NOAO >   Observing Info >   Approved Programs >   2009B-0480

Small NOAO Logo

Proposal Information for 2009B-0480


PI: Danilo Marchesini, Yale University, danilo.marchesini@yale.edu
Address: Astronomy Department, P.O. Box 208101, New Haven, CT 06520-8101, USA

CoI: Pieter van Dokkum, Yale University
CoI: Ivo Labbe, Carnegie Observatories
CoI: Gabriel Brammer, Yale University
CoI: Kate Whitaker, Yale University
CoI: Ryan Quadri, Leiden Observatory
CoI: Adam Muzzin, Yale University
CoI: Kyoung-Soo Lee, Yale University
CoI: Gregory Rudnick, University of Kansas
CoI: Rik Williams, Leiden Observatory
CoI: Mariska Kriek, Princeton University
CoI: Marijn Franx, Leiden Observatory
CoI: Garth Illingworth, UC Observatories/Lick Obs.
CoI: Rachel Bezanson, Yale University

Title: Measuring the evolution of the size-mass relation using a complete, mass- limited sample of galaxies at 1.5<z<2.5

Abstract: The evolution of the sizes of massive galaxies with cosmic time provides strong constraints on galaxy formation models, as these models predict strong size evolution for massive galaxies. Recent studies have found that massive galaxies at high redshifts are quite compact, particularly those with the lowest estimated star formation rates. However, at z>1, samples with accurate redshift estimates and rest- frame optical size measurements (observed-frame near-infrared) are very small. We propose to use NIRI on Gemini-North to measure the rest-frame optical sizes for a large and complete sample of massive galaxies at z<2.5 selected from the NEWFIRM Medium-Band Survey, a large NOAO program which uses medium band-width filters in the near-infrared to obtained well-sampled spectral energy distributions and high quality photometric redshifts over 1 square degree. In two nights, NIRI will provide reliable size measurements in the K-band for a complete sample of 95 galaxies with 1.5<z<2.5 and stellar masses M_\rm star>10^11.2 M_\sun. The main goal is to derive the evolution from z=2.5 of the sizes of massive galaxies. We will also search for radial color gradients to discriminate between the different models of formation and evolution of massive galaxies by combining the NIRI data with publicly available HST I-band imaging.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2009B-0480

noaoprop-help@noao.edu

Small NOAO Logo