egberts and P. Eger and P. Espigat and L. Fallon and C. Farnier and S. Fegan and F. Feinstein and M. V. Fernandes and A. Fiasson and A. Foerster and G. Fontaine and M. Fussling and S. Gabici and Y. A. Gallant and L. Gerard and D. Gerbig and B. Giebels and J. F. Glicenstein and B. Glueck and P. Goret and D. Goering and D. Hampf and M. Hauser and S. Heinz and G. Heinzelmann and G. Henri and G. Hermann and J. A. Hinton and A. Hoffmann and W. Hofmann and P. Hofverberg and M. Holleran and S. Hoppe and D. Horns and A. Jacholkowska and O. C. de Jager and C. Jahn and I. Jung and K. Katarzynski and U. Katz and S. Kaufmann and M. Kerschhaggl and D. Khangulyan and B. Khelifi and D. Keogh and D. Klochkov and W. Kluzniak and T. Kneiske and Nu. Komin and K. Kosack and R. Kossakowski and G. Lamanna and J. -P. Lenain and T. Lohse and C. -C. Lu and V. Marandon and A. Marcowith and J. Masbou and D. Maurin and T. J. L. McComb and M. C. Medina and J. Mehault and R. Moderski and E. Moulin and M. Naumann-Godo and M. de Naurois and D. Nedbal and D. Nekrassov and N. Nguyen and B. Nicholas and J. Niemiec and S. J. Nolan and S. Ohm and J-F. Olive and E. de Ona Wilhelmi and B. Opitz and K. J. Orford and M. Ostrowski and M. Panter and M. Paz Arribas and G. Pedaletti and G. Pelletier and P. -O. Petrucci and S. Pita and G. Puehlhofer and M. Punch and A. Quirrenbach and B. C. Raubenheimer and M. Raue and S. M. Rayner and O. Reimer and M. Renaud and R. de los Reyes and F. Rieger and J. Ripken and L. Rob and S. Rosier-Lees and G. Rowell and B. Rudak and C. B. Rulten and J. Ruppel and F. Ryde and V. Sahakian and A. Santangelo and R. Schlickeiser and F. M. Schoeck and A. Schoenwald and U. Schwanke and S. Schwarzburg and S. Schwemmer and A. Shalchi and I. Sushch and M. Sikora and J. L. Skilton and H. Sol and L. Stawarz and R. Steenkamp and C. Stegmann and F. Stinzing and G. Superina and A. Szostek and P. H. Tam and J. -P. Tavernet and R. Terrier and O. Tibolla and M. Tluczykont and K. Valerius and C. van Eldik and G. Vasileiadis and C. Venter and L. Venter and J. P. Vialle and A. Viana and P. Vincent and M. Vivier and H. J. Voelk and F. Volpe and S. Vorobiov and S. J. Wagner and M. Ward and A. A. Zdziarski and A. Zech and H. -S. Zechlin},
journal= {arXiv preprint arXiv:1005.3702},
year = {2015}
}
备注
17 pages, 13 figures, Accepted for publication to Astronomy & Astrophysics