A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: implications for annihilating dark matter
A Gaia DR2 search for dwarf galaxies towards Fermi-LAT sources: implications for annihilating dark matter
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DOI：
10.1093/mnras/sty1994
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发表时间：
2018-05
影响因子：
4.8
通讯作者：
I. Ciucă;D. Kawata;S. Ando;F. Calore;J. Read;C. Mateu
中科院分区：
文献类型：
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作者：
I. Ciucă;D. Kawata;S. Ando;F. Calore;J. Read;C. Mateu
我们首次尝试使用盖亚DR 2在八个费米-LAT扩展的，不相关的源场中找到矮星系。在用极端解卷积（XD）技术探测了以前未探测到的d < 20 kpc的日心距离后，我们在这些领域中没有发现矮星系的迹象，尽管盖亚的天体测量精度很高。通过对模拟数据应用XD方法估计了我们的探测极限，得到了恒星质量的保守极限：当d < 20 kpc时，M_* < 10^4 M_∞。如此低的恒星质量意味着要么是低质量的次晕，要么是大质量的剥离次晕。我们使用的剥离subhaloes的分析模型认为，鉴于费米-LAT源的大小和通量，我们可以拒绝的假设，他们欠暗物质湮灭。
We make the first attempt to find dwarf galaxies in eight Fermi-LAT extended, unassociated, source fields using Gaia DR2. After probing previously unexplored heliocentric distances of d < 20 kpc with an extreme-deconvolution (XD) technique, we find no sign of a dwarf galaxy in any of these fields despite Gaia’s excellent astrometric accuracy. Our detection limits are estimated by applying the XD method to mock data, obtaining a conservative limit on the stellar mass of M_* < 10^4 M_⊙ for d < 20 kpc. Such a low stellar mass implies either a low-mass subhalo or a massive stripped-down subhalo. We use an analytic model for stripped subhaloes to argue that, given the sizes and fluxes of the Fermi-LAT sources, we can reject the hypothesis that they owe to dark matter annihilation.