56 citations · 129 across the 10 of their papers we have counts for
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Nature of 4FGL J2249.4+6229: Evidence for a redback system with a cool companion and low X-ray and -ray luminosities
A. V. Karpova, D. A. Zyuzin, S. V. Zharikov +1
We report the identification of the likely X-ray and optical counterpart to the unassociated Fermi source 4FGL J2249.4+6229. To clarify its nature, we investigate the X-ray data fr…
Superflare on a rapidly-rotating solar-type star captured in X-rays
Andrey Mukhin, Roman Krivonos, Ilfan Bikmaev +5
In this work, we studied X-ray source SRGe~J021932.4040154 (SRGe J021932), which we associated with a single X-ray active star of spectral class G2V-G4V and the rotational perio…
Optical identification and follow-up observations of SRGA J213151.5+491400 -- a new magnetic cataclysmic variable discovered with SRG Observatory
Ş. Balman, I. Khamitov, A. Kolbin +21
We report results of optical identification and multi-wavelength study of a new polar-type magnetic cataclysmic variable (MCV), SRGA J213151.5+491400, discovered by Spectrum Roentg…
A Joint SRG/eROSITA + ZTF Search: Discovery of a 97-min Period Eclipsing Cataclysmic Variable with Evidence of a Brown Dwarf Secondary
Ilkham Galiullin, Antonio C. Rodriguez, Shrinivas R. Kulkarni +24
Cataclysmic variables (CVs) that have evolved past the period minimum during their lifetimes are predicted to be systems with a brown dwarf donor. While population synthesis models…
Nature of 4FGL J1838.2+3223: a flaring `spider' pulsar candidate
D. A. Zyuzin, A. Yu. Kirichenko, A. V. Karpova +4
An unidentified -ray source 4FGL J1838.2+3223 has been proposed as a pulsar candidate. We present optical time-series multi-band photometry of its likely optical companion obtai…
The black widow pulsar J1641+8049 in the optical, radio and X-rays
A. Yu. Kirichenko, S. V. Zharikov, A. V. Karpova +14
PSR J1641+8049 is a 2 ms black widow pulsar with the 2.2 h orbital period detected in the radio and -rays. We performed new phase-resolved multi-band photometry of PSR J1641+804…
Establishing accretion flares from massive black holes as a source of high-energy neutrinos
Sjoert van Velzen, Robert Stein, Marat Gilfanov +26
The origin of cosmic high-energy neutrinos remains largely unexplained. For high-energy neutrino alerts from IceCube, a coincidence with time-variable emission has been seen for th…