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Here we provide the most comprehensive determinations of the rest-frame UV luminosity function (LF) available to date with the Hubble Space Telescope (HST) at z similar to 2-9. Essentially all of the noncluster extragalactic legacy fields are utilized, including the Hubble Ultra Deep Field, the Hubble Frontier Fields parallel fields, and all five CANDELS fields, for a total survey area of 1136 arcmin(2). Our determinations include galaxies at z similar to 2-3 leveraging the deep HDUV, UVUDF, and ERS WFC3/UVIS observations available over an similar to 150 arcmin(2) area in the GOODS-North and GOODS-South regions. All together, our collective samples include >24,000 sources, >2.3x larger than previous selections with HST. We identify 5766, 6332, 7240, 3449, 1066, 601, 246, and 33 sources at z similar to 2, 3, 4, 5, 6, 7, 8, and 9, respectively. Combining our results with an earlier z similar to 10 LF determination by Oesch et al., we quantify the evolution of the UV LF. Our results indicate that there is (1) a smooth flattening of the faint-end slope alpha from alpha similar to -2.4 at z similar to 10 to alpha similar to -1.5 at z similar to 2, (2) minimal evolution in the characteristic luminosity M* at z >= 2.5, and (3) a monotonic increase in the normalization log(10) phi* from z similar to 10 to 2, which can be well described by a simple second-order polynomial, consistent with an "accelerated" evolution scenario. We find that each of these trends (from z similar to 10 to 2.5 at least) can be readily explained on the basis of the evolution of the halo mass function and a simple constant star formation efficiency model.

We make use of sensitive (9.3 mu Jy beam(-1) rms) 1.2 mm continuum observations from the Atacama Large Millimeter/submillimeter Array (ALMA) Spectroscopic Survey in the Hubble Ultra-Deep Field (ASPECS) large program to probe dust-enshrouded star formation from 1362 Lyman-break galaxies spanning the redshift range z.=.1.5-10 (to similar to 7-28 M-circle dot yr(-1) at 4s over the entire range). We find that the fraction of ALMA-detected galaxies in our z.=.1.5-10 samples increases steeply with stellar mass, with the detection fraction rising from 0% at 10(9.0) M-circle dot to 85(-18)(+9) % at >10(10) M-circle dot. Moreover, on stacking all 1253 low-mass (10(9.5) M-circle dot and an SMC-like relation at lower masses. Using stellar mass and beta measurements for z similar to 2 galaxies over the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, we derive a new empirical relation between beta and stellar mass and then use this correlation to show that our IRX-beta and IRX-stellar mass relations are consistent with each other. We then use these constraints to express the IRX as a bivariate function of beta and stellar mass. Finally, we present updated estimates of star formation rate density determinations at z > 3, leveraging present improvements in the measured IRX and recent probes of ultraluminous far-IR galaxies at z > 2.

© 2016. The American Astronomical Society. All rights reserved. Funding for this work was provided by the Spanish MINECO under projects AYA2012-39168-C03-1, AYA2012-39168-C03-2, AYA2013-446724-P, MDM-2014-0369 of ICCUB (Unidad de Excelencia "María de Maeztu"), AYA2015-70498-C02-2-R (co-funded with FEDER funds), and the Catalán DEC grant 2014SGR86. J.M.M.H. was supported by Spanish MINECO grant ESP2014-59789-P., We combine observational data on a dozen independent cosmic properties at high-z with the information on reionization drawn from the spectra of distant luminous sources and the cosmic microwave background (CMB) to constrain the interconnected evolution of galaxies and the intergalactic medium since the dark ages. The only acceptable solutions are concentrated in two narrow sets. In one of them reionization proceeds in two phases: a first one driven by Population III stars, completed at z similar to 10, and after a short recombination period a second one driven by normal galaxies, completed at z similar to 6. In the other set both kinds of sources work in parallel until full reionization at z similar to 6. The best solution with double reionization gives excellent fits to all the observed cosmic histories, but the CMB optical depth is 3 sigma larger than the recent estimate from the Planck data. Alternatively, the best solution with single reionization gives less good fits to the observed star formation rate density and cold gas mass density histories, but the CMB optical depth is consistent with that estimate. We make several predictions, testable with future observations, that should discriminate between the two reionization scenarios. As a byproduct our models provide a natural explanation to some characteristic features of the cosmic properties at high-z, as well as to the origin of globular clusters., Ministerio de Economía y Competitividad (MINECO), ICCUB (Unidad de Excelencia "María de Maeztu", FEDER funds, Catalán DEC grant, Depto. de Física de la Tierra y Astrofísica, Fac. de Ciencias Físicas, TRUE, pub