Parametric Recovery of Line‐of‐Sight Velocity Distributions from Absorption‐Line Spectra of Galaxies via Penalized Likelihood

ABSTRACT We investigate the accuracy of the parametric recovery of the line‐of‐sight velocity distribution (LOSVD) of the stars in a galaxy while working in pixel space. Problems appear when the data have a low signal‐to‐noise ratio or the observed LOSVD is not well sampled by the data. We propose a simple solution based on maximum penalized likelihood, and we apply it to the common situation in which the LOSVD is described by a Gauss‐Hermite series. We compare different techniques by extracting the stellar kinematics from observations of the barred lenticular galaxy NGC 3384 obtained with the SAURON integral‐field spectrograph.

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