Bibcode
Utomo, D.; Bolatto, Alberto D.; Wong, Tony; Ostriker, Eve C.; Blitz, Leo; Sanchez, Sebastian F.; Colombo, Dario; Leroy, Adam K.; Cao, Yixian; Dannerbauer, H.; Garcia-Benito, Ruben; Husemann, Bernd; Kalinova, Veselina; Levy, Rebecca C.; Mast, Damian; Rosolowsky, Erik; Vogel, Stuart N.
Bibliographical reference
The Astrophysical Journal, Volume 849, Issue 1, article id. 26, 16 pp. (2017).
Advertised on:
11
2017
Journal
Citations
70
Refereed citations
69
Description
We present results from the EDGE survey, a spatially resolved
CO(1‑0) follow-up to CALIFA, an optical Integral Field Unit survey
of local galaxies. By combining the data products of EDGE and CALIFA, we
study the variation in molecular gas depletion time (τ
dep) on kiloparsec scales in 52 galaxies. We divide each
galaxy into two parts: the center, defined as the region within 0.1
{R}25, and the disk, defined as the region between 0.1 and
0.7 {R}25. We find that 14 galaxies show a shorter τ
dep (∼1 Gyr) in the center relative to that in the disk
(τ dep ∼ 2.4 Gyr), which means the central region in
those galaxies is more efficient at forming stars per unit molecular gas
mass. This finding implies that the centers with shorter τ
dep resemble the intermediate regime between galactic disks
and starburst galaxies. Furthermore, the central drop in τ
dep is correlated with a central increase in the stellar
surface density, suggesting that a shorter τ dep is
associated with molecular gas compression by the stellar gravitational
potential. We argue that varying the CO-to-H2 conversion
factor only exaggerates the central drop of τ dep.
Related projects
Molecular Gas and Dust in Galaxies Across Cosmic Time
Two of the most fundamental questions in astrophysics are the conversion of molecular gas into stars and how this physical process is a function of environments on all scales, ranging from planetary systems, stellar clusters, galaxies to galaxy clusters. The main goal of this internal project is to get insight into the formation and evolution of
Helmut
Dannerbauer