@miki

Full-Data Results of Hubble Frontier Fields: UV Luminosity Functions at $z\sim6-10$ and a Consistent Picture of Cosmic Reionization

, , , , and . (2017)cite arxiv:1702.04867Comment: 20 pages, 9 figures.

Abstract

We present UV luminosity functions of star-forming galaxies at $z\sim6-10$ derived with the full-data set of the Hubble Frontier Fields (HFF) program consisting of 6 lensing-cluster and parallel-field data. We obtain a catalog of $\sim400$ dropout galaxy candidates at $z\sim6-10$ whose UV absolute magnitudes reach $\sim-14$ mag. We carefully evaluate number densities of the dropout galaxies by Monte-Carlo simulations, including all lensing effects such as magnification, distortion, and multiplication of images as well as detection completeness and contamination effects. We find that UV luminosity functions at $z\sim6-8$ have steep faint end slopes, $\alpha\sim-2$, and the evolution of UV luminosity densities show a smooth decline toward high redshift. We examine whether our HFF results consistently explain cosmic reionization with the Thomson scattering optical depth $\tau_e$ measurement from the Planck satellite and the ionized hydrogen fraction $Q_HII$ estimates at $złesssim7$ from the literature. We conduct $\chi^2$ minimization fitting of the model to the observational measurements, introducing three free parameters; the escape fraction $f_esc$, the conversion factor of the UV luminosity to the ionizing photon emission rate $\xi_ion$, and the faint limit of the galaxy UV luminosity function $M_trunc$. We find that there exist reionizaiton scenarios that consistently explain all of the observational measurements with the allowed parameters of $f_esc = 0.15^+0.06_-0.02$ and $M_trunc > -12.5$ for $\xi_ion/\rm erg^-1Hz = 25.34$. Our results indicate that the length of the reionization period is $\Delta z = 4.1\pm1.7$ (for $0.1 < Q_HII < 0.99$), which is consistent with the Planck's kinetic Sunyaev-Zel'dovich effect estimate.

Description

[1702.04867] Full-Data Results of Hubble Frontier Fields: UV Luminosity Functions at $z\sim6-10$ and a Consistent Picture of Cosmic Reionization

Links and resources

Tags