We present constraints on masses of active and sterile neutrinos in the context of the \Lambda CDM \nu and \Lambda WDM models , respectively .
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 ) measured by Palanque-Delabrouille et al . [ ] , 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 ^ { -1 } .
We compare the obtained 1D Ly \alpha flux power spectrum to the one measured by Irsic et al . [ ] to k -modes of 0.057 s km ^ { -1 } .

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 _ { \nu } < 0.8 eV ( 95 % C.L . )
including all identified sources of systematic uncertainties .
With the addition of CMB data , this bound is tightened to \sum m _ { \nu } < 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 \ > keV ( 95 % C.L . )
for early decoupled thermal relics , and m _ { s } \gtrsim 10.2 \ > 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 \ > keV and m _ { s } \gtrsim 25.0 \ > keV ( 95 % C.L .
) , slightly more constraining than what was achieved in Baur et al .
2015 [ ] with BOSS data alone .
The 3 ~ { } \sigma bound shows a more significant improvement , increasing from m _ { X } \gtrsim 2.74 \ > keV for BOSS alone to m _ { X } \gtrsim 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 [ ] 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 \ > keV and m _ { s } \gtrsim 28.8 \ > keV ( 95 % C.L .
) .