LBQS 0103-2753: A Binary QSO In A Major Merger

LBQS 0103-27 is binary QSO at z = 0.85 with a component separation of 2 kpc, one of the closest spacings known (Junkkarinen et al. 2001, ApJ 549, L155). One component is a BAL QSO. We present imaging in two colors with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. The images reveal the host galaxy and a prominent tidal arm on a scale of 10 kpc, confirming that the object involves a major merger in progress. We also present spectra obtained with STIS on HST and with UKIRT. The Halpha emission line confirms the redshift agreement of the two components. We discuss LBQS in the context of other binary QSOs and implications for fueling of black holes during galaxy mergers.