利用DESI DRI将恒星-暗晕质量关系扩展至矮星系
Extending the Stellar-to-Halo Mass Relation to Dwarf Galaxies with DESI DR1
查看机构详情
- Shanghai Jiao Tong University（上海交通大学）
- University of Arizona（亚利桑那大学）
机构由 AI 辅助整理，请以论文原文为准。
浏览论文内容
中文总结 AI 辅助
本研究利用DESI DR1数据，结合新观测量卫星星系占据数，将恒星-暗晕质量关系推断至矮星系尺度，揭示了矮星系区域SHMR的幂律斜率和散射特征，凸显DESI在相关研究中的重要作用。
中文摘要 AI 辅助
约束最小星系的暗物质晕可为暗物质本质和恒星反馈提供基础认知。本研究利用暗能量光谱仪（DESI）数据发布1（DESI DR1），在不从更高质量范围外推的情况下，将恒星-暗晕质量关系（SHMR）推断至矮星系尺度（恒星质量M⋆<10⁹M⊙）。借助DESI亮星系巡天在0.01<z<0.2的前所未有的深度，我们构建了12个样本，覆盖近四个数量级的恒星质量，并测量了它们的投影聚类w_p、星系-星系引力透镜ΔΣ以及一种新的观测量：卫星星系占据数N_sat。加入N_sat可在12个单独的暗晕占据分布分析中对w_p和ΔΣ的卫星贡献进行稳健扣除，得到平均暗晕-恒星质量关系（HSMR）为log⟨M_h(M⋆)⟩=12.06+0.58log(M⋆/10¹¹)+(M⋆/10¹¹)^0.73。将此HSMR与观测到的恒星质量函数结合，我们约束了覆盖五个数量级暗晕质量的SHMR，其幂律斜率从银河系质量以上的0.32±0.06陡增到矮星系区域的2.08±0.21。值得注意的是，SHMR的散射从类银河系尺度的0.17±0.02 dex增长到与大麦哲伦云相当系统的0.68⁺⁰.²¹₋₀.₃³ dex，表明更小的星系遵循日益多样的演化路径。本研究凸显了DESI在探测矮星系区域星系-暗晕关联方面的能力，为未来弥合大尺度与近场宇宙学之间的差距提供了令人兴奋的途径。
英文摘要
Constraining the dark matter halos of the smallest galaxies offers fundamental insights into the nature of dark matter and stellar feedback. Using the Dark Energy Spectroscopic Instrument (DESI) Data Release 1, we infer the stellar-to-halo mass relation (SHMR) down to the dwarf scale ($M_\star < 10^9\,M_\odot$), without extrapolation from the higher mass range. Leveraging the unprecedented depth of the DESI Bright Galaxy Survey at $0.01 < z < 0.2$, we construct 12 samples spanning nearly four orders of magnitude in stellar mass, and measure their projected clustering $w_p$, galaxy-galaxy lensing $ΔΣ$, as well as a novel observable: satellite occupation number $N_{\rm sat}$. The addition of $N_{\rm sat}$ enables robust subtraction of satellite contributions to both $w_p$ and $ΔΣ$ across the 12 individual halo occupation distribution analyses, yielding an average halo-to-stellar mass relation (HSMR) of $\log \langle M_h(M_\star) \rangle = 12.06 + 0.58\log(M_\star/10^{11}) + (M_\star/10^{11})^{0.73}$. Combining this HSMR with an observed stellar mass function, we constrain the SHMR across five orders of magnitude in halo mass, with the power-law slope steepening from $0.32 \pm 0.06$ above the Milky Way mass to $2.08 \pm 0.21$ in the dwarf regime. Interestingly, the scatter about the SHMR grows from $0.17 \pm 0.02$ dex at Milky Way-like scales to $0.68_{-0.33}^{+0.21}$ dex for systems comparable to the Large Magellanic Cloud, suggesting that smaller galaxies follow increasingly diverse evolutionary paths. Our work highlights the power of DESI in probing the galaxy-halo connection within the dwarf regime, offering an exciting avenue to bridge the gap between large-scale and near-field cosmologies in the future.
