A Search for "Dwarf" Seyfert Nuclei. VII. A Catalog of Central Stellar Velocity Dispersions of Nearby Galaxies

TL;DR

This paper provides new measurements of central stellar velocity dispersions for 428 nearby galaxies, including many with low dispersions, using a robust pixel-fitting method to improve data quality and reliability.

Contribution

It introduces a new dataset of stellar velocity dispersions for 428 galaxies, including 142 with no prior data, using an improved pixel-fitting technique suitable for diverse galaxy types.

Findings

Measured dispersions for 142 previously unreported galaxies.

Demonstrated the effectiveness of the pixel-fitting method across various galaxy types.

Provided updated dispersions with reduced uncertainties for existing data.

Abstract

We present new central stellar velocity dispersion measurements for 428 galaxies in the Palomar spectroscopic survey of bright, northern galaxies. Of these, 142 have no previously published measurements, most being relatively late-type systems with low velocity dispersions (< 100 km/s). We provide updates to a number of literature dispersions with large uncertainties. Our measurements are based on a direct pixel-fitting technique that can accommodate composite stellar populations by calculating an optimal linear combination of input stellar templates. The original Palomar survey data were taken under conditions that are not ideally suited for deriving stellar velocity dispersions for galaxies with a wide range of Hubble types. We describe an effective strategy to circumvent this complication and demonstrate that we can still obtain reliable velocity dispersions for this sample of well-studied nearby galaxies.