论文标题
银河系矮星系的适当运动，轨道和潮汐影响
Proper Motions, Orbits, and Tidal Influences of Milky Way Dwarf Spheroidal Galaxies
论文作者
论文摘要
我们将GAIA EDR3天文测量与准确的光度法结合在一起，并利用概率混合物模型来测量银河系（MW）的52矮人球形（DSPH）卫星星系的全身性运动。对于具有文献视线速度的46个DSPH，我们在MW和MW +大型麦哲伦云（LMC）中计算轨道，并识别CAR II，CAR III，HOR I，HOR I，HYI I，PHX II和RET II的可能性很可能LMC卫星。我们的DSPH样本中有40％的折扣和/或apecenter具有> 25％的变化，具有MW + LMC电位。对于这些轨道，我们在每个DSPH的观察不确定性以及MW和LMC电位中的不确定性上进行了蒙特卡洛样品。我们预测，ANT II，BOO III，CRA II，GRU II和TUC III应该通过比较每个DSPH的平均密度相对于其候选物的MW密度来潮湿。具有较大椭圆度的DSPH（CVN I，HE，TUC V，UMA I，UMA II，UMI，WIL 1）显示出对它们的轨道方向的偏爱，即使对于具有较大居民的DSPHS，它们的轨道方向也与它们的主要轴线保持一致。我们将DSPH径向轨道相与MW样的N体模拟中的Subhalos进行了比较，并推断其周围的卫星没有过多的卫星。随着未来GAIA数据发布的预测，我们发现DSPH轨道精度将受到距离和/或MW潜力的不确定性而不是适当的运动精度的限制。最后，我们提供会员目录以实现社区后续行动。
We combine Gaia EDR3 astrometry with accurate photometry and utilize a probabilistic mixture model to measure the systemic proper motion of 52 dwarf spheroidal (dSph) satellite galaxies of the Milky Way (MW). For the 46 dSphs with literature line-of-sight velocities we compute orbits in both a MW and a combined MW + Large Magellanic Cloud (LMC) potential and identify Car II, Car III, Hor I, Hyi I, Phx II, and Ret II as likely LMC satellites. 40% of our dSph sample has a >25% change in pericenter and/or apocenter with the MW + LMC potential. For these orbits, we Monte Carlo sample over the observational uncertainties for each dSph and the uncertainties in the MW and LMC potentials. We predict that Ant II, Boo III, Cra II, Gru II, and Tuc III should be be tidally disrupting by comparing each dSph's average density relative to the MW density at its pericenter. dSphs with large ellipticity (CVn I, Her, Tuc V, UMa I, UMa II, UMi, Wil 1) show a preference for their orbital direction to align with their major axis even for dSphs with large pericenters. We compare the dSph radial orbital phase to subhalos in MW-like N-body simulations and infer that there is not an excess of satellites near their pericenter. With projections of future Gaia data releases, we find dSph orbital precision will be limited by uncertainties in the distance and/or MW potential rather than proper motion precision. Finally, we provide our membership catalogs to enable community follow-up.
