TY - JOUR
T1 - Combined CO and dust scaling relations of depletion time and molecular gas fractions with cosmic time, specific star-formation rate, and stellar mass
AU - Genzel, R.
AU - Tacconi, L. J.
AU - Lutz, D.
AU - Saintonge, A.
AU - Berta, S.
AU - Magnelli, B.
AU - Combes, F.
AU - García-Burillo, S.
AU - Neri, R.
AU - Bolatto, A.
AU - Contini, T.
AU - Lilly, S.
AU - Boissier, J.
AU - Boone, F.
AU - Bouché, N.
AU - Bournaud, F.
AU - Burkert, A.
AU - Carollo, M.
AU - Colina, L.
AU - Cooper, M. C.
AU - Cox, P.
AU - Feruglio, C.
AU - Förster Schreiber, N. M.
AU - Freundlich, J.
AU - Gracia-Carpio, J.
AU - Juneau, S.
AU - Kovac, K.
AU - Lippa, M.
AU - Naab, T.
AU - Salome, P.
AU - Renzini, A.
AU - Sternberg, A.
AU - Walter, F.
AU - Weiner, B.
AU - Weiss, A.
AU - Wuyts, S.
N1 - Publisher Copyright:
© 2015. The American Astronomical Society. All rights reserved.
PY - 2015/2/10
Y1 - 2015/2/10
N2 - We combine molecular gas masses inferred from CO emission in 500 star-forming galaxies (SFGs) between z = 0 and 3, from the IRAM-COLDGASS, PHIBSS1/2, and other surveys, with gas masses derived from Herschel far-IR dust measurements in 512 galaxy stacks over the same stellar mass/redshift range. We constrain the scaling relations of molecular gas depletion timescale (tdepl) and gas to stellar mass ratio (Mmol gas/M∗) of SFGs near the star formation "main-sequence" with redshift, specific star-formation rate (sSFR), and stellar mass (M∗). The CO- and dust-based scaling relations agree remarkably well. This suggests that the CO → H2 mass conversion factor varies little within ±0.6 dex of the main sequence (sSFR(ms, z, M∗)), and less than 0.3 dex throughout this redshift range. This study builds on and strengthens the results of earlier work. We find that tdepl scales as (1 + z)-0.3 × (sSFR/sSFR(ms, z, M∗))-0.5, with little dependence on M∗. The resulting steep redshift dependence of Mmol gas/M∗≈ (1 + z)3 mirrors that of the sSFR and probably reflects the gas supply rate. The decreasing gas fractions at high M∗are driven by the flattening of the SFR-M∗relation. Throughout the probed redshift range a combination of an increasing gas fraction and a decreasing depletion timescale causes a larger sSFR at constant M∗. As a result, galaxy integrated samples of the Mmol gas-SFR rate relation exhibit a super-linear slope, which increases with the range of sSFR. With these new relations it is now possible to determine Mmol gas with an accuracy of ±0.1 dex in relative terms, and ±0.2 dex including systematic uncertainties.
AB - We combine molecular gas masses inferred from CO emission in 500 star-forming galaxies (SFGs) between z = 0 and 3, from the IRAM-COLDGASS, PHIBSS1/2, and other surveys, with gas masses derived from Herschel far-IR dust measurements in 512 galaxy stacks over the same stellar mass/redshift range. We constrain the scaling relations of molecular gas depletion timescale (tdepl) and gas to stellar mass ratio (Mmol gas/M∗) of SFGs near the star formation "main-sequence" with redshift, specific star-formation rate (sSFR), and stellar mass (M∗). The CO- and dust-based scaling relations agree remarkably well. This suggests that the CO → H2 mass conversion factor varies little within ±0.6 dex of the main sequence (sSFR(ms, z, M∗)), and less than 0.3 dex throughout this redshift range. This study builds on and strengthens the results of earlier work. We find that tdepl scales as (1 + z)-0.3 × (sSFR/sSFR(ms, z, M∗))-0.5, with little dependence on M∗. The resulting steep redshift dependence of Mmol gas/M∗≈ (1 + z)3 mirrors that of the sSFR and probably reflects the gas supply rate. The decreasing gas fractions at high M∗are driven by the flattening of the SFR-M∗relation. Throughout the probed redshift range a combination of an increasing gas fraction and a decreasing depletion timescale causes a larger sSFR at constant M∗. As a result, galaxy integrated samples of the Mmol gas-SFR rate relation exhibit a super-linear slope, which increases with the range of sSFR. With these new relations it is now possible to determine Mmol gas with an accuracy of ±0.1 dex in relative terms, and ±0.2 dex including systematic uncertainties.
KW - Galaxies: evolution
KW - Galaxies: high-redshift
KW - Galaxies: kinematics and dynamics
KW - Infrared: galaxies
UR - https://www.scopus.com/pages/publications/84922745313
UR - https://www.scopus.com/pages/publications/84922745313#tab=citedBy
U2 - 10.1088/0004-637X/800/1/20
DO - 10.1088/0004-637X/800/1/20
M3 - Article
AN - SCOPUS:84922745313
SN - 0004-637X
VL - 800
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 20
ER -