TY - JOUR
T1 - MUFASA
T2 - Time-scales for HI consumption and SFR depletion of satellite galaxies in groups
AU - Rafieferantsoa, Mika
AU - Davé, Romeel
AU - Naab, Thorsten
N1 - Funding Information:
MR and RD acknowledge support from the South African Research Chairs Initiative and the South African National Research Foundation. TN acknowledges support from the German Federal Ministry of Education and Research (BMBF) within the German-South-African collaboration project 01DG 15006. MR acknowledges financial support from Max-Planck-Institut für Astrophysik. Support for MR was also provided by the Square Kilometre Array post-graduate bursary program. The zoom simulations were run on DRACO, which is part of the Max Planck Computing & Data Facility (http://www.mpcdf.mpg.de).
Publisher Copyright:
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
PY - 2019/7/1
Y1 - 2019/7/1
N2 - We investigate the connection between the HI content, star formation rate (SFR), and environment of galaxies using a hydrodynamic simulation that incorporates scaling relations for galactic wind and a heuristic halo mass based quenching prescription.We run two zoom-in simulations of galaxy groups with Mhalo > 1013M⊙ at z = 0, selected to have quiet merger histories. We track galaxies as they become satellites, and compute the delay time τd during which the satellites are similar to central galaxies at a given stellar mass, and a fading time τf during which satellites go from gas-rich and star-forming to gas-poor and quiescent. We find 0.7 ≲ τd ≲ 3Gyr at z = 0, and depends inversely on the satellite halo mass at infall. At z ~ 1 we find ~0.3 ≲ τd ≲ 2Gyr, broadly consistent with a positive correlation with the Hubble time. For low halo mass at infall, lower stellar mass galaxies at infall time have higher τd. We generally find τf ≈ τd, ranging between ~150 Myr at z ~ 0 and ~80 Myr at z ~ 1 based on linear interpolation, with some uncertainty because they are smaller than our simulation output frequency (200.300 Myr). τf has no obvious dependence on infall halomass. Both time-scales show little difference between HI depletion and SF quenching, indicating that using up the gas reservoir by star formation without refilling is the main mechanism to transform satellite galaxies at these halo masses. At a given physical distance from the centre of the main halo of interest, higher redshift galaxies have on average higher cold gas content, but the ratio of gas (HI or H2) to SFR is similar, indicating that star formation is consistently fed through reservoirs of HI then H2. For a given amount of HI, galaxies have shorter consumption times in more massive halo structures at infall. Our results suggest that group-scale simulations naturally yield a delayed-then-rapid satellite quenching scenario as inferred from observations both today and at earlier epochs, though we highlight some quantitative discrepancies.
AB - We investigate the connection between the HI content, star formation rate (SFR), and environment of galaxies using a hydrodynamic simulation that incorporates scaling relations for galactic wind and a heuristic halo mass based quenching prescription.We run two zoom-in simulations of galaxy groups with Mhalo > 1013M⊙ at z = 0, selected to have quiet merger histories. We track galaxies as they become satellites, and compute the delay time τd during which the satellites are similar to central galaxies at a given stellar mass, and a fading time τf during which satellites go from gas-rich and star-forming to gas-poor and quiescent. We find 0.7 ≲ τd ≲ 3Gyr at z = 0, and depends inversely on the satellite halo mass at infall. At z ~ 1 we find ~0.3 ≲ τd ≲ 2Gyr, broadly consistent with a positive correlation with the Hubble time. For low halo mass at infall, lower stellar mass galaxies at infall time have higher τd. We generally find τf ≈ τd, ranging between ~150 Myr at z ~ 0 and ~80 Myr at z ~ 1 based on linear interpolation, with some uncertainty because they are smaller than our simulation output frequency (200.300 Myr). τf has no obvious dependence on infall halomass. Both time-scales show little difference between HI depletion and SF quenching, indicating that using up the gas reservoir by star formation without refilling is the main mechanism to transform satellite galaxies at these halo masses. At a given physical distance from the centre of the main halo of interest, higher redshift galaxies have on average higher cold gas content, but the ratio of gas (HI or H2) to SFR is similar, indicating that star formation is consistently fed through reservoirs of HI then H2. For a given amount of HI, galaxies have shorter consumption times in more massive halo structures at infall. Our results suggest that group-scale simulations naturally yield a delayed-then-rapid satellite quenching scenario as inferred from observations both today and at earlier epochs, though we highlight some quantitative discrepancies.
KW - Galaxies: evolution
KW - Methods: numerical
KW - Methods: statistical
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U2 - 10.1093/mnras/stz1199
DO - 10.1093/mnras/stz1199
M3 - Article
AN - SCOPUS:85068001451
SN - 0035-8711
VL - 486
SP - 5184
EP - 5196
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -