First Results from the 3D-HST Survey: The Striking Diversity of Massive Galaxies at z>1

Дата и время публикации : 2011-08-30T20:00:04Z

Авторы публикации и институты :
Pieter G. van Dokkum
Gabriel Brammer
Mattia Fumagalli
Erica Nelson
Marijn Franx
Hans-Walter Rix
Mariska Kriek
Rosalind E. Skelton
Shannon Patel
Kasper B. Schmidt
Rachel Bezanson
Fuyan Bian
Elisabete da Cunha
Dawn K. Erb
Xiaohui Fan
Natascha Forster Schreiber
Garth D. Illingworth
Ivo Labbe
Britt Lundgren
Dan Magee
Danilo Marchesini
Patrick McCarthy
Adam Muzzin
Ryan Quadri
Charles C. Steidel
Tomer Tal
David Wake
Katherine E. Whitaker
Anna Williams

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: Accepted for publication in ApJ Letters
Первичная категория: astro-ph.CO

Все категории : astro-ph.CO, astro-ph.GA

Краткий обзор статьи: We present first results from the 3D-HST program, a near-IR spectroscopic survey performed with the Wide Field Camera 3 on the Hubble Space Telescope. We have used 3D-HST spectra to measure redshifts and Halpha equivalent widths for a stellar mass-limited sample of 34 galaxies at 1<z<1.5 with M(stellar)>10^11 M(sun) in the COSMOS, GOODS, and AEGIS fields. We find that a substantial fraction of massive galaxies at this epoch are forming stars at a high rate: the fraction of galaxies with Halpha equivalent widths >10 A is 59%, compared to 10% among SDSS galaxies of similar masses at z=0.1. Galaxies with weak Halpha emission show absorption lines typical of 2-4 Gyr old stellar populations. The structural parameters of the galaxies, derived from the associated WFC3 F140W imaging data, correlate with the presence of Halpha: quiescent galaxies are compact with high Sersic index and high inferred velocity dispersion, whereas star-forming galaxies are typically large two-armed spiral galaxies, with low Sersic index. Some of these star forming galaxies might be progenitors of the most massive S0 and Sa galaxies. Our results challenge the idea that galaxies at fixed mass form a homogeneous population with small scatter in their properties. Instead we find that massive galaxies form a highly diverse population at z>1, in marked contrast to the local Universe.

Category: Physics