TY - JOUR
T1 - The Evolution of the Interstellar Medium in Post-starburst Galaxies
AU - Li, Zhihui
AU - French, K. Decker
AU - Zabludoff, Ann I.
AU - Ho, Luis C.
N1 - Funding Information:
2019-07-10 2019-07-16 14:30:15 cgi/release: Article released bin/incoming: New from .zip NASA HST-HF2-51391.001-A NASA ADP- NNX10AE88G National Key R&D Program of China 2016YFA0400702 National Science Foundation of China 11721303 yes
Publisher Copyright:
© 2019. The American Astronomical Society. All rights reserved..
PY - 2019/7/10
Y1 - 2019/7/10
N2 - We derive dust masses (M dust) from the spectral energy distributions of 58 post-starburst galaxies (PSBs). There is an anticorrelation between specific dust mass (M dust/M ∗) and the time elapsed since the starburst ended, indicating that dust was either destroyed, expelled, or rendered undetectable over the ∼1 Gyr after the burst. The M dust/M ∗ depletion timescale, , is consistent with that of the CO-traced , suggesting that dust and gas are altered via the same process. Extrapolating these trends leads to the M dust/M ∗ and values of early-type galaxies (ETGs) within 1-2 Gyr, a timescale consistent with the evolution of other PSB properties into ETGs. Comparing M dust and for PSBs yields a calibration, log , that allows us to place 33 PSBs on the Kennicutt-Schmidt (KS) plane, . Over the first ∼200-300 Myr, the PSBs evolve down and off of the KS relation, as their star formation rate (SFR) decreases more rapidly than . Afterwards, continues to decline whereas the SFR levels off. These trends suggest that the star formation efficiency bottoms out at 10-11 yr-1 and will rise to ETG levels within 0.5-1.1 Gyr afterwards. The SFR decline after the burst is likely due to the absence of gas denser than the CO-traced H2. The mechanism of the M dust/M ∗ and decline, whose timescale suggests active galactic nucleus/low-ionization nuclear emission-line region feedback, may also be preventing the large CO-traced molecular gas reservoirs from collapsing and forming denser star-forming clouds.
AB - We derive dust masses (M dust) from the spectral energy distributions of 58 post-starburst galaxies (PSBs). There is an anticorrelation between specific dust mass (M dust/M ∗) and the time elapsed since the starburst ended, indicating that dust was either destroyed, expelled, or rendered undetectable over the ∼1 Gyr after the burst. The M dust/M ∗ depletion timescale, , is consistent with that of the CO-traced , suggesting that dust and gas are altered via the same process. Extrapolating these trends leads to the M dust/M ∗ and values of early-type galaxies (ETGs) within 1-2 Gyr, a timescale consistent with the evolution of other PSB properties into ETGs. Comparing M dust and for PSBs yields a calibration, log , that allows us to place 33 PSBs on the Kennicutt-Schmidt (KS) plane, . Over the first ∼200-300 Myr, the PSBs evolve down and off of the KS relation, as their star formation rate (SFR) decreases more rapidly than . Afterwards, continues to decline whereas the SFR levels off. These trends suggest that the star formation efficiency bottoms out at 10-11 yr-1 and will rise to ETG levels within 0.5-1.1 Gyr afterwards. The SFR decline after the burst is likely due to the absence of gas denser than the CO-traced H2. The mechanism of the M dust/M ∗ and decline, whose timescale suggests active galactic nucleus/low-ionization nuclear emission-line region feedback, may also be preventing the large CO-traced molecular gas reservoirs from collapsing and forming denser star-forming clouds.
KW - galaxies: ISM
KW - galaxies: evolution
KW - galaxies: starburst
KW - infrared: galaxies
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U2 - 10.3847/1538-4357/ab1f68
DO - 10.3847/1538-4357/ab1f68
M3 - Article
AN - SCOPUS:85071938751
VL - 879
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 2
M1 - 131
ER -