Illuminating the dark ages: Cosmic backgrounds from accretion onto primordial black hole dark matter. (arXiv:2003.05150v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Hasinger_G/0/1/0/all/0/1">G. Hasinger</a>
Cold dark matter as the sum of different mass Primordial Black Hole (PBH)
could explain a number of mysteries, like the massive seed BH needed for the
earliest QSOs, the massive LIGO/VIRGO binary BH, or the putative “Planet X” PBH
in our Solar System. The most abundant PBH should be around the Chandrasekhar
mass. This may already have been vindicated by the recent OGLE/GAIA population
of putative BH of 1-10 Msun. I assume that all dark matter exists in the form
of 1.4 Msun PBH and estimate the contribution of baryon accretion onto PBH to
the cosmic backgrounds, concentrating on the Cosmic X-ray/Cosmic infrared
background fluctuations discovered in deep Chandra and Spitzer surveys. Bondi
accretion over cosmic time, assuming appropriate values of baryon density and
effective relative velocity, as well as accretion and radiation efficiencies,
predict a PBH contribution consistent with the residual X-ray fluctuations,
peaking at z~17-30 consistent with other constraints requiring high redshifts
for this signal. The PBH contribution to the Cosmic Infrared fluctuations is
only about 1%, thus these are likely from star formation processes associated
with the PBH. Other phenomena could be affected by the PBH accretion. Magnetic
fields are an essential ingredient in the accretion process, and PBH can play
an important role in amplifying magnetic seed fields in the early universe. The
contribution of PBH to the re-ionization history of the universe does not
conflict with the stringent limits from the most recent Planck data. X-ray
heating from PBH can contribute to the entropy floor observed in groups of
galaxies. The redshifted 21-cm absorption line feature observed by EDGES could
be connected to the PBH radio emission. The diffuse X-ray emission in the
Galactic Center region is not violated by PBH; some of the discrete sources in
the Chandra Galactic Ridge observations could be PBH.
Cold dark matter as the sum of different mass Primordial Black Hole (PBH)
could explain a number of mysteries, like the massive seed BH needed for the
earliest QSOs, the massive LIGO/VIRGO binary BH, or the putative “Planet X” PBH
in our Solar System. The most abundant PBH should be around the Chandrasekhar
mass. This may already have been vindicated by the recent OGLE/GAIA population
of putative BH of 1-10 Msun. I assume that all dark matter exists in the form
of 1.4 Msun PBH and estimate the contribution of baryon accretion onto PBH to
the cosmic backgrounds, concentrating on the Cosmic X-ray/Cosmic infrared
background fluctuations discovered in deep Chandra and Spitzer surveys. Bondi
accretion over cosmic time, assuming appropriate values of baryon density and
effective relative velocity, as well as accretion and radiation efficiencies,
predict a PBH contribution consistent with the residual X-ray fluctuations,
peaking at z~17-30 consistent with other constraints requiring high redshifts
for this signal. The PBH contribution to the Cosmic Infrared fluctuations is
only about 1%, thus these are likely from star formation processes associated
with the PBH. Other phenomena could be affected by the PBH accretion. Magnetic
fields are an essential ingredient in the accretion process, and PBH can play
an important role in amplifying magnetic seed fields in the early universe. The
contribution of PBH to the re-ionization history of the universe does not
conflict with the stringent limits from the most recent Planck data. X-ray
heating from PBH can contribute to the entropy floor observed in groups of
galaxies. The redshifted 21-cm absorption line feature observed by EDGES could
be connected to the PBH radio emission. The diffuse X-ray emission in the
Galactic Center region is not violated by PBH; some of the discrete sources in
the Chandra Galactic Ridge observations could be PBH.
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