Evolution histories of massive galaxies at z∼2 over the past 3 Gyr. Issue Volume 15:Issue S341(2019) (November 2019)

• Record Type: Journal Article
• Authors: Morishita, T.; Abramson, L. E.; Treu, T.; Brammer, G. B.; Jones, T.; Kelly, P.; Stiavelli, M.; Trenti, M.; Vulcani, B.; Wang, X.
• 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: 50
• Page End: 54
• Publication Date: 2019-11
• Subjects: galaxies: evolution, -- galaxies: metallicity; Astronomy -- Congresses; Astronomy -- Periodicals; 520
• DOI: 10.1017/S1743921319002734
• Languages: English
• ISSNs: 1743-9213

Abstract

Abstract: We study star formation and metallicity enrichment histories of 24 massive galaxies at 1.6 < z < 2.5. Deep slitless spectroscopy + imaging data set collected from multiple HST surveys allows robust determination of their SEDs. Our new SED modeling with no functional assumptions on star formation histories revels that 1. most of the sample galaxies have already formed >50% of their extant masses ∼1.5 Gyr before the time of observed redshifts, with a trend where more massive galaxies form earlier, 2. most of our galaxies already have stellar metallicities compatible with those of local early-type galaxies, and 3. inferred metallicities are on average ∼ 0.25 dex higher than observed gas-phase metallicities of star forming galaxies at the time of their formation. Continuation of low-level star formation, rather than abrupt termination of star forming activity, may explain the observed gap of metallicities.