Ground-based Paα narrow-band imaging of local luminous infrared galaxies. II. Bulge structure and star formation activity. (16th May 2019)

• Record Type: Journal Article
• Authors: Tateuchi, Ken; Motohara, Kentaro; Konishi, Masahiro; Takahashi, Hidenori; Kitagawa, Yutaro; Kato, Natsuko; Todo, Soya; Komugi, Shinya; Ohsawa, Ryou; Doi, Mamoru; Yoshii, Yuzuru
• Is Part Of: Publications of the Astronomical Society of Japan. Volume 71:Number 3(2019:Jun.)
• Publication Date: 2019-05-16
• Subjects: HII regions -- galaxies: interactions -- galaxies: star formation -- galaxies: starburst -- infrared: galaxies; Astronomy -- Periodicals; 520.5
• DOI: 10.1093/pasj/psz042
• Languages: English
• ISSNs: 0004-6264

Abstract

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, K s, and 1.91$\mu$ m 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 K s -band images. The result shows a tentative bimodal distribution of Sérsic indices with a separation at log ( n b ) ≈ 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.