Alexandre G. Kuranov
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
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Research Subjects
Alexandre G. Kuranov has a total of 18 co-authors. Here are the top co-authors by number of shared publications:
- Konstantin A. Postnov
Sternberg Astronomical Institute, Moscow State University
4 shared publications - Lev Yungelson
Institute of Astronomy, Russian Academy of Sciences, Pyatnitskaya 48, 119017 Moscow, Russia
3 shared publications - Alexander D. Dolgov
Novosibirsk State University, Novosibirsk, Russia
2 shared publications - Ivan V. Simkin
Centre for Soft Matter and Physics of Fluids, Cluster for Engineering for Life Sciences (CELS), Bauman Moscow State Technical University, Moscow 105005, Russia
2 shared publications K. A. Postnov
M.V Sternberg Astronomical Institute Lomonosov Moscow University
2 shared publicationsL. R. Yungelson
Institute of Astronomy Russian Academy of Sciences
2 shared publications
Latest Publications
- Open Access
I-Process Nucleosynthesis in AM CVn Systems
We investigate nucleosynthesis during very strong, non-dynamical recurrent He-flashes that are expected to occur in close binary systems hosting a carbon–oxygen white dwarf and a type-B subdwarf companion. In these systems, due to gravitational wave emissions, the subdwarf star is expected to fill its Roche lobe on a short timescale, resulting in mass transfer onto the companion. As accreted matter also deposits angular momentum, the external layers of the accretor begin to rotate very fast. So, dynamical He burning is avoided, and the WD instead experiences recurrent strong He flashes, which secularly reduce its mass. We consider the PTF J2238+743015.1 system as representative of the whole class of similar objects and compute its evolution by coupling our evolutionary code with a full nuclear network, including isotopes with a lifetime longer than 0.8 s. We find that during He-flash episodes, the delivered neutron flux is typical for the i-process nucleosynthesis, even if it is available for a very short time (1–10 h). As a consequence, only weak s-process nucleosynthesis takes place. The nucleosynthetic path in the ejected matter is quite similar to that of supernovae descending from massive stars. However, due to the rarity of these systems, as well as to the small amount of matter ejected during the He-flashes phase, their contribution to the evolution of the interstellar medium is negligible.
Open AccessI-Process Nucleosynthesis in AM CVn Systems
We investigate nucleosynthesis during very strong, non-dynamical recurrent He-flashes that are expected to occur in close binary systems hosting a carbon–oxygen white dwarf and a type-B subdwarf companion. In these systems, due to gravitational wave emissions, the subdwarf star is expected to fill its Roche lobe on a short timescale, resulting in mass transfer onto the companion. As accreted matter also deposits angular momentum, the external layers of the accretor begin to rotate very fast. So, dynamical He burning is avoided, and the WD instead experiences recurrent strong He flashes, which secularly reduce its mass. We consider the PTF J2238+743015.1 system as representative of the whole class of similar objects and compute its evolution by coupling our evolutionary code with a full nuclear network, including isotopes with a lifetime longer than 0.8 s. We find that during He-flash episodes, the delivered neutron flux is typical for the i-process nucleosynthesis, even if it is available for a very short time (1–10 h). As a consequence, only weak s-process nucleosynthesis takes place. The nucleosynthetic path in the ejected matter is quite similar to that of supernovae descending from massive stars. However, due to the rarity of these systems, as well as to the small amount of matter ejected during the He-flashes phase, their contribution to the evolution of the interstellar medium is negligible.
- Open Access
Population synthesis of ultraluminous X-ray sources with magnetised neutron stars
A model of population of ultraluminous X-ray sources with magnetised neutron stars (NULX) in a spiral galaxy with the star formation history similar to that in the thin disc of Milky Way is computed using a hybrid approach. First, applying analytical approximations (code BSE) we construct the ensemble of close binaries (CBS) which can be potential precursors of NULX. Next, evolution with accretion onto magnetised neutron stars (NS) is computed by the evolutionary code MESA. Accretion rate onto NS and X-ray luminosity are calculated for the models of sub- and supercritical discs and for the discs with advection. During accretion onto magnetised NS, super-Eddington luminosity $L_\mathrm{X}>10^{38}$ erg~s$^{-1}$ is attained already at the subcritical stage, when the energy release at the inner boundary of the disc defined by the NS magnetosphere is sub-Eddington. It is shown that standard evolution of CBS with an account of the peculiarities specific for accretion onto magnetised NS allows us to explain quantitatively observed characteristics of NULX (X-ray luminosities, NS spin periods, orbital periods and masses of visual components) without additional model assumptions on the collimation of X-ray emission from NS with high observed super-Eddington luminosity. In a model galaxy with star formation rate 3--5 $M_\odot {\rm yr^{-1}}$ there can exist several NULX. Discovery of a powerful wind from NULX with $L_{\mathrm X} \sim 10^{41}$ erg~s$^{-1}$ would be a signature of super-Eddington accretion onto magnetised NS.Open AccessPopulation synthesis of ultraluminous X-ray sources with magnetised neutron stars
A model of population of ultraluminous X-ray sources with magnetised neutron stars (NULX) in a spiral galaxy with the star formation history similar to that in the thin disc of Milky Way is computed using a hybrid approach. First, applying analytical approximations (code BSE) we construct the ensemble of close binaries (CBS) which can be potential precursors of NULX. Next, evolution with accretion onto magnetised neutron stars (NS) is computed by the evolutionary code MESA. Accretion rate onto NS and X-ray luminosity are calculated for the models of sub- and supercritical discs and for the discs with advection. During accretion onto magnetised NS, super-Eddington luminosity $L_\mathrm{X}>10^{38}$ erg~s$^{-1}$ is attained already at the subcritical stage, when the energy release at the inner boundary of the disc defined by the NS magnetosphere is sub-Eddington. It is shown that standard evolution of CBS with an account of the peculiarities specific for accretion onto magnetised NS allows us to explain quantitatively observed characteristics of NULX (X-ray luminosities, NS spin periods, orbital periods and masses of visual components) without additional model assumptions on the collimation of X-ray emission from NS with high observed super-Eddington luminosity. In a model galaxy with star formation rate 3--5 $M_\odot {\rm yr^{-1}}$ there can exist several NULX. Discovery of a powerful wind from NULX with $L_{\mathrm X} \sim 10^{41}$ erg~s$^{-1}$ would be a signature of super-Eddington accretion onto magnetised NS. - 1 December 2020
- Published by IOP Publishing in Journal of Cosmology and Astroparticle Physics
- Vol. 2020 (12) , 017
On mass distribution of coalescing black holes
- 1 December 2020
- Published by IOP Publishing in Journal of Cosmology and Astroparticle Physics
- Vol. 2020 (12) , 017
On mass distribution of coalescing black holes
- Open Access
On mass distribution of coalescing black holes
Available data on the chirp mass distribution of the coalescing black hole binaries in O1-O3 LIGO/Virgo runs are analyzed and compared statistically with the distribution calculated under the assumption that these black holes are primordial with a log-normal mass spectrum. The theoretically calculated chirp mass distribution with the inferred best acceptable mass spectrum parameters, $M_0=17 M_\odot$ and $\gamma=0.9$, perfectly describes the data. The value of $M_0$ very well agrees with the theoretically expected one. On the opposite, the chirp mass distribution of black hole binaries originated from massive binary star evolution requires additional model adjustments to reproduce the observed chirp mass distributionOpen AccessOn mass distribution of coalescing black holes
Available data on the chirp mass distribution of the coalescing black hole binaries in O1-O3 LIGO/Virgo runs are analyzed and compared statistically with the distribution calculated under the assumption that these black holes are primordial with a log-normal mass spectrum. The theoretically calculated chirp mass distribution with the inferred best acceptable mass spectrum parameters, $M_0=17 M_\odot$ and $\gamma=0.9$, perfectly describes the data. The value of $M_0$ very well agrees with the theoretically expected one. On the opposite, the chirp mass distribution of black hole binaries originated from massive binary star evolution requires additional model adjustments to reproduce the observed chirp mass distribution - 1 October 2020
- Published by Pleiades Publishing Ltd in Astronomy Letters
- Vol. 46 (10) , 658-676
Population Synthesis of Ultraluminous X-ray Sources with Magnetized Neutron Stars
A model of a population of ultraluminous X-ray sources with magnetized neutron stars (NULXs) in a spiral galaxy with a star formation history as in the thin disk of the Milky Way is constructed by the hybrid population synthesis method. First, based on analytical approximations (BSE code), we compute a set of close binary systems (CBSs), potential precursors of NULXs, and, then, the evolution with mass accretion onto magnetized neutron stars (NSs) is computed by the MESA evolutionary code. The accretion rate onto NSs and the X-ray luminosity of sources are calculated for the models of sub- or supercritical disks and disks with advection. During accretion onto magnetized NSs, super-Eddington luminosities \(L_{\textrm{X}}>10^{38}\) erg s\({}^{-1}\) are reached already at the subcritical stage, when the energy release at the inner boundary of the disk defined by the NS magnetosphere is sub-Eddington one. Our calculations show that the standard evolution of CBSs, given the peculiarities of accretion onto magnetized NSs, allows the observed properties of NULXs (X-ray luminosities, NS spin periods, CBS orbital periods, and optical component masses) to be quantitatively explained without requiring additional model assumptions about the collimation of X-ray emission from NSs with a high observed super-Eddington luminosity. In a model galaxy with a star formation rate \({\sim}5M_{\odot}\) yr\({}^{-1}\) there can be several NULXs. The detection of a powerful wind from NULXs with \(L_{\textrm{X}}\sim 10^{41}\) erg s\({}^{-1}\) may suggest supercritical accretion onto magnetized NSs.- 1 October 2020
- Published by Pleiades Publishing Ltd in Astronomy Letters
- Vol. 46 (10) , 658-676
Population Synthesis of Ultraluminous X-ray Sources with Magnetized Neutron Stars
A model of a population of ultraluminous X-ray sources with magnetized neutron stars (NULXs) in a spiral galaxy with a star formation history as in the thin disk of the Milky Way is constructed by the hybrid population synthesis method. First, based on analytical approximations (BSE code), we compute a set of close binary systems (CBSs), potential precursors of NULXs, and, then, the evolution with mass accretion onto magnetized neutron stars (NSs) is computed by the MESA evolutionary code. The accretion rate onto NSs and the X-ray luminosity of sources are calculated for the models of sub- or supercritical disks and disks with advection. During accretion onto magnetized NSs, super-Eddington luminosities \(L_{\textrm{X}}>10^{38}\) erg s\({}^{-1}\) are reached already at the subcritical stage, when the energy release at the inner boundary of the disk defined by the NS magnetosphere is sub-Eddington one. Our calculations show that the standard evolution of CBSs, given the peculiarities of accretion onto magnetized NSs, allows the observed properties of NULXs (X-ray luminosities, NS spin periods, CBS orbital periods, and optical component masses) to be quantitatively explained without requiring additional model assumptions about the collimation of X-ray emission from NSs with a high observed super-Eddington luminosity. In a model galaxy with a star formation rate \({\sim}5M_{\odot}\) yr\({}^{-1}\) there can be several NULXs. The detection of a powerful wind from NULXs with \(L_{\textrm{X}}\sim 10^{41}\) erg s\({}^{-1}\) may suggest supercritical accretion onto magnetized NSs.- Open Access
- 13 November 2017
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 474 (2) , 2750-2756
A young contracting white dwarf in the peculiar binary HD 49798/RX J0648.0–4418 ?
HD 49798/RX J0648.0–4418 is a peculiar X-ray binary with a hot subdwarf (sdO) mass donor. The nature of the accreting compact object is not known, but its spin period P = 13.2 s and $$\dot{P} =-2.15 \times 10^{-15}$$s s−1, prove that it can be only either a white dwarf or a neutron star. The spin-up has been very stable for more than 20 years. We demonstrate that the continuous stable spin-up of the compact companion of HD 49798 can be best explained by contraction of a young white dwarf with an age ∼2 Myrs. This allows us to interpret all the basic parameters of the system in the framework of an accreting white dwarf. We present examples of binary evolution which result in such systems. If correct, this is the first direct evidence for a white dwarf contraction on early evolutionary stages.- 13 November 2017
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 474 (2) , 2750-2756
Open AccessA young contracting white dwarf in the peculiar binary HD 49798/RX J0648.0–4418 ?
HD 49798/RX J0648.0–4418 is a peculiar X-ray binary with a hot subdwarf (sdO) mass donor. The nature of the accreting compact object is not known, but its spin period P = 13.2 s and $$\dot{P} =-2.15 \times 10^{-15}$$s s−1, prove that it can be only either a white dwarf or a neutron star. The spin-up has been very stable for more than 20 years. We demonstrate that the continuous stable spin-up of the compact companion of HD 49798 can be best explained by contraction of a young white dwarf with an age ∼2 Myrs. This allows us to interpret all the basic parameters of the system in the framework of an accreting white dwarf. We present examples of binary evolution which result in such systems. If correct, this is the first direct evidence for a white dwarf contraction on early evolutionary stages. - Open Access
A young contracting white dwarf in the peculiar binary HD 49798/RX J0648.0--4418?
HD 49798/RX J0648.0--4418 is a peculiar X-ray binary with a hot subdwarf (sdO) mass donor. The nature of the accreting compact object is not known, but its spin period $P=13.2$~s and $\dot P =-2.15 \times 10^{-15}$s~s$^{-1}$, prove that it can be only either a white dwarf or a neutron star. The spin-up has been very stable for more than 20 years. We demonstrate that the continuous stable spin-up of the compact companion of HD 49798 can be best explained by contraction of a young white dwarf with an age $\sim 2$~Myrs. This allows us to interpret all the basic parameters of the system in the framework of an accreting white dwarf. We present examples of binary evolution which result in such systems. If correct, this is the first direct evidence for a white dwarf contraction on early evolutionary stages.Open AccessA young contracting white dwarf in the peculiar binary HD 49798/RX J0648.0--4418?
HD 49798/RX J0648.0--4418 is a peculiar X-ray binary with a hot subdwarf (sdO) mass donor. The nature of the accreting compact object is not known, but its spin period $P=13.2$~s and $\dot P =-2.15 \times 10^{-15}$s~s$^{-1}$, prove that it can be only either a white dwarf or a neutron star. The spin-up has been very stable for more than 20 years. We demonstrate that the continuous stable spin-up of the compact companion of HD 49798 can be best explained by contraction of a young white dwarf with an age $\sim 2$~Myrs. This allows us to interpret all the basic parameters of the system in the framework of an accreting white dwarf. We present examples of binary evolution which result in such systems. If correct, this is the first direct evidence for a white dwarf contraction on early evolutionary stages. - 1 March 2015
- Published by Pleiades Publishing Ltd in Astronomy Letters
- Vol. 41 (3-4) , 114-127
Symbiotic X-ray binaries systems in the galaxy
The evolution of symbiotic X-ray binaries in the Galaxy is studied by the population synthesis method. We show that allowance for the nonstationarity of the regime of quasi-spherical subsonic...
- 1 March 2015
- Published by Pleiades Publishing Ltd in Astronomy Letters
- Vol. 41 (3-4) , 114-127
Symbiotic X-ray binaries systems in the galaxy
The evolution of symbiotic X-ray binaries in the Galaxy is studied by the population synthesis method. We show that allowance for the nonstationarity of the regime of quasi-spherical subsonic...
- 3 January 2014
- Published by Pleiades Publishing Ltd in Astronomy Letters
- Vol. 40 (1) , 29-45
Modeling the luminosity function of galactic low-mass X-ray binaries
The evolution of the family of binaries with a low-mass star and a compact neutron star companion (low-mass X-ray binaries (LMXBs) with neutron stars) ismodeled by the method of population synthesis....
- 3 January 2014
- Published by Pleiades Publishing Ltd in Astronomy Letters
- Vol. 40 (1) , 29-45
Modeling the luminosity function of galactic low-mass X-ray binaries
The evolution of the family of binaries with a low-mass star and a compact neutron star companion (low-mass X-ray binaries (LMXBs) with neutron stars) ismodeled by the method of population synthesis....