| Type |
Journal Article |
| Names |
J. Brinchmann, S. Charlot, G. Kauffmann, T. Heckman, S. D. M. White, C. Tremonti |
| Publication |
VizieR Online Data Catalog |
| Volume |
743 |
| Pages |
22112 |
| Journal Abbreviation |
VizieR Online Data Catalog |
| Date |
July 1, 2014 |
| Short Title |
VizieR Online Data Catalog |
| URL |
http://adsabs.org/2014yCat.74322112B |
| Library Catalog |
adslabs.org |
| Abstract |
We present a method to estimate the total gas column density,
dust-to-gas and dust-to-metal ratios of distant galaxies from rest-frame
optical spectra. The technique exploits the sensitivity of certain
optical lines to changes in depletion of metals on to dust grains and
uses photoionization models to constrain these physical ratios along
with the metallicity and dust column density. We compare our gas column
density estimates with HI and CO gas mass estimates in nearby galaxies
to show that we recover their total gas mass surface density to within a
factor of 2 up to a total surface gas mass density of
~75M⊙/pc2. Our technique is independent of the conversion
factor of CO to H2 and we show that a metallicity-dependent
XCO is required to achieve good agreement between our
measurements and that provided by CO and HI. However, we also show that
our method cannot be reliably aperture corrected to total integrated gas
mass. We calculate dust-to-gas ratios for all star-forming galaxies in
the Sloan Digital Sky Survey Data Release 7 and show that the resulting
dependence on metallicity agrees well with the trend inferred from
modelling of the dust emission of nearby galaxies using far-IR data. We
also present estimates of the variation of the dust-to-metal ratio with
metallicity and show that this is poorly constrained at metallicities
below 50% solar. We conclude with a study of the inventory of gas in the
central regions, defined both in terms of a fixed physical radius and as
a fixed fraction of the half-light radius, of ~70000 star-forming
galaxies from the Sloan Digital Sky Survey. We show that their central
gas content and gas depletion time are not accurately predicted by a
single parameter, but in agreement with recent studies we find that a
combination of the stellar mass and some measure of central
concentration provides a good predictor of gas content in galaxies. We
also identify a population of galaxies with low surface densities of
stars and very long gas depletion times.
(2 data files). |
| Tags |
Equivalent widths, Galaxies: optical |