ON THE ROLE OF THE MAGNETIC FIELD ON JET EMISSION IN X-RAY BINARIES

The large-scale accretion flow in the intermediate polars (IPs) is still a matter of vigorous debate. It is known that the magnetic field of the white dwarf (WD) controls the accretion flow close to the surface, channeling the plasma onto the polecaps and giving rise to X-ray emission modulated at the WD spin period (Pspin). After their discovery it was assumed that IPs were the WD analogues of the pulsing X-ray binaries, where a magnetic neutron star accretes from a disrupted accretion disc. However, a number of authors have pointed out that the criteria for disc formation in IPs are less certain than those for the X-ray binaries.The simplest possible criterion for disc formation in a binary is that the accretion flow should be able to orbit freely about the primary star (see Frank, King & Raine 1991 for a review). In non-magnetic systems this is merely the condition that the minimum approach distance of the free stream (Rmin) should exceed the radius of the primary. The situation in magnetic systems is more complex, as the magnetic field of the primary presents an obstacle to the infalling accretion stream. In many treatments of IPs it is assumed that the plasma stream is able to orbit freely about the WD until the ram pressure of the stream is of the same order as the magnetic pressureρv2~B2/8π, whereρis the stream density,vthe stream velocity andBthe local magnetic field strength. This condition fixes the magnetospheric radius,Rmag, inside which the magnetic field is assumed to thread the stream material and direct the accretion flow along the fieldlines.

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Early neutron star evolution in high-mass X-ray binaries

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa675 ◽

2020 ◽

Vol 494 (1) ◽

pp. 44-49 ◽

Cited By ~ 2

Author(s):

Wynn C G Ho ◽

M J P Wijngaarden ◽

Nils Andersson ◽

Thomas M Tauris ◽

F Haberl

Keyword(s):

Magnetic Field ◽

Neutron Star ◽

Thermal Emission ◽

Equilibrium Phase ◽

High Mass ◽

X Ray ◽

Spin Period ◽

Long Duration ◽

X Ray Binaries ◽

The Magnetic Field

ABSTRACT The application of standard accretion theory to observations of X-ray binaries provides valuable insights into neutron star (NS) properties, such as their spin period and magnetic field. However, most studies concentrate on relatively old systems, where the NS is in its late propeller, accretor, or nearly spin equilibrium phase. Here, we use an analytic model from standard accretion theory to illustrate the evolution of high-mass X-ray binaries (HMXBs) early in their life. We show that a young NS is unlikely to be an accretor because of the long duration of ejector and propeller phases. We apply the model to the recently discovered ∼4000 yr old HMXB XMMU J051342.6−672412 and find that the system’s NS, with a tentative spin period of 4.4 s, cannot be in the accretor phase and has a magnetic field B > a few × 1013 G, which is comparable to the magnetic field of many older HMXBs and is much higher than the spin equilibrium inferred value of a few × 1011 G. The observed X-ray luminosity could be the result of thermal emission from a young cooling magnetic NS or a small amount of accretion that can occur in the propeller phase.

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Effect of Photon Rocket in X-ray Binaries

International Astronomical Union Colloquium ◽

10.1017/s0252921100060905 ◽

2000 ◽

Vol 177 ◽

pp. 653-654

Author(s):

V. D. Pal’shin ◽

A. I. Tsygan

Keyword(s):

Magnetic Field ◽

Neutron Star ◽

Gravitational Attraction ◽

Dipolar Field ◽

X Ray ◽

The Galaxy ◽

Star Surface ◽

X Ray Binaries ◽

The Magnetic Field

AbstractIt is shown that X-ray binaries can be accelerated by their own radiation. It is possible if the magnetic field of a neutron star in a binary differs from the dipolar field. Asymmetric X-ray emission generated due to accretion of matter onto a neutron star surface creates an accelerating force. Its magnitude can be comparable or even larger than gravitational attraction of the binary to the Galaxy.

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CONSTRAINTS ON X-RAY POLARIZATION OF SYNCHROTRON JETS FROM STELLAR-MASS BLACK HOLES

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194512004473 ◽

2012 ◽

Vol 08 ◽

pp. 102-107

Author(s):

D. M. RUSSELL

Keyword(s):

Magnetic Field ◽

Black Holes ◽

Black Hole ◽

Synchrotron Emission ◽

Relativistic Jets ◽

X Ray ◽

Linearly Polarized ◽

Hard State ◽

X Ray Binaries ◽

The Magnetic Field

For most black hole X-ray binaries, the fraction of X-ray flux originating in the synchrotron jets is generally thought to be low in the hard state. However in one intriguing case, the infrared – X-ray correlations, evolution of broadband spectra and timing signatures suggest that synchrotron emission from a jet likely dominated both the infrared and X-ray flux on the hard state decline of an outburst of XTE J1550–564 at a luminosity of ~ (2 × 10-4 – 2 × 10-3) L Edd . Synchrotron emission from the relativistic jets launched close to black holes can be highly linearly polarized, depending on the configuration of the magnetic field. It has recently been shown that the polarimetric signature of their jets is detected in the infrared and is highly variable. This reveals the magnetic geometry in a region of the compact jet near its base, close to the black hole. From these results, it is predicted that in some cases, high (possibly up to 10%), variable levels of X-ray polarization from synchrotron emission originating in jets will be detected from accreting black holes by future spaceborne X-ray polarimeters.

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Probability Distribution of Magnetic Field Strengths through the Cyclotron Lines in High-Mass X-ray Binaries

Jordan Journal of Physics ◽

10.47011/13.3.8 ◽

2020 ◽

Vol 13 (3) ◽

pp. 243-251

Keyword(s):

Magnetic Field ◽

Neutron Stars ◽

Accretion Rate ◽

High Mass ◽

X Ray ◽

Different Types ◽

The Difference ◽

Field Formation ◽

X Ray Binaries ◽

The Magnetic Field

Abstract: The study of variation of measured cyclotron lines is of fundamental importance to understand the physics of the accretion process in magnetized neutron star systems. We investigate the magnetic field formation, evolution and distribution for several High- Mass X-ray Binaries (HMXBs). We focus our attention on the cyclotron lines that have been detected in HMXB classes in their X-ray spectra. As has been correctly pointed out, several sources show variation in cyclotron lines, which can result due to the effect of accretion dynamics and hence that would reflect the magnetic field characteristics. Besides, the difference in time scales of variation of accretion rate and different types of companion can be used to distinguish between magnetized neutron stars. Keywords: Stars: neutron stars, High-Mass X-ray binaries, Stars: magnetic field, Cyclotron lines.

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X-rays from accretion shocks in classical T Tauri stars: 2D MHD modeling and the role of local absorption

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314001707 ◽

2013 ◽

Vol 9 (S302) ◽

pp. 48-49

Author(s):

C. Argiroffi ◽

R. Bonito ◽

S. Orlando ◽

M. Miceli ◽

F. Reale ◽

...

Keyword(s):

Magnetic Field ◽

T Tauri Stars ◽

X Rays ◽

X Ray ◽

T Tauri ◽

Shock Region ◽

Post Shock ◽

The Magnetic Field ◽

Accretion Shocks

AbstractIn classical T Tauri stars (CTTS) strong shocks are formed where the accretion funnel impacts with the denser stellar chromosphere. Although current models of accretion provide a plausible global picture of this process, some fundamental aspects are still unclear: the observed X-ray luminosity in accretion shocks is order of magnitudes lower than predicted; the observed density and temperature structures of the hot post-shock region are puzzling and still unexplained by models.To address these issues we performed 2D MHD simulations describing an accretion stream impacting onto the chromosphere of a CTTS, exploring different configurations and strengths of the magnetic field. From the model results we then synthesized the X-ray emission emerging from the hot post-shock, taking into account the local absorption due to the pre-shock stream and surrounding atmosphere.We find that the different configurations and strengths of the magnetic field profoundly affect the hot post-shock properties. Moreover the emerging X-ray emission strongly depends also on the viewing angle under which accretion is observed. Some of the explored configuration are able to reproduce the observed features of X-ray spectra of CTTS.

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On the role of rotation in the outflows of the Crab pulsar

International Journal of Modern Physics D ◽

10.1142/s021827181550042x ◽

2015 ◽

Vol 24 (06) ◽

pp. 1550042

Author(s):

Gudavadze Irakli ◽

Osmanov Zaza ◽

Rogava Andria

Keyword(s):

Magnetic Field ◽

Rotation Axis ◽

Three Dimensional ◽

Rotating Magnetic Field ◽

Crab Pulsar ◽

X Ray ◽

Field Lines ◽

The Magnetic Field ◽

Component Parallel

In order to study constraints imposed on kinematics of the Crab pulsar's jet, we consider motion of particles along co-rotating field lines in the magnetosphere of the Crab pulsar. It is shown that particles following the co-rotating magnetic field lines may attain velocities close to observable values. In particular, we demonstrate that if the magnetic field lines are within the light cylinder (LC), the maximum value of the velocity component parallel to the rotation axis is limited by 0.5c. This result in the context of the X-ray observations performed by Chandra X-ray Observatory seems to be quite indicative and useful to estimate the density of field lines inside the jet. Considering the three-dimensional (3D) field lines crossing the LC, we found that for explaining the force-free regime of outflows the magnetic field lines must asymptotically tend to the Archimedes spiral configuration. It is also shown that the 3D case may explain the observed jet velocity for appropriately chosen parameters of magnetic field lines.

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Jets from neutron star X-ray binaries: towards a unified scheme

Proceedings of the International Astronomical Union ◽

10.1017/s174392131001608x ◽

2010 ◽

Vol 6 (S275) ◽

pp. 233-241

Author(s):

Simone Migliari

Keyword(s):

Magnetic Field ◽

Black Holes ◽

Neutron Star ◽

Accretion Rate ◽

X Ray ◽

Multi Wavelength ◽

Observational Knowledge ◽

Low Magnetic Field ◽

X Ray Binaries

AbstractSystematic multi-wavelength studies of neutron stars (NSs) have shown a jet and disk-jet coupling phenomenology which resembles, although with some important differences, that observed in black holes; ultra-relativistic transient ejection, steady compact jets, accretion-ejection cycles are indeed observed in NSs. I will review our observational knowledge of jet in NS X-ray binaries, focusing on the role of the parameters of the system which might be involved in the production of jets. First, I will discuss the role of the accretion rate, presenting a unified scheme for accretion-jet production throughout the different sub-classes of low-magnetic field NSs. Then, I will attempt to (make the first steps to) quantify the role of spin and magnetic field in powering the jet.

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Enhanced X-ray emission arising from laser-plasma confinement by a strong transverse magnetic field

Scientific Reports ◽

10.1038/s41598-021-87651-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Evgeny D. Filippov ◽

Sergey S. Makarov ◽

Konstantin F. Burdonov ◽

Weipeng Yao ◽

Guilhem Revet ◽

...

Keyword(s):

Magnetic Field ◽

Transverse Magnetic ◽

Radiative Properties ◽

Magnetic Field Direction ◽

Solid Target ◽

Total Plasma ◽

Plasma Confinement ◽

X Ray ◽

Magnetic Compression ◽

The Magnetic Field

AbstractWe analyze, using experiments and 3D MHD numerical simulations, the dynamic and radiative properties of a plasma ablated by a laser (1 ns, 10$$^{12}$$ 12 –10$$^{13}$$ 13 W/cm$$^2$$ 2 ) from a solid target as it expands into a homogeneous, strong magnetic field (up to 30 T) that is transverse to its main expansion axis. We find that as early as 2 ns after the start of the expansion, the plasma becomes constrained by the magnetic field. As the magnetic field strength is increased, more plasma is confined close to the target and is heated by magnetic compression. We also observe that after $$\sim 8$$ ∼ 8 ns, the plasma is being overall shaped in a slab, with the plasma being compressed perpendicularly to the magnetic field, and being extended along the magnetic field direction. This dense slab rapidly expands into vacuum; however, it contains only $$\sim 2\%$$ ∼ 2 % of the total plasma. As a result of the higher density and increased heating of the plasma confined against the laser-irradiated solid target, there is a net enhancement of the total X-ray emissivity induced by the magnetization.

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