TY - JOUR
T1 - A Universal Correlation between Star Formation Activity and Molecular Gas Properties Across Environments
AU - Koyama, Shuhei
AU - Koyama, Yusei
AU - Yamashita, Takuji
AU - Morokuma-Matsui, Kana
AU - Matsuhara, Hideo
AU - Nakagawa, Takao
AU - Hayashi, Masao
AU - Kodama, Tadayuki
AU - Shimakawa, Rhythm
AU - Suzuki, Tomoko
AU - Tadaki, Ken Ichi
AU - Tanaka, Ichi
AU - Yamamoto, Moegi
N1 - Funding Information:
This work was financially supported in part by a Grant-in-Aid for the Scientific Research (No. 26800107, 26247030) by the Japanese Ministry of Education, Culture, Sports and Science. Facility: NRO 45m. Software: NEWSTAR.
Funding Information:
Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The SDSS-III web site ishttp://www.sdss3.org/.
PY - 2017/10/1
Y1 - 2017/10/1
N2 - We present the molecular gas mass fraction ( fH2) and star formation efficiency (SFE) of local galaxies on the basisof our new CO(J = 1 - 0) observations with the Nobeyama 45 m radio telescope, combined with theCOLDGASS galaxy catalog, as a function of galaxy environment defined as the local number density of galaxiesmeasured with SDSS DR7 spectroscopic data. Our sample covers a wide range in the stellar mass and starformation rate (SFR), and also covers a wide environmental range over two orders of magnitude. This allows us toconduct the first systematic study of environmental dependence of molecular gas properties in galaxies from thelowest- to the highest-density environments in the local universe. We confirm that both fH2 and SFE have strongpositive correlations with the SFR offset from the star-forming main sequence (δMS) and, most importantly, wefind that these correlations are universal across all environments. Our result demonstrates that star formationactivity within individual galaxies is primarily controlled by their molecular gas content, regardless of their globalenvironment. Therefore, we claim that one always needs to be careful about the δMS distribution of the samplewhen investigating the environmental effects on the H2 gas content in galaxies.
AB - We present the molecular gas mass fraction ( fH2) and star formation efficiency (SFE) of local galaxies on the basisof our new CO(J = 1 - 0) observations with the Nobeyama 45 m radio telescope, combined with theCOLDGASS galaxy catalog, as a function of galaxy environment defined as the local number density of galaxiesmeasured with SDSS DR7 spectroscopic data. Our sample covers a wide range in the stellar mass and starformation rate (SFR), and also covers a wide environmental range over two orders of magnitude. This allows us toconduct the first systematic study of environmental dependence of molecular gas properties in galaxies from thelowest- to the highest-density environments in the local universe. We confirm that both fH2 and SFE have strongpositive correlations with the SFR offset from the star-forming main sequence (δMS) and, most importantly, wefind that these correlations are universal across all environments. Our result demonstrates that star formationactivity within individual galaxies is primarily controlled by their molecular gas content, regardless of their globalenvironment. Therefore, we claim that one always needs to be careful about the δMS distribution of the samplewhen investigating the environmental effects on the H2 gas content in galaxies.
KW - galaxies: ISM
KW - galaxies: evolution
KW - galaxies: star formation
KW - large-scale structure of universe
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U2 - 10.3847/1538-4357/aa8a6c
DO - 10.3847/1538-4357/aa8a6c
M3 - Article
AN - SCOPUS:85031085822
VL - 847
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 137
ER -