Constraining Variable High Velocity Winds from Broad Absorption Line
  Quasars with Multi-Epoch Spectroscopy
  Broad absorption line (BAL) quasars probe the high velocity gas ejected by
luminous accreting black holes. BAL variability timescales place constraints on
the size, location, and dynamics of the emitting and absorbing gas near the
supermassive black hole. We present multi-epoch spectroscopy of seventeen BAL
QSOs from the Sloan Digital Sky Survey (SDSS) using the Fred Lawrence Whipple
Observatory's 1.5m telescope's FAST Spectrograph. These objects were identified
as BALs in SDSS, observed with Chandra, and then monitored with FAST at
observed-frame cadences of 1, 3, 9, 27, and 81 days, as well as 1 and 2 years.
We also monitor a set of non-BAL quasars with matched redshift and luminosity
as controls. We identify significant variability in the BALs, particularly at
the 1 and 2 year cadences, and use its magnitude and frequency to constrain the
outflows impacting the broad absorption line region.
