X-ray emission from high-redshift miniquasars: self-regulating the population of massive black holes through global warming

摘要: Observations of high-redshift quasars at z � 6 imply that supermassive black holes (SMBHs) with masses M 10 9 M⊙ were in place less than 1 Gyr after the Big Bang. If these SMBHs assembled from “seed” BHs left behind by first stars, then they must have accreted gas close to Eddington limit during a large fraction ( 50%) time. A generic problem this scenario, however, is mass density already exceeds locally observed SMBH several orders magnitude; order avoid overproduction, BH seed formation and growth become significantly efficientin massive protogalaxies through some form feedback, while proceeding unabated most galaxies formed first. Using Monte-Carlo realizations merger history BHs, we show X-rays earliest accreting can provide such feedback mechanism, on global scale. Our calculations paint self-consistent picture black-hole-made climate change, which miniquasars—among them ancestors quasar SMBHs—globally warm intergalactic medium suppress subsequent generations BHs. We present two specific models miniquasar excellent agreement recent estimates = function. For each models, estimate rate mergers > could be detected proposed gravitational-wave observatory eLISA/NGO.