论文标题
在工会中发现了一个新的本地矮人矮人星系候选人：Boötesv
Discovery of a new Local Group Dwarf Galaxy Candidate in UNIONS: Boötes V
论文作者
论文摘要
我们介绍了新的超生产矮人星系候选人BoötesV的发现。该卫星被检测为在持续搜索工会光度数据集中新的本地组矮星系候选时恒星的过度密度。它具有26.9 $^{+7.5} _ { - 5.4} $ pc的物理半光半径，$ v $ -band的大小为$ - $ - $ 4.5 $ \ pm $ 0.4 mag，并居住在大约100 kpc的地中心距离。我们使用Gaia DR3天文学来识别成员恒星，表征系统性正确的运动，并确认这种微弱的恒星系统的现实。使用Gemini GMOS-N长期光谱镜进行跟踪该系统中最亮的恒星，并测量具有[Fe/H] $ = $ = $ $ -2.85 $ \ $ 2.85 $ \ $ 0.10 dex的金属性和Helipentric radial速度$ v_r $ = 5.1 $ = 5.1 $ \ pm $ \ $ \ $ 13.4 km $ 13.4 kms $ s $^$^ - 1}。 BoötesV比绝大多数球状簇更大（在规模半径上），更遥远，更贫穷。 Boötesv可能是一个超生物的矮人星系，尽管未来的光谱研究对于确定对该对象进行了分类是必要的。
We present the discovery of Boötes V, a new ultra-faint dwarf galaxy candidate. This satellite is detected as a resolved overdensity of stars during an ongoing search for new Local Group dwarf galaxy candidates in the UNIONS photometric dataset. It has a physical half-light radius of 26.9$^{+7.5}_{-5.4}$ pc, a $V$-band magnitude of $-$4.5 $\pm$ 0.4 mag, and resides at a heliocentric distance of approximately 100 kpc. We use Gaia DR3 astrometry to identify member stars, characterize the systemic proper motion, and confirm the reality of this faint stellar system. The brightest star in this system was followed up using Gemini GMOS-N long-slit spectroscopy and is measured to have a metallicity of [Fe/H] $=$ $-$2.85 $\pm$ 0.10 dex and a heliocentric radial velocity of $v_r$ = 5.1 $\pm$ 13.4 km s$^{-1}$. Boötes V is larger (in terms of scale radius), more distant, and more metal-poor than the vast majority of globular clusters. It is likely that Boötes V is an ultra-faint dwarf galaxy, though future spectroscopic studies will be necessary to definitively classify this object.
