UVUDF: UV Luminosity Functions at the Cosmic High Noon
Abstract
We present the rest-1500 Å UV luminosity functions (LF) for star-forming galaxies during the cosmic high noon—the peak of cosmic star formation rate at 1.5 < z < 3. We use deep NUV imaging data obtained as part of the Hubble Ultra-Violet Ultra Deep Field (UVUDF) program, along with existing deep optical and NIR coverage on the HUDF. We select F225W, F275W, and F336W dropout samples using the Lyman break technique, along with samples in the corresponding redshift ranges selected using photometric redshifts, and measure the rest-frame UV LF at z ~ 1.7, 2.2, 3.0, respectively, using the modified maximum likelihood estimator. We perform simulations to quantify the survey and sample incompleteness for the UVUDF samples to correct the effective volume calculations for the LF. We select galaxies down to M_(UV) = -15.9, -16.3, -16.8 and fit a faint-end slope of α = -1.20^(+0.10)_(-0.13), -1.32^(+0.10)_(-0.14), -1.39^(+0.08)_(-0.12) at 1.4 < z < 1.9, 1.8 < z < 2.6, and 2.4 < z < 3.6, respectively. We compare the star formation properties of z ~ 2 galaxies from these UV observations with results from Hα and UV+IR observations. We find a lack of high-SFR sources in the UV LF compared to the Hα and UV+IR, likely due to dusty SFGs not being properly accounted for by the generic IRX-β relation used to correct for dust. We compute a volume-averaged UV-to-Hα ratio by abundance matching the rest-frame UV LF and Hα LF. We find an increasing UV-to-Hα ratio toward low-mass galaxies (M_∗ ≾ 5 x 10^9 M_⊙). We conclude that this could be due to a larger contribution from starbursting galaxies compared to the high-mass end.
Additional Information
© 2017 The American Astronomical Society. Received 2016 December 8; revised 2017 February 9; accepted 2017 February 20; published 2017 March 21. We thank the anonymous referee for providing comments that helped improve the quality of the manuscript. We would like to thank Dan Coe for help with implementing the photometric redshift algorithm (BPZ) into the completeness simulations. Support for HST Program GO-12534 was provided by NASA through grants from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. M.R. also acknowledges support from an appointment to the NASA Postdoctoral Program at Goddard Space Flight Center. M.B.K. acknowledges support from the National Science Foundation (grant AST-1517226) and from NASA through HST theory grants (programs AR-12836, AR-13888, AR-13896, and AR-14282) awarded by the Space Telescope Science Institute (STScI), which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555.Attached Files
Published - Mehta_2017_ApJ_838_29.pdf
Submitted - 1702.06953.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:8dfbaaa47842c50c7d70bf1d8d44df79
|
1.7 MB | Preview Download |
|
md5:6a07e63705d55d8bcb355a1743956fe3
|
7.6 MB | Preview Download |
Additional details
- Eprint ID
- 75265
- Resolver ID
- CaltechAUTHORS:20170321-091301187
- NAS5-26555
- NASA
- NASA Postdoctoral Program
- AST-1517226
- NSF
- AR-12836
- NASA Hubble Fellowship
- AR-13888
- NASA Hubble Fellowship
- AR-13896
- NASA Hubble Fellowship
- AR-14282
- NASA Hubble Fellowship
- Created
-
2017-03-21Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)