NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-22 T05:59:48 PDT
Help | Comment | NED Home

For refcode 2011ApJ...730L..13B:
Retrieve 30 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2011ApJ...730L..13B A Constant Molecular Gas Depletion Time in Nearby Disk Galaxies Bigiel, F.; Leroy, A. K.; Walter, F.; Brinks, E.; de Blok, W. J. G.; Kramer, C.; Rix, H. W.; Schruba, A.; Schuster, K.-F.; Usero, A.; Wiesemeyer, H. W. Abstract. We combine new sensitive, wide-field CO data from the HERACLES survey with ultraviolet and infrared data from GALEX and Spitzer to compare the surface densities of H_2_, {SIGMA}_H2_, and the recent star formation rate, {SIGMA}_SFR_, over many thousands of positions in 30 nearby disk galaxies. We more than quadruple the size of the galaxy sample compared to previous work and include targets with a wide range of galaxy properties. Even though the disk galaxies in this study span a wide range of properties, we find a strong, and approximately linear correlation between {SIGMA}_SFR_ and {SIGMA}_H2_ at our common resolution of 1 kpc. This implies a roughly constant median H_2_ consumption time, {tau}^H2^_Dep_ = {SIGMA}_H2_/{SIGMA}_SFR_, of ~2.35 Gyr (including heavy elements) across our sample. At 1 kpc resolution, there is only a weak correlation between {SIGMA}_H2_ and {tau}^H2^_Dep_ over the range {SIGMA}_H2_ ~ 5-100 M_sun_ pc^-2^, which is probed by our data. We compile a broad set of literature measurements that have been obtained using a variety of star formation tracers, sampling schemes, and physical scales and show that overall, these data yield almost exactly the same results, although with more scatter. We interpret these results as strong, albeit indirect evidence that star formation proceeds in a uniform way in giant molecular clouds in the disks of spiral galaxies. Key words: galaxies: evolution, galaxies: ISM, radio lines: galaxies, stars: formation
Retrieve 30 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home