GASP. XXII. the Molecular Gas Content of the JW100 Jellyfish Galaxy at z ∼ 0.05: Does Ram Pressure Promote Molecular Gas Formation?

Moretti, Alessia; Paladino, Rosita; Poggianti, Bianca M.; Serra, Paolo; Roediger, Elke; Gullieuszik, Marco; Tomičić, Neven; Radovich, Mario; Vulcani, Benedetta; Jaffé, Yara L.; Fritz, Jacopo; Bettoni, Daniela; Ramatsoku, Mpati; Wolter, Anna

Abstract

Within the GASP survey, aimed at studying the effect of ram pressure stripping on star formation quenching in cluster galaxies, we analyze here ALMA observations of the jellyfish galaxy JW100. We find an unexpected large amount of molecular gas (∼2.5 × 1010 ), 30% of which is located in the stripped gas tail out to ∼35 kpc from the galaxy center. The overall kinematics of the molecular gas is similar to the one shown by the ionized gas, but for clear signatures of double components along the stripping direction detected only out to 2 kpc from the disk. The line ratio r 21 has a clumpy distribution and in the tail can reach large values (≥1), while its average value is low (0.58 with a 0.15 dispersion). All these evidence strongly suggest that the molecular gas in the tail is newly born from stripped H i gas or newly condensed from stripped diffuse molecular gas. The analysis of interferometric data at different scales reveals that a significant fraction (∼40%) of the molecular gas is extended over large scales (≥8 kpc) in the disk, and this fraction becomes predominant in the tail (∼70%). By comparing the molecular gas surface density with the star formation rate surface density derived from the Hα emission from MUSE data, we find that the depletion time on 1 kpc scale is particularly large (5-10 Gyr) both within the ram-pressure-disturbed region in the stellar disk and in the complexes along the tail.

Citation

Moretti, A., Paladino, R., Poggianti, B. M., Serra, P., Roediger, E., Gullieuszik, M., Tomičić, N., Radovich, M., Vulcani, B., Jaffé, Y. L., Fritz, J., Bettoni, D., Ramatsoku, M., & Wolter, A. (2020). GASP. XXII. the Molecular Gas Content of the JW100 Jellyfish Galaxy at z ∼ 0.05: Does Ram Pressure Promote Molecular Gas Formation?. The Astrophysical journal, 889(1), https://doi.org/10.3847/1538-4357/ab616a

• Journal Article Type: Article
• Acceptance Date: Dec 11, 2019
• Online Publication Date: Jan 20, 2020
• Publication Date: Jan 20, 2020
• Deposit Date: Jan 22, 2020
• Publicly Available Date: Jan 27, 2020
• Journal: Astrophysical Journal
• Print ISSN: 0004-637X
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 889
• Issue: 1
• DOI: https://doi.org/10.3847/1538-4357/ab616a
• Keywords: Space and Planetary Science; Astronomy and Astrophysics; D galaxies (346); Galaxy clusters (584); Molecular gas (1073); Galaxy evolution (594)
• Public URL: https://hull-repository.worktribe.com/output/3352218
• Publisher URL: https://iopscience.iop.org/article/10.3847/1538-4357/ab616a
• Additional Information: Journal title: The Astrophysical Journal; Article type: paper; Article title: GASP. XXII. The Molecular Gas Content of the JW100 Jellyfish Galaxy at z ∼ 0.05: Does Ram Pressure Promote Molecular Gas Formation?; Copyright information: © 2020. The American Astronomical Society. All rights reserved.; Date received: 2019-09-17; Date accepted: 2019-12-11; Online publication date: 2020-01-20
• Contract Date: Jan 27, 2020