Structures in Warm Dark Matter (WDM) models are exponentially suppressed below a certain scale, characterized by the dark matter particle mass, mx . Since structures form hierarchically, the presence of collapsed objects at high-redshifts can set strong lower limits on mx . We place robust constraints on mx using recent results from the Swift database of high-redshift gamma-ray bursts (GRBs). We parameterize the redshift evolution of the ratio between the cosmic GRB rate and star formation rate (SFR) as ∝ (1+z)α , thereby allowing astrophysical uncertainties to partially mimic the cosmological suppression of structures in WDM models. Using a maximum likelihood estimator on two different z > 4 GRB subsamples (including two bursts at z > 8), we constrain mx 1.6-1.8 keV at 95% CL, when marginalized over a flat prior in α. We further estimate that 5 years of a SVOM-like mission would tighten these constraints to mx 2.3 keV. Our results show that GRBs are a powerful probe of high-redshift structures, providing robust and competitive constraints on mx .
Titolo: | Constraints on warm dark matter models from high-redshift long gamma-ray bursts | |
Autori: | ||
Editore: | ArXiv astro-ph | |
Data di pubblicazione: | 2013 | |
Rivista: | ||
Digital Object Identifier (DOI): | http://dx.doi.org/10.1093/mnras/stt674 | |
Parole chiave (inglese): | astrophysics cosmology cosmology. dark matter gamma-ray burst. general methods. statistical Physics | |
Handle: | http://hdl.handle.net/11384/24403 | |
Appare nelle tipologie: | 1.1 Articolo in rivista |
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1303.5060v2.pdf | Altro materiale allegato | Accesso gratuito (sola lettura) | Open Access Visualizza/Apri |