English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We model, via Monte Carlo simulations, the distribution of observed U-B, B-V,V-I galaxy colors in the range 1.75<z<5 caused by variations in theline-of-sight opacity due to neutral hydrogen (HI). We also include HI internalto the source galaxies. Even without internal HI absorption, comparison of thedistribution of simulated colors to the analytic approximations of Madau (1995)and Madau et al (1996) reveals systematically different mean colors andscatter. Differences arise in part because we use more realistic distributionsof column densities and Doppler parameters. However, there are alsomathematical problems of applying mean and standard deviation opacities, andsuch application yields unphysical results. These problems are corrected usingour Monte Carlo approach. Including HI absorption internal to the galaxiesgeneraly diminishes the scatter in the observed colors at a given redshift, butfor redshifts of interest this diminution only occurs in the colors using thebluest band-pass. Internal column densities < 10^17 cm^2 do not effect theobserved colors, while column densities > 10^18 cm^2 yield a limitingdistribution of high redshift galaxy colors. As one application of ouranalysis, we consider the sample completeness as a function of redshift for asingle spectral energy distribution (SED) given the multi-color selectionboundaries for the Hubble Deep Field proposed by Madau et al (1996). We arguethat the only correct procedure for estimating the z>3 galaxy luminosityfunction from color-selected samples is to measure the (observed) distributionof redshifts and intrinsic SED types, and then consider the variation in colorfor each SED and redshift. A similar argument applies to the estimation of theluminosity function of color-selected, high redshift QSOs.Comment: accepted for publication in ApJ; 25 pages text, 14 embedded figure

The Distribution of High‐Redshift Galaxy Colors: Line‐of‐Sight Variations in Neutral Hydrogen Absorption