A Molecular Tidal Tail in the Medusa Minor Merger

Abstract

We have detected CO 1-0 emission along the tidal tail of the NGC 4194 (the Medusa) merger. It is the first CO detection in the optical tail of a minor merger. Emission is detected both in the centre of the tail and at its tip. The molecular mass in the 33'' Onsala 20m beam is estimated to be >= 8.5 x 10^7 M_{sun} which is at least 4% of the total molecular mass measured so far in this system. We suggest that the emission is a molecular tidal tail which is part of the extended structure of the main body, and that the molecular gas was thrown out by the collision instead of having formed in situ from condensing atomic material. We find it unlikely that the emission is associated with a tidal dwarf galaxy (even if the future formation of such an object is possible), but high resolution HI, CO and optical observations are necessary to resolve the issue. The Medusa is very likely the result of an elliptical+spiral collison and our detection supports the notion that molecular gas in minor mergers can be found at great distances from the merger centre.

4 Pages, 2 figures included, accepted for A&A letters

References in corpus (1)

• The Molecule-Rich Tail of the Peculiar Galaxy NGC 2782 (Arp 215)

Cited by in corpus (14)

• Enhanced atomic gas fractions in recently merged galaxies: quenching is not a result of post-merger gas exhaustion
• Molecular Gas in Compact Galaxies
• ALMA Observations of a Candidate Molecular Outflow in an Obscured Quasar
• Star Formation Suppresion by Tidal Removal of Cold Molecular Gas from an Intermediate-Redshift Massive Post-Starburst Galaxy
• Magnetic fields in the absence of spiral density waves - NGC 4414
• The Massive Star Clusters in the Dwarf Merger ESO 185-IG13: is the Red Excess Ubiquitous in Starbursts?
• The IBISCO survey: I. Multiphase discs and winds in the Seyfert galaxy Markarian 509
• A titanic interstellar medium ejection from a massive starburst galaxy at redshift 1.4
• Major impact from a minor merger - The extraordinary hot molecular gas flow in the Eye of the NGC 4194 Medusa galaxy
• VV 655 and NGC 4418: Implications of an interaction for the evolution of a LIRG
• The HI content of the advanced merger NGC 4441
• Molecular tendrils feeding star formation in the Eye of the Medusa - The Medusa merger in high resolution 12CO 2-1 maps
• Sub-arcsecond imaging of the radio continuum and neutral hydrogen in the Medusa merger
• Stars and gas in the Medusa merger