Presentation #126.03 in the session Elliptical and Other Galaxies.
Central velocity dispersions are very commonly used to both help classify and study scaling relationships of galaxies. However, most galaxies only have single-aperture spectra requiring a correction to the common aperture considered “central” in any given study. While such corrections have previously been published based on IFU data for early-type galaxies (Cappellari et al. 2006), late-type galaxies have not had their own corrections despite having a bias due to rotation on their measured velocity dispersion. To address this, we sampled the 4615 available galaxies in the MaNGA Data Release 15 Sloan Digital Sky Survey, 2689 of which are late-type galaxies. We first binned the IFU spectra into circular aperture summed spectra and then used the penalized Pixel Fitting Method (pPXF) to find the stellar velocity dispersion at each circular aperture radius. We then grouped galaxies into different mass and ellipticity bins (proxy for inclination) and applied a power-law fit. This provides, for a given mass and ellipticity range, a correction for a galaxy’s stellar velocity dispersion at a user’s choice of circular aperture.