VERITAS 搜寻矮椭球星系中的甚高能伽马射线辐射
宇宙学与河外天体物理
2015-05-19 v2
摘要
利用地基伽马射线天文台进行间接暗物质搜索，为识别暗物质的粒子性质提供了一种替代方法，与直接搜索或加速器产生实验互补。我们展示了 VERITAS 对矮椭球星系 Draco、Ursa Minor、Bootes 1 和 Willman 1 的观测结果。这些星系是邻近的暗物质主导天体，位于典型距离几十千秒差距处，其暗物质密度分布已通过恒星速度测量得到良好测定。由于这些天体的常规甚高能伽马射线天体物理背景似乎可忽略不计，它们是搜索由相互作用或衰变的暗物质粒子产生的次级伽马射线光子的良好目标。在约 20 小时的典型曝光时间内，未从这四个矮星系探测到高于 200 GeV 的显著伽马射线流量。积分伽马射线流量的 95% 置信上限在 0.4-2.2×10^-12 光子 cm^-2s^-1 范围内。我们在弱相互作用大质量粒子对湮灭的背景下解释这一极限流量，并推导出总自湮灭截面与 WIMPs 相对速度的热平均乘积的约束。这些极限是在关于矮星系中暗物质分布的保守假设下获得的，比最小超对称标准模型框架下 WIMPs 的通用理论预测大约高三个数量级。然而，暗物质分布以及中性子截面存在显著不确定性，在有利假设下可能进一步降低这些极限。
引用
@article{arxiv.1006.5955,
title = {VERITAS Search for VHE Gamma-ray Emission from Dwarf Spheroidal Galaxies},
author = {The VERITAS Collaboration and V. A. Acciari and T. Arlen and T. Aune and M. Beilicke and W. Benbow and D. Boltuch and S. M. Bradbury and J. H. Buckley and V. Bugaev and K. Byrum and A. Cannon and A. Cesarini and J. L. Christiansen and L. Ciupik and W. Cui and R. Dickherber and C. Duke and J. P. Finley and G. Finnegan and A. Furniss and N. Galante and S. Godambe and J. Grube and R. Guenette and G. Gyuk and D. Hanna and J. Holder and C. M. Hui and T. B. Humensky and A. Imran and P. Kaaret and N. Karlsson and M. Kertzman and D. Kieda and A. Konopelko and H. Krawczynski and F. Krennrich and G. Maier and S. McArthur and A. McCann and M. McCutcheon and P. Moriarty and R. A. Ong and A. N. Otte 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 E. Roache and H. J. Rose and M. Schroedter and G. H. Sembroski and G. Demet Senturk and A. W. Smith and D. Steele and S. P. Swordy and G. Tešić and M. Theiling and S. Thibadeau and A. Varlotta and V. V. Vassiliev and S. Vincent and R. G. Wagner and S. P. Wakely and J. E. Ward and T. C. Weekes and A. Weinstein and T. Weisgarber and D. A. Williams and S. Wissel and M. D. Wood and B. Zitzer},
journal= {arXiv preprint arXiv:1006.5955},
year = {2015}
}
备注
21 pages, 2 figures, updated to reflect version published in ApJ. NOTE: M.D. Wood added as author