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Two-dimensional schematic representation of the initial condition. The jet enters from the nozzle at the bottom boundary into a hot cavity region confined by the supernova remnants (SNR) expanding into the outer interstellar medium (ISM). Tick labels are given in units of the jet radius R j .
Source publication
We investigate the dynamical propagation of the South-East jet from the Crab
pulsar interacting with supernova ejecta by means of three-dimensional
relativistic MHD numerical simulations with the PLUTO code.
The initial jet structure is set up from the inner regions of the Crab
Nebula.
We study the evolution of hot, relativistic hollow outflows ini...
Contexts in source publication
Context 1
... initial conditions draw upon the same configuration used by dZAB04 where a freely expanding supernova rem- nant initially fills the region 0.2 < r/rej < 1 where r is the spherical radius and rej = 1 ly, see Fig 2. The supernova ejecta is unmagnetized with total mass given by ...
Context 2
... jets advance slowly (0.016 v head /c 0.023) owing to the large density contrast and evolve en- tirely within the remnant confined by the outer SN shock (see Fig 2). For increasing magnetization the propagation is driven by the additional magnetic pressure support while the mechanism of instability tends to saturate. ...
Context 3
... the outer regions reveals the formation of short-lived current peaks that diffuse on a time scale which is of the same order or less than our temporal resolution, approximately ∼ 3.8 months. The 3D spatial distribution of the current density, corresponding to the dashed line in the bottom panel of Fig. 19, is shown at t = 64.73 yrs in Fig. 20 for the A3 jet. Note that the formation of the strong current peak at z ≈ 1 ly occurs concurrently with the development of a jet kink and the abrupt change of flow direction. The sudden rise of these localized current peaks favors the formation of reconnection layers where induced electric fields may lead to efficient par- ticle ...
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Citations
... They interact with the surrounding ambient, generating pulsar wind nebulae (PWNe), observable from radio to γ-rays. PWNe often shows a torus-jet structure [84]. Orientation of the torus-jet structures is referenced with respect to the line of sight to the Earth: For the view of the front side of the remnant, the north is up and the east is to the left. ...
Multipulse laser–matter interactions initiate nonlinear and nonequilibrium plasma fluid flow dynamics and their instability creating microscale vortex filaments, loop-soliton chains, and helically paired structures, similar to those at the astrophysical mega scale. We show that the equation with the Hasimoto structure describes both, the creation of loop solitons by torsion of vortex filaments and the creation of solitons by helical winding of magnetic field lines in the Crab Nebula. Our experiments demonstrate that the breakup of the loop solitons creates vortex rings with (i) quasistatic toroidal Kelvin waves and (ii) parametric oscillatory modes—i.e., with the hierarchical instability order. For the first time, we show that the same hierarchical instability at the micro- and the megascale establishes the conceptual frame for their unique classification based on the hierarchical order of Bessel functions. Present findings reveal that conditions created in the laser-target regions of a high filament density lead to their collective behavior and formation of helically paired and filament-braided “complexes”. We also show, for the first time, that morphological and topological characteristics of the filament-bundle “complexes” with the loop solitons indicate the analogy between similar laser-induced plasma instabilities and those of the Crab and Double-Helix Nebulas—thus enabling conceptualization of fundamental characteristics. These results reveal that the same rotating metric accommodates the complexity of the instabilities of helical filaments, vortex rings, and filament jets in the plasmatic micro- and megascale astrophysical objects.
... For later phases, when the pulsar leaves the supernova remnant and starts interacting with the ISM, a bow shock nebula forms around the runaway pulsar. This phenomenon has been extensively studied using 3D simulations (Bucciantini & Bandiera 2001 ;Bucciantini 2002aBucciantini , b , 2018Bucciantini et al. 2004 ;Bark ov, Lyutik ov & Khangulyan 2019a and further detailed models have been tailored to the Crab Nebula (Mignone et al. 2013 ). Despite the high complexity of these simulations and the numerous questions the y leav e unanswered , all of these studies still neglect the effects of the circumstellar medium of the defunct star in which the supernova remnant and the PWN expand during the initial phases. ...
... These objects naturally exhibit both an equatorial structure and a jet/counter-jet system, as observed in studies such as Kargaltsev & P avlo v ( 2010 ), Kargaltsev et al. ( 2012 ), and references therein. Notable examples include the famous Crab Nebula with its twisted double jet (Mignone et al. 2013 ) and the Vela supernova remnant. MHD models have successfully reproduced such structures without considering the stellar wind or supernova ejecta as initial conditions, as demonstrated in Klingler et al. ( 2014 ). ...
Pulsar wind nebulae are a possible final stage of the circumstellar evolution of massive stars, where a fast-rotating, magnetised neutron star produces a powerful wind that interacts with the supernova ejecta. The shape of these so-called plerionic supernova remnants is influenced by the distribution of circumstellar matter at the time of the explosion, itself impacted by the magnetic field of the ambient medium, responsible for the expansion of the circumstellar bubble of the progenitor star. To understand the effects of magnetization on the circumstellar medium and resulting pulsar nebulae, we conduct 2D magneto-hydrodynamical simulations. Our models explore the impact of the ISM’s magnetic field on the morphology of a supernova remnant and pulsar wind nebula that develop in the circumstellar medium of massive star progenitor in the warm phase of the Milky Way’s ISM. Our simulations reveal that the jet-like structures formed on both sides perpendicularly to the equatorial plane of the pulsar, creating complex radio synthetic synchrotron emissions. This morphology is characterized by a rectangular-like remnant, which is typical of the circumstellar medium of massive stars in a magnetized medium, along with the appearance of a spinning top structure within the projected rectangle. We suggest that this mechanism may be partially responsible for the complex morphologies observed in pulsar wind nebulae that do not conform to the typical torus/jet or bow shock/tail shapes observed in most cases.
... Finally, there are 600 cells in the zdirection. Our prescription for the jet closely follows that of Mignone et al. (2009Mignone et al. ( , 2013 and Gottlieb et al. (2020), with a few modifications aimed at matching as much as possible the values of quantities in this simulation to those of our datainjected simulation. Within r 0 , we assume a density ρ 0 , which is taken to be the mean density in the injection domain of M20 and is then radially smoothed out as we multiply the density along the xy-plane by the profile ...
... It should be noted that the jet in this simulation tilts a bit toward the left side in the x-direction (and also a little toward the right in the y-direction). Although this behavior is fairly normal in jets (Mignone et al. 2013), we cannot elaborate much on its future behavior; i.e., we cannot say whether this tilt would be reversed or become even more pronounced. This is due to the very nature of our injection process, which consisted of 38 snapshots being mapped into our grid in a constant loop. ...
The origin of short gamma-ray bursts is associated with outflows powered by the remnant of a binary neutron star merger. This remnant can be either a black hole or a highly magnetized, fast-spinning neutron star, also known as a magnetar. Here we present the results of two relativistic magnetohydrodynamical simulations aimed at investigating the large-scale dynamics and propagation of magnetar collimated outflows through the medium surrounding the remnant. The first simulation evolves a realistic jet by injecting external simulation data, while the second evolves an analytical model jet with similar properties for comparison. We find that both outflows remain collimated and successfully emerge through the static medium surrounding the remnant. However, they fail to attain relativistic velocities and only reach a mean maximum speed of ∼0.7 c for the realistic jet and ∼0.6 c for the analytical jet. We also find that the realistic jet has a much more complex structure. The lack of highly relativistic speeds, which makes these jets unsuitable as short gamma-ray burst sources, is due to numerical limitations and is not general to all possible magnetar outflows. A jet like the one we study, however, could give rise to or augment a blue kilonova component. In addition, it would make the propagation of a relativistic jet easier, should one be launched after the neutron star collapses into a black hole.
... Beyond this region, the jet becomes more susceptible to instabilities forming at the interface between the flow and the ambient medium. In particular, magnetic pinch instabilities lead to the formation of eddies that trap matter from the wind and drive it inwards through the jet-wind interface, allowing for mass entrainment (Mignone et al. 2013 ;Gourgouliatos & Komissarov 2018 ;Bodo et al. 2021 ). Without such eddies, significant mass entrainment into the jet from the external medium may not be possible due to the jet's strong magnetic field. ...
Astrophysical jets are relativistic outflows that remain collimated for remarkably many orders of magnitude. Despite decades of research, the origin of cosmic rays (CRs) remains unclear, but jets launched by both supermassive black holes in the centre of galaxies and stellar-mass black holes harboured in X-ray binaries (BHXBs) are among the candidate sources for CR acceleration. When CRs accelerate in astrophysical jets, they initiate particle cascades that form γ-rays and neutrinos. In the so-called hadronic scenario, the population of accelerated CRs requires a significant amount of energy to properly explain the spectral constraints similarly to a purely leptonic scenario. The amount of energy required often exceeds the Eddington limit, or even the total energy available within the jets. The exact energy source for the accelerated protons is unclear, but due to energy conservation along the jets, it is believed to come from the jet itself via transfer of energy from the magnetic fields, or kinetic energy from the outflow. To address this hadronic energy issue and to self-consistently evolve the energy flux along the flows, we explore a novel treatment for including hadronic content, in which instabilities along the jet/wind border play a critical role. We discuss the impact of the different jet composition on the jet dynamics for a pair dominated and an electron-proton jet, and consequently the emitted spectrum, accounting for both leptonic and hadronic processes. Finally, we discuss the implications of this mass-loading scenario to address the proton energy issue.
... Configurations with a toroidal magnetic field are subject to current driven instabilities (kink-like, Begelman 1998;Nalewajko & Begelman 2012), and signs of such a process have been detected in different PWNe (Mori et al., 2004;Pavlov et al., 2003). Numerical simulations of the Crab nebula jet proved not only that the kink instability efficiently develops in the nebula, but that it is also responsible for the variations seen in the jets at different epochs (Mignone et al., 2013). Mixing of the magnetic field induced by kinklike instabilities is so efficient that, even if the initial field configuration is fully toroidal, a poloidal component raises rapidly in 3D, becoming even dominant immediately outside the inner nebula (see e.g. ...
Pulsar wind nebulae are fascinating systems, and archetypal sources for high-energy astrophysics in general. Due to their vicinity, brightness, to the fact that they shine at multi-wavelengths, and especially to their long-living emission at gamma-rays, modelling their properties is particularly important for the correct interpretation of the visible Galaxy. A complication in this respect is the variety of properties and morphologies they show at different ages. Here we discuss the differences among the evolutionary phases of pulsar wind nebulae, how they have been modeled in the past and what progresses have been recently made. We approach the discussion from a phenomenological, theoretical (especially numerical) and observational point of view, with particular attention to the most recent results and open questions about the physics of such intriguing sources.
... Fiducial value(s) Definition Status 0 1.11 bulk Lorentz factor at the jet base 0 fixed 0 10 − 50 magnetisation of the flow at the jet base free /keV 500 electron peak energy at the jet base free acc 2 − 10 bulk Lorentz factor at acc free ℎ acc ℎ 0 † jet specific enthalpy at acc fixed 10 jet mass density increase factor fixed diss / 100 region where the mass entrainment initiates ‡ free load,end / diss 100 region where the mass entrainment finishes fixed ambient medium. In particular, magnetic pinch instabilities lead to the formation of eddies that trap matter from the wind and drive it inwards through the jet-wind interface, allowing for mass entrainment (Mignone et al. 2013;Gourgouliatos & Komissarov 2018;Bodo et al. 2021). Without such eddies, significant mass entrainment into the jet from the external medium may not be possible due to the jet's strong magnetic field. ...
Astrophysical jets are relativistic outflows that remain collimated for remarkably many orders of magnitude. Despite decades of research, the origin of cosmic rays (CRs) remains unclear, but jets launched by both supermassive black holes in the centre of galaxies and stellar-mass black holes harboured in X-ray binaries (BHXBs) are among the candidate sources for CR acceleration. When CRs accelerate in astrophysical jets, they initiate particle cascades that form {\gamma}-rays and neutrinos. In the so-called hadronic scenario, the population of accelerated CRs requires a significant amount of energy to properly explain the spectral constraints similarly to a purely leptonic scenario. The amount of energy required often exceeds the Eddington limit, or even the total energy available within the jets. The exact energy source for the accelerated protons is unclear, but due to energy conservation along the jets, it is believed to come from the jet itself via transfer of energy from the magnetic fields, or kinetic energy from the outflow. To address this hadronic energy issue and to self-consistently evolve the energy flux along the flows, we explore a novel treatment for including hadronic content, in which instabilities along the jet/wind border play a critical role. We discuss the impact of the different jet composition on the jet dynamics for a pair dominated and an electron-proton jet, and consequently the emitted spectrum, accounting for both leptonic and hadronic processes. Finally, we discuss the implications of this mass-loading scenario to address the proton energy issue.
... Finally, there are 600 cells in the z−direction. Our prescription for the jet follows closely that of Mignone et al. (2009Mignone et al. ( , 2013; Gottlieb et al. (2020), with a few modifications aimed at matching as much as possible the values of quantities in this simulation to those of our data-injected simulation. Within r 0 , we assume a density ρ 0 , which is taken to be the mean density in the injection domain of M20, and is then radially smoothed out as we multiply the density along the xy-plane by the profile 1 cosh (r/a) 8 , ...
... It should be noted that the jet in this simulation tilts a bit towards the left side in the x-direction (and also a little towards the right in the y-direction). Although this behavior is fairly normal in jets (Mignone et al. 2013), we cannot elaborate much on its future behavior, i.e., we cannot say whether this tilt would be reversed, or become even more pronounced. This is due to the very nature of our injection process, which consisted of 38 snapshots being mapped into our grid in a constant loop. ...
The origin of short gamma-ray bursts (sGRBs) is associated with outflows powered by the remnant of a binary neutron star merger. This remnant can be either a black hole or a highly magnetized, fastly spinning neutron star, also known as a magnetar. Here, we present the results of two relativistic magnetohydrodynamical (RMHD) simulations aimed at investigating the large-scale dynamics and propagation of magnetar collimated outflows through the environment surrounding the remnant. The first simulation evolves a realistic jet by injecting external simulation data, while the second evolves an analytical model jet with similar properties for comparison. We find that both outflows remain collimated and successfully emerge through the environment. However, they fail to attain relativistic velocities and only reach a mean maximum speed of ~0.7c for the realistic jet, and ~0.6c for the analytical jet. We also find that the realistic jet has a much more complex structure. The lack of highly relativistic speeds, that makes these jets unsuitable as short GRB sources, appears to be due to the specific injected properties and not general to all possible magnetar outflows.
... Global 3D MHD and RMHD simulations resulting in the development of current-driven instabilities have been performed for nonrelativistic and relativistic jets in AGNs (Nakamura & Meier 2004;Moll et al. 2008;McKinney & Blandford 2009;Mignone et al. 2010;, gamma-ray bursts , and pulsar wind nebulae (Mignone et al. 2013;Porth et al. 2014). These simulations demonstrated consistently that the dominant modes are either pinch or kink. ...
Relativistic magnetized jets, such as those from AGN, GRBs, and XRBs, are susceptible to current- and pressure-driven MHD instabilities that can lead to particle acceleration and nonthermal radiation. Here, we investigate the development of these instabilities through 3D kinetic simulations of cylindrically symmetric equilibria involving toroidal magnetic fields with electron–positron pair plasma. Generalizing recent treatments by Alves et al. and Davelaar et al., we consider a range of initial structures in which the force due to toroidal magnetic field is balanced by a combination of forces due to axial magnetic field and gas pressure. We argue that the particle energy limit identified by Alves et al. is due to the finite duration of the fast magnetic dissipation phase. We find a rather minor role of electric fields parallel to the local magnetic fields in particle acceleration. In all investigated cases, a kink mode arises in the central core region with a growth timescale consistent with the predictions of linearized MHD models. In the case of a gas-pressure-balanced (Z-pinch) profile, we identify a weak local pinch mode well outside the jet core. We argue that pressure-driven modes are important for relativistic jets, in regions where sufficient gas pressure is produced by other dissipation mechanisms.
... Global 3D MHD and RMHD simulations resulting in the development of current-driven instabilities have been performed for non-relativistic and relativistic jets in AGNs (Nakamura & Meier 2004;Moll et al. 2008;McKinney & Blandford 2009;Mignone et al. 2010;, gamma-ray bursts , and pulsar wind nebulae (Mignone et al. 2013;Porth et al. 2014). These simulations demonstrated consistently that the dominant modes are either pinch or kink. ...
Relativistic magnetized jets, such as those from AGN, GRBs and XRBs, are susceptible to current- and pressure-driven MHD instabilities that can lead to particle acceleration and non-thermal radiation. Here we investigate the development of these instabilities through 3D kinetic simulations of cylindrically symmetric equilibria involving toroidal magnetic fields with electron-positron pair plasma. Generalizing recent treatments by valves et al. (2018) and Davelaar et al. (2020), we~consider a~range of~initial structures in~which the~force due~to~toroidal magnetic field is~balanced by~a~combination of~forces due~to~axial magnetic field and~gas pressure. We~argue that the~particle energy limit identified by Alves et al. (2018) is~due to~the~finite duration of~the~fast magnetic dissipation phase. We~find a~rather minor role of~electric fields parallel to~the~local magnetic fields in~particle acceleration. In~all investigated cases a~kink mode arises in~the~central core region with a~growth timescale consistent with the~predictions of~linearized MHD models. In the~case of~a~gas-pressure-balanced (Z-pinch) profile, we identify a~weak local pinch mode well outside the~jet core. We argue that pressure-driven modes are important for relativistic jets, in regions where sufficient gas pressure is produced by other dissipation mechanisms.
... We define the toroidal magnetic field profile at the injection point following Mignone et al. (2009Mignone et al. ( , 2013; Gottlieb et al. (2020a): ...
Gamma-ray bursts (GRBs) are powered by relativistic jets that exhibit intermittency over a broad range of timescales - from $ \sim $ ms to seconds. Previous numerical studies have shown that hydrodynamic (i.e., unmagnetized) jets that are expelled from a variable engine are subject to strong mixing of jet and cocoon material, which strongly inhibits the GRB emission. In this paper we conduct 3D RMHD simulations of mildly magnetized jets with power modulation over durations of 0.1 s and 1 s, and a steady magnetic field at injection. We find that when the jet magnetization at the launching site is $\sigma \sim 0.1$, the initial magnetization is amplified by shocks formed in the flow to the point where it strongly suppresses baryon loading. We estimate that a significant contamination can be avoided if the magnetic energy at injection constitutes at least a few percent of the jet energy. The variability timescales of the jet after it breaks out of the star are then governed by the injection cycles rather than by the mixing process, suggesting that in practice jet injection should fluctuate on timescales as short as $ \sim 10 $ ms in order to account for the observed light curves. Better stability is found for jets with shorter modulations. We conclude that for sufficiently hot jets, the Lorentz factor near the photosphere can be high enough to allow efficient photospheric emission. Our results imply that jets with $ 10^{-2} < \sigma < 1 $ injected by a variable engine with $ \sim 10 $ ms duty cycle are plausible sources of long GRBs.
