33 citations · 82 across the 8 of their papers we have counts for
8 papers
Reverberation responses in light curves of the SBS1520+530 quasar
Liudmyla Berdina, Victoria Tsvetkova
Purpose: We aim to investigate an accretion disk (AD) temperature profile of a doubly lensed quasar SBS 1520+530. Temperature profiles of accretion disks are known to be diagnostic…
Analysis of modern astrometric catalogues in the Gaia era
V. S. Akhmetov, P. N. Fedorov, V. S. Tsvetkova +1
We investigate of the systems of proper motions of stars in the ground-based catalogues HSOY, UCAC5, GPS1 and PMA derived by combining with the Gaia DR1 space data. Assuming the sy…
Super-Eddington accretion in the Q2237+0305 quasar?
L. A. Berdina, V. S. Tsvetkova, V. M. Shulga
The interband time lags between the flux variations of the Q2237+0305 quasar have been determined from light curves in the Johnson-Cousins V, R, and I spectral bands. The values of…
Detection of the rapid variability in the Q2237+0305 quasar
L. Berdina, V. S. Tsvetkova
Rapid intrinsic variability has been detected for the first time in the Einstein Cross QSO 2237+0305, a radio quiet flat spectrum quasar at z=1.7 that is quadruply lensed by a fore…
PG 1115+080: variations of the A2/A1 flux ratio and new values of the time delays
V. S. Tsvetkova, V. G. Vakulik, V. M. Shulga +15
We report the results of our multicolor observations of PG 1115+080 with the 1.5-m telescope of the Maidanak Observatory (Uzbekistan, Central Asia) in 2001-2006. Monitoring data in…
Time delays in PG1115+080: new estimates
V. G. Vakulik, V. M. Shulga, R. E. Schild +13
We report new estimates of the time delays in the quadruple gravitationally lensed quasar PG1115+080, obtained from the monitoring data in filter R with the 1.5-m telescope at the…
Observational determination of the time delays in gravitational lens system Q2237+030
V. Vakulik, R. Schild, V. Dudinov +4
We present new brightness monitoring observations of the 4 components of gravitationally lensed system Q2237+0305, which show detection of an intrinsic quasar brightness fluctuatio…
Color Effects Associated with the 1999 Microlensing Brightness Peaks in Gravitationally Lensed Quasar Q2237+0305
V. G. Vakulik, R. E. Schild, V. N. Dudinov +9
Photometry of the Q2237+0305gravitational lens in VRI spectral bands with the 1.5-m telescope of the high-altitude Maidanak observatory in 1995-2000 is presented. Monitoring of Q22…