Effective Resistivity in Relativistic Collisionless Reconnection
Magnetic reconnection can power spectacular high-energy astrophysical phenomena by producing nonthermal energy distributions in highly magnetized regions around compact objects. By means of two-dimensional fully kinetic particle-in-cell (PIC) simulations, we investigate relativistic collisionless pl...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2023-01-01
|
| Series: | The Astrophysical Journal |
| Subjects: | |
| Online Access: | https://doi.org/10.3847/1538-4357/acd0b0 |
| _version_ | 1827828804938104832 |
|---|---|
| author | S. Selvi O. Porth B. Ripperda F. Bacchini L. Sironi R. Keppens |
| author_facet | S. Selvi O. Porth B. Ripperda F. Bacchini L. Sironi R. Keppens |
| author_sort | S. Selvi |
| collection | DOAJ |
| description | Magnetic reconnection can power spectacular high-energy astrophysical phenomena by producing nonthermal energy distributions in highly magnetized regions around compact objects. By means of two-dimensional fully kinetic particle-in-cell (PIC) simulations, we investigate relativistic collisionless plasmoid-mediated reconnection in magnetically dominated pair plasmas with and without a guide field. In X-points, where diverging flows result in a nondiagonal thermal pressure tensor, a finite residence time for particles gives rise to a localized collisionless effective resistivity. Here, for the first time for relativistic reconnection in a fully developed plasmoid chain, we identify the mechanisms driving the nonideal electric field using a full Ohm law by means of a statistical analysis based on our PIC simulations. We show that the nonideal electric field is predominantly driven by gradients of nongyrotropic thermal pressures. We propose a kinetic physics motivated nonuniform effective resistivity model that is negligible on global scales and becomes significant only locally in X-points. It captures the properties of collisionless reconnection with the aim of mimicking its essentials in nonideal magnetohydrodynamic descriptions. This effective resistivity model provides a viable opportunity to design physically grounded global models for reconnection-powered high-energy emission. |
| first_indexed | 2024-03-12T03:54:59Z |
| format | Article |
| id | doaj.art-aee8ceb822c844c9885ddc9ec30cf7da |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:54:59Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-aee8ceb822c844c9885ddc9ec30cf7da2023-09-03T12:01:32ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01950216910.3847/1538-4357/acd0b0Effective Resistivity in Relativistic Collisionless ReconnectionS. Selvi0https://orcid.org/0000-0001-9508-1234O. Porth1https://orcid.org/0000-0002-4584-2557B. Ripperda2https://orcid.org/0000-0002-7301-3908F. Bacchini3https://orcid.org/0000-0002-7526-8154L. Sironi4https://orcid.org/0000-0002-1227-2754R. Keppens5https://orcid.org/0000-0003-3544-2733Anton Pannekoek Institute , Science Park 904, 1098 XH, Amsterdam, The Netherlands ; s.c.selvi@uva.nlAnton Pannekoek Institute , Science Park 904, 1098 XH, Amsterdam, The Netherlands ; s.c.selvi@uva.nlSchool of Natural Sciences, Institute for Advanced Study , 1 Einstein Drive, Princeton, NJ 08540, USA; Princeton University , Department of Astrophysical Sciences, 4 Ivy Lane, Princeton, NJ 08544, USA; Flatiron Institute , Center for Computational Astrophysics, 162 Fifth Avenue, New York, NY 10010, USACentre for mathematical Plasma Astrophysics , Department of Mathematics, KU Leuven, Celestijnenlaan 200B, B-3001 Leuven, Belgium; Royal Belgian Institute for Space Aeronomy , Solar-Terrestrial Centre of Excellence, Ringlaan 3, 1180 Uccle, BelgiumColumbia University , Department of Astronomy, 550 West 120th, New York, NY 10027, USACentre for mathematical Plasma Astrophysics , Department of Mathematics, KU Leuven, Celestijnenlaan 200B, B-3001 Leuven, BelgiumMagnetic reconnection can power spectacular high-energy astrophysical phenomena by producing nonthermal energy distributions in highly magnetized regions around compact objects. By means of two-dimensional fully kinetic particle-in-cell (PIC) simulations, we investigate relativistic collisionless plasmoid-mediated reconnection in magnetically dominated pair plasmas with and without a guide field. In X-points, where diverging flows result in a nondiagonal thermal pressure tensor, a finite residence time for particles gives rise to a localized collisionless effective resistivity. Here, for the first time for relativistic reconnection in a fully developed plasmoid chain, we identify the mechanisms driving the nonideal electric field using a full Ohm law by means of a statistical analysis based on our PIC simulations. We show that the nonideal electric field is predominantly driven by gradients of nongyrotropic thermal pressures. We propose a kinetic physics motivated nonuniform effective resistivity model that is negligible on global scales and becomes significant only locally in X-points. It captures the properties of collisionless reconnection with the aim of mimicking its essentials in nonideal magnetohydrodynamic descriptions. This effective resistivity model provides a viable opportunity to design physically grounded global models for reconnection-powered high-energy emission.https://doi.org/10.3847/1538-4357/acd0b0High energy astrophysicsPlasma astrophysicsCompact objectsMagnetic fieldsRelativityMagnetohydrodynamics |
| spellingShingle | S. Selvi O. Porth B. Ripperda F. Bacchini L. Sironi R. Keppens Effective Resistivity in Relativistic Collisionless Reconnection The Astrophysical Journal High energy astrophysics Plasma astrophysics Compact objects Magnetic fields Relativity Magnetohydrodynamics |
| title | Effective Resistivity in Relativistic Collisionless Reconnection |
| title_full | Effective Resistivity in Relativistic Collisionless Reconnection |
| title_fullStr | Effective Resistivity in Relativistic Collisionless Reconnection |
| title_full_unstemmed | Effective Resistivity in Relativistic Collisionless Reconnection |
| title_short | Effective Resistivity in Relativistic Collisionless Reconnection |
| title_sort | effective resistivity in relativistic collisionless reconnection |
| topic | High energy astrophysics Plasma astrophysics Compact objects Magnetic fields Relativity Magnetohydrodynamics |
| url | https://doi.org/10.3847/1538-4357/acd0b0 |
| work_keys_str_mv | AT sselvi effectiveresistivityinrelativisticcollisionlessreconnection AT oporth effectiveresistivityinrelativisticcollisionlessreconnection AT bripperda effectiveresistivityinrelativisticcollisionlessreconnection AT fbacchini effectiveresistivityinrelativisticcollisionlessreconnection AT lsironi effectiveresistivityinrelativisticcollisionlessreconnection AT rkeppens effectiveresistivityinrelativisticcollisionlessreconnection |