75 citations · 218 across the 7 of their papers we have counts for
7 papers
Long-term optical spectral monitoring of a changing-look AGN NGC 3516 I: Continuum and broad-line flux variability
A. I. Shapovalova, L. C. Popovic, V. L. Afanasiev +11
Here we present the long-term optical spectral monitoring of a changing-look active galactic nuclei (AGN) NGC 3516 that covers 22 years (from 1996 to 2018). We explore a variabilit…
Long-term optical spectral monitoring of NGC 7469
Alla I. Shapovalova, L. C. Popović, V. H. Chavushyan +11
We present the results of the long-term (20-year period, from 1996 to 2015) optical spectral monitoring of the Seyfert 1 galaxy NGC 7469. The variation in the light-curves of the b…
Polarization angle swings in blazars: The case of 3C 279
S. Kiehlmann, T. Savolainen, S. G. Jorstad +61
Over the past few years, several occasions of large, continuous rotations of the electric vector position angle (EVPA) of linearly polarized optical emission from blazars have been…
First long-term optical spectro-photometric monitoring of a binary black hole candidate E1821+643: I. Variability of spectral lines and continuum
A. I. Shapovalova, L. C. Popovic, V. H. Chavushyan +9
We report the results of the first long-term (1990-2014) optical spectro-photometric monitoring of a binary black hole candidate QSO E1821+643, a low-redshift high-luminosity radio…
Analyzing polarization swings in 3C 279
S. Kiehlmann, T. Savolainen, S. G. Jorstad +53
Quasar 3C 279 is known to exhibit episodes of optical polarization angle rotation. We present new, well-sampled optical polarization data for 3C 279 and introduce a method to disti…
Spectral optical monitoring of a double-peaked emission line AGN Arp 102B: I. Variability of spectral lines and continuum
A. I. Shapovalova, L. C. Popovic, A. N. Burenkov +14
Here we present results of the long-term (1987-2010) optical spectral monitoring of the broad line radio galaxy Arp 102B, a prototype of active galactic nuclei with the double-peak…
Long-term variability of the optical spectra of NGC 4151: I. Light curves and flux correlations
A. I. Shapovalova, L. C. Popovic, S. Collin +13
Results of a long-term spectral monitoring of the active galactic nucleus of NGC 4151 are presented (11 years, from 1996 to 2006). High quality spectra (S/N>50 in the continuum nea…