Siam Physics Congress 2016

Variability Study of Active Galactic Nuclei at Visible and X-ray Wavelength

9 Jun 2016, 10:45

15m

Room J1

Oral presentaion Astronomy, Astrophysics and Cosmology Session XIX

Speakers

Mr Pakawee Surarittikul (Chulalongkorn)Mr Tinn Thongmeearkom (Chulalongkorn)

Description

Active galactic nuclei (AGNs) are signposts of accreting supermassive
black holes at the center of active galaxies. They often have large
and rapid variation in brightness, whose investigation can provide us
with insights on the innermost environment of the accretion disk. To
study their variability, we conduct photometric monitoring of a sample
of nearby AGNs at visible and X-ray wavelength; these AGNs are
selected from the Hamburg/ESO Catalog, whose parent sample comprise
330 quasars at redshift < 0.3. We obtain visible wavelength data for
our AGN sample in Johnson B, V and R filters with the robotic Thai
Southern Hemisphere Telescope at Cerro Tololo Inter-American
Observatory, Chile. At X-ray wavelength, we obtain archival data in
2.0 – 6.0 keV band from the Monitor of All-Sky X-ray Image (MAXI) on
board the International Space Station. Using these data, we then
construct light curves of each AGN at both wavelength. Here, we
present early result from the study that indicates marginal
variabilities in X-ray and optical. We will discuss the implications
of variability limits on the fluctuation of power output of these AGNs
in optical and X-ray.