The forest of Lyman-α absorption lines detected in the spectra of distant quasars encodes information on the nature and properties of dark matter and the thermodynamics of diffuse baryonic material. Its main observable - the 1D flux power spectrum (FPS) - should exhibit a suppression on small scales and an enhancement on large scales in warm dark matter (WDM) cosmologies compared to standard ΛCDM. Here, we present an unprecedented suite of 1080 high-resolution cosmological hydrodynamical simulations run with the graphics processing unit-accelerated code cholla to study the evolution of the Lyman-α forest under a wide range of physically motivated gas thermal histories along with different free-streaming lengths of WDM thermal relics in the early Universe. A statistical comparison of synthetic data with the forest FPS measured down to the smallest velocity scales ever probed at redshifts 4.0≲z≲5.2 [E. Boera et al., Revealing reionization with the thermal history of the intergalactic medium: New constraints from the Lyα flux power spectrum, Astrophys. J. 872, 101 (2019)ASJOAB0004-637X10.3847/1538-4357/aafee4] yields a lower-limit mWDM>3.1 keV (95% C.L.) for the WDM particle mass and constrains the amplitude and spectrum of the photoheating and photoionizing background produced by star-forming galaxies and active galactic nuclei at these redshifts. Interestingly, our Bayesian inference analysis appears to weakly favor WDM models with a peak likelihood value at the thermal relic mass of mWDM=4.5 keV. We find that the suppression of the FPS from free-streaming saturates at k≳0.1 s km-1 because of peculiar velocity smearing, and this saturated suppression combined with a slightly lower gas temperature provides a moderately better fit to the observed small-scale FPS for WDM cosmologies.

Villasenor, B., Robertson, B., Madau, P., Schneider, E. (2023). New constraints on warm dark matter from the Lyman- α forest power spectrum. PHYSICAL REVIEW D, 108(2) [10.1103/PhysRevD.108.023502].

New constraints on warm dark matter from the Lyman- α forest power spectrum

Madau P.;
2023

Abstract

The forest of Lyman-α absorption lines detected in the spectra of distant quasars encodes information on the nature and properties of dark matter and the thermodynamics of diffuse baryonic material. Its main observable - the 1D flux power spectrum (FPS) - should exhibit a suppression on small scales and an enhancement on large scales in warm dark matter (WDM) cosmologies compared to standard ΛCDM. Here, we present an unprecedented suite of 1080 high-resolution cosmological hydrodynamical simulations run with the graphics processing unit-accelerated code cholla to study the evolution of the Lyman-α forest under a wide range of physically motivated gas thermal histories along with different free-streaming lengths of WDM thermal relics in the early Universe. A statistical comparison of synthetic data with the forest FPS measured down to the smallest velocity scales ever probed at redshifts 4.0≲z≲5.2 [E. Boera et al., Revealing reionization with the thermal history of the intergalactic medium: New constraints from the Lyα flux power spectrum, Astrophys. J. 872, 101 (2019)ASJOAB0004-637X10.3847/1538-4357/aafee4] yields a lower-limit mWDM>3.1 keV (95% C.L.) for the WDM particle mass and constrains the amplitude and spectrum of the photoheating and photoionizing background produced by star-forming galaxies and active galactic nuclei at these redshifts. Interestingly, our Bayesian inference analysis appears to weakly favor WDM models with a peak likelihood value at the thermal relic mass of mWDM=4.5 keV. We find that the suppression of the FPS from free-streaming saturates at k≳0.1 s km-1 because of peculiar velocity smearing, and this saturated suppression combined with a slightly lower gas temperature provides a moderately better fit to the observed small-scale FPS for WDM cosmologies.
Articolo in rivista - Articolo scientifico
Dark Matter, Large-Scale Structure of the Universe, Cosmology, Simulations
English
2023
108
2
023502
none
Villasenor, B., Robertson, B., Madau, P., Schneider, E. (2023). New constraints on warm dark matter from the Lyman- α forest power spectrum. PHYSICAL REVIEW D, 108(2) [10.1103/PhysRevD.108.023502].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/452467
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