Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 10, 2012 | Published
Journal Article Open

The Taiwan ECDFS Near-Infrared Survey: Very Bright End of the Luminosity Function at z > 7

Abstract

The primary goal of the Taiwan ECDFS Near-Infrared Survey (TENIS) is to find well-screened galaxy candidates at z > 7 (z' dropout) in the Extended Chandra Deep Field-South (ECDFS). To this end, TENIS provides relatively deep J and K_s data (~25.3 ABmag, 5σ) for an area of 0.5 × 0.5 deg. Leveraged with existing data at mid-infrared to optical wavelengths, this allows us to screen for the most luminous high-z objects, which are rare and thus require a survey over a large field to be found. We introduce new color selection criteria to select a z > 7 sample with minimal contaminations from low-z galaxies and Galactic cool stars; to reduce confusion in the relatively low angular resolution Infrared Array Camera (IRAC) images, we introduce a novel deconvolution method to measure the IRAC fluxes of individual sources. Illustrating perhaps the effectiveness at which we screen out interlopers, we find only one z > 7 candidate, TENIS-ZD1. The candidate has a weighted z_phot of 7.8, and its colors and luminosity indicate a young (45M years old) starburst galaxy with a stellar mass of 3.2 × 10^(10) M_☉. The result matches with the observational luminosity function analysis and the semianalytic simulation result based on the Millennium Simulations, which may over predict the volume density for high-z massive galaxies. The existence of TENIS-ZD1, if confirmed spectroscopically to be at z > 7, therefore poses a challenge to current theoretical models for how so much mass can accumulate in a galaxy at such a high redshift.

Additional Information

© 2012 American Astronomical Society. Received 2011 October 3; accepted 2012 February 7; published 2012 March 26. We thank the referee for comments that greatly improved the manuscript. We are grateful to the CFHT staff for their help obtaining the data, and H. K. C. Yee and Y. T. Lin for useful discussions. This paper is based on observations obtained with the WIRCam, a joint project of CFHT, Taiwan, Korea, Canada, France, and the Canada–France–Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institute National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii. Access to the CFHT was made possible by the Ministry of Education, the National Science Council of Taiwan as part of the Cosmology and Particle Astrophysics (CosPA), the Institute of Astronomy and Astrophysics, Academia Sinica, and National Tsing Hua University, Taiwan. We gratefully acknowledge support from the National Science Council of Taiwan Grant 98-2112-M-001-003-MY2 (W.H.W.), 99-2112-M-001-012-MY3 (W.H.W), and Japanese Government FIRST program (H.K.).

Attached Files

Published - Hsieh2012p17946Astrophys_J.pdf

Files

Hsieh2012p17946Astrophys_J.pdf
Files (2.1 MB)
Name Size Download all
md5:3efcf96ee74ba346413b092dbeb595b4
2.1 MB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 17, 2023