2015/06/30 by Pieter G. van Dokkum, Erica June Nelson, Marijn Franx +14 · 303 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Grism #Photometry (optics) #Population #RADIUS #Redshift #Stars #Stellar mass #Stellar population #astro-ph.CO #astro-ph.GA #astro-ph.SR
paper · pdf · doi:10.1088/0004-637x/813/1/23
published in The Astrophysical Journal 813(1), 23 (IOP Publishing) · Accepted for publication in ApJ. Figure 18 summarizes the kinematics part of the paper. Figure 22 demonstrates how star forming galaxies grow in size and mass (in observations and simulations), and Figure 28 is a cartoon version of a model that describes the evolution of star forming and quiescent galaxies since z~3
arxiv created 2015/09/20 · openalex publication_date 2015/10/22 · arxiv updated 2015/10/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
In this paper we study a key phase in the formation of massive galaxies: the transition of star-forming galaxies into massive ( M stars ∼ 10 11 M ⊙ ), compact ( r e ∼ 1 kpc) quiescent galaxies, which takes place from z ∼ 3 to z ∼ 1.5. We use HST grism redshifts and extensive photometry in all five 3D- HST /CANDELS fields, more than doubling the area used previously for such studies, and combine these data with Keck MOSFIRE and NIRSPEC spectroscopy. We first confirm that a population of massive, compact, star-forming galaxies exists at z ≳ 2, using K -band spectroscopy of 25 of these objects at 2.0 < z < 2.5. They have a median [N ii ]/H α ratio of 0.6, are highly obscured with SFR(tot)/SFR(H α ) ∼10, and have a large range of observed line widths. We infer from the kinematics and spatial distribution of H α that the galaxies have rotating disks of ionized gas that are a factor of ∼2 more extended than the stellar distribution. By combining measurements of individual galaxies, we find that the kinematics are consistent with a nearly Keplerian fall-off from V rot ∼ 500 km s −1 at 1 kpc to V rot ∼ 250 km s −1 at 7 kpc, and that the total mass out to this radius is dominated by the dense stellar component. Next, we study the size and mass evolution of the progenitors of compact massive galaxies. Even though individual galaxies may have had complex histories with periods of compaction and mergers, we show that the population of progenitors likely followed a simple inside-out growth track in the size–mass plane of This mode of growth gradually increases the stellar mass within a fixed physical radius, and galaxies quench when they reach a stellar density or velocity dispersion threshold. As shown in other studies, the mode of growth changes after quenching, as dry mergers take the galaxies on a relatively steep track in the size–mass plane.