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Title: Constraints on neutrino masses from Lyman-alpha forest power spectrum with BOSS and XQ-100

Abstract

We present constraints on masses of active and sterile neutrinos in the context of the ΛCDMν and ΛWDM models, respectively. We use the one-dimensional Lyα-forest power spectrum from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS-III) measured by Palanque-Delabrouille et al. [1], and from the VLT/XSHOOTER legacy survey (XQ-100). In this paper, we present our own measurement of the publicly released XQ-100 quasar spectra, focusing in particular on an improved determination of the spectrograph resolution that allows us to push to smaller scales than the public release and reach k -modes of 0.070 s km{sup −1}. We compare the obtained 1D Lyα flux power spectrum to the one measured by Irsic et al. [2] to k -modes of 0.057 s km{sup −1}. Fitting Lyα data alone leads to cosmological parameters in excellent agreement with the values derived independently from Planck 2015 Cosmic Microwave Background (CMB) data. Combining BOSS and XQ-100 Lyα power spectra, we constrain the sum of neutrino masses to ∑ m {sub ν} < 0.8 eV (95% C.L.) including all identified sources of systematic uncertainties. With the addition of CMB data, this bound is tightened to ∑ m {sub ν} < 0.14 eVmore » (95% C.L.). With their sensitivity to small scales, Lyα data are ideal to constrain ΛWDM models. Using XQ-100 alone, we issue lower bounds on pure dark matter particles: m {sub X} ∼> 2.08 : keV (95% C.L.) for early decoupled thermal relics, and m {sub s} ∼> 10.2 : keV (95% C.L.) for non-resonantly produced right-handed neutrinos. Combining the 1D Lyα-forest power spectrum measured by BOSS and XQ-100, we improve the two bounds to m {sub X} ∼> 4.17 : keV and m {sub s} ∼> 25.0 : keV (95% C.L.), slightly more constraining than what was achieved in Baur et al. 2015 [3] with BOSS data alone. The 3 σ bound shows a more significant improvement, increasing from m {sub X} ∼> 2.74 : keV for BOSS alone to m {sub X} ∼> 3.10 : keV for the combined BOSS+XQ-100 data set. Finally, we include in our analysis the first two redshift bins ( z = 4.2 and z = 4.6) of the power spectrum measured by Viel et al. 2013 [4] with the high-resolution HIRES/MIKE spectrographs. The addition of HIRES/MIKE power spectrum allows us to further improve the two limits to m {sub X} ∼> 4.65 : keV and m {sub s} ∼> 28.8 : keV (95% C.L.).« less

Authors:
; ; ;  [1]
  1. CEA, Centre de Saclay, IRFU/SPP, F-91191 Gif-sur-Yvette (France)
Publication Date:
OSTI Identifier:
22676141
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2017; Journal Issue: 06; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BARYONS; COMPARATIVE EVALUATIONS; KEV RANGE; LYMAN LINES; MASS; ONE-DIMENSIONAL CALCULATIONS; OSCILLATIONS; QUASARS; RED SHIFT; RELICT RADIATION; RESOLUTION; SPECTRA; STERILE NEUTRINOS

Citation Formats

Yèche, Christophe, Palanque-Delabrouille, Nathalie, Baur, Julien, and Bourboux, Hélion du Mas des, E-mail: christophe.yeche@cea.fr, E-mail: nathalie.palanque-delabrouille@cea.fr, E-mail: julien.baur@cea.fr, E-mail: helion.du-mas-des-bourboux@cea.fr. Constraints on neutrino masses from Lyman-alpha forest power spectrum with BOSS and XQ-100. United States: N. p., 2017. Web. doi:10.1088/1475-7516/2017/06/047.
Yèche, Christophe, Palanque-Delabrouille, Nathalie, Baur, Julien, & Bourboux, Hélion du Mas des, E-mail: christophe.yeche@cea.fr, E-mail: nathalie.palanque-delabrouille@cea.fr, E-mail: julien.baur@cea.fr, E-mail: helion.du-mas-des-bourboux@cea.fr. Constraints on neutrino masses from Lyman-alpha forest power spectrum with BOSS and XQ-100. United States. doi:10.1088/1475-7516/2017/06/047.
Yèche, Christophe, Palanque-Delabrouille, Nathalie, Baur, Julien, and Bourboux, Hélion du Mas des, E-mail: christophe.yeche@cea.fr, E-mail: nathalie.palanque-delabrouille@cea.fr, E-mail: julien.baur@cea.fr, E-mail: helion.du-mas-des-bourboux@cea.fr. Thu . "Constraints on neutrino masses from Lyman-alpha forest power spectrum with BOSS and XQ-100". United States. doi:10.1088/1475-7516/2017/06/047.
@article{osti_22676141,
title = {Constraints on neutrino masses from Lyman-alpha forest power spectrum with BOSS and XQ-100},
author = {Yèche, Christophe and Palanque-Delabrouille, Nathalie and Baur, Julien and Bourboux, Hélion du Mas des, E-mail: christophe.yeche@cea.fr, E-mail: nathalie.palanque-delabrouille@cea.fr, E-mail: julien.baur@cea.fr, E-mail: helion.du-mas-des-bourboux@cea.fr},
abstractNote = {We present constraints on masses of active and sterile neutrinos in the context of the ΛCDMν and ΛWDM models, respectively. We use the one-dimensional Lyα-forest power spectrum from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS-III) measured by Palanque-Delabrouille et al. [1], and from the VLT/XSHOOTER legacy survey (XQ-100). In this paper, we present our own measurement of the publicly released XQ-100 quasar spectra, focusing in particular on an improved determination of the spectrograph resolution that allows us to push to smaller scales than the public release and reach k -modes of 0.070 s km{sup −1}. We compare the obtained 1D Lyα flux power spectrum to the one measured by Irsic et al. [2] to k -modes of 0.057 s km{sup −1}. Fitting Lyα data alone leads to cosmological parameters in excellent agreement with the values derived independently from Planck 2015 Cosmic Microwave Background (CMB) data. Combining BOSS and XQ-100 Lyα power spectra, we constrain the sum of neutrino masses to ∑ m {sub ν} < 0.8 eV (95% C.L.) including all identified sources of systematic uncertainties. With the addition of CMB data, this bound is tightened to ∑ m {sub ν} < 0.14 eV (95% C.L.). With their sensitivity to small scales, Lyα data are ideal to constrain ΛWDM models. Using XQ-100 alone, we issue lower bounds on pure dark matter particles: m {sub X} ∼> 2.08 : keV (95% C.L.) for early decoupled thermal relics, and m {sub s} ∼> 10.2 : keV (95% C.L.) for non-resonantly produced right-handed neutrinos. Combining the 1D Lyα-forest power spectrum measured by BOSS and XQ-100, we improve the two bounds to m {sub X} ∼> 4.17 : keV and m {sub s} ∼> 25.0 : keV (95% C.L.), slightly more constraining than what was achieved in Baur et al. 2015 [3] with BOSS data alone. The 3 σ bound shows a more significant improvement, increasing from m {sub X} ∼> 2.74 : keV for BOSS alone to m {sub X} ∼> 3.10 : keV for the combined BOSS+XQ-100 data set. Finally, we include in our analysis the first two redshift bins ( z = 4.2 and z = 4.6) of the power spectrum measured by Viel et al. 2013 [4] with the high-resolution HIRES/MIKE spectrographs. The addition of HIRES/MIKE power spectrum allows us to further improve the two limits to m {sub X} ∼> 4.65 : keV and m {sub s} ∼> 28.8 : keV (95% C.L.).},
doi = {10.1088/1475-7516/2017/06/047},
journal = {Journal of Cosmology and Astroparticle Physics},
number = 06,
volume = 2017,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2017},
month = {Thu Jun 01 00:00:00 EDT 2017}
}
  • We present constraints on neutrino masses, the primordial fluctuation spectrum from inflation, and other parameters of the ΛCDM model, using the one-dimensional Lyα-forest power spectrum measured by [1] from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS-III), complemented by Planck 2015 cosmic microwave background (CMB) data and other cosmological probes. This paper improves on the previous analysis by [2] by using a more powerful set of calibrating hydrodynamical simulations that reduces uncertainties associated with resolution and box size, by adopting a more flexible set of nuisance parameters for describing the evolution of the intergalactic medium,more » by including additional freedom to account for systematic uncertainties, and by using Planck 2015 constraints in place of Planck 2013. Fitting Lyα data alone leads to cosmological parameters in excellent agreement with the values derived independently from CMB data, except for a weak tension on the scalar index n{sub s}. Combining BOSS Lyα with Planck CMB constrains the sum of neutrino masses to ∑ m{sub ν} < 0.12 eV (95% C.L.) including all identified systematic uncertainties, tighter than our previous limit (0.15 eV) and more robust. Adding Lyα data to CMB data reduces the uncertainties on the optical depth to reionization τ, through the correlation of τ with σ{sub 8}. Similarly, correlations between cosmological parameters help in constraining the tensor-to-scalar ratio of primordial fluctuations r. The tension on n{sub s} can be accommodated by allowing for a running dn{sub s}/d ln k. Allowing running as a free parameter in the fits does not change the limit on ∑ m{sub ν}. We discuss possible interpretations of these results in the context of slow-roll inflation.« less
  • We present the first measurement of the large-scale cross-correlation of Lyα forest absorption and Damped Lyman α systems (DLA), using the 9th Data Release of the Baryon Oscillation Spectroscopic Survey (BOSS). The cross-correlation is clearly detected on scales up to 40h{sup −1}Mpc and is well fitted by the linear theory prediction of the standard Cold Dark Matter model of structure formation with the expected redshift distortions, confirming its origin in the gravitational evolution of structure. The amplitude of the DLA-Lyα cross-correlation depends on only one free parameter, the bias factor of the DLA systems, once the Lyα forest bias factorsmore » are known from independent Lyα forest correlation measurements. We measure the DLA bias factor to be b{sub D} = (2.17±0.20)β{sub F}{sup 0.22}, where the Lyα forest redshift distortion parameter β{sub F} is expected to be above unity. This bias factor implies a typical host halo mass for DLAs that is much larger than expected in present DLA models, and is reproduced if the DLA cross section scales with halo mass as M{sub h}{sup α}, with α = 1.1±0.1 for β{sub F} = 1. Matching the observed DLA bias factor and rate of incidence requires that atomic gas remains extended in massive halos over larger areas than predicted in present simulations of galaxy formation, with typical DLA proper sizes larger than 20 kpc in host halos of masses ∼ 10{sup 12}M{sub ☉}. We infer that typical galaxies at z ≅ 2 to 3 are surrounded by systems of atomic clouds that are much more extended than the luminous parts of galaxies and contain ∼ 10% of the baryons in the host halo.« less
  • For this research, we have developed two independent methods for measuring the one-dimensional power spectrum of the transmitted flux in the Lyman-α forest. The first method is based on a Fourier transform and the second on a maximum-likelihood estimator. The two methods are independent and have different systematic uncertainties. Determination of the noise level in the data spectra was subject to a new treatment, because of its significant impact on the derived power spectrum. We applied the two methods to 13 821 quasar spectra from SDSS-III/BOSS DR9 selected from a larger sample of over 60 000 spectra on the basismore » of their high quality, high signal-to-noise ratio (S/N), and good spectral resolution. The power spectra measured using either approach are in good agreement over all twelve redshift bins from = 2.2 to = 4.4, and scales from 0.001 km s -1 to 0.02 km s -1. We determined the methodological andinstrumental systematic uncertainties of our measurements. We provide a preliminary cosmological interpretation of our measurements using available hydrodynamical simulations. The improvement in precision over previously published results from SDSS is a factor 2–3 for constraints on relevant cosmological parameters. For a ΛCDM model and using a constraint on H 0 that encompasses measurements based on the local distance ladder and on CMB anisotropies, we infer σ 8 = 0.83 ± 0.03 and n s = 0.97 ± 0.02 based on H i absorption in the range 2.1 < z < 3.7.« less
  • Using a sample of approximately 14,000 z > 2.1 quasars observed in the first year of the Baryon Oscillation Spectroscopic Survey (BOSS), we measure the three-dimensional correlation function of absorption in the Lyman-α forest. The angle-averaged correlation function of transmitted flux (F = e{sup −τ}) is securely detected out to comoving separations of 60 h{sup −1}Mpc, the first detection of flux correlations across widely separated sightlines. A quadrupole distortion of the redshift-space correlation function by peculiar velocities, the signature of the gravitational instability origin of structure in the Lyman-α forest, is also detected at high significance. We obtain a goodmore » fit to the data assuming linear theory redshift-space distortion and linear bias of the transmitted flux, relative to the matter fluctuations of a standard ΛCDM cosmological model (inflationary cold dark matter with a cosmological constant). At 95% confidence, we find a linear bias parameter 0.16 < b < 0.24 and redshift-distortion parameter 0.44 < β < 1.20, at central redshift z = 2.25, with a well constrained combination b(1+β) = 0.336±0.012. The errors on β are asymmetric, with β = 0 excluded at over 5σ confidence level. The value of β is somewhat low compared to theoretical predictions, and our tests on synthetic data suggest that it is depressed (relative to expectations for the Lyman-α forest alone) by the presence of high column density systems and metal line absorption. These results set the stage for cosmological parameter determinations from three-dimensional structure in the Lyman-α forest, including anticipated constraints on dark energy from baryon acoustic oscillations.« less