The bright end of the z~9 and z~10 UV luminosity functions using all five CANDELS fields.

Authors

R. J. Bouwens, Leiden University
P. A. Oesch, Yale University
I. Labbe, Leiden University
G. D. Illingworth, University of California, Santa Cruz
G. G. Fazio, Harvard-Smithsonian Center for Astrophysics
D. Coe, Harvard-Smithsonian Center for Astrophysics
Benne W. Holwerda, University of Louisville
R. Smit, Department of Physics and Astronomy, South Road, Durham, DH
M. Stefanon, Leiden University
P. G. van Dokkum, Yale University
M. Trenti, University of Melbourne
M. L. N. Ashby, Harvard-Smithsonian Center for Astrophysics
J. S. Huang, Harvard-Smithsonian Center for Astrophysics
L. Spitler, Macquarie University
C. Straatman, Leiden University
L. Bradley, Space Telescope Science Institute
D. Magee, University of California, Santa Cruz

Document Type

Article

Publication Date

10-2016

Department

Physics and Astronomy

Abstract

The deep, wide-area (∼800–900 arcmin2 ) near-infrared/WFC3/IR + Spitzer/IRAC observations over the CANDELS fields have been a remarkable resource for constraining the bright end of high-redshift UV luminosity functions. However, the lack of Hubble Space Telescope (HST) 1.05 μm observations over the CANDELS fields has made it difficult to identify z ∼ 9–10 sources robustly, since such data are needed to confirm the presence of an abrupt Lyman break at 1.2 μm. Here, we report on the successful identification of many such z ∼ 9–10 sources from a new HST program (z9-CANDELS) that targets the highest-probability z ∼ 9–10 galaxy candidates with observations at 1.05 μm, to search for a robust Lyman-break at 1.2 μm. The potential z ∼ 9–10 candidates were preselected from the full HST, Spitzer/IRAC S-CANDELS observations, and the deepest-available ground-based optical+near-infrared observations (CFHTLS-DEEP+HUGS+UltraVISTA+ZFOURGE). We identified 15 credible z ∼ 9–10 galaxies over the CANDELS fields. Nine of these galaxies lie at z ∼ 9 and five are new identifications. Our targeted follow-up strategy has proven to be very efficient in making use of scarce HST time to secure a reliable sample of z ∼ 9–10 galaxies. Through extensive simulations, we replicate the selection process for our sample (both the preselection and follow-up) and use it to improve current estimates for the volume density of bright z ∼ 9 and z ∼ 10 galaxies. The volume densities we find are 5- ´+ 2 3 and - ´+8 3 9 lower, respectively, than those found at z ∼ 8. When compared with the best-fit evolution (i.e., d log 0.29 0.0 r dz =-  2 10 UV ) in the UV luminosity densities from z ∼ 8 to z ∼ 4 integrated to * 0.3Lz=3 (−20 mag), these luminosity densities are - ´ + 2.6 0.9 1.5 and - ´ + 2.2 1.1 2.0 lower, respectively, than the extrapolated trends. Our new results are broadly consistent with the “accelerated evolution” scenario at z > 8, consistent with that seen in many models.

Comments

© 2016. The American Astronomical Society. All rights reserved.

http://dx.doi.org/10.3847/0004-637X/830/2/67

Original Publication Information

Bouwens, R. J., et al. "The Bright End of the z~9 and z~10 UV Luminosity Functions Using All Five CANDELS Fields." 2016. The Astrophysical Journal 830(2): 67-88.

ThinkIR Citation

Bouwens, R. J.; Oesch, P. A.; Labbe, I.; Illingworth, G. D.; Fazio, G. G.; Coe, D.; Holwerda, Benne W.; Smit, R.; Stefanon, M.; van Dokkum, P. G.; Trenti, M.; Ashby, M. L. N.; Huang, J. S.; Spitler, L.; Straatman, C.; Bradley, L.; and Magee, D., "The bright end of the z~9 and z~10 UV luminosity functions using all five CANDELS fields." (2016). Faculty and Staff Scholarship. 153.
https://ir.library.louisville.edu/faculty/153

DOI

10.3847/0004-637X/830/2/67