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.

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 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 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 amplitude of the kilohertz quasi-periodic oscillations in 4U 1636–53 in the frequency-energy space

2019 ◽  
Vol 489 (4) ◽  
pp. 4980-4991 ◽  
Author(s):  
Evandro M Ribeiro ◽  
Mariano Méndez ◽  
Marcio G B de Avellar ◽  
Guobao Zhang ◽  
Konstantinos Karpouzas
Keyword(s):  
Neutron Star ◽  
Local Maximum ◽  
Radiative Properties ◽  
Energy Bands ◽  
Periodic Oscillations ◽  
X Ray ◽  
High Energies ◽  
Low Mass ◽  
First Time ◽  
Rms Amplitude

ABSTRACT We present for the neutron-star low-mass X-ray binary 4U 1636–53, and for the first time for any source of kilohertz quasi-periodic oscillations (kHz QPOs), the two-dimensional behaviour of the fractional rms amplitude of the kHz QPOs in the parameter space defined by QPO frequency and photon energy. We find that the rms amplitude of the lower kHz QPO increases with energy up to $\sim \!\!12$ keV and then decreases at higher energies, while the rms amplitude of the upper kHz QPO either continues increasing or levels off at high energies. The rms amplitude of the lower kHz QPO increases and then decreases with frequency, peaking at $\sim \!\!760$ Hz, while the amplitude of the upper kHz QPO decreases with frequency, with a local maximum at around $\sim \!\!770$ Hz, and is consistent with becoming zero at the same QPO frequency, $\sim \!\!1400$ Hz, in all energy bands, thus constraining the neutron-star mass at $M_{NS} \le 1.6 \, \mathrm{M}_{\odot }$, under the assumption that this QPO reflects the Keplerian frequency at the inner edge of the accretion disc. We show that the slope of the rms energy spectrum is connected to the changing properties of the kHz QPOs in different energy bands as its frequencies change. Finally, we discuss a possible mechanism responsible for the radiative properties of the kHz QPOs and, based on a model in which the QPO arises from oscillations in a Comptonizing cloud of hot electrons, we show that the properties of the kHz QPOs can constrain the thermodynamic properties of the inner accretion flow.

scholarly journals Scaling laws in high-energy inverse Compton scattering

2010 ◽  
Vol 81 (4) ◽  
Author(s):  
Satoshi Nozawa ◽  
Yasuharu Kohyama ◽  
Naoki Itoh
Keyword(s):  
Compton Scattering ◽  
Scaling Laws ◽  
High Energy ◽  
Inverse Compton Scattering ◽  
Inverse Compton
Sign in / Sign up

Export Citation Format

Share Document