We measure and analyse the sizes of 82 massive (M >= 10^11 M_Sun) galaxies at 1.7<z<3 utilizing deep HST NICMOS data taken in the GOODS North and South fields. Our sample provides the first statistical study of massive galaxy sizes at z>2. We split our sample into disk-like (Sersic index n<=2) and spheroid-like (Sersic index n>2) galaxies, and find that at a given stellar mass, disk-like galaxies at z~2.3 are a factor of 2.6+/-0.3 smaller than present day equal mass systems, and spheroid-like galaxies at the same redshift are 4.3+/-0.7 times smaller than comparatively massive elliptical galaxies today. We furthermore show that the stellar mass densities of very massive galaxies at z~2.5 are similar to present-day globular clusters with values ~2x10^10 M_Sun kpc^-3
@article{arxiv.0811.2931,
title = {Extremely Compact Massive Galaxies at 1.7<z<3},
author = {Fernando Buitrago and Ignacio Trujillo and Christopher J. Conselice},
journal= {arXiv preprint arXiv:0811.2931},
year = {2008}
}
Comments
4 pages, 2 figures, To appear in " Highlights of Spanish Astrophysics V " Proceedings of the VIII Scientific Meeting of the Spanish Astronomical Society (SEA) held in Santander, July 7-11, 2008, Poster #61