TY - JOUR
T1 - Implications of Increased Central Mass Surface Densities for the Quenching of Low-mass Galaxies
AU - Guo, Yicheng
AU - Carleton, Timothy
AU - Bell, Eric F.
AU - Chen, Zhu
AU - Dekel, Avishai
AU - Faber, S. M.
AU - Giavalisco, Mauro
AU - Kocevski, Dale D.
AU - Koekemoer, Anton M.
AU - Koo, David C.
AU - Kurczynski, Peter
AU - Lee, Seong Kook
AU - Liu, F. S.
AU - Papovich, Casey
AU - Pérez-González, Pablo G.
N1 - Publisher Copyright:
© 2021. The American Astronomical Society. All rights reserved..
PY - 2021/6/10
Y1 - 2021/6/10
N2 - We use the Cosmic Assembly Deep Near-infrared Extragalactic Legacy Survey data to study the relationship between quenching and the stellar mass surface density within the central radius of 1 kpc (Σ1) of low-mass galaxies (stellar mass M ∗ ≲ 109.5 M o˙) at 0.5 ≤ z < 1.5. Our sample is mass complete down to ∼109 M o˙ at 0.5 ≤ z < 1.0. We compare the mean Σ1 of star-forming galaxies (SFGs) and quenched galaxies (QGs) at the same redshift and M ∗. We find that low-mass QGs have a higher Σ1 than low-mass SFGs, similar to galaxies above 1010 M o˙. The difference of Σ1 between QGs and SFGs increases slightly with M ∗ at M ∗ ≲ 1010 M o˙ and decreases with M ∗ at M ∗ ⪆ 1010 M o˙. The turnover mass is consistent with the mass where quenching mechanisms transition from internal to environmental quenching. At 0.5 ≤ z < 1.0, we find that Σ1 of galaxies increases by about 0.25 dex in the green valley (i.e., the transition region from star forming to fully quenched), regardless of their M ∗. Using the observed specific star formation rate gradient in the literature as a constraint, we estimate that the quenching timescale (i.e., time spent in the transition) of low-mass galaxies is a few (∼4) Gyr at 0.5 ≤ z < 1.0. The mechanisms responsible for quenching need to gradually quench star formation in an outside-in way, i.e., preferentially ceasing star formation in outskirts of galaxies while maintaining their central star formation to increase Σ1. An interesting and intriguing result is the similarity of the growth of Σ1 in the green valley between low-mass and massive galaxies, which suggests that the role of internal processes in quenching low-mass galaxies is a question worthy of further investigation.
AB - We use the Cosmic Assembly Deep Near-infrared Extragalactic Legacy Survey data to study the relationship between quenching and the stellar mass surface density within the central radius of 1 kpc (Σ1) of low-mass galaxies (stellar mass M ∗ ≲ 109.5 M o˙) at 0.5 ≤ z < 1.5. Our sample is mass complete down to ∼109 M o˙ at 0.5 ≤ z < 1.0. We compare the mean Σ1 of star-forming galaxies (SFGs) and quenched galaxies (QGs) at the same redshift and M ∗. We find that low-mass QGs have a higher Σ1 than low-mass SFGs, similar to galaxies above 1010 M o˙. The difference of Σ1 between QGs and SFGs increases slightly with M ∗ at M ∗ ≲ 1010 M o˙ and decreases with M ∗ at M ∗ ⪆ 1010 M o˙. The turnover mass is consistent with the mass where quenching mechanisms transition from internal to environmental quenching. At 0.5 ≤ z < 1.0, we find that Σ1 of galaxies increases by about 0.25 dex in the green valley (i.e., the transition region from star forming to fully quenched), regardless of their M ∗. Using the observed specific star formation rate gradient in the literature as a constraint, we estimate that the quenching timescale (i.e., time spent in the transition) of low-mass galaxies is a few (∼4) Gyr at 0.5 ≤ z < 1.0. The mechanisms responsible for quenching need to gradually quench star formation in an outside-in way, i.e., preferentially ceasing star formation in outskirts of galaxies while maintaining their central star formation to increase Σ1. An interesting and intriguing result is the similarity of the growth of Σ1 in the green valley between low-mass and massive galaxies, which suggests that the role of internal processes in quenching low-mass galaxies is a question worthy of further investigation.
UR - http://www.scopus.com/inward/record.url?scp=85108074267&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/abf115
DO - 10.3847/1538-4357/abf115
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AN - SCOPUS:85108074267
SN - 0004-637X
VL - 914
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 7
ER -