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 universe with VLT/XSHOOTER '' .
Using 100 quasar spectra with medium resolution and signal-to-noise ratio we measure the power spectrum over a range of redshifts z = 3 - 4.2 and over a range of scales k = 0.003 - 0.06 \mathrm { km ^ { -1 } s } .
The results agree well with the measurements of the one-dimensional power spectrum found in the literature .
The data analysis used in this paper is based on the Fourier transform and has been tested on synthetic data .
Systematic and statistical uncertainties of our measurements are estimated , with a total error ( statistical and systematic ) comparable to the one of the BOSS data in the overlapping range of scales , and smaller by more than 50 \% for higher redshift bins ( z > 3.6 ) and small scales ( k > 0.01 \mathrm { km ^ { -1 } s } ) .
The XQ-100 data set has the unique feature of having signal-to-noise ratios and resolution intermediate between the two data sets that are typically used to perform cosmological studies , i.e .
BOSS and high-resolution spectra ( e.g .
UVES/VLT or HIRES ) .
More importantly , the measured flux power spectra span the high redshift regime which is usually more constraining for structure formation models .