论文标题
Pegasus V-在仙女座的郊区，新发现的超品种矮人星系
Pegasus V -- a newly discovered ultra-faint dwarf galaxy on the outskirts of Andromeda
论文作者
论文摘要
我们报告了在Pegasus星座中发现了一个超品种的矮人。 Pegasus〜V（PEG〜V）最初是在DESI传统成像调查的公共成像数据发布中鉴定的，并通过Gemini/GMOS-N的深度成像进行了确认。颜色刻度图显示了稀疏的红色巨型分支（RGB）种群和蓝色水平分支星星的强密度。我们的距离为$ d = 692^{+33} _ { - 31} $ 〜kpc的距离，使其成为andromeda的遥远卫星，$ m_v = -6.3 \ pm0.2 $ and Halfight-Light Radius of $ r _ {\ rm falmemed aft pm pm41 = 89 \ pm41 $ 41 $ 41 $ 41 $ 41 $ 〜pc。它位于Anromeda的$ \ sim260 $ 〜kpc，位于光环的郊区。 RGB通过[Fe/H] $ = -3.2 $的金属贫困等异节很好地拟合，这表明它非常贫穷。结合其蓝色的水平分支可能意味着它是一种再离子化石。这是深泛 - 安德罗梅达考古调查区以外的一个超矮人的发现，并指出了我们最近邻居郊区的丰富而微弱的卫星种群。
We report the discovery of an ultra-faint dwarf in the constellation of Pegasus. Pegasus~V (Peg~V) was initially identified in the public imaging data release of the DESI Legacy Imaging Surveys and confirmed with deep imaging from Gemini/GMOS-N. The colour-magnitude diagram shows a sparse red giant branch (RGB) population and a strong over-density of blue horizontal branch stars. We measure a distance to Peg~V of $D=692^{+33}_{-31}$~kpc, making it a distant satellite of Andromeda with $M_V=-6.3\pm0.2$ and a half-light radius of $r_{\rm half}=89\pm41$~pc. It is located $\sim260$~kpc from Andromeda in the outskirts of its halo. The RGB is well-fit by a metal-poor isochrone with [Fe/H]$=-3.2$, suggesting it is very metal poor. This, combined with its blue horizontal branch could imply that it is a reionisation fossil. This is the first detection of an ultra-faint dwarf outside the deep Pan-Andromeda Archaeological Survey area, and points to a rich, faint satellite population in the outskirts of our nearest neighbour.
