An Intrinsic Absorption Complex Toward RXJ1230.8+0115: Geometry and Photoionization Conditions

We present HST/STIS and FUSE spectra of the quasar RXJ1230.8+0115 (V=14.4, z=0.117). In addition to Galactic, Virgo, and intervening absorption, this quasar is host to a remarkable intrinsic absorption complex. Four narrow absorption line systems, strong in CIV, NV, and OVI, lie within 5000 km/s of the QSO redshift. Three of the systems appear to be line-locked, two in NV, and two in OVI, with the common system residing in between the other two (in velocity). All three systems show signs of an intrinsic origin -- smooth wind-like profiles, high ionization, and partial coverage of the central engine. The fourth system, which appears at the systemic redshift of the QSO, may originate from host galaxy or intervening gas. Photoionization analyses imply column densities in the range 19.1<log N(H)<21 and ionization parameters in the range -1.3<log U<0.3. Revisiting the issue of line-locking, we discuss a possible model in the context of the accretion-disk/wind scenario and point out several issues that remain for future simulations and observations.