发表机构
Tata Institute of Fundamental Research; Indian Institute of Technology Bombay（塔塔基础研究所; 印度理工学院孟买分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究构建了包含3250万颗恒星六维相空间信息的均质化星表，覆盖至250 kpc，通过多巡天交叉匹配实现高精度距离和速度测量，为银河系质量建模和暗物质研究提供了最大外晕示踪样本。
AI 中文摘要
我们呈现了一个包含32,552,876颗恒星源的全面且均质化的星表，这些源具有完整的六维相空间信息，覆盖从银河系内部（约大于5 kpc）到外部晕（约250 kpc）的银心距范围。通过将《Gaia》DR3天体测量与来自14个巡天（包括DESI、SDSS-BOSS、APOGEE、LAMOST、GALAH和GES）的分光光度距离和视线速度进行交叉匹配，我们实现了日心距d_helio≤15 kpc时中位分数距离不确定度约为2.7%，以及15<d_helio≤250 kpc时约为29%。星表整体的中位分数径向速度不确定度约为8.31%。基于《Gaia》的零点校正和统计归一化抑制了随机误差和系统误差。此外，我们从联合测光和光谱数据中推导出分光光度视差。重叠的巡天数据被聚合以替换不可靠的值并补充缺失的速度，从而提高了完整性和内部一致性。这种多巡天综合结果经过球状星团、矮星系和恒星流的独立验证，产生了精确的运动学数据。值得注意的是，该样本包含517,123颗晕星，其距离远超《Gaia》视差极限（约大于10 kpc）。这些主要为暗弱（G>17）且金属贫乏（[Fe/H]<-1）的示踪天体，包括天琴座RR型变星、蓝水平分支星和K巨星，构成了迄今为止最大的、校准良好的外晕示踪天体样本。这一独特数据集非常适合用于银河系的多组分质量建模、银河考古学以及暗物质搜索。
英文摘要
We present a comprehensive, homogenised catalogue of $32{,}552{,}876$ stellar sources with full 6D phase-space information, spanning Galactocentric distances from the inner galaxy ($\gtrsim 5$\,kpc) to the outer halo ($\sim\!250$\,kpc). By cross-matching \textit{Gaia} DR3 astrometry with spectrophotometric distances and line-of-sight velocities from 14 surveys (including \textsc{desi}, \textsc{sdss-boss}, \textsc{apogee}, \textsc{lamost}, \textsc{galah}, and \textsc{ges}), we achieve median fractional distance uncertainties of $\approx2.7\%$ for $d_{\rm helio}\le15$\,kpc, and $\approx29\%$ for $15<d_{\rm helio}\le250$\,kpc. The catalogue-wide median fractional radial velocity uncertainty is $\approx8.31\%$. \textit{Gaia}-anchored zero-point corrections and statistical normalisation suppress both random and systematic errors. Furthermore, we derive spectrophotometric parallaxes from joint photometric and spectroscopic data. Overlapping survey data is aggregated to replace unreliable values and supplement absent velocities, improving completeness and internal consistency. This multi-survey synthesis is externally validated against globular clusters, dwarf galaxies, and stellar streams, yielding precise kinematics. Notably, the sample features $517{,}123$ halo stars extending well beyond the \textit{Gaia} parallax limit ($\gtrsim\!10$\,kpc). These predominantly faint ($G > 17$) and metal-poor ($[\mathrm{Fe/H}] < -1$) tracers, including RR~Lyrae, blue horizontal-branch, and K~giant stars, constitute the largest well-calibrated sample of outer-halo tracers to date. This unique dataset is ideal for multi-component mass modelling, galactic archaeology, and dark matter searches across the Milky Way.
Comments46 pages, 28 figures. Submitted to Astronomy & Astrophysics (A&A). The code and the data will be made public once the paper is accepted for publication. In the meantime, we are happy to share the data with anyone, upon personal request, who would like to use it for any research problem
