Stellar and gas mass distributions for understanding the nature of spiral arms. Issue Volume 15:Issue S341(2019) (November 2019)

• Record Type: Journal Article
• Authors: Egusa, Fumi; Cooper, Erin Mentuch; Koda, Jin; Baba, Junichi
• Editors: Boquien, Médéric; Lusso, Elisabeta; Gruppioni, Carlotta; Tissera, Patricia
• Is Part Of: Proceedings of the International Astronomical Union. Volume 15:Issue S341(2019)
• Page Start: 266
• Page End: 267
• Publication Date: 2019-11
• Subjects: galaxies: individual (M51 or NGC 5194, -- M74 or NGC 0628), -- galaxies: spiral, -- galaxies: structure; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921319002503
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: Numerical simulations of disk galaxies with steady (long-lived) and dynamic (short-lived) spiral arms suggest that offsets between stellar and gas spiral arms depend on their nature or lifetime (Baba et al. 2015 ). Based on this theoretical study, we investigated gas-star offsets in the nearby grand-design spiral galaxy M51, and found that its two spiral arms exhibit different offset dependences against radius. One arm is consistent with a steady arm, while the other is consistent with a dynamic arm. We deduce that this difference is likely due to a tidal interaction with the companion galaxy (Egusa et al. 2017 ). For this study, a stellar mass distribution with a high accuracy at a high spatial resolution is essential, which has come to be available by applying recent SED fitting techniques to multi-wavelength images. We are now working to extend this study to other nearby spiral galaxies.