On the Faint End of the Galaxy Luminosity Function in the Epoch of Reionization: Updated Constraints from the HST Frontier Fields
Journal
Date Issued
2018
Author(s)
Yue, B.
•
•
Ferrara, A.
•
•
•
Amorín, R.
•
•
Mármol-Queralto, E.
•
Michałowski, M. J.
•
Mortlock, A.
•
•
Parsa, S.
•
•
•
Abstract
Ultra-faint galaxies are hosted by small dark matter halos with shallow gravitational potential wells, hence their star formation activity is more sensitive to feedback effects. The shape of the faint end of the high-z galaxy luminosity function (LF) contains important information on star formation and its interaction with the reionization process during the Epoch of Reionization. High-z galaxies with {M}UV}≳ -17 have only recently become accessible thanks to the Frontier Fields (FFs) survey combining deep HST imaging and the gravitational lensing effect. In this paper we investigate the faint end of the LF at redshift >5 using the data of FFs clusters Abell 2744 (A2744), MACSJ0416.1-2403 (M0416), MACSJ0717.5+3745 (M0717), and MACSJ1149.5+2223 (M1149). We analyze both an empirical and a physically motivated LF model to obtain constraints on a possible turnover of LF at faint magnitudes. In the empirical model the LF drops fast when the absolute UV magnitude {M}UV} is much larger than a turnover absolute UV magnitude {M}UV}{{T}}. We obtain {M}UV}{{T}}≳ -14.6 (15.2) at the 1 (2)σ confidence level (C.L.) for z ∼ 6. In the physically motivated analytical model, star formation in halos with circular velocity below {v}c* is fully quenched if these halos are located in ionized regions. Using updated lensing models and new additional FFs data, we re-analyze previous constraints on {v}c* and f esc presented by Castellano et al. using a smaller data set. We obtain new constraints on {v}c* ≲ 59 km s-1 and f esc ≲ 56% (both at 2σ C.L.) and conclude that there is no turnover detected so far from the analyzed FFs data. Forthcoming JWST observations will be key to tightening these constraints further.
Volume
868
Issue
2
Start page
115
Issn Identifier
0004-637X
Ads BibCode
2018ApJ...868..115Y
Rights
open.access
File(s)![Thumbnail Image]()
![Thumbnail Image]()
Loading...
Name
Yue_2018_ApJ_868_115.pdf
Description
Pdf editoriale
Size
1.23 MB
Format
Adobe PDF
Checksum (MD5)
1159c285a870d94ccf5801aaebda47c0
Loading...
Name
1711.05130.pdf
Description
preprint
Size
1.03 MB
Format
Adobe PDF
Checksum (MD5)
81761caffb23b681ce3e015b887f309a