AI 中文总结
研究孤立星系氢Ⅰ发射线轮廓不对称性起源，通过编制样本并基于多调查单 dish 光谱测量，发现星系特性及样本差异，合并率高，特定质量下不对称星系特定恒星形成率高，还公布相关测量和属性。
AI 中文摘要
星系中氢Ⅰ不对称性的起源仍是个难以捉摸的问题，主要因难以区分其长期和外部影响因素。我们从 UNAM - KIAS 和最新的 AMIGA 样本中编制了本地孤立星系样本，对氢Ⅰ线不对称性有近乎完整的波束覆盖和可靠估计。氢Ⅰ测量基于来自五项调查的单 dish 光谱。我们的星系多为晚型、形成恒星的中心星系，质量各异，但特定恒星形成率略低，氢Ⅰ含量高于预期。AMIGA 的氢Ⅰ质量系统地高于 UNAM - KIAS。两个样本的棒状频率与正常螺旋星系相似。我们的星系合并率意外高，不对称星系在特定质量下特定恒星形成率更高，还公布了氢Ⅰ测量及相关星系和晕属性供公众使用。
英文摘要
The origin of asymmetry in the ${\rm H}\,{\scriptsize{\rm I}}$ of galaxies remains an elusive problem, largely due to the difficulties associated with distinguishing between its secular and external contributors. We have compiled a sample of local isolated galaxies from the UNAM-KIAS and the latest AMIGA samples with near-complete beam coverage and robust estimates of ${\rm H}\,{\scriptsize{\rm I}}$ line asymmetry. The ${\rm H}\,{\scriptsize{\rm I}}$ measurements are based on single-dish spectra sourced from five surveys: ${\rm H}\,{\scriptsize{\rm I}}$-MaNGA, NIBLES, KLUN, ALFALFA, and xGASS. Our galaxies tend to be late-type, star-forming centrals at all masses but exhibit slightly lower specific star formation rates (sSFRs) and higher ${\rm H}\,{\scriptsize{\rm I}}$ contents than expected. The latter is likely driven by lower star formation efficiency, weaker outflows, and additionally, higher accretion rate of gas onto the galaxy at $M_\star\lesssim 10^{10.3}\,\mathrm{M}_\odot$. AMIGA, however, shows systematically higher ${\rm H}\,{\scriptsize{\rm I}}$ masses than UNAM-KIAS, which we attribute to higher local densities probed by the latter. Furthermore, both samples show bar frequencies similar to normal spirals, indicating that the gravitational instabilities leading to bars predominantly stem from internal processes, as suggested by recent works. Our galaxies show unexpectedly high merger fractions, possibly due to sampling bias and/or the inability of the classification method to distinguish between flybys and encounters leading to coalescence. We also find higher sSFRs for asymmetric galaxies below $M_\star\sim 10^{10.3}\,\mathrm{M}_\odot$, in agreement with the predictions for centrals from the ${\scriptsize{\rm EAGLE}}$ simulation. We release the ${\rm H}\,{\scriptsize{\rm I}}$ measurements along with ancillary galaxy and halo properties for public use.
CommentsAccepted for publication in MNRAS. The catalog will be available as supplementary material with the online version of the paper at MNRAS
