TY - JOUR
T1 - The role of atomic hydrogen in regulating the scatter of the mass-metallicity relation
AU - Brown, Toby
AU - Cortese, Luca
AU - Catinella, Barbara
AU - Kilborn, Virginia
PY - 2018/1/1
Y1 - 2018/1/1
N2 - In this paper, we stack neutral atomic hydrogen (H I) spectra for 9720 star-forming galaxies along the mass-metallicity relation. The sample is selected according to stellar mass (109 ≤ M*/M⊙ ≤1011) and redshift (0.02≤z≤0.05) from the overlap of the Sloan Digital Sky Survey and Arecibo Legacy Fast ALFA survey. We confirm and quantify the strong anticorrelation between HI mass and gas-phase metallicity at fixed stellar mass. Furthermore, we show for the first time that the relationship between gas content and metallicity is consistent between different metallicity estimators, contrary to the weaker trends found with star formation which are known to depend on the observational techniques used to derive oxygen abundances and star formation rates. When interpreted in the context of theoretical work, this result supports a scenario where galaxies exist in an evolving equilibrium between gas, metallicity and star formation. The fact that deviations from this equilibrium are most strongly correlated with gas mass suggests that the scatter in the mass-metallicity relation is primarily driven by fluctuations in gas accretion.
AB - In this paper, we stack neutral atomic hydrogen (H I) spectra for 9720 star-forming galaxies along the mass-metallicity relation. The sample is selected according to stellar mass (109 ≤ M*/M⊙ ≤1011) and redshift (0.02≤z≤0.05) from the overlap of the Sloan Digital Sky Survey and Arecibo Legacy Fast ALFA survey. We confirm and quantify the strong anticorrelation between HI mass and gas-phase metallicity at fixed stellar mass. Furthermore, we show for the first time that the relationship between gas content and metallicity is consistent between different metallicity estimators, contrary to the weaker trends found with star formation which are known to depend on the observational techniques used to derive oxygen abundances and star formation rates. When interpreted in the context of theoretical work, this result supports a scenario where galaxies exist in an evolving equilibrium between gas, metallicity and star formation. The fact that deviations from this equilibrium are most strongly correlated with gas mass suggests that the scatter in the mass-metallicity relation is primarily driven by fluctuations in gas accretion.
KW - Galaxies: abundances
KW - Galaxies: evolution
KW - Galaxies: formation
KW - Galaxies: ISM
KW - ISM: lines and bands
KW - Radio lines: galaxies
UR - http://www.scopus.com/inward/record.url?scp=85046119114&partnerID=8YFLogxK
U2 - 10.1093/mnras/stx2452
DO - 10.1093/mnras/stx2452
M3 - Article
AN - SCOPUS:85046119114
VL - 473
SP - 1868
EP - 1878
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 2
ER -