The molecular gas of four ram pressure stripped galaxies in the core of the Hydra I cluster

@misc{casa2026molecular,
  title = {{The molecular gas of four ram pressure stripped galaxies in the core of the Hydra I cluster}},
  author = {Clara C. de la Casa and Kelley M. Hess and Nikki Zabel and Emanuela Pompei and Yara L. Jaffé and Nazir Makda and Julia Healy and Johanna Hartke and Lourdes Verdes-Montenegro and Enrichetta Iodice and Sarah Blyth and Ralf Kotulla and Marie-Lou Gendron-Marsolais and Renée C. Kraan-Korteweg and Brenda Namumba and Amidou Sorgho and Roger Ianjamasimanana and John S. Gallagher},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.26697},
  eprint = {2609.26697},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.26697},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - The molecular gas of four ram pressure stripped galaxies in the core of the Hydra I cluster
AU  - Clara C. de la Casa
AU  - Kelley M. Hess
AU  - Nikki Zabel
AU  - Emanuela Pompei
AU  - Yara L. Jaffé
AU  - Nazir Makda
AU  - Julia Healy
AU  - Johanna Hartke
AU  - Lourdes Verdes-Montenegro
AU  - Enrichetta Iodice
AU  - Sarah Blyth
AU  - Ralf Kotulla
AU  - Marie-Lou Gendron-Marsolais
AU  - Renée C. Kraan-Korteweg
AU  - Brenda Namumba
AU  - Amidou Sorgho
AU  - Roger Ianjamasimanana
AU  - John S. Gallagher
PY  - 2026
DA  - 2026/09/22
PB  - arXiv
DO  - 10.48550/arxiv.2609.26697
UR  - https://arxiv.org/abs/2609.26697
AB  - 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 (∼15'', ∼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 (log M_⋆/M_⊙ = 8.6) is below the stellar mass limit of the reference samples (log M_⋆/M_⊙ = 9), but its 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.
ER  -