58 citations · 242 across the 21 of their papers we have counts for
11 papers · 1 filter
Bimodal abundance pattern in M51: evidence for corotation resonance effects
I. A. Acharova, O. A. Galazutdinova, J. R. D. Lépine +2
A chemical evolution model for the bimodal-like abundance distribution in the external galaxy M51 recently derived on the basis of HST data for more than a half million red supergi…
VV124 (UGC4879): A new transitional dwarf galaxy in the periphery of the Local Group
Alexander I. Kopylov, Nikolay A. Tikhonov, Sergey Fabrika +2
We present the first resolved-star photometry of VV124 (UGC4879) and find that this is the most isolated dwarf galaxy in the periphery of the Local Group. Based on imaging and spec…
Optical monitoring of the z=4.40 quasar Q 2203+292
E. P. Ovcharov, P. L. Nedialkov, A. T. Valcheva +5
We report Cousins R-band monitoring of the high-redshift (z=4.40) radio quiet quasar Q 2203+292 from May 1999 to October 2007. The quasar shows maximum peak-to-peak light curve amp…
Stellar Subsystems of the Galaxy NGC 2366
N. A. Tikhonov, O. A. Galazutdinova
Hubble Space Telescope archive data are used to perform photometry of stars in seven fields at the center and periphery of the galaxy NGC2366. The variation of the number density o…
Stellar Structure of Irregular Galaxies. Edge-On Galaxies
N. A. Tikhonov
Stellar photometry obtained using the Hubble Space Telescope is used to study the distributions of the number densities of stars of various ages in 12 irregular and dwarf spiral ga…
Stellar Structure of Irregular Galaxies. I. Face-on Galaxies
N. A. Tikhonov
Stellar photometry of nearby irregular galaxies of the Local Group is used to identify and study the young and old stellar populations of these galaxies. An analysis of the spatial…
Stellar halos and thick disks around edge-on spiral galaxies IC2233, IC5052, NGC4631 and NGC5023
N. A. Tikhonov, O. A. Galazutdinova, I. O. Drozdovsky
Aims. The extraplanar stellar populations of highly-inclined disk galaxies IC 2233, IC 5052, NGC 4631 and NGC 5023 are analyzed with the goal to quantify their vertical extent and…
Stellar disks and halos of the edge-on spiral galaxies: NGC 891, NGC 4144 and NGC 4244
N. A. Tikhonov, O. A. Galazutdinova
The results of the stellar photometry of the images ACS/WFC and WFPC2 of the HST are used to study stellar population and spatial distribution of stars in three edge-on galaxies: N…
The Stellar Content of the Polar Rings in the Galaxies NGC 2685 and NGC 4650A
G. M. Karataeva, I. O. Drozdovsky, V. A. Hagen-Thorn +3
We present the results of stellar photometry of polar-ring galaxies NGC 2685 and NGC 4650A, using the archival data obtained with the Hubble Space Telescope's Wide Field Planetary…
First optical identification of a suprsoft X-ray source in M31
P. Nedialkov, M. Orio, K. Birkle +5
We propose the first association of an optical counterpart with a luminous supersoft X-ray source in M31, RX J0044.0+4118, observed with ROSAT in July 1991. The PSPC position is at…
DDO 187: Do dwarf galaxies have extended halos?
A. Aparicio, N. Tikhonov, I. Karachentsev
If dwarf galaxies are primeval objects in the Universe, as hierarchical galaxy formation scenarios predict, they should show traces of their old stellar populations, perhaps distri…