NOAO >   Observing Info >   Approved Programs >   2010B-0407

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Proposal Information for 2010B-0407


PI: Danilo Marchesini, Tufts University, danilo.marchesini@tufts.edu
Address: Physics Department, 212 College Avenue, Medford, MA 02155, USA

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

Title: Measuring the Rest-Frame UV Properties and the Number Density of Massive Galaxies at 3<z<4

Abstract: One of the most controversial questions regarding the build-up of the stellar content of the universe is when and how the most massive galaxies formed. Recent studies have found that the number density of the most massive galaxies has evolved little from z=4 to z~1.5, contrary to the predictions from galaxy formation models, with the largest disagreement being at 3<z<4. The discovery of a large, unexpected population of massive galaxies at 3<z<4 is confirmed by NEWFIRM Medium-Band Survey (NMBS), a NOAO Survey program using medium band-width filters in the NIR to obtained high-accuracy photometric redshifts. We propose to use IMACS on Magellan-I to obtain spectroscopic redshifts of a large, unique, and homogeneous sample of 31 very massive galaxies at 3<z<4 selected from the NMBS. In two nights, IMACS should provide continuum detection for ~25% of the sample, and emission line detection for a larger fraction of the sample, allowing us to 1) calibrate any systematic effects in the photometric redshift estimates; 2) robustly measure the number density of massive galaxies at 3<z<4; 3) robustly determine the AGN and Lyman (alpha) emitter fraction; and 4) determine superwind outflows in the brightest galaxies, providing an unprecedented view of the rest-frame UV properties of massive galaxies at 3<z<4.


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



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