Speaker
Description
Theoretical models and observations suggest that primordial Stellar Black Holes
(Pop-III-BHs) were prolifically formed in HMXBs, which are powerful relativistic jet sources of synchrotron radiation called Microquasars (MQs).
Large populations of BH-HMXB-MQs at cosmic dawn produce a smooth synchrotron cos-
mic radio background (CRB) that could account for the excess amplitude of atomic hydrogen absorption at z∼17, recently reported by EDGES.
BH-HMXB-MQs at cosmic dawn precede supernovae, neutron stars and dust. BH-HMXB-
MQs promptly inject into the IGM hard X-rays and relativistic jets, which overtake the slowly expanding HII regions ionized by progenitor Pop-III stars, heating and partially ionizing the IGM over larger distance scales.
BH-HMXBs are channels for the formation of Binary-Black-Holes (BBHs). The large masses of BBHs detected by gravitational waves, relative to the masses of BHs detected by X-rays, and the high rates of BBH-mergers, are consistent with high formation rates of BH-HMXBs and BBHs in the early universe.
Recent references on this subject:
Mirabel, I.F. 2017, New Astron. Revs. 78, 1
Mirabel, I.F. 2019, Invited review at IAUS 346: arXiv#1902.00511.pdf
