Results from the Las Campanas Program to Monitor QSO Optical Brightness Variations
Session 24 -- AGNs/QSOs - High Luminosity
Display presentation, Tuesday, June 13, 1995, 9:20am - 6:30pm

## [24.02] Results from the Las Campanas Program to Monitor QSO Optical Brightness Variations

C.J.Sirola, D.A.Turnshek, E.Monier, S.Sheaffer (University of Pittsburgh), R.J.Weymann, S.Morris, O.Duhalde, W.Krzeminski, W. Kunkel, M. Roth (OCIW)

We present results from a brightness monitoring program of $>$ 150 QSOs. Short exposures were obtained using a CCD chip on the Las Campanas 40-inch Swope Telescope. Observations of the QSOs have been taken several times per year from late 1987 to early 1994. Brightness variations have been determined relative to stars contained in an $\approx$ 5 arcmin square field. The purpose of the program is to investigate the characteristics of the brightness variations among various types of QSOs: (1) radio-quiet QSOs with broad absorption lines (BALs), (2) radio-quiet QSOs without BALs, and (3) radio-loud QSOs. We compute the ensemble average structure function and autocorrelation function of the light curves in the rest frames of the QSOs. We find no large differences in the variability properties between the two types of radio-quiet QSOs over time scales of $\leq$ 1.5 years (proper time in the QSO rest frame), but we do find a substantial difference in the variability properties of radio-quiet and radio-loud QSOs over the same time scales.