Sample variance and Lyman α forest transmission statistics.

摘要: We compare the observed probability distribution function (PDF) of transmission in H I Lyman α forest, measured from Ultraviolet and Visual Echelle Spectrograph (UVES) ‘Large Programme’ sample at redshifts z = [2, 2.5, 3], to results GIMIC cosmological simulations. Our values for mean its PDF are good agreement with published results. Errors on statistics high-resolution data typically estimated using bootstrap or jackknife resampling techniques after splitting spectra into chunks. demonstrate that these methods tend underestimate variance unless chunk size is much larger than commonly case. therefore estimate conclude simulated agreement; particular, we do not require temperature–density relation be ‘inverted’.