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Title: The effect of surface brightness dimming in the selection of high-z galaxies

Cosmological surface brightness (SB) dimming of the form (1 + z){sup –4} affects all sources. The strong dependence of SB dimming on redshift z suggests the presence of a selection bias when searching for high-z galaxies, i.e., we tend to detect only those galaxies with a high SB. However, unresolved knots of emission are not affected by SB dimming, thus providing a way to test the clumpiness of high-z galaxies. Our strategy relies on the comparison of the total flux detected for the same source in surveys characterized by different depth. For all galaxies, deeper images permit the better investigation of low-SB features. Cosmological SB dimming makes these low-SB features hard to detect when going to higher and higher redshifts. We used the GOODS and HUDF Hubble Space Telescope legacy data sets to study the effect of SB dimming on low-SB features of high-z galaxies and compare it to the prediction for smooth sources. We selected a sample of Lyman-break galaxies at z ∼ 4 (i.e., B {sub 435}-band dropouts) detected in all of the data sets and found no significant trend when comparing the total magnitudes measured from images with different depth. Through Monte Carlo simulations we derived themore » expected trend for galaxies with different SB profiles. The comparison to the data hints at a compact distribution for most of the rest-frame ultraviolet light emitted from high-z galaxies.« less
Authors:
; ;  [1] ;  [2] ;  [3]
  1. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
  2. Dipartimento di Fisica e Astronomia "G. Galilei," Vicolo dell'Osservatorio 3, I-35122 Padova (PD) (Italy)
  3. The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)
Publication Date:
OSTI Identifier:
22370145
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 796; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BRIGHTNESS; COMPUTERIZED SIMULATION; DISTRIBUTION; EMISSION; FORECASTING; GALAXIES; MONTE CARLO METHOD; PHOTOMETRY; RED SHIFT; SPACE; STAR EVOLUTION; SURFACES; TELESCOPES; ULTRAVIOLET RADIATION; VISIBLE RADIATION