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 Extended X-ray Emission from FRIIs and RL Quasars

2002 ◽  
Vol 199 ◽  
pp. 227-230 ◽  
Author(s):  
G. Setti ◽  
G. Brunetti ◽  
A. Comastri
Keyword(s):  
Compton Scattering ◽  
Radio Galaxies ◽  
Relativistic Electrons ◽  
X Rays ◽  
Powerful Radio ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton

We review the evidence that detectable fluxes of X-rays are produced by inverse Compton scattering of nuclear photons with the relativistic electrons in the radio lobes of strong FRII radio galaxies within the FRII-RL quasar unification scheme. We report here on the possible detection of this effect in two steep spectrum RL quasars. This may have important implications on the physics and evolution of powerful radio galaxies.

Visualization of microvessels by angiography using inverse-Compton scattering X-rays in animal models

2014 ◽  
Vol 21 (6) ◽  
pp. 1327-1332 ◽  
Author(s):  
Toshiharu Fujii ◽  
Naoto Fukuyama ◽  
Chiharu Tanaka ◽  
Yoshimori Ikeya ◽  
Yoshiro Shinozaki ◽  
...  
Keyword(s):  
Compton Scattering ◽  
Photon Number ◽  
High Gain ◽  
Image Sensor ◽  
Clinical Settings ◽  
X Rays ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Small Vessels ◽  
Inverse Compton

The fundamental performance of microangiography has been evaluated using the S-band linac-based inverse-Compton scattering X-ray (iCSX) method to determine how many photons would be required to apply iCSX to human microangiography. ICSX is characterized by its quasi-monochromatic nature and small focus size which are fundamental requirements for microangiography. However, the current iCSX source does not have sufficient flux for microangiography in clinical settings. It was determined whether S-band compact linac-based iCSX can visualize small vessels of excised animal organs, and the amount of X-ray photons required for real time microangiography in clinical settings was estimated. The iCSX coupled with a high-gain avalanche rushing amorphous photoconductor camera could visualize a resolution chart with only a single iCSX pulse of ∼3 ps duration; the resolution was estimated to be ∼500 µm. The iCSX coupled with an X-ray cooled charge-coupled device image sensor camera visualized seventh-order vascular branches (80 µm in diameter) of a rabbit ear by accumulating the images for 5 and 30 min, corresponding to irradiation of 3000 and 18000 iCSX pulses, respectively. The S-band linac-based iCSX visualized microvessels by accumulating the images. An iCSX source with a photon number of 3.6 × 103–5.4 × 104times greater than that used in this study may enable visualizing microvessels of human fingertips even in clinical settings.

scholarly journals Nested Kirkpatrick–Baez (Montel) optics for hard X-rays

2015 ◽  
Vol 48 (2) ◽  
pp. 558-564 ◽  
Author(s):  
Giacomo Resta ◽  
Boris Khaykovich ◽  
David Moncton
Keyword(s):  
Ray Tracing ◽  
Compton Scattering ◽  
Analytical Procedure ◽  
X Rays ◽  
Multilayer Mirrors ◽  
Comprehensive Description ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Proper Orientation

A comprehensive description and ray-tracing simulations are presented for symmetric nested Kirkpatrick–Baez (KB) mirrors, commonly used at synchrotrons and in commercial X-ray sources. This paper introduces an analytical procedure for determining the proper orientation between the two surfaces composing the nested KB optics. This procedure has been used to design and simulate collimating optics for a hard-X-ray inverse Compton scattering source. The resulting optical device is composed of two 12 cm-long parabolic surfaces coated with a laterally graded multilayer and is capable of collimating a 12 keV beam with a divergence of 5 mrad (FWHM) by a factor of ∼250. A description of the ray-tracing software that was developed to simulate the graded multilayer mirrors is included.

scholarly journals Very High Energy γ-Ray Generation Near The Light Cylinder of an Axisymmetric Rotator: Cos-B Like γ-Ray Sources

1992 ◽  
Vol 128 ◽  
pp. 207-208
Author(s):  
S. V. Bogovalov ◽  
YU. D. Kotov
Keyword(s):  
High Energy ◽  
Relativistic Electrons ◽  
X Rays ◽  
Inverse Compton Scattering ◽  
Light Cylinder ◽  
Radiation Spectra ◽  
Inverse Compton ◽  
Very High Energy ◽  
Γ Ray ◽  
Very High

AbstractSuper-hard γ-ray radiation spectra have been calculated. This radiation is generated near the velocity-of-light cylinder through the process of inverse-Compton scattering of relativistic electrons by thermal photons radiated by a neutron star. These calculations have been compared with observations of the Crab and Vela pulsars at 1000-GeV γ-ray energies. A correlation between γ-ray flares and those in soft (Ex ≃ lkeV) X-rays are predicted.

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 Starburst and post-starburst high-redshift protogalaxies

2019 ◽  
Vol 626 ◽  
pp. A85 ◽  
Author(s):  
Ellis R. Owen ◽  
Kinwah Wu ◽  
Xiangyu Jin ◽  
Pooja Surajbali ◽  
Noriko Kataoka
Keyword(s):  
Star Formation ◽  
High Redshift ◽  
High Energy ◽  
Starburst Galaxies ◽  
X Rays ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
High Energy Cosmic Rays ◽  
Radiation Fields ◽  
Inverse Compton

Quenching of star-formation has been identified in many starburst and post-starburst galaxies, indicating burst-like star-formation histories (SFH) in the primordial Universe. Galaxies undergoing violent episodes of star-formation are expected to be rich in high energy cosmic rays (CRs). We have investigated the role of these CRs in such environments, particularly how they could contribute to this burst-like SFH via quenching and feedback. These high energy particles interact with the baryon and radiation fields of their host via hadronic processes to produce secondary leptons. The secondary particles then also interact with ambient radiation fields to generate X-rays through inverse-Compton scattering. In addition, they can thermalise directly with the semi-ionised medium via Coulomb processes. Heating at a rate of ∼10−25 erg cm−3 s−1can be attained by Coulomb processes in a star-forming galaxy with one core-collapse SN event per decade, and this is sufficient to cause quenching of star-formation. At high-redshift, a substantial amount of CR secondary electron energy can be diverted into inverse-Compton X-ray emission. This yields an X-ray luminosity of above 1041 erg s−1by redshiftz = 7 which drives a further heating effect, operating over larger scales. This would be able to halt inflowing cold gas filaments, strangulating subsequent star-formation. We selected a sample of 16 starburst and post-starburst galaxies at 7 ≲ z ≲ 9 and determine the star-formation rates they could have sustained. We applied a model with CR injection, propagation and heating to calculate energy deposition rates in these 16 sources. Our calculations show that CR feedback cannot be neglected as it has the strength to suppress star-formation in these systems. We also show that their currently observed quiescence is consistent with the suffocation of cold inflows, probably by a combination of X-ray and CR heating.

The Munich Compact Light Source: initial performance measures

2016 ◽  
Vol 23 (5) ◽  
pp. 1137-1142 ◽  
Author(s):  
Elena Eggl ◽  
Martin Dierolf ◽  
Klaus Achterhold ◽  
Christoph Jud ◽  
Benedikt Günther ◽  
...  
Keyword(s):  
Light Source ◽  
Large Scale ◽  
Source Size ◽  
Relativistic Electrons ◽  
X Rays ◽  
Beam Hardening ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Compact Light Source

While large-scale synchrotron sources provide a highly brilliant monochromatic X-ray beam, these X-ray sources are expensive in terms of installation and maintenance, and require large amounts of space due to the size of storage rings for GeV electrons. On the other hand, laboratory X-ray tube sources can easily be implemented in laboratories or hospitals with comparatively little cost, but their performance features a lower brilliance and a polychromatic spectrum creates problems with beam hardening artifacts for imaging experiments. Over the last decade, compact synchrotron sources based on inverse Compton scattering have evolved as one of the most promising types of laboratory-scale X-ray sources: they provide a performance and brilliance that lie in between those of large-scale synchrotron sources and X-ray tube sources, with significantly reduced financial and spatial requirements. These sources produce X-rays through the collision of relativistic electrons with infrared laser photons. In this study, an analysis of the performance, such as X-ray flux, source size and spectra, of the first commercially sold compact light source, the Munich Compact Light Source, is presented.

scholarly journals Inverse-Compton scattering in the resolved jet of the high-redshift quasar PKS J1421−0643

2020 ◽  
Vol 497 (1) ◽  
pp. 988-1000 ◽  
Author(s):  
D M Worrall ◽  
M Birkinshaw ◽  
H L Marshall ◽  
D A Schwartz ◽  
A Siemiginowska ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
Lorentz Factor ◽  
High Energy ◽  
Radio Spectrum ◽  
X Rays ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Jet Power

ABSTRACT Despite the fact that kpc-scale inverse-Compton (iC) scattering of cosmic microwave background (CMB) photons into the X-ray band is mandated, proof of detection in resolved quasar jets is often insecure. High redshift provides favourable conditions due to the increased energy density of the CMB, and it allows constraints to be placed on the radio synchrotron-emitting electron component at high energies that are otherwise inaccessible. We present new X-ray, optical, and radio results from Chandra, HST, and the VLA for the core and resolved jet in the z = 3.69 quasar PKS J1421−0643. The X-ray jet extends for about 4.5 arcsec (32 kpc projected length). The jet’s radio spectrum is abnormally steep and consistent with electrons being accelerated to a maximum Lorentz factor of about 5000. Results argue in favour of the detection of iC X-rays for modest magnetic field strength of a few nT, Doppler factor of about 4, and viewing angle of about 15°, and predict the jet to be largely invisible in most other spectral bands including the far- and mid-infrared and high-energy gamma-ray. The jet power is estimated to be about 3 × 1046 erg s−1 which is of order a tenth of the quasar bolometric power, for an electron–positron jet. The jet radiative power is only about 0.07 per cent of the jet power, with a smaller radiated power ratio if the jet contains heavy particles, so most of the jet power is available for heating the intergalactic medium.

Predictions of inverse Compton radiation from PSR B1259–63

2000 ◽  
Vol 177 ◽  
pp. 531-532
Author(s):  
J. G. Kirk ◽  
Lewis Ball ◽  
O. Skjæraasen
Keyword(s):  
Synchrotron Radiation ◽  
Delta Function ◽  
Companion Paper ◽  
High Energy ◽  
Termination Shock ◽  
Relativistic Electrons ◽  
X Rays ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Function Approximations

Unpulsed high energy (TeV) emission has been detected from several isolated pulsars (Aharonian 1999) and presumably results from relativistic electrons accelerated at the termination shock of an MHD wind driven by the pulsar itself. These electrons inverse Compton scatter target photons from either the cosmic microwave background, or from their own synchrotron radiation.The rotation-powered binary pulsar PSR B1259–63 (Johnston et al. 1996) is also thought to drive an MHD wind, and the synchrotron radiation of electrons accelerated at its termination shock is probably the source of the unpulsed X-rays seen from this object by ROSAT, OSSE and ASCA (Tavani & Arons 1997). Compared to the isolated pulsars, however, the the pulsar’s Be-star companion provides an energy density of target photons available for inverse Compton scattering which is some 11 orders of magnitude larger. Using delta-function approximations to the emissivities and a monochromatic approximation to the spectrum of the target photons, we modelled the observed X-ray synchrotron emission and predicted the TeV emission in a recent paper (Kirk et al. 1999). In this contribution we improve these calculations in two respects – by treating the target spectrum more precisely, as described in the companion paper (Ball & Kirk 1999), and by relaxing the approximations made in the emissivities.

scholarly journals Opacities for photon splitting and pair creation in neutron star magnetospheres

2019 ◽  
Vol 486 (3) ◽  
pp. 3327-3349 ◽  
Author(s):  
Kun Hu ◽  
Matthew G Baring ◽  
Zorawar Wadiasingh ◽  
Alice K Harding
Keyword(s):  
High Energy ◽  
Pair Creation ◽  
X Rays ◽  
Static Vacuum ◽  
Curved Space ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Photon Splitting ◽  
Magnetic Pair

ABSTRACT Over the last four decades, persistent and flaring emission of magnetars observed by various telescopes has provided us with a suite of light curves and spectra in soft and hard X-rays, with no emission yet detected above around 1 MeV. Attenuation of such high-energy photons by magnetic pair creation and photon splitting is expected to be active in the magnetospheres of magnetars, possibly accounting for the paucity of gamma-rays in their signals. This paper explores polarization-dependent opacities for these two QED processes in static vacuum dipole magnetospheres of highly magnetized neutron stars, calculating attenuation lengths and determining escape energies, which are the maximum photon energies for transparency out to infinity. The numerical trajectory integral analysis in flat and curved space–times provides upper bounds of a few MeV or less to the visible energies for magnetars for locales proximate to the stellar surface. Photon splitting opacity alone puts constraints on the possible emission locales in their magnetospheres: regions within field loops of maximum altitudes $\, r_{{\rm max}}\sim 2\!-\!4\,$ stellar radii are not commensurate with maximum detected energies of around 250 keV. These constraints apply not only to magnetar flares but also to their quiescent hard X-ray tail emission. An exploration of photon splitting attenuation in the context of a resonant inverse Compton scattering model for the hard X-ray tails derives distinctive phase-resolved spectroscopic and polarimetric signatures, of significant interest for future MeV-band missions such as AMEGO and e-ASTROGAM.

Sign in / Sign up

Export Citation Format

Share Document