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...
Weak gravitational lensing of galaxy cluster provides a direct method
to probe their mass distribution. We report our preliminary results on the
analysis of a complete sample of $\sim 50$ massive galaxy clusters,
in the redshift range 0.1 - 0.6, in the Canada France Hawaii Telescope Legacy Survey (CFHT-LS), drawn from the large sample built by Covone et al. (2014). For each galaxy...
RX Hydrae is a short-period (2d.2815) Algol-type eclipsing binary system with a pulsating primary component. This system was discovered by H.S. Leavitt (Pickering, 1907), the first spectroscopic elements were determined by Struve (1946) and the absolute parameters of this system was derived by Vyas & Abhyankar (1989). Short-periodic pulsations in a light curve of a primary component were...
The mass of supermassive black holes (SMBHs) of high redshift (z) quasars is crucial for understanding SMBH-galaxy co-evolution. The traditional method, spectroscopic reverberation mapping (SRM), would fail for most high-z quasars and is inefficient for a large quasar sample. Photometric reverberation mapping (PRM) has been recently proposed in order to utilise the up-coming high cadence,...
Fast radio bursts (FRBs) are intense transient millisecond radio signal with large dispersion measures (DM). Radio signal, which propagates through cold plasma, is dispersed as frequency square. After subtracted from the effect from galactic interstellar medium, the FRB's DMs are still large. This can be interpreted as FRBs have an extragalatic origin.As DM is related to the free electron...
