Cosmological test using the highredshift detection rate of FSRQs with the Square Kilometre Array
Abstract
We present a phenomenological method for predicting the number of flatspectrum radio quasars (FSRQs) that should be detected by upcoming Square Kilometre Array (SKA) SKA1MID Wide Band 1 and MediumDeep Band 2 surveys. We use the Fermi blazar sequence and mass estimates of Fermi FSRQs, and γray emitting narrowline Seyfert 1 galaxies, to model the radio emission of FSRQs as a function of mass alone, assuming a nearEddington accretion rate, which is suggested by current quasar surveys at z ≳ 6. This is used to determine the smallest visible black hole mass as a function of redshift in two competing cosmologies we compare in this paper: the standard Λ cold dark matter (ΛCDM) model and the R_{h} = ct universe. We then apply lockstep growth to the observed black hole mass function at z = 6 in order to devolve that population to higher redshifts and determine the number of FSRQs detectable by the SKA surveys as a function of z. We find that at the redshifts for which this method is most valid, ΛCDM predicts ∼30 times more FSRQs than R_{h} = ct for the Wide survey, and ∼100 times more in the MediumDeep survey. These stark differences will allow the SKA surveys to strongly differentiate between these two models, possibly rejecting one in comparison with the other at a high level of confidence.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 August 2019
 DOI:
 10.1093/mnras/stz1396
 arXiv:
 arXiv:1905.08086
 Bibcode:
 2019MNRAS.487.2030L
 Keywords:

 galaxies: general;
 distance scale;
 largescale structure of Universe;
 cosmology: observations;
 cosmology: theory;
 Astrophysics  High Energy Astrophysical Phenomena;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 Astrophysics  Astrophysics of Galaxies
 EPrint:
 8 pages, 5 figures, 3 tables. Accepted for publication in MNRAS