A SPITZER STUDY OF PSEUDOBULGES IN S0 GALAXIES: SECULAR EVOLUTION OF DISKS
- IUCAA, Post Bag 4, Ganeshkhind, Pune 411007 (India)
- South African Astronomical Observatory, P.O. Box 9, 7935 Observatory, Cape Town (South Africa)
In this Letter, we present a systematic study of lenticular (S0) galaxies based on mid-infrared imaging data on 185 objects taken using the Spitzer Infrared Array Camera. We identify the S0s hosting pseudobulges based on the position of the bulge on the Kormendy diagram and the Sersic index of the bulge. We find that pseudobulges preferentially occur in the fainter luminosity class (defined as having total K-band absolute magnitude M{sub K} fainter than -22.66 in the AB system). We present relations between bulge and disk parameters obtained as a function of the bulge type. The disks in the pseudobulge hosting galaxies are found to have distinct trends on the r{sub e}-r{sub d} and {mu}{sub d}(0)-r{sub d} correlations compared to those in galaxies with classical bulges. We show that the disks of pseudobulge hosts possess on average a smaller scale length and have a fainter central surface brightness than their counterparts occurring in classical bulge hosting galaxies. The differences found for discs in pseudobulge and classical bulge hosting galaxies may be a consequence of the different processes creating the central mass concentrations.
- OSTI ID:
- 22130718
- Journal Information:
- Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 767; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
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