SPECTROSCOPIC CONFIRMATION OF FAINT LYMAN BREAK GALAXIES NEAR REDSHIFT FIVE IN THE HUBBLE ULTRA DEEP FIELD

Journal Article · Wed May 20 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/697/1/942; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21300544

Rhoads, James E; Malhotra, Sangeeta; Cohen, Seth; Grogin, Norman; Hathi, Nimish; Ryan, Russell; Straughn, Amber; Pirzkal, Norbert; Chun, Xu; Koekemoer, Anton; Panagia, Nino ^[1]; Dickinson, Mark ^[2]; Ferreras, Ignacio ^[3]; Gronwall, Caryl ^[4]; Kuemmel, Martin; Walsh, Jeremy ^[5]; Meurer, Gerhardt ^[6]; Pasquali, Anna ^[7]; Yan, H -J ^[8]

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1. Space Telescope Science Institute, Baltimore, MD (United States)
2. National Optical Astronomy Observatory (United States)
3. University College, London (United Kingdom)
4. Pennsylvania State University, PA (United States)
5. Space Telescope-European Coordinating Facility (Germany)
6. Johns Hopkins University, MD (United States)
7. Max-Planck Institute for Astronomy (Germany)
8. Observatories of the Carnegie Institute of Washington, DC (United States)

We present the faintest spectroscopically confirmed sample of z {approx} 5 Lyman break galaxies (LBGs) to date. The sample is based on slitless grism spectra of the Hubble Ultra Deep Field region from the Grism ACS Program for Extragalactic Science (GRAPES) and Probing Evolution and Reionization Spectroscopically (PEARS) projects, using the G800L grism on the Hubble Space Telescope Advanced Camera for Surveys. We report here confirmations of 39 galaxies, preselected as candidate LBGs using photometric selection criteria. We compare a 'traditional' V-dropout selection, based on the work of Giavalisco et al., to a more liberal one (with V - i > 0.9), and find that the traditional criteria are about 64% complete and 81% reliable. We also study the Ly{alpha} emission properties of our sample. We find that Ly{alpha} emission is detected in {approx}1/4 of the sample, and that the liberal V-dropout color selection includes {approx}55% of previously published line-selected Ly{alpha} sources. Finally, we examine our stacked two-dimensional spectra. We demonstrate that strong, spatially extended ({approx}1'') Ly{alpha} emission is not a generic property of these LBGs, but that a modest extension of the Ly{alpha} photosphere (compared to the starlight) may be present in those galaxies with prominent Ly{alpha} emission.

• OSTI ID: 21300544
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 697; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
CAMERAS
COLOR
EMISSION
GALAXIES
PHOTOSPHERE
RED SHIFT
TELESCOPES