Dynamics of Relativistic Magnetized Flows.
Lead Research Organisation:
University of Leeds
Department Name: Applied Mathematics
Abstract
Magnetically-dominated relativistic outflows are naturally generated as extentions of magnetospheres of rapidly rotating black holes and neutron stars. They are powered by the rotational energy of the central object and carry out this energy mainly in the form of Poynting flux. When this energy is dissipated via interaction with external medium, strong sources of non-thermal electromagnetic emission are produced. This is how the origin of Pulsar Wind Nebulae, Radio Galaxies, Quasars, Galactic Micro-quasars and GRB jets is often explained in modern theoretical astrophysics. However, these theories are based on simplistic analytical and semi-analytical models of the flow dynamics and the numerical studies have been confined mostly to the case of axisymmetric flows so far. On the other hand, many magnetic configurations are known to be unstable with non-axisymmetric modes growing at highest rates in linear regime. Until the non-linear effects of these instabilities are fully understood these theories are not complete. In fact, a number of long standing problems in the theory of Pulsar Wind Nebulae and Extragalactic Jets could reflect the limitations of imposed axisymmetry. One of such problems is the very slow rate of conversion of the Poynting flux into the kinetic energy, the so-called 'sigma-problem'. The randomization of magnetic field due to the instabilities may significantly improve the efficiency because the dynamics of random magnetic field mimics that of ultra-relativistic gas. We propose to use massive parallel relativistic MHD simulations in order to study the complex three-dimensional dynamics of magnetically dominated relativistic flows. The recent progress in development of robust numerical schemes for RMHD and Adaptive Mesh Refinement algorithms combined with availability of powerful computer clusters make this project both feasible and timely. We have been involved in the development of Computational Astrophysics of Relativistic Plasma from the very beginning and have accumulated internationally-recognised expertise in the area.
People |
ORCID iD |
Serguei Komissarov (Principal Investigator) |
Publications
Lyutikov Maxim
(2016)
Particle acceleration in explosive relativistic reconnection events and Crab Nebula gamma-ray flares
in arXiv e-prints
Monceau-Baroux R
(2013)
Relativistic 3D precessing jet simulations for the X-ray binary SS433
in Astronomy & Astrophysics
Monceau-Baroux R
(2015)
The SS433 jet from subparsec to parsec scales
in Astronomy & Astrophysics
Komissarov SS
(2015)
Stationary relativistic jets.
in Computational astrophysics and cosmology
PORTH O
(2014)
SOLUTION TO THE SIGMA PROBLEM OF PULSAR WIND NEBULAE
in International Journal of Modern Physics: Conference Series
PORTH O
(2014)
SOLUTION TO THE SIGMA PROBLEM OF PULSAR WIND NEBULAE
in International Journal of Modern Physics: Conference Series
Xie Z
(2014)
Hawking Temperature of Acoustic Black Hole
in Journal of Astrophysics and Astronomy
Keppens R
(2014)
Scalar hyperbolic PDE simulations and coupling strategies
in Journal of Computational and Applied Mathematics
Porth O
(2015)
Causality and stability of cosmic jets
in Monthly Notices of the Royal Astronomical Society
Kim J
(2015)
On the linear stability of magnetized jets without current sheets - non-relativistic case
in Monthly Notices of the Royal Astronomical Society
Description | 1. We have carried out the most advanced ever simulations of nebulae created by magnetized relativistic winds (PWN) from neutron stars and laid out the foundations of their current theory. In particularly, we have established the importance of magnetic dissipation inside the nebulae and hence explained how the deduced high magnetization of the winds can agree with the observed low magnetization of the nebulae (the so-called sigma-problem, which remained unresolved for about thirty years). 2. The jets of active galaxies appear incredibly stable - if the gaseous jets produced by rocket engines were that stable they would be able to reach all the way to the Moon unscathed. We have found a way to explain this apparent stability, as well as to show how the instabilities may eventually develop in these jets. The theory has been supported by our advanced computer simulations of relativistic magnetized plasma jets using an ingenious modification of the traditional setup used in previous studies of this type. |
Exploitation Route | Our findings set new directions for modern astrophysical research in the field of relativistic astrophysics. |
Sectors | Education Other |
URL | https://ui.adsabs.harvard.edu/abs/2013MNRAS.431L..48P/abstract,https://ui.adsabs.harvard.edu/abs/2014MNRAS.438..278P,https://ui.adsabs.harvard.edu/abs/2015MNRAS.452.1089P, |
Description | Public lectures on the Astrophysics of the Crab Nebula. Leeds Astronomy Club |
First Year Of Impact | 2014 |
Sector | Other |
Impact Types | Cultural |
Description | Astrophysics of Crab Nebula |
Organisation | Catholic University of Louvain |
Department | Department of Mathematics |
Country | Belgium |
Sector | Academic/University |
PI Contribution | Theoretical investigation of Pulsar Wind Nebulae and Astrophysical jets. Computer simulations. |
Collaborator Contribution | The computer code ARMVAC and technical assistance with its utilization. |
Impact | Numerous publications |
Start Year | 2012 |
Description | Astrophysics of Crab Nebula |
Organisation | Purdue University |
Department | Department of Physics and Astronomy |
Country | United States |
Sector | Academic/University |
PI Contribution | Theoretical investigation of Pulsar Wind Nebulae and Astrophysical jets. Computer simulations. |
Collaborator Contribution | The computer code ARMVAC and technical assistance with its utilization. |
Impact | Numerous publications |
Start Year | 2012 |
Description | Stability of astrophysical jets |
Organisation | University of Notre Dame |
Department | Department of Physics |
Country | United States |
Sector | Academic/University |
PI Contribution | Joint study of the jet stability problem |
Collaborator Contribution | Joint study of the jet stability problem |
Impact | Joint publication in a scientific journal. |
Start Year | 2015 |
Description | poular science article |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | Yes |
Type Of Presentation | Paper Presentation |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | Article Porth, Keppens, "In the heart of the Crab Nebula" september issue 2013, pages 106-109 ( in dutch). Wider dissemination of our results |
Year(s) Of Engagement Activity | 2013 |