The Nuclear Activities of Nearby S0 Galaxies

Abstract

We present a study of nuclear activities in nearby S0 galaxies. After cross-matching the Sloan Digital Sky Survey Data Release 7 (SDSS DR7) with the Third Reference Catalog of Bright Galaxies (RC3) and visually checking the SDSS images, we derive a sample of 583 S0 galaxies with the central spectrophotometric information. In order to separate nebular emission lines from the underlying stellar contribution, we fit the stellar population model to the SDSS spectra of these S0 galaxies. According to the BPT diagram, we find that $8\%$ of S0 galaxies show central star-forming activity, while the fractions of Seyfert, Composite and LINERs are 2\%, 8\%, and 21.4\%, respectively. We also find that star-forming S0s have the lowest stellar masses, over one magnitude lower than the others, and that the active S0s locate mainly in the sparse environment, while the normal S0s in the dense environment, which might suggest that the environment plays an important role in quenching star formation and/or AGN activity in S0 galaxies. By performing bulge-disk decomposition of 45 star-forming S0s in {\em g}- and {\em r}-bands with the 2D fitting software \textsc{Galfit}, as well as exploiting the catalog of 2D photometric decompositions of \citet{Meert2015}, we find that the bulges of $\sim$ 1/3 star-forming S0 galaxies (16/45) are bluer than their disks, while for other types of S0s, the bulge and disk components show similar color distributions. Besides, the Sérsic index of most star-forming S0s bulges is less than 2, while for normal S0s, it is between 2 and 6.

15 pages, 13 figures, accepted to ApJ (831:63)

References in corpus (4)

• UV Star Formation Rates in the Local Universe
• Suppression of star formation in early-type galaxies by feedback from supermassive black holes
• The clustering of narrow-line AGN in the local Universe
• SDSS-IV MaNGA: Properties of galaxies with kinematically decoupled stellar and gaseous components

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• The local universe in the era of large surveys. I. Spectral classification of S0 galaxies
• The physical properties of S0 galaxy PGC 26218: the origin of starburst and star formation
• The local Universe in the era of large surveys -- II. Multi-wavelength characterisation of activity in nearby S0 galaxies
• Asymmetric star formation triggered by gas inflow in a barred lenticular galaxy PGC 34107
• The Nature of the Double Nuclei in the Barred S0 Galaxy IC676
• Observations of cold gas and star formation in dwarf S0 galaxies