activity
20012020
most citedSteps Toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XVI. A Thirteen-Year Study of Spectral Variability in NGC 5548

201 citations · 337 across the 9 of their papers we have counts for

collaborators
Showing astro-ph.COShow all

2 papers · 1 filter

astro-ph.CO2012★ 30 cited

Oxygen and nitrogen abundances of HII regions in six spiral galaxies

Alexander S. Gusev, Leonid S. Pilyugin, Firouz Sakhibov +3

Spectroscopic observations of 63 HII regions in six spiral galaxies (NGC 628, NGC 783, NGC 2336, NGC 6217, NGC 7331, and NGC 7678) were carried out with the 6-meter telescope (BTA)…

astro-ph.CO2012★ 20 cited

Time delay between images of the lensed quasar UM673

E. Koptelova, W. P. Chen, T. Chiueh +11

We study brightness variations in the double lensed quasar UM673 (Q0142-100) with the aim of measuring the time delay between its two images. In the paper we combine our previously…