Title: Variability Study of Intrinsic NAL and Mini-BAL Systems
Author(s): Toru Misawa, Mike Eracleous, Jane Charlton
Abstract: 

About 20% of quasar absorption lines are believed to arise at
outflowing winds from the accretion disks of quasars.  We
conventionally classify these "intrinsic" absorption lines into broad
absorption lines (BALs), narrow absorption lines (NALs), and their
intermediate class (mini-BALs), according to their line width.  Among
these, mini-BALs and NALs have a great advantage over BALs because
they are not self-blended, hence we can determine their column
densities and Doppler parameters using profile fit.  Multiple spectra
also enable us to search for time variability of them.  Based on these
observations, we can place valuable constraints on the physical
condition of absorbers, the structure of quasar central engines, and
the fueling history of active galaxies over cosmic time.  We are
embarking on a variability study of 6 mini-BALs and 14 NALs in 12
quasars, using high resolution (R~40,000) archival and our observed
spectra taken with Subaru, VLT and Keck since 1994.  Surprisingly,
variability is seen only in mini-BALs and all NALs are changeless in a
few years in the quasar rest-frame, which implies that ionization
condition and/or kinematical motion are/is more variable in mini-BAL
absorbers compared to NALs.  By comparing our result with numerical
simulations, we can more precisely place constraints on the geometry,
kinematics, and physical conditions of quasar outflows.  Thus, we will
be able to treat NALs/mini-BALs in the context of outflow models and
assess the role of such outflows in galaxy evolution as well as AGN
feedback to the nearby ISM and the IGM.