Star Formation History at the Centers of Lenticular Galaxies with Bars and Purely Exponential Outer Disks from SAURON Data

TL;DR

This study uses SAURON data to analyze stellar populations in lenticular galaxy centers, revealing chemically decoupled nuclei with varied ages and ongoing starburst activity, shedding light on galaxy evolution.

Contribution

It provides new insights into the stellar population properties and formation scenarios of lenticular galaxies with bars and exponential disks.

Findings

Chemically decoupled nuclei with higher metallicity detected in 7 of 8 galaxies.

Stellar ages in nuclei range from 1 to 11 Gyr.

Ongoing starburst activity observed in one galaxy.

Abstract

We have investigated the stellar population properties in the central regions of a sample of lenticular galaxies with bars and single-exponential outer stellar disks using the data from the SAURON integral-field spectrograph retrieved from the open Isaac Newton Group Archive. We have detected chemically decoupled compact stellar nuclei with a metallicity twice that of the stellar population in the bulges in seven of the eight galaxies. A starburst is currently going on at the center of the eighth galaxy and we have failed to determine the stellar population properties from its spectrum. The mean stellar ages in the chemically decoupled nuclei found range from 1 to 11 Gyr. The scenarios for the origin of both decoupled nuclei and lenticular galaxies as a whole are discussed.