Ground-based Paα narrow-band imaging of local luminous infrared galaxies. II. Bulge structure and star formation activity
Abstract
We present properties of two types of bulges (classical and pseudobulges) in 20 luminous infrared galaxies observed in the near infrared of the H, Ks, and 1.91μm narrow-band targeting of the hydrogen Paα emission line by the University of Tokyo Atacama Observatory 1 m telescope. To classify the two types of bulges, we first perform a two-dimensional bulge-disk decomposition analysis in the Ks-band images. The result shows a tentative bimodal distribution of Sérsic indices with a separation at log (nb) ≈ 0.5, which is consistent with that of classical and normal galaxies. We next measure the extents of the distributions of star-forming regions in Paα emission line images, normalized by the size of the bulges, and find that they decrease with increasing Sérsic indices. These results suggest that star-forming galaxies with classical bulges have compact star-forming regions concentrated within the bulges, while those with pseudobulges have extended star-forming regions beyond the bulges, suggesting that there are different formation scenarios at work in classical and pseudobulges.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- June 2019
- DOI:
- 10.1093/pasj/psz042
- arXiv:
- arXiv:1903.10317
- Bibcode:
- 2019PASJ...71...64T
- Keywords:
-
- HII regions;
- galaxies: interactions;
- galaxies: star formation;
- galaxies: starburst;
- infrared: galaxies;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 10 pages, 25 figures, 1 tables, accepted for publication in PASJ