Bouwens, RJ;
Illingworth, G;
Ellis, RS;
Oesch, P;
Stefanon, M;
(2022)
z ∼ 2–9 Galaxies Magnified by the Hubble Frontier Field Clusters. II. Luminosity Functions and Constraints on a Faint-end Turnover.
The Astrophysical Journal
, 940
(1)
p. 55.
10.3847/1538-4357/ac86d1.
Preview |
Text
Bouwens_2022_ApJ_940_55.pdf - Published Version Download (3MB) | Preview |
Abstract
We present new determinations of the rest-UV luminosity functions (LFs) at z = 2–9 to extremely low luminosities (>−14 mag) from a sample of >2500 lensed galaxies found behind the Hubble Frontier Fields (HFF) clusters. For the first time, we present faint-end slope results from lensed samples that are fully consistent with blank-field results over the redshift range z = 2–9, while reaching to much lower luminosities than possible from the blank-field studies. Combining the deep lensed sample with the large blank-field samples allows us to set tight constraints on the faint-end slope α of the z = 2–9 UV LFs and its evolution. We find a smooth flattening in α from −2.28 ± 0.10 (z = 9) to −1.53 ± 0.03 (z = 2) with cosmic time (dα/dz = −0.11 ± 0.01), fully consistent with dark matter halo buildup. We utilize these new results to present new measurements of the evolution in the UV luminosity density ρ UV brighter than −13 mag from z ∼ 9 to z ∼ 2. Accounting for the star formation rate (SFR) densities to faint luminosities implied by our LF results, we find that unobscured star formation dominates the SFR density at z ≳ 4, with obscured star formation dominant thereafter. Having shown we can quantify the faint-end slope α of the LF accurately with our lensed HFF samples, we also quantify the apparent curvature in the shape of the UV LF through a curvature parameter δ. The constraints on the curvature δ strongly rule out the presence of a turn-over brighter than −13.1 mag at z ∼ 3, −14.3 mag at z ∼ 6, and −15.5 mag at all other redshifts between z ∼ 9 and z ∼ 2.
| Type: | Article |
|---|---|
| Title: | z ∼ 2–9 Galaxies Magnified by the Hubble Frontier Field Clusters. II. Luminosity Functions and Constraints on a Faint-end Turnover |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-4357/ac86d1 |
| Language: | English |
| Additional information: | Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
| Keywords: | Luminosity function – Strong gravitational lensing – Deep space probes – High-redshift galaxies |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10160955 |
Archive Staff Only
 |
View Item |
