| タイトル | Geometry of Star-Forming Galaxies from SDSS, 3D-HST, and CANDELS |
| 本文（外部サイト） | http://hdl.handle.net/2060/20150004442 |
| 著者（英） | van Dokkum, P. G.; Primack, J.; Van Der Wel, A.; Franx, M.; Koo, D. C.; Mozena, M.; Holden, B. P.; Whitaker, K.; Faber, S. M.; Dekel, A.; Skelton, R.; Chang, Yu-Yen; Ferguson, H. C.; Ceverino, D.; Momcheva, I.; Giavalisco, M.; Rix, H.-W.; Brammer, G.; Bell, E. F.; Martig, M.; Kassin, S. A. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2014-08-12 |
| 言語 | eng |
| 内容記述 | We determine the intrinsic, three-dimensional shape distribution of star-forming galaxies at 0 < zeta < 2.5, as inferred from their observed projected axis ratios. In the present-day universe, star-forming galaxies of all masses 10(exp 9)-10(exp 11) Stellar Mass are predominantly thin, nearly oblate disks, in line with previous studies. We now extend this to higher redshifts, and find that among massive galaxies (M* > 10(exp 10)Stellar Mass) disks are the most common geometric shape at all zeta < or approx. 2. Lower-mass galaxies at zeta > 1 possess a broad range of geometric shapes: the fraction of elongated (prolate) galaxies increases toward higher redshifts and lower masses. Galaxies with 10(exp 9) Stellar Mass (10(exp 10) Stellar Mass) are a mix of roughly equal numbers of elongated and disk galaxies at zeta approx. 1 (zeta approx. 2). This suggests that galaxies in this mass range do not yet have disks that are sustained over many orbital periods, implying that galaxies with present-day stellar mass comparable to that of the Milky Way typically first formed such sustained stellar disks at redshift zeta approx. 1.5-2. Combined with constraints on the evolution of the star formation rate density and the distribution of star formation over galaxies with different masses, our findings imply that, averaged over cosmic time, the majority of stars formed in disks. |
| NASA分類 | Astrophysics |
| レポートNO | GSFC-E-DAA-TN20981 |
| 権利 | Copyright, Distribution under U.S. Government purpose rights |
|
