beecee Posted December 17, 2021 Posted December 17, 2021 https://phys.org/news/2021-12-black-holes-immediately-big.html Did black holes form immediately after the Big Bang? How did supermassive black holes form? What is dark matter? In an alternative model for how the universe came to be, as compared to the 'textbook' history of the universe, a team of astronomers propose that both of these cosmic mysteries could be explained by so-called "primordial black holes." Nico Cappelluti (University of Miami), Günther Hasinger (ESA Science Director) and Priyamvada Natarajan (Yale University), suggest that black holes existed since the beginning of the universe and that these primordial black holes could themselves be the as-of-yet unexplained dark matter. The new study is accepted for publication in The Astrophysical Journal. MORE AT LINK................ The paper: https://arxiv.org/pdf/2109.08701.pdf Exploring the high-redshift PBH-ΛCDM Universe: early black hole seeding, the first stars and cosmic radiation backgrounds. ABSTRACT: We explore the observational implications of a model in which primordial black holes (PBHs) with a broad birth mass function ranging in mass from a fraction of a solar mass to ∼106 M, consistent with current observational limits, constitute the dark matter component in the Universe. The formation and evolution of dark matter and baryonic matter in this PBH-ΛCDM Universe are presented. In this picture, PBH DM mini-halos collapse earlier than in standard ΛCDM, baryons cool to form stars at z ∼ 15 − 20, and growing PBHs at these early epochs start to accrete through Bondi capture. The volume emissivity of these sources peaks at z ∼ 20 and rapidly fades at lower redshifts. As a consequence, PBH DM could also provide a channel to make early black hole seeds and naturally account for the origin of an underlying dark matter halo - host galaxy and central black hole connection that manifests as the Mbh − σ correlation. To estimate the luminosity function and contribution to integrated emission power spectrum from these high-redshift PBH DM halos, we develop a Halo Occupation Distribution (HOD) model. In addition to tracing the star formation and reionizaton history, it permits us to evaluate the Cosmic Infrared and X-ray Backgrounds (CIB and CXB). We find that accretion onto PBHs/AGN successfully accounts for the detected backgrounds and their crosscorrelation, with the inclusion of an additional IR stellar emission component. Detection of the deep IR source count distribution by the JWST could reveal the existence of this population of high-redshift star-forming and accreting PBH DM.
joigus Posted December 21, 2021 Posted December 21, 2021 Final preparations for James Webb telescope: https://blogs.nasa.gov/webb/2021/12/18/nasas-webb-space-telescope-launch-confirmed-for-dec-24/?utm_source=FBPAGE&utm_medium=NASA's+James+Webb+Space+Telescope&utm_campaign=NASASocial&linkId=144816059&fbclid=IwAR1B123ZizvSW9293DGEWK3OACEfQfmuH5CUoqnOFji34qmP0k6HHqLzxbI We may be entering a new era of astrophysics and cosmology. Fingers crossed. After LIGO's enormous success, this looks very promising. Primordial BHs are my favourite explanation of DM. 1
beecee Posted December 21, 2021 Author Posted December 21, 2021 10 hours ago, joigus said: Final preparations for James Webb telescope: https://blogs.nasa.gov/webb/2021/12/18/nasas-webb-space-telescope-launch-confirmed-for-dec-24/?utm_source=FBPAGE&utm_medium=NASA's+James+Webb+Space+Telescope&utm_campaign=NASASocial&linkId=144816059&fbclid=IwAR1B123ZizvSW9293DGEWK3OACEfQfmuH5CUoqnOFji34qmP0k6HHqLzxbI We may be entering a new era of astrophysics and cosmology. Fingers crossed. After LIGO's enormous success, this looks very promising. Primordial BHs are my favourite explanation of DM. I actually concur with your final comment.
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