论文标题
来自球状簇流的适当运动的矮星系的暗物质密度曲线的新约束
New constraints on the dark matter density profiles of dwarf galaxies from proper motions of globular cluster streams
论文作者
论文摘要
矮星系光环中的中央密度曲线在很大程度上取决于暗物质的性质。最近，在Malhan等。 （2021），我们采用了N体模拟来表明，宇宙学模拟预测的cuspy冷暗物质（CDM）Subhalos可以使用振底球（GC）流的特性来区分与Cored subhalos区分开，因为这些GCS经历了在其父母在appretion上的潮汐剥离。我们先前发现，在cuspy subhalos中积聚的簇产生的河流与在核心subhalos中积聚的流相比，在视线速度和角动量中具有更大的物理宽度和更高的分散体。在这里，我们使用相同的模拟套件来证明流的分散速度（$σ_{V_ {V_ \ Mathrm {tan}} $）也对其父型和GC的中央DM密度概况也很敏感，这些dwarfs和gcs从：CUSPY SUBHALOS中获得了较大的subhalos流， $σ_{v_ \ mathrm {tan}} $，比在核心subhalos中积聚的$。使用多个GC流的GAIA EDR3观察，我们将其$σ_{v_ \ Mathrm {tan}} $值与模拟进行比较。测得的$σ_{v_ \ mathrm {tan}} $值都与``原点''的起源均一致，并且与$ m \ sim 10^{8-9} m _ {8-9} m _ {\ odot} $（或非常低的cus cuspy subhalos的cosed subhalos coreced subhalos cored subhalos cored subhalos cosed subhalos cose cuspy sib $ $ $ 10^8M尽管$σ_{V_ \ Mathrm {tan}} $中的电流不确定性很大，但我们发现，从$ m _ {\ rm subhalo} \ rm subhalo}} \ buildr> buildr> \ sim flod \ sim $ 10^9 m _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ = GAIA切向速度测量值的不确定性预计将来会减少，并将允许对Subhalo DM密度曲线的限制更强。
The central density profiles in dwarf galaxy halos depend strongly on the nature of dark matter. Recently, in Malhan et al. (2021), we employed N-body simulations to show that the cuspy cold dark matter (CDM) subhalos predicted by cosmological simulations can be differentiated from cored subhalos using the properties of accreted globular cluster (GC) streams since these GCs experience tidal stripping within their parent halos prior to accretion onto the Milky Way. We previously found that clusters that are accreted within cuspy subhalos produce streams with larger physical widths and higher dispersions in line-of-sight velocity and angular momentum than streams that are accreted within cored subhalos. Here, we use the same suite of simulations to demonstrate that the dispersion in the tangential velocities of streams ($σ_{v_\mathrm{Tan}}$) is also sensitive to the central DM density profiles of their parent dwarfs and GCs that were accreted from: cuspy subhalos produce streams with larger $σ_{v_\mathrm{Tan}}$ than those accreted inside cored subhalos. Using Gaia EDR3 observations of multiple GC streams we compare their $σ_{v_\mathrm{Tan}}$ values with simulations. The measured $σ_{v_\mathrm{Tan}}$ values are consistent with both an ``in situ'' origin and with accretion inside cored subhalos of $M\sim 10^{8-9}M_{\odot}$ (or very low-mass cuspy subhalos of mass $\sim 10^8M_{\odot}$). Despite the large current uncertainties in $σ_{v_\mathrm{Tan}}$, we find a low probability that any of the progenitor GCs were accreted from cuspy subhalos of $M_{\rm subhalo}\buildrel > \over \sim$ $10^9 M_{\odot}$. The uncertainties on Gaia tangential velocity measurements are expected to decrease in future and will allow for stronger constraints on subhalo DM density profiles.
