Bibcode
Polednikova, J.; Ederoclite, Alessandro; Cepa, J.; de Diego Onsurbe, José Antonio; González-Serrano, José Ignacio
Bibliographical reference
Multiwavelength AGN Surveys and Studies, Proceedings of the International Astronomical Union, IAU Symposium, Volume 304, pp. 403-406
Advertised on:
7
2014
Citations
0
Refereed citations
0
Description
We present results from a project focused on searching optical
microvariabilty (also known as ``intra-night'' variability) in type 2 -
obscured - quasars. Optical microvariability can be described as very
small changes in the flux, typically in the order of hundredths of
magnitude, which can be observed on timescales of hours. Such studies
have been so far conducted for samples of blazars and type 1,
unobscured, AGNs, where the optical microvariability was detected with
success. We have focused on obscured targets which would pose a
challenge to the AGN standard model. In the present work, however, we
have observed a sample of three bright (g mag < 17) type 2 quasar,
based on the catalog of type 2 quasars from SDSS of Reyes et al. (2008).
The observations were carried out with the 1.5 meter telescope at San
Pedro Martir observatory in Mexico. The sample was observed during an
observation period of four days in Johnsons V filter, resulting in at
least two continuous intervals of observations per target during the
observational run. We have obtained differential light curves for our
sources as well as for the comparison stars. They were analyzed using
one-way analysis of variance statistical test (ANOVA), which has been
repeatedly used in the past for studies of unobscured targets. Based on
the results from the statistical analysis, we show that at least two out
of three observed targets appear to be variable on time scales of hours.
So far, this is the first study which confirmed existence of optical
microvariability in type 2 quasars.