X-ray pre-ionization powered by accretion on the first black holes - II. Cosmological simulations and observational signatures

X-ray Preionisation Powered by Accretion on the First Black Holes. II: Cosmological Simulations and Observational Signatures

We use numerical simulations of a cosmological volume to study the X-ray ionisation and heating of the intergalactic medium by an early population of accreting black holes. By considering theoretical limits on the accretion rate and observational constraints from the X-ray background and faint X-ray source counts, we find that the maximum value of the optical depth to Thompson scattering that c...

X-ray Preionisation Powered by Accretion on the First Black Holes. I: a Model for the WMAP Polarisation Measurement

In this paper we investigate the possibility that there is a first phase of partial ionisation due to X-rays produced by black hole accretion in small-mass galaxies at redshifts 7 < z < 20. This is followed by complete reionisation by stellar sources at z ≃ 7. This scenario is motivated by the large optical depth to Thompson scattering, τe ≃ 0.17 ± 0.04, recently measured by WMAP. But it is als...

Discovery of the First Accretion-powered Millisecond X-ray Pulsar

X-ray Emission From Accretion Disks of AGN: Signatures of Supermassive Black Holes

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Spin, Accretion and the Cosmological Growth of Supermassive Black Holes

If supermassive black holes (SMBHs) are the energy sources that power quasars and active galactic nuclei, then QSO SDSS 1148+5251, the quasar with the highest redshift (zQSO = 6.43), hosts a supermassive black hole formed within ∼ 0.9 Gyr after the Big Bang. This requirement places constraints on the cosmological formation of SMBHs, believed to grow from smaller initial seeds by a combination o...