The ALPINE-ALMA [C II] survey: Molecular gas budget in the Early Universe as traced by [C II]
| dc.contributor.author | Ibar, Eduardo | |
| dc.date.accessioned | 2021-07-28T16:50:07Z | |
| dc.date.available | 2021-07-28T16:50:07Z | |
| dc.date.issued | 2020 | |
| dc.description.abstract | The molecular gas content of normal galaxies at z > 4 is poorly constrained because the commonly used molecular gas tracers become hard to detect at these high redshifts. We use the [C II] 158 μm luminosity, which was recently proposed as a molecular gas tracer, to estimate the molecular gas content in a large sample of main sequence star-forming galaxies at z = 4.4 − 5.9, with a median stellar mass of 109.7 M⊙, drawn from the ALMA Large Program to INvestigate [C II] at Early times survey. The agreement between the molecular gas masses derived from [C II] luminosities, dynamical masses, and rest-frame 850 μm luminosities extrapolated from the rest-frame 158 μm continuum supports [C II] as a reliable tracer of molecular gas in our sample. We find a continuous decline of the molecular gas depletion timescale from z = 0 to z = 5.9, which reaches a mean value of (4.6 ± 0.8) × 108 yr at z ∼ 5.5, only a factor of between two and three shorter than in present-day galaxies. This suggests a mild enhancement of the star formation efficiency toward high redshifts. Our estimates also show that the previously reported rise in the molecular gas fraction flattens off above z ∼ 3.7 to achieve a mean value of 63%±3% over z = 4.4 − 5.9. This redshift evolution of the gas fraction is in line with that of the specific star formation rate. We use multi-epoch abundance-matching to follow the gas fraction evolution across cosmic time of progenitors of z = 0 Milky Way-like galaxies in ∼1013 M⊙ halos and of more massive z = 0 galaxies in ∼1014 M⊙ halos. Interestingly, the former progenitors show a monotonic increase of the gas fraction with redshift, while the latter show a steep rise from z = 0 to z ∼ 2 followed by a constant gas fraction from z ∼ 2 to z = 5.9. We discuss three possible effects, namely outflows, a pause in gas supply, and over-efficient star formation, which may jointly contribute to the gas fraction plateau of the latter massive galaxies. | en_ES |
| dc.identifier.doi | https://doi.org/10.1051/0004-6361/202038231 | |
| dc.identifier.uri | http://repositoriobibliotecas.uv.cl/handle/uvscl/2215 | |
| dc.language.iso | en | en_ES |
| dc.publisher | European Southern Observatory | en_ES |
| dc.source | European Southern Observatory | en_ES |
| dc.subject | GALAXIES: EVOLUTION | en_ES |
| dc.subject | GALAXIES: HIGH-REDSHIFT | en_ES |
| dc.subject | GALAXIES: ISM | en_ES |
| dc.subject | ISM: MOLECULES | en_ES |
| dc.title | The ALPINE-ALMA [C II] survey: Molecular gas budget in the Early Universe as traced by [C II] | en_ES |
| dc.type | Articulo | en_ES |
| uv.catalogador | RCR DIBRA | en_ES |
| uv.notageneral | Varios autores | en_ES |