Spiral galaxies as progenitors of pseudo-bulge hosting S0s

Autor: Ajit K. Kembhavi, Kaustubh Vaghmare, Smita Mathur, Sudhanshu Barway
Rok vydání: 2015
Předmět:
Zdroj: Monthly Notices of the Royal Astronomical Society. 450:873-882
ISSN: 1365-2966
0035-8711
DOI: 10.1093/mnras/stv668
Popis: We present observations of pseudobulges in S0 and spiral galaxies using imaging data taken with the Spitzer Infra-Red Array Camera. We have used 2-d bulge-disk-bar decomposition to determine structural parameters of 185 S0 galaxies and 31 nearby spiral galaxies. Using the Sersic index and the position on the Kormendy diagram to classify their bulges as either classical or pseudo, we find that 25 S0s (14%) and 24 spirals (77%) host pseudoblges. The fraction of pseudobulges we find in spiral galaxies is consistent with previous results obtained with optical data and show that the evolution of a large fraction of spirals is governed by secular processes rather than by major mergers. We find that the bulge effective radius is correlated with the disk scale length for pseudobulges of S0s and spirals, as expected for secular formation of bulges from disk instabilities, though the disks in S0s are significantly smaller than those in spirals. We show that early-type pseudobulge hosting spirals can transform to pseudobulge hosting S0s by simple gas stripping. However, simple gas stripping mechanism is not sufficient to transform the late-type pseudobulge hosting spirals into pseudobulge hosting S0s.
12 pages, 7 figures, accepted for publication in MNRAS
Databáze: OpenAIRE