High star formation rates in turbulent atomic-dominated gas in the interacting galaxies IC 2163 and NGC 2207

Bruce G. Elmegreen, Michele Kaufman, Frederic Bournaud, Debra Meloy Elmegreen, Curtis Struck, E. Brinks, Stephanie Juneau

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)
67 Downloads (Pure)

Abstract

CO observations of the interacting galaxies IC 2163 and NGC 2207 are combined with HI, Halpha and 24 microns to study the star formation rate (SFR) surface density as a function of the gas surface density. More than half of the high SFR regions are HI dominated. When compared to other galaxies, these HI-dominated regions have excess SFRs relative to their molecular gas surface densities but normal SFRs relative to their total gas surface densities. The HI-dominated regions are mostly located in the outer part of NGC 2207, where the HI velocity dispersion is high, 40 - 50 km/s. We suggest that the star-forming clouds in these regions have envelopes at lower densities than normal, making them predominantly atomic, and cores at higher densities than normal because of the high turbulent Mach numbers. This is consistent with theoretical predictions of a flattening in the density probability distribution function for compressive, high Mach number turbulence.
Original languageEnglish
Number of pages7
JournalThe Astrophysical Journal
Volume823
Issue number1
Early online date18 May 2016
DOIs
Publication statusPublished - 20 May 2016

Keywords

  • astro-ph.GA
  • ISM : molecules
  • Galaxies: interactions
  • galaxies: star formation

Fingerprint

Dive into the research topics of 'High star formation rates in turbulent atomic-dominated gas in the interacting galaxies IC 2163 and NGC 2207'. Together they form a unique fingerprint.

Cite this