Flow Structure in the Eclipsing Polar V808 Aur. Results of 3D Numerical Simulations

Жилкин, А. Г.; Sobolev, A. V.; Бисикало, Д. В.; Gabdeev, M. M.

doi:10.1134/s1063772919090087

Cited by 13 publications

(4 citation statements)

References 63 publications

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“…The u-band flux is larger during posteclipse due to the absence of pre-eclipse self-absorption by the accretion curtain. Previous observations and numerical simulations have been able to reproduce remarkably similar lightcurves (Breytenbach et al 2019;Zhilkin et al 2019).…”

Section: Eclipse: a Likely One-pole Systemmentioning

confidence: 67%

Discovery of Two Polars from a Crossmatch of ZTF and the SRG/eFEDS X-Ray Catalog

Rodriguez

Kulkarni

Prince

et al. 2023

ApJ

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Magnetic cataclysmic variables (CVs) are luminous Galactic X-ray sources, which have been difficult to find in purely optical surveys due to their lack of outburst behavior. The eROSITA telescope on board the Spektr-RG mission is conducting an all-sky X-ray survey and recently released the public eROSITA Final Equatorial Depth Survey (eFEDS) catalog. We crossmatched the eFEDS catalog with photometry from the Zwicky Transient Facility and discovered two new magnetic CVs. We obtained high-cadence optical photometry and phase-resolved spectroscopy for each magnetic CV candidate and found them both to be polars. Among the newly discovered magnetic CVs is eFEDS J085037.2+044359/ZTFJ0850+0443, an eclipsing polar with orbital period P orb = 1.72 hr and WD mass M WD = 0.81 ± 0.08M ⊙. We suggest that eFEDS J085037.2+044359/ZTFJ0850+0443 is a low magnetic field strength polar, with B WD ≲ 10 MG. We also discovered a non-eclipsing polar, eFEDS J092614.1+010558/ZTFJ0926+0105, with orbital period P orb = 1.47 hr and magnetic field strength B WD = 36–42 MG.

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Section: Eclipse: a Likely One-pole Systemmentioning

confidence: 67%

Discovery of Two Polars from a Crossmatch of ZTF and the SRG/eFEDS X-Ray Catalog

Rodriguez

Kulkarni

Prince

et al. 2023

ApJ

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“…In the case of slow magnetosonic characteristics, the initial Einfeldt correction does not agree with a purely gas-dynamic version of the difference Roe scheme. Therefore, for such characteristics, we use a modified entropy correction [83].…”

Section: Discussionmentioning

confidence: 99%

“…To improve the accuracy, we apply the Osher increasing correction [81]. The resulting difference scheme belongs to the class of TVD (total variation diminishing) schemes [82] and for the case of single-fluid magnetic hydrodynamics is described in detail in [83]. The scheme has the first order of approximation in time and the third order in space.…”

Section: Appendix a Difference Scheme For The Equations Of Multi-component Magnetic Hydrodynamicsmentioning

confidence: 99%

Multi-Component MHD Model of Hot Jupiter Envelopes

Жилкин

Bisikalo

2021

Universe

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A numerical model description of a hot Jupiter extended envelope based on the approximation of multi-component magnetic hydrodynamics is presented. The main attention is focused on the problem of implementing the completed MHD stellar wind model. As a result, the numerical model becomes applicable for calculating the structure of the extended envelope of hot Jupiters not only in the super-Alfvén and sub-Alfvén regimes of the stellar wind flow around and in the trans-Alfvén regime. The multi-component MHD approximation allows the consideration of changes in the chemical composition of hydrogen–helium envelopes of hot Jupiters. The results of calculations show that, in the case of a super-Alfvén flow regime, all the previously discovered types of extended gas-dynamic envelopes are realized in the new numerical model. With an increase in magnitude of the wind magnetic field, the extended envelope tends to become more closed. Under the influence of a strong magnetic field of the stellar wind, the envelope matter does not move along the ballistic trajectory but along the magnetic field lines of the wind toward the host star. This corresponds to an additional (sub-Alfvénic) envelope type of hot Jupiters, which has specific observational features. In the transient (trans-Alfvén) mode, a bow shock wave has a fragmentary nature. In the fully sub-Alfvén regime, the bow shock wave is not formed, and the flow structure is shock-less.

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“…For the calculations, a three-dimensional numerical code is used based on the Roe-Osher-Einfeldt difference scheme for magnetic hydrodynamics, which refers to Godunovtype schemes of an increased accuracy order. This difference scheme is described in detail in our paper [37]. The problem is solved in the computational domain −2.0 ≤ x/A ≤ 1.0, −1.5 ≤ y/A ≤ 1.5 and −0.75 ≤ z/A ≤ 0.75 with the number of cells 256 × 256 × 128 and an uneven grid step exponentially decreasing toward the center of the accretor.…”

Section: Numerical Modelmentioning

confidence: 99%

Hot Spots Drift in Synchronous and Asynchronous Polars: Results of Three-Dimensional Numerical Simulation

2021

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In this paper, the characteristics of hot spots on an accretor surface are investigated for two types of polars: the eclipsing synchronous polar V808 Aur and the non-eclipsing asynchronous polar CD Ind in configuration of an offset and non-offset magnetic dipole. The drift of hot spots is analyzed based on the results of numerical calculations and maps of the temperature distribution over the accretor surface. It is shown that a noticeable displacement of the spots is determined by the ratio of ballistic and magnetic parts of the jet trajectory. In the synchronous polar, the dominant influence on the drift of hot spots is exerted by variations in the mass transfer rate, which entail a change in the ballistic part of the trajectory. It was found that when the mass transfer rate changes within the range of 10−10M⊙/year to 10−7M⊙/year, the displacement of the hot spot in latitude and longitude can reach 30∘. In the asynchronous polar, a change in the position of hot spots is mainly defined by the properties of the white dwarf magnetosphere, and the displacement of hot spots in latitude and longitude can reach 20∘.

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Flow Structure in the Eclipsing Polar V808 Aur. Results of 3D Numerical Simulations

Cited by 13 publications

References 63 publications

Discovery of Two Polars from a Crossmatch of ZTF and the SRG/eFEDS X-Ray Catalog

Discovery of Two Polars from a Crossmatch of ZTF and the SRG/eFEDS X-Ray Catalog

Multi-Component MHD Model of Hot Jupiter Envelopes

Hot Spots Drift in Synchronous and Asynchronous Polars: Results of Three-Dimensional Numerical Simulation

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