Laboratory X-ray emission experiments can help explain astrophysical jet formation phenomena

Scilight ◽  
2019 ◽  
Vol 2019 (51) ◽  
pp. 510001
Author(s):  
Anashe Bandari
Keyword(s):  
Jet Formation ◽  
X Ray ◽  
Astrophysical Jet

Probing astrophysical jet formation in the laboratory

Scilight ◽  
2021 ◽  
Vol 2021 (18) ◽  
pp. 181105
Author(s):  
Alane Lim
Keyword(s):  
Jet Formation ◽  
Astrophysical Jet

scholarly journals FORMATION OF RELATIVISTIC MHD JETS: STATIONARY STATE SOLUTIONS AND NUMERICAL SIMULATIONS

2008 ◽  
Vol 17 (10) ◽  
pp. 1677-1686 ◽  
Author(s):  
CHRISTIAN FENDT ◽  
ELISABETTA MEMOLA
Keyword(s):  
Stationary State ◽  
Rest Frame ◽  
Particle Density ◽  
Acceleration Process ◽  
Jet Formation ◽  
Low Velocity ◽  
X Ray ◽  
Disk Wind ◽  
Mhd Simulations ◽  
Dynamical Parameters

We discuss numerical results of relativistic magnetohydrodynamic (MHD) jet formation models. We first review some examples of stationary state solutions treating the collimation and acceleration process of relativistic MHD jets. We provide an a posteriori check for the MHD condition in highly magnetized flows, namely the comparison of particle density to Goldreich–Julian density. Using the jet dynamical parameters calculated from the MHD model, we show the rest-frame thermal X-ray spectra of the jet, from which we derive the overall spectrum taking into account a variation of Doppler boosting and Doppler shift of emission lines along the outflow. Finally, we present preliminary results of relativistic MHD simulations of jet formation demonstrating the acceleration of a low velocity (0.01 c) disk wind to a collimated high velocity (0.8 c).

scholarly journals Jet-like structures from PSR J1135–6055

2020 ◽  
Vol 644 ◽  
pp. L4
Author(s):  
P. Bordas ◽  
X. Zhang
Keyword(s):  
High Energy ◽  
Bow Shock ◽  
Morphological Properties ◽  
Physical Origin ◽  
Pulsar Wind Nebulae ◽  
Jet Formation ◽  
X Ray ◽  
Pulsar Wind ◽  
Alternative Scenarios ◽  
High Energy Particles

Pulsar wind nebulae (PWNe) produced from supersonic runaway pulsars can render extended X-ray structures in the form of tails and prominent jets. In this Letter, we report on the analysis of ∼130 ks observations of the PWN around PSR J1135–6055 that were obtained with the Chandra satellite. The system displays bipolar jet-like structures of uncertain origin, a compact nebula around the pulsar likely formed by the bow shock ahead of it, and a trailing tail produced by the pulsar fast proper motion. The spectral and morphological properties of these structures reveal strong similarities with the PWNe in other runaway pulsars, such as PSR J1509–5850 and Geminga. We discuss their physical origin considering both canonical PWN and jet formation models as well as alternative scenarios that can also yield extended jet-like features following the escape of high-energy particles into the ambient magnetic field.

scholarly journals Penetration Evaluation of Explosively Formed Projectiles Through Air and Water Using Insensitive Munition: Simulative and Experimental Studies

2016 ◽  
Vol 6 (1) ◽  
pp. 913-916 ◽  
Author(s):  
M. Ahmed ◽  
A. Q. Malik ◽  
S. A. Rofi ◽  
Z. X. Huang
Keyword(s):  
Formation Flying ◽  
Experimental Studies ◽  
Experimental Results ◽  
Jet Formation ◽  
Depth Of Penetration ◽  
X Ray ◽  
Steel Target ◽  
Great Reliability ◽  
Polymer Bonded Explosives ◽  
The Difference

The process of formation, flying, penetration of explosively-formed projectiles (EFP) and the effect of water on performance of the charge for underwater applications is simulated by Ansysis Autodyn 2D-Hydro code. The main objective of an explosively formed projectile designed for underwater applications is to disintegrate the target at longer standoff distances. In this paper we have simulated the explosively formed projectile from OFHC-Copper liner for 1200 conical angle. The Affect of water on the penetration of EFP is determined by simulations from Ansysis Autodyn 2-D Hydrocode and by varying depth of water from 1CD-5CD. The depth of penetration against steel target is measured experimentally. Flash X-Ray Radiography (FXR) is used to capture EFP jet formation and its penetration against target is measured by depth of penetration experiments. Simulation results are compared with experimental results. The difference in simulated and experimental results for depth of penetration is about 7 mm, which lies within favorable range of error. The jet formation captured from FXR is quite clear and jet velocity determined from Flash X-ray radiography is the same as the ones obtained by using other high explosives. Therefore, it is indicated that Insensitive Munition (8701) can be utilized instead of Polymer Bonded Explosives (PBX) for air and underwater environments with great reliability and without any hazard.

JET MODELS FOR NEUTRON STAR X-RAY BINARIES

2012 ◽  
Vol 08 ◽  
pp. 108-113 ◽  
Author(s):  
SIMONE MIGLIARI ◽  
GABRIELE GHISELLINI ◽  
JAMES MILLER-JONES ◽  
DAVID RUSSELL
Keyword(s):  
Neutron Star ◽  
Compact Object ◽  
Young Stellar Objects ◽  
Jet Formation ◽  
Stellar Objects ◽  
X Ray ◽  
The Status ◽  
Observational Knowledge ◽  
X Ray Binaries

A variety of different models for jet formation have been developed over the years (mainly) for black hole systems and young stellar objects. Conclusive observational constraints which would favor one particular mechanism are difficult to obtain. Neutron star X-ray binaries are crucial for advancing our understanding of jet formation in general, building a bridge between the two most studied jet-producing classes of systems: black holes, i.e. non-magnetized, relativistic objects, and young stellar objects, i.e. non-relativistic, magnetized stars. I will briefly review the status of our observational knowledge of jets in neutron star X-ray binaries, with a focus on the parameters which might be involved in the production of jets. I will present recent works and current observational programs aiming to quantify the role of the compact object in the formation of jets in neutron star systems. Finally, I will test a jet model developed for young stellar objects, the X–wind model, on a neutron star system.

scholarly journals Radio and X-ray observations of jet ejection in Cygnus X-2

2013 ◽  
Vol 435 (1) ◽  
pp. L48-L52 ◽  
Author(s):  
R. E. Spencer ◽  
A. P. Rushton ◽  
M. Bałucińska-Church ◽  
Z. Paragi ◽  
N. S. Schulz ◽  
...  
Keyword(s):  
High Resolution ◽  
Critical Value ◽  
Horizontal Branch ◽  
Radio Observations ◽  
Jet Formation ◽  
X Ray ◽  
Relativistic Jet ◽  
Low Mass ◽  
Galactic Sources ◽  
Ejection Event

Abstract The ejection of a relativistic jet has been observed in the luminous Galactic low-mass X-ray binary Cygnus X-2. Using high-resolution radio observations, a directly resolved ejection event has been discovered while the source was on the horizontal branch of the Z-track. Contemporaneous radio and X-ray observations were made with the European VLBI Network at 6 cm and the Swift X-ray observatory in the 0.3–10 keV band. This has been difficult to achieve because of the previous inability to predict jet formation. Two sets of ∼10 h observations were spaced 12 h apart, the jet apparently switching on during Day 1. The radio results show an unresolved core evolving into an extended jet. A preliminary value of jet velocity v/c of 0.33±0.12 was obtained, consistent with previous determinations in Galactic sources. Simultaneous radio and X-ray lightcurves are presented and the X-ray hardness ratio shows the source to be on the horizontal branch where jets are expected. The observations support our proposal that jet formation can in future be predicted based on X-ray intensity increases beyond a critical value.

scholarly journals Investigating accretion disk – radio jet coupling across the stellar mass scale

2010 ◽  
Vol 6 (S275) ◽  
pp. 224-232
Author(s):  
James C. A. Miller-Jones ◽  
Gregory R. Sivakoff ◽  
Diego Altamirano ◽  
Elmar G. Körding ◽  
Hans A. Krimm ◽  
...  
Keyword(s):  
Black Hole ◽  
Neutron Star ◽  
White Dwarf ◽  
Angular Resolution ◽  
Stellar Mass ◽  
Mass Scale ◽  
High Angular Resolution ◽  
Jet Formation ◽  
X Ray ◽  
X Ray Binaries

AbstractRelationships between the X-ray and radio behavior of black hole X-ray binaries during outbursts have established a fundamental coupling between the accretion disks and radio jets in these systems. I begin by reviewing the prevailing paradigm for this disk-jet coupling, also highlighting what we know about similarities and differences with neutron star and white dwarf binaries. Until recently, this paradigm had not been directly tested with dedicated high-angular resolution radio imaging over entire outbursts. Moreover, such high-resolution monitoring campaigns had not previously targetted outbursts in which the compact object was either a neutron star or a white dwarf. To address this issue, we have embarked on the Jet Acceleration and Collimation Probe Of Transient X-Ray Binaries (JACPOT XRB) project, which aims to use high angular resolution observations to compare disk-jet coupling across the stellar mass scale, with the goal of probing the importance of the depth of the gravitational potential well, the stellar surface and the stellar magnetic field, on jet formation. Our team has recently concluded its first monitoring series, including (E)VLA, VLBA, X-ray, optical, and near-infrared observations of entire outbursts of the black hole candidate H 1743-322, the neutron star system Aquila X-1, and the white dwarf system SS Cyg. Here I present preliminary results from this work, largely confirming the current paradigm, but highlighting some intriguing new behavior, and suggesting a possible difference in the jet formation process between neutron star and black hole systems.

scholarly journals Formation, Equilibrium and Stability of Jets

1985 ◽  
Vol 107 ◽  
pp. 85-94
Author(s):  
Colin A. Norman
Keyword(s):  
Black Hole ◽  
Plasma Physics ◽  
Laval Nozzle ◽  
Magnetic Confinement ◽  
Mach Disk ◽  
Jet Physics ◽  
Particle Interactions ◽  
Jet Formation ◽  
X Ray ◽  
The Many

Consideration of the many observed types of jets on scales ranging from parsecs to megaparsecs seen in radio, optical, infrared and X-ray wavebands with a variety of morphologies both in galactic and extragalactic systems leads to some constraints on their fundamental nature. Jet formation is introduced with the concept of the Laval nozzle and related points include the problem of maintaining the nozzle, Mach disk effects due to under and over-expansion and the potential importance of magnetic confinement and focussing. Current ideas on jet formation at the black hole and accretion disk are given with emphasis on the plasma physics associated with black-hole electrodynamics, thermal and magnetically driven winds and thick disks. Stability of jet propagation is reviewed with emphasis on magnetised and unmagnetised Kelvin-Helmholtz instabilities and the various dominant modes. The particle acceleration physics of shocks, wave-particle interactions and turbulence is summarised while noting some outstanding plasma physics problems. Jet equilibrium associated with the non-linear saturation of instabilities, the formation of cocoons, shock stabilisation and magnetic fields is discussed. Detailed plasma physics studies that could significantly clarify jet physics are indicated.

scholarly journals Observational aspects of AGN jets at high energy

2014 ◽  
Vol 10 (S313) ◽  
pp. 1-11
Author(s):  
Jun Kataoka
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
Galactic Center ◽  
Radio Galaxies ◽  
High Energy ◽  
Jet Physics ◽  
Space Telescopes ◽  
Energy Bands ◽  
X Ray ◽  
Astrophysical Jet

AbstractFor the last two decades, significant and dramatic progress has been made in understanding astrophysical jet sources, particularly in the X-ray and gamma-ray energy bands. For example, the Chandra X-ray observatory reveals a number of AGN jets extending from kpc to Mpc scales. More recently, the Fermi Gamma-ray Space Telescopes launched in 2008 started monitoring the gamma-ray sky with excellent sensitivity of about ten times greater than that of EGRET onboard CGRO, and has detected more than 2,000 sources (mostly AGNs) as of 2014. Moreover, Fermi-LAT has discovered gamma-ray emissions not only from blazars but from a dozen radio galaxies not previously known to emit gamma-rays. Closer to home, the Fermi-bubbles were discovered to extend 50 degrees above and below the Galactic center. These large scale diffuse gamma-ray structures are similar in structure to AGN lobes such as those seen in Cen A and provide evidence for past activity in our Galactic center. In this review, I will first summarize recent highlights of large scale jets in radio galaxies, specifically resolved by the Chandra X-ray observatory. Next I will move on to the gamma-ray sky to present some highlights from Fermi-LAT observations of “misaligned” blazars, namely radio galaxies. I will discuss a unification scheme connecting blazars and misaligned radio galaxies. In the last part, I will also briefly comment on recent multiband observations of the Fermi-bubble and possible impacts on the AGN jet physics in the near future.

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