Lyman- α Forest Constraints on Primordial Black Holes as Dark Matter
Autor: | Riccardo Murgia, Matteo Viel, Alvise Raccanelli, Giulio Scelfo |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
Physics
Astrophysics and Astronomy Cold dark matter General Relativity and Cosmology gr-qc Cosmic microwave background Dark matter General Physics and Astronomy Observable Primordial black hole Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Parameter space General Relativity and Quantum Cosmology Redshift Settore FIS/02 - Fisica Teorica Modelli e Metodi Matematici Settore FIS/05 - Astronomia e Astrofisica astro-ph.CO Reionization Astrophysics - Cosmology and Nongalactic Astrophysics |
Popis: | The renewed interest in the possibility that primordial black holes (PBHs) may constitute a significant part of the dark matter has motivated revisiting old observational constraints, as well as developing new ones. We present new limits on the PBH abundance, from a comprehensive analysis of high-resolution, high-redshift Lyman-$\alpha$ forest data. Poisson fluctuations in the PBH number density induce a small-scale power enhancement which departs from the standard cold dark matter prediction. Using a grid of hydrodynamic simulations exploring different values of astrophysical parameters, {we obtain a marginalized upper limit on the PBH mass of $f_{\rm PBH}M_{\rm PBH} \sim 60~M_{\odot}$ at $2\sigma$, when a Gaussian prior on the reionization redshift is imposed, preventing its posterior distribution to peak on very high values, which are disfavoured by the most recent estimates obtained both through Cosmic Microwave Background and Inter-Galactic Medium observations. Such bound weakens to $f_{\rm PBH}M_{\rm PBH} \sim 170~M_{\odot}$, when a conservative flat prior is instead assumed. Both limits significantly improves previous constraints from the same physical observable.} We also extend our predictions to non-monochromatic PBH mass distributions, ruling out large regions of the parameter space for some of the most viable PBH extended mass functions. Comment: 8 pages, 5 figures, 1 table (extended version with respect to the published one) |
Databáze: | OpenAIRE |
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