Gas accretion regulates the scatter of the mass-metallicity relation
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Gas accretion regulates the scatter of the mass-metallicity relation. / De Lucia, Gabriella; Xie, Lizhi; Fontanot, Fabio; Hirschmann, Michaela.
In: Monthly Notices of the Royal Astronomical Society, Vol. 498, No. 3, 22.08.2020, p. 3215-3227.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Gas accretion regulates the scatter of the mass-metallicity relation
AU - De Lucia, Gabriella
AU - Xie, Lizhi
AU - Fontanot, Fabio
AU - Hirschmann, Michaela
PY - 2020/8/22
Y1 - 2020/8/22
N2 - In this paper, we take advantage of the GAlaxy Evolution and Assembly (GAEA) semi-analytic model to analyse the origin of secondary dependencies in the local galaxy mass-gas metallicity relation. Our model reproduces quite well the trends observed in the local Universe as a function of galaxy star formation rate and different gas-mass phases. We show that the cold gas content (whose largest fraction is represented by the atomic gas phase) can be considered as the third parameter governing the scatter of the predicted mass-metallicity relation, in agreement with the most recent observational measurements. The trends can be explained with fluctuations of the gas accretion rates: a decrease of the gas supply leads to an increase of the gas metallicity due to star formation, while an increase of the available cold gas leads to a metallicity depletion. We demonstrate that the former process is responsible for offsets above the mass-metallicity relation, while the latter is responsible for deviations below the mass-metallicity relation. In low- and intermediate-mass galaxies, these negative offsets are primarily determined by late gas cooling dominated by material that has been previously ejected due to stellar feedback.
AB - In this paper, we take advantage of the GAlaxy Evolution and Assembly (GAEA) semi-analytic model to analyse the origin of secondary dependencies in the local galaxy mass-gas metallicity relation. Our model reproduces quite well the trends observed in the local Universe as a function of galaxy star formation rate and different gas-mass phases. We show that the cold gas content (whose largest fraction is represented by the atomic gas phase) can be considered as the third parameter governing the scatter of the predicted mass-metallicity relation, in agreement with the most recent observational measurements. The trends can be explained with fluctuations of the gas accretion rates: a decrease of the gas supply leads to an increase of the gas metallicity due to star formation, while an increase of the available cold gas leads to a metallicity depletion. We demonstrate that the former process is responsible for offsets above the mass-metallicity relation, while the latter is responsible for deviations below the mass-metallicity relation. In low- and intermediate-mass galaxies, these negative offsets are primarily determined by late gas cooling dominated by material that has been previously ejected due to stellar feedback.
KW - Galaxy: abundances
KW - Galaxy: evolution
KW - Galaxy: formation
KW - galaxies: ISM
KW - STAR-FORMATION RATES
KW - GALAXY FORMATION
KW - MOLECULAR GAS
KW - SCALING RELATIONS
KW - LEGACY SURVEY
KW - EVOLUTION
KW - STELLAR
KW - ABUNDANCES
KW - ORIGIN
KW - CALIBRATIONS
U2 - 10.1093/mnras/staa2556
DO - 10.1093/mnras/staa2556
M3 - Journal article
VL - 498
SP - 3215
EP - 3227
JO - Royal Astronomical Society. Monthly Notices
JF - Royal Astronomical Society. Monthly Notices
SN - 0035-8711
IS - 3
ER -
ID: 252292259