Galaxy groups at z=0.4
Abstract
The galaxy group environment at intermediate redshift (0.3"<"z<0.55) has a critical influence on the evolution of galaxies. However, these systems are poorly studied and understood, especially at UV wavelengths. One reason for this is the difficulty in identifying such low-density systems in an unbiased way. With the recently completed CNOC2 redshift survey, we have compiled the first complete, unbiased sample of groups at this redshift. We also have follow-up high-resolution imaging from the Hubble Space Telescope, and deeper, more complete spectroscopy from the Magellan 6.5-m telescope, and therefore the best available data to study this important environment. We propose to combine NUV GALEX observations of these groups with our existing ground-based UBVRI photometry and spectroscopy to measure dust-corrected star formation rates of galaxies in 19 groups with 0.3"<"z<0.55. In addition, our GALEX fields will include most of the galaxies in the original CNOC2 redshift survey, allowing us to measure the UV luminosity function over the same redshift range, from an unprecedented sample of ~3200 galaxies. By directly comparing our data with galaxies at low redshift (from the Medium Imaging Survey overlap with the 2dFGRS and SDSS) we will determine how the growth of structure in the Universe influences galaxy evolution.
- Publication:
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GALEX Proposal
- Pub Date:
- 2004
- Bibcode:
- 2004galx.prop...37B