arXiv subjects

M. D. Afonina

Publications and source records attributed to M. D. Afonina.

4 recordsLinked to original sources

arXiv2024

Probing the propeller regime with wide neutron star binaries

We model the duration of the propeller stage in wide binary systems with neutron stars and calculate the time of accretion onset for various propeller models. We apply our modeling to the symbiotic X-ray binary SWIFT J0850.8-4219. Unless a propeller with a very slow spin-down is operating, it is very improbable to find a system similar to SWIFT J0850.8-4219 at the propeller stage. Then we model the evolution of a neutron star in a binary with a solar-like companion. We calculate for which orbital separations and magnetic fields a neutron star can start to accrete while the companion is still on the Main sequence. We demonstrate that for the magnetic field $B\lesssim10^{12}$~G neutron stars at the orbital separation $a\gtrsim 1$~AU do not reach the propeller stage. In the case of a slow propeller spin-down, neutron stars never start to accrete. For the more rapid propeller spin-down, a neutron star can start to accrete or spend a long time at the propeller stage depending on the parameters.

astro-ph.HE↗

arXiv2024

Probing the Propeller Regime with Symbiotic X-ray Binaries

At the moment, there are two neutron star X-ray binaries with massive red supergiants as donors. De et al. (2023) proposed that the system SWIFT J0850.8-4219 contains a neutron star at the propeller stage. We study this possibility by applying various models of propeller spin-down. We demonstrate that the duration of the propeller stage is very sensitive to the regime of rotational losses. Only in the case of a relatively slow propeller model proposed by Davies and Pringle (1981), the duration of the propeller is long enough to provide a significant probability to observe the system at this stage. Future determination of the system parameters (orbital and spin periods, magnetic field of the compact object, etc.) will allow putting strong constraints on the propeller behavior.

astro-ph.HE↗

arXiv2024

Early Accretion Onset in Long-Period Isolated Pulsars

We model long-term magneto-rotational evolution of isolated neutron stars with long initial spin periods. This analysis is motivated by the recent discovery of young long-period neutron stars observed as periodic radio sources: PSR J0901-4046, GLEAM-X J1627-52, and GPM J1839-10. Our calculations demonstrate that for realistically rapid spin-down during the propeller stage isolated neutron stars with velocities $\lesssim100$ km s$^{-1}$ and assumed long initial spin periods can reach the stage of accretion from the interstellar medium within at most a few billion years as they are born already at the propeller stage or sufficiently close to the critical period of the ejector-propeller transition. If neutron stars with long initial spin periods form a relatively large fraction of all Galactic neutron stars then the number of isolated accretors is substantially larger than it has been predicted by previous studies.

astro-ph.HE↗

arXiv2023

Evolutionary Status of Long-Period Radio Pulsars

We analyze the evolutionary status of recently discovered long-period radio sources PSR J0901-4046, GLEAM-X J1627-52, and GPM J1839-10. We discuss the hypothesis that all three sources are radio pulsars. In the framework of standard scenarios, it is often accepted that the pulsar mechanism is switched off when an external matter can penetrate the light cylinder. If the matter is stopped outside the light cylinder then the neutron star is at the ejector stage. We demonstrate that for realistic parameters of the interstellar medium, the 76-second pulsar PSR J0901-4046 might be at this stage. However, sources GLEAM-X J1627-52 and GPM J1839-10 with periods $\gtrsim 1000$ s can be ejectors only in the case of unrealistically large dipolar fields $\gtrsim 10^{16}$ G. Also, we show that neutron stars with spin periods $\sim 100$ s and dipolar magnetic fields $\lesssim 10^{13}$ G cannot be ejectors in a typical interstellar medium. Thus, we predict that long-period pulsars with standard fields will not be discovered.

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