Redshift of galaxies in Palomar large format camera fields: Preliminary results
Abstract
We present preliminary results obtained for the ongoing survey ``Redshift of galaxies in Palomar Large format Camera (LFC) Fields'' using the 4 m Anglo Austrailian Telescope. The fields, each covering about 1/4 square degree, were originally obtained as part of a LFC survey to find very high redshift quasars with integrated exposures ranging from 1 to 4 hours in SDSS i, r and z bands. There are about 270 galaxies brighter than i magnitude 20.5 in each field. One of the fields (SDSS1208) was observed for 1 hour in June 2006, using multi-fiber spectroscope on AAT. We obtained reliable redshifts for 55/135 (40 %) of the galaxies targeted to get the low resolution spectra in wavelength range 370 nm to 880 nm. We achieved 100% success for the brightest targets, i.e. galaxies with g (fiber) magnitude < 21.2. We attained a mean S/N per pixel of around 4 in the blue and 10 in the red for targets with g(fib) 21. However, the success rate fell rapidly for fainter galaxies. Our preliminary investigation of spectra shows the presence of passively evolving elliptical galaxies, galaxies with substantial on-going star formation, E+A or a+k type galaxies, in our sample. We also see absorption lines such as Mg, Na and Fe, as well as the Balmer lines and the CH G-band. We get information on the metallicity, for different star formation histories from such spectra. We find photometic redshift obtained through SDSS table photoz (Csabi et al. AJ 125, 580, 2003) matches best with our determined redshift.
- Publication:
-
Bulletin of the Astronomical Society of India Proceedings
- Pub Date:
- 2008
- Bibcode:
- 2008BASIP..25...70C