NaD excess objects and its implications on initial mass function. Issue Volume 10:Issue S311(2014) (10th April 2015)

• Record Type: Journal Article
• Authors: Yi, Sukyoung K.; Jeong, Hyunjin
• Editors: Cappellari, Michele; Courteau, Stéphane
• Is Part Of: Proceedings of the International Astronomical Union. Volume 10:Issue S311(2014)
• Page Start: 69
• Page End: 71
• Publication Date: 2015-04-10
• Subjects: galaxies: elliptical and lenticular, -- cD - galaxies: evolution - galaxies: formation; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921315003415
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: van Dokkum and Conroy (2010) have heralded the possible implication of NaI 8200A lines on extra bottom-heavy IMF of bright elliptical galaxies. A flurry of papers have followed it and revisited the half a century old issue all over again from various angles. For a sanity check, we investigate on the issue this time using the better measured NaD 5900A line instead. We found from the SDSS database that a large (~ 10%) fraction of galaxies (both early and late types) exhibit strong NaD lines and that the same bottom-heavy models of van Dokkum and Conroy that reproduced the strong NaI 8200 lines of elliptical galaxies are not capable of reproducing NaD line strengths at all. The mystery prevails. This article is mainly a review of our recent paper (Jeong et al. 2013).