Are Hubble Deep Field Galaxy Counts Whole Numbers?
Abstract
We compute the two-point angular correlation function and number-magnitude relation of Hubble Deep Field sources in order to assess their nature. We find that the correlation peaks between 0.25 arcsec and 0.4 arcsec with amplitude of 2 or greater, and much more for the smallest objects. This angular scale corresponds to physical scales of order 1 kpc for redshifts z > 1. The correlation must therefore derive from objects with subgalaxian separations. At faint magnitudes, the counts satisfy the relation Number prop. to 1/flux, expected for images which are subdivisions of larger ones. A conservative conjecture may explain these results. Since high redshift space (z > 0.5) dominates the volume of the sample, observational redshift effects are important. The K-correction and surface brightness dimming of diffuse sources enhances the prominence of compact, unresolved, UV-bright objects, such as star-forming regions within normal gas-rich galaxies. If such regions appear as individual sources, they could explain the subgalaxian correlation.
Cite
@article{arxiv.astro-ph/9603020,
title = {Are Hubble Deep Field Galaxy Counts Whole Numbers?},
author = {Wesley N. Colley and James E. Rhoads and Jeremiah P. Ostriker and David N. Spergel},
journal= {arXiv preprint arXiv:astro-ph/9603020},
year = {2009}
}
Comments
accepted by ApJL, AASTeX 4.0 preprint style, 2 PostScript figures, Replacing astro-ph/9603020 (major modification: improved detection alg.)