scholarly journals Inverse Compton Scattering in pulsar physics

1996 ◽  
Vol 160 ◽  
pp. 159-162
Author(s):  
G.J. Qiao
Keyword(s):  
Radio Emission ◽  
Compton Scattering ◽  
Low Frequency ◽  
Position Angle ◽  
High Energy ◽  
Particle Energy ◽  
Important Process ◽  
Frequency Wave ◽  
Inverse Compton Scattering ◽  
Inverse Compton

AbstractInverse Compton Scattering (ICS) is a very important process not only in inner gap physics, but also for radio emission. ICS of high energy particles with thermal photons is the dominant and a very efficient mechanism of the particle energy loss above the neutron star surface, and is an important process in causing gap breakdown. The pulsar distribution in theP−Pdiagram and the observed mode changing phenomenon of some pulsars can be expained by the sparking conditions due to ICS. ICS of the secondary particles with the low frequency wave from the inner gap sparking can be responsible for radio emission. In this ICS model, many observational features of pulsar radio emission can be explained, such as: one core and two conal emission components, their different emission altitudes and relative time delay effects; spectral behavior of pulse profiles; the behavior of the linear polarization and position angle.

scholarly journals An Explanation for Pulsar Mode Changing Phenomenon

1996 ◽  
Vol 160 ◽  
pp. 225-226
Author(s):  
B. Zhang ◽  
G.J. Qiao ◽  
W.P. Lin ◽  
J.L. Han
Keyword(s):  
Resonant Frequency ◽  
Compton Scattering ◽  
High Energy ◽  
Switching Effect ◽  
Inverse Compton Scattering ◽  
Thermal Peak ◽  
Curvature Radiation ◽  
Inverse Compton ◽  
High Energy Particles

AbstractThere are three mechanisms to cause pulsar inner gap breakdown: the inverse Compton scattering (ICS) of the high energy particles off the thermal-peak photons, off the resonant-frequency photons and the curvature radiation (CR). The pulsar mode-changing phenomenon can be interpreted as a switching effect between theresonant ICS sparking modeand thethermal ICS sparking mode.

scholarly journals Particle Acceleration in Extragalactic Jets and Implications for the High-Energy Emission from Blazars

1994 ◽  
Vol 159 ◽  
pp. 29-32
Author(s):  
R. Schlickeiser ◽  
C. D. Dermer
Keyword(s):  
Compton Scattering ◽  
Accretion Disk ◽  
High Energy ◽  
Relativistic Electrons ◽  
Spectral Evolution ◽  
Inverse Compton Scattering ◽  
Central Engine ◽  
Inverse Compton ◽  
Γ Rays ◽  
Γ Ray

We demonstrate that the prevalence of superluminal sources in the sample of γ-ray blazars and the peak of their luminosity spectra at γ-ray energies can be readily explained if the γ-rays result from the inverse Compton scattering of the accretion disk radiation by relativistic electrons in outflowing plasam jets. Compton scattering of external radiation by nonthermal particles in blazar jets is dominated by accretion disk photons rather than scattered radiation to distances of ∼ 0.01–0.1 pc from the central engine for standard parameters. The size of the γ-ray photosphere and the spectral evolution of the relativistic electron spectra constrain the location of the acceleration and emission sites in these objects.

scholarly journals On the nature of radio filaments near the Galactic Centre

2019 ◽  
Vol 489 (1) ◽  
pp. L28-L31 ◽  
Author(s):  
Maxim V Barkov ◽  
Maxim Lyutikov
Keyword(s):  
Large Scale ◽  
Low Frequency ◽  
High Energy ◽  
Point Sources ◽  
Galactic Centre ◽  
Pulsar Wind Nebulae ◽  
Flux Tubes ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Pulsar Wind

ABSTRACT We suggest that narrow, long radio filaments near the Galactic Centre arise as kinetic jets – streams of high-energy particles escaping from ram pressure confined pulsar wind nebulae (PWNe). The reconnection between the PWN and interstellar magnetic field allows pulsar wind particles to escape, creating long narrow features. They are the low-frequency analogues of kinetic jets seen around some fast-moving pulsars, such as The Guitar and The Lighthouse PWNe. The radio filaments trace a population of pulsars also responsible for the Fermi GeV excess produced by the Inverse Compton scattering by the pulsar wind particles. The magnetic flux tubes are stretched radially by the large-scale Galactic winds. In addition to PWNe accelerated particles can be injected at supernovae remnants. The model predicts variations of the structure of the largest filaments on scales of ∼dozens of years – smaller variations can occur on shorter time-scales. We also encourage targeted observations of the brightest sections of the filaments and of the related unresolved point sources in search of the powering PWNe and pulsars.

scholarly journals High Energy Radiation Generated at Boundary Shear Layers of Relativistic Jets

2002 ◽  
Vol 19 (1) ◽  
pp. 22-25 ◽  
Author(s):  
Ł. Stawarz ◽  
M. Ostrowski
Keyword(s):  
Electron Distribution ◽  
Low Frequency ◽  
Cosmic Ray ◽  
High Energy ◽  
Particle Energy ◽  
Relativistic Electrons ◽  
Microwave Background ◽  
Boundary Shear ◽  
Inverse Compton ◽  
Energy Gains

AbstractA simple model of cosmic ray electron acceleration at the jet boundary yields a power law particle energy distribution of ultra-relativistic electrons with an energy cut-off growing with time, and, finally, a growing particle bump at the energy where energy gains equal radiation losses. For such electron distribution, in tens-of-kpc scale jets, we derived the observed time-varying spectra of synchrotron and inverse Compton radiation, including Comptonisation of synchrotron and cosmic microwave background photons. Slowly varying spectral index along the jet in the ‘low frequency’ spectral range is a natural consequence of boundary layer acceleration. Variations of the high energy bump of the electron distribution can give rise to anomalous behaviour in the X-ray band in comparison to the lower frequencies.

scholarly journals The Effects of Inverse Compton Scattering on the Pulsars' Radiation

1987 ◽  
Vol 125 ◽  
pp. 59-59
Author(s):  
X.-Y. Xia ◽  
Z.-G. Deng ◽  
G.-J. Qiao ◽  
X.-J. Wu ◽  
H. Chen
Keyword(s):  
Radio Emission ◽  
Compton Scattering ◽  
Cross Section ◽  
Quasi Equilibrium ◽  
Polar Cap ◽  
Strong Magnetic Fields ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
S Model ◽  
Radiative Pressure

Our calculations show that the cross section of the inverse Compton scattering in strong magnetic fields may be larger than that of Thompson scattering by sevaral orders of magnitude in the case of polar cap surface of pulsars. We can also see that when the energy of e± exceeds a certain value, their energy loss caused by the inverse Compton scattering may be larger than the energy gain from electric field in the inner gap, which implies that the e± could not be accelerated to γ = 106. Meanwhile, the electrostatic forces acting on the electrons will be balanced by the radiative pressure if temperature T > 108 K.It is beleived that the surface temperarure for most of pulsars is less than 106 K, in that case the ions of iron can not be emitted from the surface of pulsars. However, the temperarure at the polar cap can be increased to 3×106 through the bombardment of electrons to the polar cap according to R-S model. This quasi-equilibrium state by self-regulating must make the coherent radio emission unstable on the contrary.

scholarly journals Suzaku observation of Jupiter’s X-rays around solar maximum

2019 ◽  
Vol 71 (5) ◽  
Author(s):  
Masaki Numazawa ◽  
Yuichiro Ezoe ◽  
Kumi Ishikawa ◽  
Takaya Ohashi ◽  
Yoshizumi Miyoshi ◽  
...  
Keyword(s):  
Solar Activity ◽  
Compton Scattering ◽  
High Energy ◽  
Spectral Studies ◽  
Relativistic Electrons ◽  
X Rays ◽  
Diffuse Emission ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton

Abstract We report on results of imaging and spectral studies of X-ray emission from Jupiter observed by Suzaku. In 2006, Suzaku found diffuse X-ray emission in 1–5 keV associated with Jovian inner radiation belts. It has been suggested that the emission is caused by the inverse-Compton scattering by ultra-relativistic electrons (∼50 MeV) in Jupiter’s magnetosphere. To confirm the existence of this emission and to understand its relation to the solar activity, we conducted an additional Suzaku observation in 2014 around the maximum of the 24th solar cycle. As a result, we successfully found the diffuse emission around Jupiter in 1–5 keV again, and also found point-like emission in 0.4–1 keV. The luminosity of the point-like emission, which was probably composed of solar X-ray scattering, charge exchange, or auroral bremsstrahlung emission, increased by a factor of ∼5 with respect to the findings from 2006, most likely due to an increase of the solar activity. The diffuse emission spectrum in the 1–5 keV band was well-fitted with a flat power-law function (Γ = 1.4 ± 0.1) as in the past observation, which supported the inverse-Compton scattering hypothesis. However, its spatial distribution changed from ∼12 × 4 Jovian radius (Rj) to ∼20 × 7 Rj. The luminosity of the diffuse emission increased by the smaller factor of ∼3. This indicates that the diffuse emission is not simply responding to the solar activity, which is also known to cause little effect on the distribution of high-energy electrons around Jupiter. Further sensitive study of the spatial and spectral distributions of the diffuse hard X-ray emission is important to understand how high-energy particles are accelerated in Jupiter’s magnetosphere.

scholarly journals The Comptonizing medium of the neutron star in 4U 1636 − 53 through its lower kilohertz quasi-periodic oscillations

2019 ◽  
Vol 492 (1) ◽  
pp. 1399-1415 ◽  
Author(s):  
Konstantinos Karpouzas ◽  
Mariano Méndez ◽  
Evandro M Ribeiro ◽  
Diego Altamirano ◽  
Omer Blaes ◽  
...  
Keyword(s):  
Neutron Star ◽  
Electron Temperature ◽  
Compton Scattering ◽  
Time Lag ◽  
High Energy ◽  
Radiative Properties ◽  
Periodic Oscillations ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Rms Amplitude

ABSTRACT Inverse Compton scattering dominates the high-energy part of the spectra of neutron star (NS) low-mass X-ray binaries (LMXBs). It has been proposed that inverse Compton scattering also drives the radiative properties of kilohertz quasi-periodic oscillations (kHz QPOs). In this work, we construct a model that predicts the energy dependence of the rms amplitude and time lag of the kHz QPOs. Using this model, we fit the rms amplitude and time lag energy spectra of the lower kHz QPO in the NS LMXB 4U 1636 − 53 over 11 frequency intervals of the QPO and report three important findings: (i) A medium that extends 1–8 km above the NS surface is required to fit the data; this medium can be sustained by the balance between gravity and radiation pressure, without forcing any equilibrium condition. (ii) We predict a time delay between the oscillating NS temperature, due to feedback, and the oscillating electron temperature of the medium, which, with the help of phase resolved spectroscopy, can be used as a probe of the geometry and the feedback mechanism. (iii) We show that the observed variability as a function of QPO frequency is mainly driven by the oscillating electron temperature of the medium. This provides strong evidence that the Comptonizing medium in LMXBs significantly affects, if not completely drives, the radiative properties of the lower kHz QPOs regardless of the nature of the dynamical mechanism that produces the QPO frequencies.

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