Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Quick Search
My eDoc
Session History
Support Wiki
Direct access to
document ID:

          Institute: MPI für Astronomie     Collection: Publikationen_mpia     Display Documents

ID: 709717.0, MPI für Astronomie / Publikationen_mpia
Dense cores in galaxies out to z = 2.5 in SDSS, UltraVISTA, and the five 3D-HST/CANDELS Fields
Authors:van Dokkum, P. G.; Bezanson, R.; van der Wel, A.; Nelson, E. J.; Momcheva, I.; Skelton, R. E.; Whitaker, K. E.; Brammer, G.; Conroy, C.; Förster Schreiber, N. M.; Fumagalli, M.; Kriek, M.; Labbé, I.; Leja, J.; Marchesini, D.; Muzzin, A.; Oesch, P.; Wuyts, S.
Date of Publication (YYYY-MM-DD):2014
Title of Journal:The Astrophysical Journal
Issue / Number:1
Start Page:id. 45 (18 pp)
Audience:Not Specified
Abstract / Description:The dense interiors of massive galaxies are among the most intriguing environments in the universe. In this paper,we ask when these dense cores were formed and determine how galaxies gradually assembled around them. We select galaxies that have a stellar mass >3 × 1010 M &sun; inside r = 1 kpc out to z = 2.5, using the 3D-HST survey and data at low redshift. Remarkably, the number density of galaxies with dense cores appears to have decreased from z = 2.5 to the present. This decrease is probably mostly due to stellar mass loss and the resulting adiabatic expansion, with some contribution from merging. We infer that dense cores were mostly formed at z > 2.5, consistent with their largely quiescent stellar populations. While the cores appear to form early, the galaxies in which they reside show strong evolution: their total masses increase by a factor of 2-3 from z = 2.5 to z = 0 and their effective radii increase by a factor of 5-6. As a result, the contribution of dense cores to the total mass of the galaxies in which they reside decreases from ~50% at z = 2.5 to ~15% at z = 0. Because of their early formation, the contribution of dense cores to the total stellar mass budget of the universe is a strong function of redshift. The stars in cores with M 1 kpc > 3 × 1010 M &sun; make up ~0.1% of the stellar mass density of the universe today but 10%-20% at z ~ 2, depending on their initial mass function. The formation of these cores required the conversion of ~1011 M &sun; of gas into stars within ~1 kpc, while preventing significant star formation at larger radii.
Free Keywords:cosmology: observations; galaxies: evolution; Galaxy: formation; Galaxy: structure
External Publication Status:published
Document Type:Article
Communicated by:N. N.
Affiliations:MPI für Astronomie
Identifiers:ISSN:0004-637X %R 10.1088/0004-637X/791/1/45
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.