Modeling reversals of galactic magnetic fields at large distances from centers of milky-way-like galaxies using computations on GPUs
Nowadays it is strongly believed that in a large number of spiral galaxies there are regular magnetic fields. Their existence is proved by measurements of the Faraday rotation of polarization plane of electromagnetic waves which are received on modern radio telescopes. The theoretical description of...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Astronomical Observatory, Department of Astronomy, Belgrade
2024-01-01
|
| Series: | Serbian Astronomical Journal |
| Subjects: | |
| Online Access: | https://doiserbia.nb.rs/img/doi/1450-698X/2024/1450-698X2400003K.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849421262490697728 |
|---|---|
| author | Khasaeva T.T. Mikhailov E.A. Teplyakov I.O. |
| author_facet | Khasaeva T.T. Mikhailov E.A. Teplyakov I.O. |
| author_sort | Khasaeva T.T. |
| collection | DOAJ |
| description | Nowadays it is strongly believed that in a large number of spiral galaxies there are regular magnetic fields. Their existence is proved by measurements of the Faraday rotation of polarization plane of electromagnetic waves which are received on modern radio telescopes. The theoretical description of magnetic fields generation is connected with the mean field dynamo mechanism. It is based on joint action of the α-effect and differential rotation. At the first stage of evolution, magnetic fields enlarge exponentially with the growth rate described by the largest eigenvalue of the corresponding differential operator. If the field becomes comparable with the equipartition value, the nonlinear terms become more important, and they are connected with saturation of the field growth. The non- linear system of equations has several stationary points, and some of them are stable. According to the contrast structures theory for a quite small turbulent viscosity and some initial conditions, in different regions there will be magnetic fields of opposite directions, and they will be divided by narrow transition layers. Such features, for example, characterize the magnetic field of the Milky Way. Most of the existing works describe reversals for quite moderate distances from the galaxy center. However, it was shown previously that the magnetic field can principally be generated also in outer parts of galaxies, which are situated at distances of more than 10 kpc from the rotation axis. It is interesting to describe the appearance of reversals in such parts of galaxies. In this work we have studied the dynamo action in outer parts of the Milky-Way-like galaxies. It is shown that it is possible to generate opposite magnetic fields there. We have used random initial conditions to obtain spatial reversals. Because of a large volume of computations, they were carried out by using graphics processing units (GPUs). |
| format | Article |
| id | doaj-art-db78be0559e441358f72d2a5e977ebaf |
| institution | Kabale University |
| issn | 1450-698X 1820-9289 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | Astronomical Observatory, Department of Astronomy, Belgrade |
| record_format | Article |
| series | Serbian Astronomical Journal |
| spelling | doaj-art-db78be0559e441358f72d2a5e977ebaf2025-08-20T03:31:30ZengAstronomical Observatory, Department of Astronomy, BelgradeSerbian Astronomical Journal1450-698X1820-92892024-01-012024209253210.2298/SAJ231101003K1450-698X2400003KModeling reversals of galactic magnetic fields at large distances from centers of milky-way-like galaxies using computations on GPUsKhasaeva T.T.0https://orcid.org/0000-0003-2431-8024Mikhailov E.A.1https://orcid.org/0000-0002-9747-4039Teplyakov I.O.2https://orcid.org/0000-0002-2355-1935M.V.Lomonosov Moscow State University, Moscow, Russia + Institute of earthquake prediction theory and mathematical geophysics, Moscow, RussiaM.V.Lomonosov Moscow State University, Moscow, Russia + P.N. Lebedev Physical Institute, Moscow, RussiaJoint Institute for High Temperatures, Moscow, RussiaNowadays it is strongly believed that in a large number of spiral galaxies there are regular magnetic fields. Their existence is proved by measurements of the Faraday rotation of polarization plane of electromagnetic waves which are received on modern radio telescopes. The theoretical description of magnetic fields generation is connected with the mean field dynamo mechanism. It is based on joint action of the α-effect and differential rotation. At the first stage of evolution, magnetic fields enlarge exponentially with the growth rate described by the largest eigenvalue of the corresponding differential operator. If the field becomes comparable with the equipartition value, the nonlinear terms become more important, and they are connected with saturation of the field growth. The non- linear system of equations has several stationary points, and some of them are stable. According to the contrast structures theory for a quite small turbulent viscosity and some initial conditions, in different regions there will be magnetic fields of opposite directions, and they will be divided by narrow transition layers. Such features, for example, characterize the magnetic field of the Milky Way. Most of the existing works describe reversals for quite moderate distances from the galaxy center. However, it was shown previously that the magnetic field can principally be generated also in outer parts of galaxies, which are situated at distances of more than 10 kpc from the rotation axis. It is interesting to describe the appearance of reversals in such parts of galaxies. In this work we have studied the dynamo action in outer parts of the Milky-Way-like galaxies. It is shown that it is possible to generate opposite magnetic fields there. We have used random initial conditions to obtain spatial reversals. Because of a large volume of computations, they were carried out by using graphics processing units (GPUs).https://doiserbia.nb.rs/img/doi/1450-698X/2024/1450-698X2400003K.pdfgalaxies: spiraldynamomagnetohydrodynamicsgalaxies: magnetic fieldsism:magnetic fields |
| spellingShingle | Khasaeva T.T. Mikhailov E.A. Teplyakov I.O. Modeling reversals of galactic magnetic fields at large distances from centers of milky-way-like galaxies using computations on GPUs Serbian Astronomical Journal galaxies: spiral dynamo magnetohydrodynamics galaxies: magnetic fields ism:magnetic fields |
| title | Modeling reversals of galactic magnetic fields at large distances from centers of milky-way-like galaxies using computations on GPUs |
| title_full | Modeling reversals of galactic magnetic fields at large distances from centers of milky-way-like galaxies using computations on GPUs |
| title_fullStr | Modeling reversals of galactic magnetic fields at large distances from centers of milky-way-like galaxies using computations on GPUs |
| title_full_unstemmed | Modeling reversals of galactic magnetic fields at large distances from centers of milky-way-like galaxies using computations on GPUs |
| title_short | Modeling reversals of galactic magnetic fields at large distances from centers of milky-way-like galaxies using computations on GPUs |
| title_sort | modeling reversals of galactic magnetic fields at large distances from centers of milky way like galaxies using computations on gpus |
| topic | galaxies: spiral dynamo magnetohydrodynamics galaxies: magnetic fields ism:magnetic fields |
| url | https://doiserbia.nb.rs/img/doi/1450-698X/2024/1450-698X2400003K.pdf |
| work_keys_str_mv | AT khasaevatt modelingreversalsofgalacticmagneticfieldsatlargedistancesfromcentersofmilkywaylikegalaxiesusingcomputationsongpus AT mikhailovea modelingreversalsofgalacticmagneticfieldsatlargedistancesfromcentersofmilkywaylikegalaxiesusingcomputationsongpus AT teplyakovio modelingreversalsofgalacticmagneticfieldsatlargedistancesfromcentersofmilkywaylikegalaxiesusingcomputationsongpus |