Home List of Titles The morphological identification of the rapidly evolving population of faint galaxies
Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/43377
|Download PDF (Accepted manuscript) (Adobe Acrobat PDF, -1 bytes)|
- The morphological identification of the rapidly evolving population of faint galaxies
- Glazebrook, Karl; Ellis, Richard S.; Santiago, Basilio X.; Griffiths, Richard
- The excess numbers of blue galaxies at faint magnitudes are a long-standing cosmological puzzle. We present new number-magnitude counts as a function of galactic morphology from the first deep fields of the Cycle 4 Hubble Space Telescope Medium Deep Survey project. From a sample of 301 galaxies we define counts for elliptical, spiral and irregular/peculiar galaxies to I=22. We find two principal results. Firstly the elliptical and spiral galaxy counts both follow the predictions of high-normalisation no-evolution models at all magnitudes, indicating that regular Hubble types evolve only slowly to z∼ 0.5. Secondly we find that irregular/peculiar galaxies, including multiple-peaked, possibly merging, objects, have a very steep number-magnitude relation and greatly exceed predictions based on proportions in local surveys. These systems make up half the total counts by I=22 and imply the rapidly-evolving component of the faint galaxy population has been identified.
- Publication type
- Journal article
- Monthly Notices of the Royal Astronomical Society, Vol. 275, no. 2 (Jul 1995), pp. L19-L22
- Publication year
- APM redshift survey; Cosmology; Counts; Evolution; Galaxies; Luminosity function; Number; Observations; Peculiar; Structure; Surveys; Universe
- Wiley-Blackwell Publishing
- Publisher URL
- Copyright © 1995 RAS. The accepted manuscript of the paper is reproduced here in accordance with the copyright policy of the publisher. The definitive publication is available at www.interscience.wiley.com.
- Full text
- Peer reviewed