Reionization of the early Universe by electromagnetic cascades produced by microquasars

MIRABEL, I. FÉLIX; DOUNA, VANESA M.; LAURENT, PHILIPPE; PELLIZZA, LEONARDO J.

San Carlos de Bariloche

Conferencia; Distant Galaxies from the Far South; 2017

Kapteyn Astronomical Institute University of Groningen

p { margin-bottom: 0.1in; direction: ltr; color: rgb(0, 0, 0); line-height: 120%; }p.western { font-family: "Liberation Serif","Times New Roman",serif; font-size: 12pt; }p.cjk { font-family: "Droid Sans Fallback"; font-size: 12pt; }p.ctl { font-family: "FreeSans"; font-size: 12pt; }Reionization is one of the main cosmological phase transitions of theUniverse. Observational evidence shows that ~1Gyr after the Big Bang,the intergalactic medium was ionized, although it had become neutralmuch before, when the Cosmic Microwave Background was released ~0.3Myr after the Big Bang. Despite the increasing knowledge of the Epochof Reionization in light of the new observational skills, the sourcesof reionization are still being debated. UV photons from massivestars seem to be the main reionization agents, although X-rays fromaccreting black-hole populations and cosmic rays have also beenconsidered. At this age, massive black holes should be in majority inthe accreting black hole populations, and thus microquasars shouldhave contributed, as they display jets in which electrons areaccelerated to multi-TeV energies and ionize the surrounding medium.With the aim of studying the kinetic feedback ofmicroquasars, we simulated by means of a Monte Carlo scheme, thepropagationof the electrons injectedby these sources. In this work, we explore thecontribution of the electromagnetic cascades they initiate to theionization and heating of the intergalactic medium at cosmic dawn.