| タイトル | The Epoch of Disk Settling: Z Approximately Equal to 1 to Now |
| 本文（外部サイト） | http://hdl.handle.net/2060/20120012551 |
| 著者（英） | Koo, David C.; Faber, S. M.; Primack, Joel R.; Willmer, N. A.; Cooper, Michael C.; Noeske, Kai G.; Gardner, Jonathan P.; Metevier, A. J.; Kassin, Susan A.; Coil, Alison L.; Guhathakurta, Puragra; Weiner, Benjamin J.; Dutton, Aaron A.; Devriendt, Julien |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2012-03-26 |
| 言語 | eng |
| 内容記述 | We present evidence from a sample of 544 galaxies from the DEEP2 Survey for evolution of the internal kinematics of blue galaxies over 0.2 < z < 1.2. DEEP2 provides a large sample of high resolution galaxy spectra and dual-band Hubble imaging from which we measure emission-line kinematics and galaxy inclinations, respectively. Our large sample allows us to overcome scatter intrinsic to galaxy properties, in order to examine trends. At a fixed stellar mass, galaxies systematically decrease in disturbed motions and increase in rotation velocity and potential well depth with time. The most massive galaxies are the most well-ordered at all times, with higher rotation velocities and less disturbed motions compared to less massive galaxies. We quantify disturbed motions with an integrated gas velocity dispersion (sigma(sub g)), which is unlike the typical pressure-supported velocity dispersion measured for early type galaxies and galaxy bulges. Due to finite slit width and seeing, sigma(sub g) integrates over unresolved velocity gradients which can correspond to non-ordered gas kinematics such as small-scale velocity gradients, gas motions due to star-formation, or super-imposed clumps along the line-of-sight. We compile surveys of galaxy kinematics over 1.2 < z < 3.8 and do not find any trends with redshift, likely because these studies are biased toward the most highly star-forming systems. In summary, over the last approx 8 billion years since z = 1.2, blue galaxies evolve from disturbed to ordered systems as they settle to become the rotation-dominated disk galaxies observed in the Universe today, with the most massive galaxies always being the most evolved at any time. |
| NASA分類 | Astrophysics |
| レポートNO | GSFC.JA.7351.2012
GSFC.JA.01209.2012 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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