A Naked Dwarf: Molecular Gas in the Completely Stripped HI Tail of VCC 1249

arXiv:2607.20626 · astro-ph.GA · Submitted 2026-07-22 · Read on arXiv

Bumhyun Lee, Aeree Chung, Paolo Serra, Nikki Zabel, Sungsoon Lim, Hyein Yoon, A. Boselli, Matteo Fossati, Yongjung Kim, Tomonari Michiyama, Juan Molina, Kana Morokuma-Matsui, Jaehyun Lee, Jeong Hwan Lee, Se-Heon Oh

astro-ph.GA

Submitted: 2026-07-22

Comments: 9 pages, 3 figures, 2 tables, accepted for publication in ApJL

License: http://creativecommons.org/licenses/by/4.0/

The gist: We present the first observational hints of the severe removal of both molecular and HI gas from the dwarf galaxy VCC 1249.

Terminology

Abstract

We present the first observational hints of the severe removal of both molecular and HI gas from the dwarf galaxy VCC 1249. This extreme stripping event is thought to be driven by the combined effects of tidal interaction and ram pressure. Using deep CO (2 - 1) observations from the James Clerk Maxwell Telescope (JCMT), we obtained marginal CO detections in three regions within the stripped HI tail, with molecular masses of about 10 5 to 10 6 M, comparable to typical masses of giant molecular clouds. In contrast, we did not find CO emission within the stellar disk of VCC 1249. This indicates the severe removal of cold gas, which likely caused the sudden cessation of star formation in the galaxy. This identifies VCC 1249 as a unique laboratory for witnessing the rapid, environmentally-driven quenching of a dwarf galaxy. Our findings provide a critical observational link between gas removal mechanisms and the dramatic phase transition of cluster dwarfs from star-forming to quiescent systems.

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