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Session 103 - Quasars & Blazars.
Display session, Saturday, January 10
Exhibit Hall,
There are two theories explaining the variability of quasars. One model proposes there are flares or hot spots on an accretion disk surrounding a super massive black hole in the center of the AGN. In the other, there are shock waves propagating down the jet interacting with denser material, which results in a temporary brightening in the jet. If optical variability is not detected in radio-loud quasars, then either the jet model is incorrect and variability is not caused by the jets, or the observer is not looking down the axis of the jet and the quasar is radio-loud for some other reason.
To test these models, a monitoring program was established to detect optical variability in quasars. Ten radio-loud quasars were observed for at least three nights each, and for all quasars there was a gap of at least three months in observations to detect long-term variability. The quasars in this study were chosen from the Palomar-Green Bright Quasar Survey (BQS). These quasars have the highest core luminosity at 5 GHz, and since they are in the BQS, they are luminous at optical wavelengths and therefore suitable for optical monitoring. The ten PG quasars in this sample are 0003+158, 1103-006, 1222+228, 1226+023, 1241+176, 1302-102, 1538+477, 1718+481, 2308+098, and 2344+092.
Preliminary results indicate that five of the ten quasars show long-term variability (over a gap in observations of approximately one year) and no quasars showed short-term variability.
This research was performed at the Lowell Observatory 31-inch telescope which, under an agreement with Northern Arizona University and the NURO Consortium, is operated 60% of the time as the National Undergraduate Research Observatory.
