Program: GN-2005B-C-8

Title:AO Studies of HzRGs Near Bright Natural Guide Stars
PI:Brian Stalder
Co-I(s): Kenneth Chambers

Abstract

There is growing evidence for a high redshift of formation for certain galaxies and stellar populations from a variety of studies. Recently, massive galaxies with indications of evolved stellar populations (> 2 Gyr old) have been discovered at z > 2.5 in surveys of host galaxies of intermediate-power radio sources. Radio surveys thereby provide a means of pinpointing a population of massive galaxies at high redshift for detailed study. By cross-correlating the FIRST VLA survey with the USNO star catalog we have identified a random sample of radio galaxies that happen to have Bright Natural Guide Stars (BNGS). These objects provide ideal candidates for studies of monolithic galaxy formation because they enable the application of the full power of Adaptive Optics to correct the wave front distortion with high-signal-to-noise on the foreground star and achieve nearly diffraction limited performance on the distant background radio galaxy. The detailed morphological and dynamical studies enabled by AO observations of objects selected in this fashion can provide clues to the puzzle of how an epoch of monolithic galaxy formation occurred in a \Lambda-CDM universe. This proposal is to continue a Ph.D. thesis project to apply the techniques of adaptive wavefront correction to cosmologically distant massive galaxies using a sample of radio galaxies selected for proximity to bright natural guide stars (BNGS). Because these are a randomly selected sub-sample of the radio source population,only a fraction will be at high redshift. In order to obtain a statistically significant number of high-z sources (e.g. 10) for detailed study, a survey of 60 or so total sources with BNGS is required. This project consists of the follow-up studies of the sub-sample of objects identified as high redshift (1<z<5) based on the multi-color imaging survey. We would like to confirm the photometric redshifts with low resolution optical spectroscopy on Gemini.

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