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Session 40 - The Interstellar Medium.
Display session, Tuesday, June 09
Atlas Ballroom,
We recently obtained two hours of Keck HIRES data for the gravitational lens candidate HE 1104-1805A,B (z_ QSO=2.303). We observed with a fixed position angle so that both quasar images (separation \approx 3'') fell on the slit simultaneously. The resulting high-resolution spectra (FWHM = 8 km/s) have a signal-to-noise ratio of 30 for the brighter component (A) while the fainter B component has S/N \approx 10 at 6000 ÅLower resolution spectra had previously revealed the presence of a damped Ly\alpha absorber (z_damped=1.665) toward A which was absent in the spectrum of B (Wisotzki et al.\ 1993). Our spectra cover numerous weak low-ionization lines including Fe II, Zn II, Cr II, Ni II and Ti II which we use for abundance and dust depletion analyses. There also is a metal-line system at lower redshift (z_metal=1.321) which does\/ cover both lines of sight, although the velocity profiles of the Fe II lines are significantly different. To complement the spectral data and verify the nature of the damped and metal-line absorbers, we have imaged the system with the UH 2.2m Tip-Tilt system and QUIRC infrared array. Our images have excellent image quality (FWHM = 0.3'') and cover \approx 1.5' centered on the QSO. This corresponds to a diameter of \approx 750 kpc at the absorption redshift of the damped Ly\alpha system (Ømega=0.3, H_\circ=65 km s^-1 Mpc^-1). A 10 kpc galactic disk at this redshift would have an angular extent of 1.2''. This data was obtained as part of an ongoing program designed to relate the absorption characteristics of damped Ly\alpha absorbers to the ISM of nearby galaxies and image the intervening systems responsible (see Jim amp; Roth, Bauer et al., amp; Kolhatkar et al. also presenting at this session).
The author(s) of this abstract have provided an email address for comments about the abstract: kroth@ifa.hawaii.edu