Vyacheslav N. Shalyapin

Time Delay and Accretion Disk Size Measurements in the Lensed Quasar SBS?0909+532 from Multiwavelength Microlensing Analysis

We present three complete seasons and two half-seasons of Sloan Digital Sky Survey (SDSS) r-band photometry of the gravitationally lensed quasar SBS?0909+532 from the U.S. Naval Observatory, as well as two seasons each of SDSS g-band and r-band monitoring from the Liverpool Robotic Telescope. Using Monte Carlo simulations to simultaneously measure the systems time delay and model the r-band microlensing variability, we confirm and significantly refine the precision of the systems time delay to , where the stated uncertainties represent the bounds of the formal 1? confidence interval. There may be a conflict between the time delay measurement and a lens consisting of a single galaxy. While models based on the Hubble Space Telescope astrometry and a relatively compact stellar distribution can reproduce the observed delay, the models have somewhat less dark matter than we would typically expect. We also carry out a joint analysis of the microlensing variability in the r and g bands to constrain the size of the quasars continuum source at these wavelengths, obtaining log {(r s, r /cm)[cos i/0.5]1/2} = 15.3 ? 0.3 and log {(r s, g /cm)[cos i/0.5]1/2} = 14.8 ? 0.9, respectively. Our current results do not formally constrain the temperature profile of the accretion disk but are consistent with the expectations of standard thin disk theory.

Doubly Imaged Quasar SDSS J1515+1511: Time Delay and Lensing Galaxies

We analyse new optical observations of the gravitational lens system SDSS J1515+1511. These include a 2.6-year photometric monitoring with the Liverpool Telescope (LT) in the

Discovery of the optically bright, wide separation double quasar SDSS J1442+4055

r

Gravitational lens system SDSS J1339+1310: microlensing factory and time delay

band, as well as a spectroscopic follow-up with the LT and the Gran Telescopio Canarias (GTC). Our

Deep optical imaging and spectroscopy of the lens system SDSS J1339+1310

r

A 5.5-year robotic optical monitoring of Q0957+561: substructure in a non-local cD galaxy

-band LT light curves cover a quiescent microlensing period of the doubly imaged quasar at

QSO size ratios from multiband monitoring of a microlensing high-magnification event

z_{\rm s}

Spectra of faint sources in crowded fields with FRODOSpec on the Liverpool Robotic Telescope

= 2.049, which permits us to robustly estimate the time delay between the two images A and B: 211

Crowded-field image simulator for WSO-UV/ISSIS: first functional version developed by the Glendama team

\pm

Spectroscopic follow-up of double quasar candidates

5 days (1