Poster abstract details
Microvariability of type 2 QSOs
Abstract
Fast brightness variations are a unique tool to probe the innermost regions of active galactic nuclei. These variations are called microvariability or intra night variability and the monitoring of this phenomenon has been carried out on samples of blazars and unobscured AGNs, both radio-loud and radio-quiet. It has been previously detected in unobscured type 1 AGNs and blazars. However in the case of type 2 AGNs, the detection of microvariability is hampered by the low contrast between the presumably variable nucleus and the host galaxy, resulting in few attempts for detection.Moreover, detecting optical microvariations in targets hidden by the obscuring torus is a challenging task as the region responsible for the variations is hidden from our sight.
We have used statistical approach to search for the microvariations, namely the enhanced F-test proposed by \citet{die14}. The main advantage of the test is a high statistical power which is achieved by calibrating the whole star field.
We applied this statistical method to three type 2 quasars. Evidence of microvariations is clear in the case of quasar J0802+2552 in all used filters ($g′$ ,$r′$ and $i′$), and they also may be present in one of the nights of observations of both, J1258+5239 and J1316+4452.
This phenomenon, presents a puzzle to our current understanding of the type 2 quasars. A possible explanation might lie in several causes including the misclassification of the targets. There is also a possible interesting connection between the merging state of the targets and detection of microvariability.
We have used statistical approach to search for the microvariations, namely the enhanced F-test proposed by \citet{die14}. The main advantage of the test is a high statistical power which is achieved by calibrating the whole star field.
We applied this statistical method to three type 2 quasars. Evidence of microvariations is clear in the case of quasar J0802+2552 in all used filters ($g′$ ,$r′$ and $i′$), and they also may be present in one of the nights of observations of both, J1258+5239 and J1316+4452.
This phenomenon, presents a puzzle to our current understanding of the type 2 quasars. A possible explanation might lie in several causes including the misclassification of the targets. There is also a possible interesting connection between the merging state of the targets and detection of microvariability.