TY - JOUR
T1 - Gas inflow and metallicity drops in star-forming galaxies
AU - Ceverino, Daniel
AU - Sánchez Almeida, Jorge
AU - Muñoz Tuñón, Casiana
AU - Deke, Avishai
AU - Elmegreen, Bruce G.
AU - Elmegreen, Debra M.
AU - Primack, Joel
N1 - Publisher Copyright:
© 2016 The Authors.
PY - 2016/4/11
Y1 - 2016/4/11
N2 - Gas inflow feeds galaxies with low-metallicity gas from the cosmic web, sustaining star formation across the Hubble time.We make a connection between these inflows and metallicity inhomogeneities in star-forming galaxies, by using synthetic narrow-band images of the Ha emission line from zoom-in AMR cosmological simulations of galaxies with stellar masses of M* ∼ 109 M⊙ at redshifts z = 2-7. In ~50 per cent of the cases at redshifts lower than 4, the gas inflow gives rise to star-forming, Ha-bright, off-centre clumps. Most of these clumps have gas metallicities, weighted by Ha luminosity, lower than the metallicity in the surrounding interstellar medium by ~0.3 dex, consistent with observations of chemical inhomogeneities at high and low redshifts. Due to metal mixing by shear and turbulence, these metallicity drops are dissolved in a few disc dynamical times. Therefore, they can be considered as evidence for rapid gas accretion coming from cosmological inflow of pristine gas.
AB - Gas inflow feeds galaxies with low-metallicity gas from the cosmic web, sustaining star formation across the Hubble time.We make a connection between these inflows and metallicity inhomogeneities in star-forming galaxies, by using synthetic narrow-band images of the Ha emission line from zoom-in AMR cosmological simulations of galaxies with stellar masses of M* ∼ 109 M⊙ at redshifts z = 2-7. In ~50 per cent of the cases at redshifts lower than 4, the gas inflow gives rise to star-forming, Ha-bright, off-centre clumps. Most of these clumps have gas metallicities, weighted by Ha luminosity, lower than the metallicity in the surrounding interstellar medium by ~0.3 dex, consistent with observations of chemical inhomogeneities at high and low redshifts. Due to metal mixing by shear and turbulence, these metallicity drops are dissolved in a few disc dynamical times. Therefore, they can be considered as evidence for rapid gas accretion coming from cosmological inflow of pristine gas.
KW - Evolution - galaxies
KW - Formation
KW - Galaxies
UR - http://www.scopus.com/inward/record.url?scp=84976869957&partnerID=8YFLogxK
U2 - 10.1093/mnras/stw064
DO - 10.1093/mnras/stw064
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AN - SCOPUS:84976869957
SN - 0035-8711
VL - 457
SP - 2605
EP - 2612
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
M1 - stw124
ER -