ﻻ يوجد ملخص باللغة العربية
We present constraints on masses of active and sterile neutrinos. We use the one-dimensional Ly$alpha$-forest power spectrum from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey (SDSS-III) and from the VLT/XSHOOTER legacy survey (XQ-100). In this paper, we present our own measurement of the power spectrum with the publicly released XQ-100 quasar spectra. Fitting Ly$alpha$ 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 Ly$alpha$ power spectra, we constrain the sum of neutrino masses to $sum m_ u < 0.8$ eV (95% C.L). With the addition of CMB data, this bound is tightened to $sum m_ u < 0.14$ eV (95% C.L.). With their sensitivity to small scales, Ly$alpha$ data are ideal to constrain $Lambda$WDM models. Using XQ-100 alone, we issue lower bounds on pure dark matter particles: $m_X gtrsim 2.08 : rm{keV}$ (95% C.L.) for early decoupled thermal relics, and $m_s gtrsim 10.2 : rm{keV}$ (95% C.L.) for non-resonantly produced right-handed neutrinos. Combining the 1D Ly$alpha$ forest power spectrum measured by BOSS and XQ-100, we improve the two bounds to $m_X gtrsim 4.17 : rm{keV}$ and $m_s gtrsim 25.0 : rm{keV}$ (95% C.L.). The $3~sigma$ bound shows a more significant improvement, increasing from $m_X gtrsim 2.74 : rm{keV}$ for BOSS alone to $m_X gtrsim 3.10 : rm{keV}$ 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 with the high-resolution HIRES/MIKE spectrographs. The addition of HIRES/MIKE power spectrum allows us to further improve the two limits to $m_X gtrsim 4.65 : rm{keV}$ and $m_s gtrsim 28.8 : rm{keV}$ (95% C.L.).
We present the Lyman-$alpha$ flux power spectrum measurements of the XQ-100 sample of quasar spectra obtained in the context of the European Southern Observatory Large Programme Quasars and their absorption lines: a legacy survey of the high redshift
We present constraints on neutrino masses, the primordial fluctuation spectrum from inflation, and other parameters of the $Lambda$CDM model, using the one-dimensional Ly$alpha$-forest power spectrum measured by Palanque-Delabrouille et al. (2013) fr
The Lyman-alpha forest is the large-scale structure probe for which we appear to have modeling control to the highest wavenumbers, which makes it of great interest for constraining the warmness/fuzziness of the dark matter and the timing of reionizat
We measure the 1D Ly$,alpha$ power spectrum poned from Keck Observatory Database of Ionized Absorption toward Quasars (KODIAQ), The Spectral Quasar Absorption Database (SQUAD) and XQ-100 quasars using the optimal quadratic estimator. We combine KODIA
We have developed two independent methods to measure the one-dimensional power spectrum of the transmitted flux in the Lyman-$alpha$ forest. The first method is based on a Fourier transform, and the second on a maximum likelihood estimator. The two m