These data includes observations conducted with the MagE spectrograph at 'Las Campanas' observatory, in April 2008 and March 2009. They were obtained targeting quasar pairs separated by small angles in the sky and are not publicly available in other archives. These quasar pair spectra are part of a larger dataset used to measure the transverse coherence in the absorption due to the effect of thermal pressure in the intergalactic medium of the ancient universe.

The repository contains both science and calibration frames, as marked in the header of each files. More information about the targets and the observing run can be found in Prochaska, Hennawi et al,2013 ApJ, 776, 136