Publication: Constraining the epoch of reionization fron the observed properties of the high-z universe
Full text at PDC
Advisors (or tutors)
American Astronomical Society
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.
© 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.