Properties of dark subhaloes from gaps in tidal streams
Properties of dark subhaloes from gaps in tidal streams
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DOI：
10.1093/mnras/stv2122
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发表时间：
2015-07
影响因子：
4.8
通讯作者：
D. Erkal;V. Belokurov
中科院分区：
文献类型：
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作者：
D. Erkal;V. Belokurov
根据最新的莱曼-阿尔法测量，无论是冷的还是暖的，暗物质亚结构光谱必须延伸到质量低至10^7 M_\ODOT$的天体。在一个类似银河系的星系周围，一千多个这样的亚晕将不能形成恒星，但密度足够高，即使在其宿主的势井深处也能存活下来。在那里，在恒星光环内，这些暗色小球将在潮汐流围绕银河系流动时轰炸它们，对流密度分布造成微小但可识别的破坏。对这些流破裂的探测和表征将使我们能够限制次晕流相互作用的细节。在这项工作中，我们将第一次演示如何从它在潮流中产生的间隙可靠地推断出次光晕的性质，最重要的是它的质量和大小。对于一系列真实的观测装置，模拟SDSS、DES、GAIA和LSST数据，我们发现可以用$M>；10^7M_\ODOT测量暗微扰动子的全集性质(包括飞越时的相空间坐标)，质量和速度之间的简并程度可达一维。
Cold or Warm, the Dark Matter substructure spectrum must extend to objects with masses as low as $10^7 M_\odot$, according to the most recent Lyman-$\alpha$ measurements. Around a Milky Way-like galaxy, more than a thousand of these subhaloes will not be able to form stars but are dense enough to survive even deep down in the potential well of their host. There, within the stellar halo, these dark pellets will bombard tidal streams as they travel around the Galaxy, causing small but recognizable damage to the stream density distribution. The detection and characterization of these stream ruptures will allow us to constrain the details of the subhalo-stream interaction. In this work, for the first time, we will demonstrate how the properties of a subhalo, most importantly its mass and size, can be reliably inferred from the gap it produces in a tidal stream. For a range of realistic observational setups, mimicking e.g. SDSS, DES, Gaia and LSST data, we find that it is possible to measure the {\it complete set} of properties (including the phase-space coordinates during the flyby) of dark perturbers with $M>10^7 M_\odot$, up to a 1d degeneracy between the mass and velocity.