11 citations · 61 across the 14 of their papers we have counts for
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The Nature of the Emission Spectrum of NGC 7793 P13: modeling the atmosphere of the donor star
A. S. Vinokurov, A. E. Kostenkov, K. E. Atapin +1
We continue to study the ultra-luminous X-ray source NGC 7793 P13 in the optical range. In this work, we are testing the model of a spherically symmetric wind atmosphere of the don…
Optical Counterparts of Two Candidate Ultraluminous X-ray Sources in NGC 4536
H. Avdan, E. Sonbas, K. S. Dhuga +7
Archival {\it XMM-Newton}, {\it Chandra} and {\it Hubble Space Telescope (HST)} data have been used to study the X-ray and optical properties of two candidate ultraluminous X-ray s…
Simultaneous X-ray/UV observations of ultraluminous X-ray source Holmberg II X-1 with Indian space mission AstroSat
A. Vinokurov, K. Atapin, O. P. Bordoloi +11
We present the results of 8 epochs of simultaneous UV and X-ray observations of the highly variable ultraluminous X-ray source (ULX) Holmberg II X-1 with AstroSat -- Indian multiwa…
Optical Counterparts of ULXs in Two Dwarf Galaxies: NGC 4861 and NGC 4449
M. Ozdogan Ela, A. Akyuz, N. Aksaker +7
We present the results of a search for optical candidates of Ultraluminous X-ray sources (ULXs) in two dwarf galaxies: NGC 4861 and NGC 4449 using Hubble Space Telescope {\it HST}…
NGC 5474 X-1: a neutron star ULX in an old stellar cluster?
Kirill Atapin, Alexander Vinokurov, Arkadiy Sarkisyan +4
We present the optical and X-ray study of the ultraluminous X-ray source (ULX) NGC 5474 X-1. The X-ray spectrum taken during the bright state of the source ($L_X \sim 2\times10^{40…
Observations of ultraluminous X-ray sources with the 6-m telescope of the SAO RAS
A. Vinokurov, K. Atapin, Y. Solovyeva +2
The nature of ultraluminous X-ray sources (ULXs) is not yet fully understood but it can be done in the most efficient way by analyzing its optical emission and environment. We pres…
Optical Counterpart to the Ultraluminous X-Ray Source in the UGC6456 Galaxy
Alexander Vinokurov, Kirill Atapin, Yulia Solovyeva
We report the identification of the optical counterpart to the transient ultraluminuos X-ray source in the blue dwarf galaxy UGC6456 (VII Zw 403). The source is highly variable in…