paper

High-Resolution Imaging of Faint Blue Galaxies

arXiv:astro-ph/9401028 · doi:10.1093/mnras/267.4.1108

Abstract

We have used HRCam on the CFHT to obtain subarcsecond images of 26 galaxies with z=0.1--0.7. The primary sample of 17 galaxies have enhanced star formation indicated by [OII] equivalent widths greater than 20Å, while the comparison sample of 9 galaxies have equivalent widths less than 10Å. By fitting disks or bulges to BVI images we derive scalelengths for the blue and red stellar populations and locate the star-formation in each galaxy. These moderate-redshift galaxies generally have straightforward low-redshift analogues, in that their colours, sizes and luminosities are consistent with those of various types of z0 galaxies. The star-forming objects have structures consistent with the full range of present-day disk galaxies, and absolute magnitudes M1 to M+5. Some have star-formation concentrated in their nuclei but in most it occurs across the entire disk. We find companions at projected distances closer than 10 kpc for 30% of the star-forming galaxies, whereas none of the comparison sample have such close companions. This provides the first direct evidence linking interactions or mergers to the increased fraction of star-forming field galaxies at moderate redshifts.

MNRAS, in press, 15 pages, Latex, MNRAS style (mn.sty), full paper with figures available as {}~ftp/pub/colless/mmc_94-1.tar.Z (compressed tar archive of PS files) via anonymous ftp to merlin.anu.edu.au, MSSSO_MMC_94-1

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