The effect of neutrinos on the matter distribution as probed by the intergalactic medium
- INAF-Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, I-34131 Trieste (Italy)
- Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom)
- Max-Planck Institut für Astrophysik, Karl-Schwarzschild Str. 1, 85748 Garching (Germany)
We present a suite of full hydrodynamical cosmological simulations that quantitatively address the impact of neutrinos on the (mildly non-linear) spatial distribution of matter and in particular on the neutral hydrogen distribution in the Intergalactic Medium (IGM), which is responsible for the intervening Lyman-α absorption in quasar spectra. The free-streaming of neutrinos results in a (non-linear) scale-dependent suppression of power spectrum of the total matter distribution at scales probed by Lyman-α forest data which is larger than the linear theory prediction by about 25 % and strongly redshift dependent. By extracting a set of realistic mock quasar spectra, we quantify the effect of neutrinos on the flux probability distribution function and flux power spectrum. The differences in the matter power spectra translate into a ∼ 2.5% (5%) difference in the flux power spectrum for neutrino masses with Σm{sub ν} = 0.3 eV (0.6 eV). This rather small effect is difficult to detect from present Lyman-α forest data and nearly perfectly degenerate with the overall amplitude of the matter power spectrum as characterised by σ{sub 8}. If the results of the numerical simulations are normalized to have the same σ{sub 8} in the initial conditions, then neutrinos produce a smaller suppression in the flux power of about 3% (5%) for Σm{sub ν} = 0.6 eV (1.2 eV) when compared to a simulation without neutrinos. We present constraints on neutrino masses using the Sloan Digital Sky Survey flux power spectrum alone and find an upper limit of Σm{sub ν} < 0.9 eV (2σ C.L.), comparable to constraints obtained from the cosmic microwave background data or other large scale structure probes.
- OSTI ID:
- 22272915
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2010, Issue 06; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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