A census of orbital properties of the M31 satellites
A census of orbital properties of the M31 satellites
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M31 卫星轨道特性普查
DOI：
10.1093/mnras/sts634
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发表时间：
2012
影响因子：
4.8
通讯作者：
Glenn van de Ven
中科院分区：
文献类型：
--
作者：
Laura L. Watkins;N. Wyn Evans;Glenn van de Ven
我们提出了M31卫星系统的动力学分析。只有两颗M31卫星存在自行数据。我们占这种不完整的速度数据的统计分析，使用的时间参数和相空间分布函数的组合。M31卫星的大部分都很适合这些模型，我们提供了一个轨道特性表，包括周期，偏心率和半长轴。这使我们能够根据轨道的相似性而不是天空的接近性来寻找群体坠落的证据。我们的研究结果支持卡斯II和NGC 185之间的关联，因为轨道参数非常接近，但NGC 185和NGC 147之间的关联却不是这样，因为它们在过去常常是关联的。其他可能的卫星组合包括And I和And XVII对，And IX和And X对，以及三个And V，And XXV和NGC 147。XXII被认为是M33的一颗卫星，我们发现它们并不是独立地沿着同一轨道运动，但不能确定它们是相互环绕还是没有关系。两颗卫星，和XII和和XIV，有很高的视线速度，与最近从本星系群边缘坠落的情况一致。他们没有很好地描述我们的基础光滑相空间分布函数，并重新分析没有先验的轨道参数。对于和XIV，多个着丝粒间通道是可能的，需要改进的距离信息来得出进一步的结论。对于And XII来说，假设至少有一个近心点通道的轨道可以被排除，它必须是第一次进入M31系统。
We present an analysis of the dynamics of the M31 satellite system. Proper motion data exist for only two of the M31 satellites. We account for this incompleteness in velocity data by a statistical analysis using a combination of the timing argument and phase-space distribution functions. The bulk of the M31 satellites are well fit by these models and we offer a table of orbital properties, including period, eccentricity and semi-major axis. This enables us to search for evidence of group infall based on orbital similarity rather than propinquity on the sky. Our results favour an association between Cass II and NGC 185, as the orbital parameters are in close agreement, but not for NGC 185 and NGC 147, which have often been associated in the past. Other possible satellite groupings include the pair And I and And XVII; the pair And IX and And X; and the triple And V, And XXV and NGC 147. And XXII has been claimed as a satellite of M33; we find that they are not moving independently along the same orbit, but cannot determine whether they are orbiting each other or are unrelated. Two satellites, And XII and And XIV, have high line-of-sight velocities, consistent with very recent infall from the edge of the Local Group. They are not well described by our underlying smooth phase space distribution function, and are reanalysed without priors on their orbital parameters. For And XIV, multiple pericentric passages are possible and improved distance information is needed to draw further conclusions. For And XII, orbits which assume at least one pericentric passage can be ruled out and it must be on its first infall into the M31 system.
深入光度观察仙女座的两个矮球体：X 和 XVII
DOI：
10.1088/0004-637x/729/1/23
发表时间：
2011
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Brasseur;Martin
通讯作者：
Martin