This catalog contains the best-fit spectroscopic redshift and corresponding model flux for each DR17 MaNGA spectrum that has sufficient signal-to-noise to be fitted. Redshifts are derived by iterative application of the BOSS pipeline's spec1d software (Bolton et al. 2012), using mean derived redshift as a prior, which allows determination of redshifts on spectra that would not otherwise have sufficient signal-to-noise to result in a reliable measurement. Since the MaNGA survey uses an IFU, the radial velocity profile of the galaxy can significantly impact the redshift of each spectra: the spectroscopic redshifts can both be a benefit to galaxy kinematic measurements and improve the accuracy of spectra modeling and analysis. In addition, the catalog contains the mean spectroscopic redshift of each MaNGA galaxy sampled within a radius (R_inner) with sufficiently high signal-to-noise that each spectroscopic redshift is within three times the dispersion of the redshifts from the median of the enclosed sample. This catalog has been used by Talbot et al. (2018) to search for background emission lines to discover strong gravitational lenses in MaNGA.
In addition to the catalog files, images (PDF and PNG) of redshift and signal-to-noise (S/N) as a function of radius for individual galaxies are available here. Red open symbols are for redshift, and black filled symbols for S/N. The green vertical dashed line represents R_inner. The blue horizontal dashed line represents the mean redshift within R_inner.
We always recommend that you use the latest version of this catalog, which is DR17. The earlier DR15 version of this catalog is still available on the SAS here, with datamodels available here.
