Central velocity dispersion catalog of LAMOST-DR7 galaxies
  The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) is a
major facility to carry out spectroscopic surveys for cosmology and galaxy
evolution studies. The seventh data release of the LAMOST ExtraGAlactic Survey
(LEGAS) is currently available and including redshifts of 193\,361 galaxies.
These sources are spread over $\sim 11\,500$ deg$^2$ of the sky, largely
overlapping with other imaging (SDSS, HSC) and spectroscopic (BOSS) surveys.
The estimated depth of the galaxy sample, $r\sim17.8$, the high signal-to-noise
ratio, and the spectral resolution $R=1800$, make the LAMOST spectra suitable
for galaxy velocity dispersion measurements, which are invaluable to study the
structure and formation of galaxies and to determine their central dark matter
(DM) content. We present the first estimates of central velocity dispersion of
$\sim86\,000$ galaxies in LAMOST footprint. We have used a wrap-up procedure to
perform the spectral fitting using \textsc{pPXF}, and derive velocity
dispersion measurements. Statistical errors are also assessed by comparing
LAMOST velocity dispersion estimates with the ones of SDSS and BOSS over a
common sample of $\sim51\,000$ galaxies. The two datasets show a good
agreement, within the statistical errors, in particular when velocity
dispersion values are corrected to 1 effective radius aperture. We also present
a preliminary Mass-$\sigma$ relation and find consistency with previous
analyses based on local galaxy samples. These first results suggest that LAMOST
spectra are suitable for galaxy velocity dispersion measurements to complement
the available catalogs of galaxy internal kinematics in the northern
hemisphere. We plan to expand this analysis to next LAMOST data releases.
