%0 Journal Article
%4 sid.inpe.br/mtc-m21b/2020/06.25.17.05
%2 sid.inpe.br/mtc-m21b/2020/06.25.17.05.16
%@doi 10.1093/mnras/staa1568
%@issn 0035-8711
%@issn 1365-2966
%F self-archiving-INPE-MCTIC-GOV-BR
%T Effects of the Hubble parameter on the cosmic growth of the first quasars
%D 2020
%9 journal article
%A Nunes, Rafael da Costa,
%A Pacucci, Fabio,
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Harvard University
%@electronicmailaddress rafadcnunes@gmail.com
%@electronicmailaddress fabio.pacucci@cfa.harvard.edu
%B Monthly Notices of the Royal Astronomical Society
%V 496
%N 1
%P 888–893
%K quasars: supermassive black holes – cosmological parameters – dark ages, reionization, first stars – early Universe – cosmology: observations – cosmology: theory.
%X Supermassive black holes (SMBHs) play a crucial role in the evolution of galaxies and are currently detected up to z∼7.5. Theories describing black hole (BH) growth are challenged by howrapidly seeds with initialmassM 105M, formed at z∼2030, grewtoM ∼ 109M by z ∼ 7. Here we study the effects of the value of the Hubble parameter, H0, on models describing the early growth of BHs. First, we note that the predicted mass of a quasar at z = 6 changes by > 300 per cent if the underlying Hubble parameter used in the model varies from H0 = 65 to H0 = 74 km s−1Mpc−1, a range encompassing current estimates. Employing an MCMCapproach based on priors from z6.5 quasars and onH0,we study the interconnection between H0 and the parameters describing BH growth: seed mass Mi and Eddington ratio fEdd. Assuming an Eddington ratio of fEdd = 0.7, in agreement with previous estimates, we find H0 = 73.6+1.2 −3.3 km s−1Mpc−1. In a second analysis, allowing all the parameters to vary freely, we find log (Mi/M) > 4.5 (at 95 per cent CL), H0 = 74+1.5 −1.4 km s−1Mpc−1 and fEdd = 0.77+0.035 −0.026 at 68 per cent CL. Our results on the typical Eddington ratio are in agreement with previous estimates. Current values of the Hubble parameter strongly favour heavy seed formation scenarios, with Mi 104M. In our model, with the priors on BH masses of quasars used, light seed formation scenarios are rejected at ∼3σ.
%@language en
%3 nunes_effects.pdf