We have obtained high Signal-to-Noise (S/N>50) spectra near the atmospheric cutoff to search for Mg II doublet absorption in the spectra of 17 bright QSOs with 0.137 < z < 0.36. The spectral resolution is 1.3 Angstroms \ over a wavelength range of 3180 to 3820 Angstroms, providing a limiting rest equivalent width of 0.1 Angstroms or better. These data for bright QSOs, collected with the 2.1 m at KPNO, are being used to assist the target selection for a Space Telescope Imaging Spectrograph (STIS) key project. Future HST data of UV absorption features in bright QSO spectra will be used to examine element abundances and physical conditions in intervening gas systems at low red shifts. These results will then be compared with those found for systems at much higher z (observed from the ground). We can also relate our results to properties of galaxies that are close enough to be studied by other means. The ultimate goal is to learn about the enrichment patterns of various elements and changes in physical conditions as extended gas systems evolved from lookback times of many Gyr to the present. Results from the present ground-based data can be combined with previous searches for Mg II absorption lines at low z to yield an improved estimate for how frequently such systems can be seen in our part of the universe.
American Astronomical Society Meeting Abstracts #189
- Pub Date:
- January 1997