发表机构
Instituto de Astrofísica de Andalucía (CSIC); European Southern Observatory; Chalmers University of Technology; ASTRON, the Netherlands Institute for Radio Astronomy; University of Cape Town; South African Astronomical Observatory; Universidad Técnica Federico Santa María; Millennium Nucleus for Galaxies (MINGAL); Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester; United Kingdom SKAO Regional Centre (UKSRC); Finnish Centre for Astronomy with ESO, (FINCA)（安达卢西亚天体物理研究所; 欧洲南方天文台; 查尔姆斯理工大学; 荷兰射电天文研究所; 开普敦大学; 南非天文台; 弗雷德里科·圣玛丽亚技术大学; 银河系千年核; 曼彻斯特大学物理与天文学院乔德雷克银行天体物理学中心; 英国SKAO区域中心; 芬兰ESO天文中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用ALMA和MeerKAT观测长蛇座I星系团核心四个冲压剥离星系的CO和HI，发现CO盘不对称且无剥离CO，表明RPS在剥离CO之前已影响其储库，并揭示了不同演化阶段。
AI 中文摘要
我们展示了来自ALMA的新的CO(1-0)测量结果和来自MeerKAT的新的HI测量结果，这些测量针对长蛇座I星系团核心中的四个冲压剥离（RPS）星系：NGC 3312、NGC 3314a、NGC 3314b和LEDA 753342。这些深度数据在CO和HI中具有兼容的空间分辨率（约15角秒，约4千秒差距），有助于增加在极端内落阶段观测到CO的星系的低统计量，以探究在高ICM压力下分子气体和原子气体的行为。我们研究了这些星系的冷气体形态，发现其探测到的CO盘相对于其HI和光学盘存在不对称性。在尾部未发现被剥离的CO，这可能支持H2在从星系中被剥离之前，其形态和速度不对称性已经在盘中显现的情景。然后，我们比较了这四个长蛇座I星系、以场星系为主的xCOLDGASS样本以及VIVA-VERTICO室女座RPS星系之间的H2/HI比值以及H2与HI的缺失程度。LEDA 753342（log M*/M_sun = 8.6）低于参考样本的恒星质量下限（log M*/M_sun = 9），但其M_H2/M_HI和冷气体缺失程度与较低恒星质量的场星系和室女座星系团星系相当。NGC 3312和NGC 3314a处于场星系与更先进的RPS室女座星系之间的中间阶段。NGC 3314b与在RPS中更先进的室女座星系更为一致，而非场星系。我们认为LEDA 753342处于RPS的非常早期阶段，NGC 3314a和NGC 3312处于早期但非常活跃的RPS的相似时间尺度，其差异可能源于初始总重子质量和内落角度的不同，而NGC 3314b是该样本中RPS的最新阶段。这些星系展示了不同演化阶段的RPS，并表明RPS在CO储库开始从星系中被剥离之前就开始影响它。
英文摘要
We present new CO(1-0) measurements from ALMA and new HI measurements from MeerKAT in four ram pressure stripped (RPS) galaxies in the core of the Hydra I cluster: NGC 3312, NGC 3314a, NGC 3314b and LEDA 753342. These deep data, with compatible spatial resolution in CO and HI ($\sim15''$, $\sim$4 kpc), help increase the low statistics of galaxies observed in CO at extreme infall stage for probing how molecular and atomic gas behave under high ICM pressures. We studied the cold gas morphologies of these galaxies, and found asymmetries in their detected CO disks with respect to their HI and optical disks. No stripped CO was found in the tails, which could support the scenario that H$_2$ displays morphological and velocity asymmetries in the disks before being stripped. We then compared the H$_{2}$/HI ratios and H$_{2}$ vs. HI deficiencies between the four Hydra I galaxies, the xCOLDGASS sample dominated by field galaxies and VIVA-VERTICO Virgo RPS galaxies. LEDA 753342 ($\rm log~M_{\star}/M_{\odot} = 8.6$) is below the stellar mass limit of the reference samples ($\rm log~M_{\star}/M_{\odot} = 9$), but its $\rm M_{H_2}/M_{HI}$ and cold gas deficiencies are compatible with lower stellar mass field and Virgo cluster galaxies. NGC 3312 and NGC 3314a are in an intermediate stage between field galaxies and more advanced RPS Virgo galaxies. NGC 3314b is more consistent with Virgo galaxies more advanced in RPS, than with field galaxies. We reason that LEDA 753342 is at a very early stage of RPS, that NGC 3314a and NGC 3312 are at a similar timescale of early but very active RPS with differences potentially due to unequal initial total baryonic mass and infall angles, and that NGC 3314b is the latest stage in RPS in the sample. These galaxies display RPS across different evolutionary stages, and suggest that RPS starts affecting the CO reservoir before it starts being stripped from the galaxy.
