The gzipped tar file civ.tar.gz contains:

48146 FITS files with the NMF reconstructions described in Allen et
al. (2011 MNRAS 410, 860. arXiv:1007.3991)
index.dat - a list of the SDSS objects included and their
corresponding FITS files
README.txt - this file

The FITS files are organised in subdirectories according to their
spectroscopic plate numbers. Filenames are of the form

PPPP/spSpec-MMMMM-PPPP-FFF_civ.fit

for MJD MMMMM, plate number PPPP, fiber number FFF.

Each FITS file contains a single Header and associated image:
Row 1 - SDSS spectrum
Row 2 - Noise array
Row 3 - NMF reconstruction
Row 4 - Flag showing which pixels were used in the fit.

Only the rest-frame region with velocities of -30000 to +5000 km/s
relative to the reference rest-frame wavelength 1550.77 Angstroms is
included. The restframe wavelengths are calculated using the Header
keyword z_NMF. 

The file index.dat contains 48146 lines of 5 columns:
Column 1 - SDSS name, taken from the SDSS DR7 Legacy Release where
available
Column 2 - MJD of observation
Column 3 - Plate number of observation
Column 4 - Fiber number of observation
Column 5 - Relative path to FITS file