利用 MAGIC 望远镜的 TeV 观测约束英仙座星系团中的宇宙线与磁场
高能天体物理现象
2012-05-11 v3 宇宙学与河外天体物理
摘要
星系团在等级结构形成最剧烈的阶段中逐渐聚集，该过程表现为强大的激波，对宇宙线（CRs）的能量密度贡献显著。因此，星系团有望成为明亮的伽马射线辐射体，因为它们也充当了其他宇宙线源（如活动星系核和超新星驱动的星系风）的能量库。为了探测宇宙线与周围星系团气体相互作用产生的伽马射线辐射，我们开展了迄今为止针对星系团最深度的甚高能伽马射线观测活动，利用 MAGIC 切伦科夫望远镜对英仙座星系团进行了总计约 85 小时的有效观测。此次观测在 E > 100 GeV 能量下探测到了中心射电星系 NGC 1275，其能谱非常陡峭。在此，我们将分析限制在 E > 630 GeV 的能量范围，未探测到显著的伽马射线超出。这将平均宇宙线与热压比限制在 <= 1-2%，具体取决于假设和宇宙线辐射模型。将这些伽马射线上限与包含宇宙线的宇宙学星系团模拟预测进行比较，将结构形成激波处的最大宇宙线加速效率限制在 < 50%。或者，这可能意味着存在不可忽略的宇宙线传输过程，如宇宙线流和扩散进入星系团外部区域。最后，假设英仙座射电迷你晕是由强子宇宙线相互作用中产生的次级电子/正电子生成的，我们推导了磁场分布的下限：假设在 TeV 能量附近具有 E^-2.2 的谱（如星系团模拟所暗示），我们将中心磁场限制为 > 4-9 microG，具体取决于磁场强度向更大半径衰减的速率。
引用
@article{arxiv.1111.5544,
title = {Constraining Cosmic Rays and Magnetic Fields in the Perseus Galaxy Cluster with TeV observations by the MAGIC telescopes},
author = {MAGIC Collaboration and J. Aleksić and E. A. Alvarez and L. A. Antonelli and P. Antoranz and M. Asensio and M. Backes and U. Barres de Almeida and J. A. Barrio and D. Bastieri and J. Becerra González and W. Bednarek and A. Berdyugin and K. Berger and E. Bernardini and A. Biland and O. Blanch and R. K. Bock and A. Boller and G. Bonnoli and D. Borla Tridon and I. Braun and T. Bretz and A. Cañellas and E. Carmona and A. Carosi and P. Colin and E. Colombo and J. L. Contreras and J. Cortina and L. Cossio and S. Covino and F. Dazzi and A. De Angelis and G. De Caneva and E. De Cea del Pozo and B. De Lotto and C. Delgado Mendez and A. Diago Ortega and M. Doert and A. Domínguez and D. Dominis Prester and D. Dorner and M. Doro and D. Eisenacher and D. Elsaesser and D. Ferenc and M. V. Fonseca and L. Font and C. Fruck and R. J. García López and M. Garczarczyk and D. Garrido and G. Giavitto and N. Godinović and S. R. Gozzini and D. Hadasch and D. Häfner and A. Herrero and D. Hildebrand and D. Höhne-Mönch and J. Hose and D. Hrupec and T. Jogler and H. Kellermann and S. Klepser and T. Krähenbühl and J. Krause and J. Kushida and A. La Barbera and D. Lelas and E. Leonardo and N. Lewandowska and E. Lindfors and S. Lombardi and M. López and R. López-Coto and A. López-Oramas and E. Lorenz and M. Makariev and G. Maneva and N. Mankuzhiyil and K. Mannheim and L. Maraschi and M. Mariotti and M. Martínez and D. Mazin and M. Meucci and J. M. Miranda and R. Mirzoyan and J. Moldón and A. Moralejo and P. Munar-Adrover and A. Niedzwiecki and D. Nieto and K. Nilsson and N. Nowak and R. Orito and S. Paiano and D. Paneque and R. Paoletti and S. Pardo and J. M. Paredes and S. Partini and M. A. Perez-Torres and M. Persic and L. Peruzzo and M. Pilia and J. Pochon and F. Prada and P. G. Prada Moroni and E. Prandini and I. Puerto Gimenez and I. Puljak and I. Reichardt and R. Reinthal and W. Rhode and M. Ribó and J. Rico and S. Rügamer and A. Saggion and K. Saito and T. Y. Saito and M. Salvati and K. Satalecka and V. Scalzotto and V. Scapin and C. Schultz and T. Schweizer and M. Shayduk and S. N. Shore and A. Sillanpää and J. Sitarek and I. Snidaric and D. Sobczynska and F. Spanier and S. Spiro and V. Stamatescu and A. Stamerra and B. Steinke and J. Storz and N. Strah and S. Sun and T. Surić and L. Takalo and H. Takami and F. Tavecchio and P. Temnikov and T. Terzić and D. Tescaro and M. Teshima and O. Tibolla and D. F. Torres and A. Treves and M. Uellenbeck and H. Vankov and P. Vogler and R. M. Wagner and Q. Weitzel and V. Zabalza and F. Zandanel and R. Zanin and C. Pfrommer and A. Pinzke},
journal= {arXiv preprint arXiv:1111.5544},
year = {2012}
}
备注
Corresponding authors are F. Zandanel, C. Pfrommer, P. Colin, A. Pinzke and S. Lombardi. Accepted for publication in A&A on 06/03/2012