The interstellar medium of quiescent galaxies and its evolution with time
Research output: Contribution to journal › Journal article › Research › peer-review
Documents
- aa39280-20
Final published version, 8.19 MB, PDF document
We characterise the basic far-IR properties and the gas mass fraction of
massive (⟨log(M*/M⊙)⟩ ≈ 11.0)
quiescent galaxies (QGs) and explore how these evolve from z = 2.0 to
the present day. We use robust, multi-wavelength (mid- to far-IR and
sub-millimetre to radio) stacking ensembles of homogeneously selected
and mass complete samples of
log(M*/M⊙)≳10.8 QGs. We find that the
dust to stellar mass ratio (Mdust/M*) rises
steeply as a function of redshift up to z ∼ 1.0 and then remains
flat at least out to z = 2.0. Using Mdust as a proxy of gas
mass (Mgas), we find a similar trend for the evolution of the
gas mass fraction (fgas), with z > 1.0 QGs having
fgas ≈ 7.0% (for solar metallicity). This fgas
is three to ten times lower than that of normal star-forming galaxies
(SFGs) at their corresponding redshift but ≳3 and ≳10 times
larger compared to that of z = 0.5 and local QGs. Furthermore, the
inferred gas depletion time scales are comparable to those of local SFGs
and systematically longer than those of main sequence galaxies at their
corresponding redshifts. Our analysis also reveals that the average dust
temperature (Td) of massive QGs remains roughly constant
(⟨Td⟩ = 21.0 ± 2.0 K) at least out to z ≈
2.0 and is substantially colder (ΔTd ≈ 10 K)
compared to that of SFGs. This motivated us to construct and release a
redshift-invariant template IR SED, that we used to make predictions for
ALMA observations and to explore systematic effects in the
Mgas estimates of massive, high-z QGs. Finally, we discuss
how a simple model that considers progenitor bias can effectively
reproduce the observed evolution of Mdust/M* and
fgas. Our results indicate universal initial interstellar
medium conditions for quenched galaxies and a large degree of uniformity
in their internal processes across cosmic time.
Original language | English |
---|---|
Article number | A33 |
Journal | Astronomy & Astrophysics |
Volume | 647 |
Number of pages | 17 |
ISSN | 0004-6361 |
DOIs | |
Publication status | Published - 1 Mar 2021 |
- galaxies: evolution, galaxies: ISM, galaxies: formation
Research areas
Number of downloads are based on statistics from Google Scholar and www.ku.dk
No data available
ID: 258400756