An Australian Broad-band Satellite for X-ray Astronomy

1985 ◽  
Vol 6 (2) ◽  
pp. 186-194 ◽  
Author(s):  
J. G. Greenhill ◽  
K. B. Fenton ◽  
R. K. Sood ◽  
I. R. Tuohy
Keyword(s):  
Broad Band ◽  
High Sensitivity ◽  
Wide Energy Range ◽  
Line Production ◽  
Power Sources ◽  
X Ray ◽  
Wide Energy ◽  
X Ray Background ◽  
Cyclotron Line ◽  
Better Than

AbstractA broad-band (2-190 keV) Australian X-ray satellite could provide a spectral sensitivity substantially better than HEAO-1 or any presently approved spacecraft. It would be virtually unique by providing simultaneously data over a wide energy range with high sensitivity and energy resolution in the little measured region above 30 keV. These measurements are vital to our understanding of such diverse topics as the cyclotron line production mechanism in binary sources, the structure of the magnetosphere of neutron stars, the origin of the diffuse cosmic X-ray background and the nature of the giant power sources in active galaxies and stellar black holes. Details of the proposed spacecraft and scientific objectives are given.

scholarly journals The X-ray Astronomy Satellite SAX

1990 ◽  
Vol 115 ◽  
pp. 302-306
Author(s):  
R.C. Butler
Keyword(s):  
Energy Range ◽  
Scintillation Counter ◽  
Broad Band ◽  
Wide Energy Range ◽  
Wide Field ◽  
X Ray ◽  
Wide Energy ◽  
Cyclotron Line ◽  
Galactic Sources

AbstractThe SAX satellite is forseen for launch at the end of 1992 to study the X-ray emission from galactic and extra-galactic sources in the energy range 0.1-200 keV. The payload consists of four concentrator/spectrometer systems (3 units 1-10keV, 1 unit 0.1-10keV), a high pressure gas scintillation proportional counter (3-120keV), a phoswich scintillation counter (15-200keV), and two wide field cameras (2-30keV). Together these instruments will perform the following:- - Broad band spectroscopy (E/ΔE=12) in the energy range 0.1-10 keV with imaging resolution of 1 arcmin- Continuum and cyclotron line spectroscopy (E/ΔE=5-20) in the wide energy range 3-200 keV- Variability studies of bright source energy spectra on time scales from milliseconds to days and months- Systematic long term source variability studies in selected regions of the sky down to a source intensity of 1 mCrab.

Design of an ultrahigh-energy-resolution and wide-energy-range soft X-ray beamline

2013 ◽  
Vol 21 (1) ◽  
pp. 273-279 ◽  
Author(s):  
L. Xue ◽  
R. Reininger ◽  
Y.-Q. Wu ◽  
Y. Zou ◽  
Z.-M. Xu ◽  
...  
Keyword(s):  
Energy Range ◽  
Energy Resolution ◽  
Wide Energy Range ◽  
Ultrahigh Energy ◽  
Exit Slit ◽  
Shanghai Synchrotron Radiation Facility ◽  
X Ray ◽  
Variable Line ◽  
Line Spacing ◽  
Wide Energy

A new ultrahigh-energy-resolution and wide-energy-range soft X-ray beamline has been designed and is under construction at the Shanghai Synchrotron Radiation Facility. The beamline has two branches: one dedicated to angle-resolved photoemission spectroscopy (ARPES) and the other to photoelectron emission microscopy (PEEM). The two branches share the same plane-grating monochromator, which is equipped with four variable-line-spacing gratings and covers the 20–2000 eV energy range. Two elliptically polarized undulators are employed to provide photons with variable polarization, linear in every inclination and circular. The expected energy resolution is approximately 10 meV at 1000 eV with a flux of more than 3 × 1010 photons s−1at the ARPES sample positions. The refocusing of both branches is based on Kirkpatrick–Baez pairs. The expected spot sizes when using a 10 µm exit slit are 15 µm × 5 µm (horizontal × vertical FWHM) at the ARPES station and 10 µm × 5 µm (horizontal × vertical FWHM) at the PEEM station. The use of plane optical elements upstream of the exit slit, a variable-line-spacing grating and a pre-mirror in the monochromator that allows the influence of the thermal deformation to be eliminated are essential for achieving the ultrahigh-energy resolution.

XAFS and X-MCD spectroscopies with undulator gap scan

1998 ◽  
Vol 5 (3) ◽  
pp. 989-991 ◽  
Author(s):  
Andrei Rogalev ◽  
Vincent Gotte ◽  
Jose´ Goulon ◽  
Christophe Gauthier ◽  
Joel Chavanne ◽  
...  
Keyword(s):  
Energy Range ◽  
Absorption Spectroscopy ◽  
Emission Peak ◽  
Photon Statistics ◽  
Wide Energy Range ◽  
X Ray ◽  
Polarization Rate ◽  
Spin Polarized ◽  
Wide Energy ◽  
X Ray Absorption

The first experimental applications of the undulator gap-scan technique in X-ray absorption spectroscopy are reported. The key advantage of this method is that during EXAFS scans the undulator is permanently tuned to the maximum of its emission peak in order to maximize the photon statistics. In X-MCD or spin-polarized EXAFS studies with a helical undulator of the Helios type, the polarization rate can also be kept almost constant over a wide energy range.

scholarly journals Review of GRANAT Observations of AGNs

1994 ◽  
Vol 159 ◽  
pp. 63-72 ◽  
Author(s):  
E. Churazov ◽  
M. Gilfanov ◽  
A. Finoguenov ◽  
R. Sunyaev ◽  
M. Chernyakova ◽  
...  
Keyword(s):  
Time Scales ◽  
Gamma Ray ◽  
Broad Band ◽  
Band 3 ◽  
X Rays ◽  
X Ray ◽  
X Ray Background

Brief review of AGNs observations in the X-ray / soft gamma-ray bands with the orbital observatory GRANAT is presented.For three well known bright objects (3C273, NGC4151 and Cen A) broad band (3 keV–few hundreds keV) spectra have been obtained. Imaging capabilities allowed accurate (several arcminutes) identification of these objects with sources of hard X-rays.The spectrum of NGC4151 above ≈ 50 keV was found to be much steeper than that in most of the previous observations, while in standard X-ray band the spectrum agrees with observed previously. The comparison of the observed spectra with that of the X-Ray Background (XRB) indicates that sources similar to NGC4151 could reproduce the shape of XRB spectrum in 3–60 keV band.Cen A was observed in the very low state during most of observations in 1990–1993, except for two observations in 1991. The variability of the hard X-ray flux has been detected on the time scales of several days.

ASCA Observations of White Dwarfs, Neutron Stars and Black Holes

1996 ◽  
Vol 165 ◽  
pp. 321-331
Author(s):  
H. Inoue
Keyword(s):  
Black Holes ◽  
Focal Plane ◽  
Thin Foil ◽  
Effective Area ◽  
Wide Energy Range ◽  
Ccd Cameras ◽  
X Ray ◽  
Different Types ◽  
Wide Energy ◽  
Large Effective Area

ASCA, the fourth Japanese X-ray astronomy satellite, was launched by the Institute of Space and Astronautical Science (ISAS) on 1993 February 20. ASCA is designed to be a high-capability X-ray observatory (Tanaka et al. 1994). It is equipped with nested thin-foil mirrors which provide a large effective area over a wide energy range from 0.5 to 10 keV. Two different types of detectors, CCD cameras (SIS) and imaging gas scintillation proportional counters (GIS) are employed as the focal plane instruments.

A new extra-focus monochromator designed for high-performance VUV beamlines

2015 ◽  
Vol 22 (2) ◽  
pp. 328-335 ◽  
Author(s):  
Chaofan Xue ◽  
Yanqing Wu ◽  
Ying Zou ◽  
Lian Xue ◽  
Yong Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Vacuum Ultraviolet ◽  
Wide Energy Range ◽  
X Ray ◽  
Ultraviolet Range ◽  
Line Spacing ◽  
Wide Energy ◽  
Focus Spot ◽  
Grating Monochromator ◽  
Mechanical Compatibility

A new monochromator called an extra-focus constant-included-angle varied-line-spacing (VLS) cylindrical-grating monochromator (extra-focus CIA-VCGM) is described. This monochromator is based on the Hettrick–Underwood scheme where the plane VLS grating is replaced by a cylindrical one in order to zero the defocus at three reference photon energies in the vacuum-ultraviolet range. It has a simple mechanical structure and a fixed focus spot with high performance over a wide energy range. Furthermore, its mechanical compatibility with a standard VLS plane-grating monochromator allows convenient extension into the soft-X-ray range.

scholarly journals Cosmological Evolution of X-ray Selected AGNs and Synthesis of the X-ray Background

2013 ◽  
Vol 9 (S304) ◽  
pp. 125-131
Author(s):  
Yoshihiro Ueda ◽  
Masayuki Akiyama ◽  
Günther Hasinger ◽  
Takamitsu Miyaji ◽  
Michael G. Watson
Keyword(s):  
Broad Band ◽  
Likelihood Method ◽  
Energy Bands ◽  
Redshift Distribution ◽  
Absorption Function ◽  
X Ray ◽  
Standard Population ◽  
Rate Versus ◽  
X Ray Background ◽  
Biased Samples

AbstractX-ray surveys provide us with one of the least biased samples of Active Galactic Nuclei (AGNs) against obscuration. Here we present the most up-to-date AGN X-ray luminosity function (XLF) and absorption function over the redshift range from 0 to 5, using the largest, highly complete sample ever available obtained from surveys of various depth, depth, and energy bands. We utilize a maximum likelihood method to reproduce the count-rate versus redshift distribution for each survey, by taking into account the evolution of the absorbed fraction, contribution from Compton-thick AGNs, and AGN broad band X-ray spectra including reflection components from tori based on the luminosity and redshift dependent unified scheme. We find that the shape of the XLF at z ~ 1–3 is significantly different from that in the local universe, for which the luminosity dependent density evolution (LDDE) model gives the best description. These results establish the standard population synthesis model of the X-Ray Background (XRB), which well reproduces the source counts in both soft and hard bands, the observed fractions of Compton-thick AGNs, and the spectrum of the XRB.

scholarly journals ASCA Deep Sky Survey

1998 ◽  
Vol 188 ◽  
pp. 469-470
Author(s):  
Y. Ogasaka ◽  
T. Kii ◽  
Y. Ueda ◽  
T. Takahashi ◽  
H. Inoue ◽  
...  
Keyword(s):  
Energy Range ◽  
High Sensitivity ◽  
Wide Energy Range ◽  
Sky Survey ◽  
Source Confusion ◽  
Wide Energy ◽  
Confusion Limit

ASCA DSS was intended to carry out unbiased surveys in wide energy range of 0.5-10 keV. The strategy of this project is to survey small sky region with extremely high sensitivity reaching to the source confusion limit of ASCA XRT, in contrast to the Large Sky Survey project (Ueda 1996) which covers much larger sky area with relatively shallow exposure.

scholarly journals NuSTAR view of Be/X-ray binary pulsar 2S 1417−624 during 2018 giant outburst

2019 ◽  
Vol 490 (2) ◽  
pp. 2458-2466 ◽  
Author(s):  
Shivangi Gupta ◽  
Sachindra Naik ◽  
Gaurava K Jaisawal
Keyword(s):  
Broad Band ◽  
Gaussian Function ◽  
Physical Models ◽  
Spectral Studies ◽  
Band Spectrum ◽  
X Ray ◽  
Binary Pulsar ◽  
Double Peak Structure ◽  
Peak Structure ◽  
Cyclotron Line

ABSTRACT We report the results obtained from a detailed timing and spectral studies of Be/X-ray binary pulsar 2S 1417−624 using data from Swift and NuSTAR observatories. The observations were carried out at the peak of a giant outburst of the pulsar in 2018. X-ray pulsations at ∼17.475 s were detected in the source light curves up to 79 keV. The evolution of the pulse profiles with energy was found to be complex. A four-peaked profile at lower energies gradually evolved into a double-peak structure at higher energies. The pulsed fraction of the pulsar, calculated from the NuSTAR observation was found to follow an anticorrelation trend with luminosity as observed during previous giant X-ray outburst studies in 2009. The broad-band spectrum of the pulsar is well described by a composite model consisting of a cut-off power-law model modified with the interstellar absorption, a thermal blackbody component with a temperature of ≈1 keV, and a Gaussian function for the 6.4 keV iron emission line. Though the pulsar was observed at the peak of the giant outburst, there was no signature of presence of any cyclotron line feature in the spectrum. The radius of the blackbody emitting region was estimated to be ≈2 km, suggesting that the most probable site of its origin is the stellar surface of the neutron star. Physical models were also explored to understand the emission geometry of the pulsar and are discussed in the paper.

Nanoscale determination of interatomic distance by ptychography-EXAFS method using advanced Kirkpatrick–Baez mirror focusing optics

2020 ◽  
Vol 27 (2) ◽  
pp. 455-461
Author(s):  
Makoto Hirose ◽  
Kei Shimomura ◽  
Takaya Higashino ◽  
Nozomu Ishiguro ◽  
Yukio Takahashi
Keyword(s):  
Wide Energy Range ◽  
X Rays ◽  
Bulk Materials ◽  
Interatomic Distances ◽  
X Ray ◽  
Combination Technique ◽  
Wide Energy ◽  
Diffraction Patterns ◽  
X Ray Absorption

This work demonstrates a combination technique of X-ray ptychography and the extended X-ray absorption fine structure (ptychography-EXAFS) method, which can determine the interatomic distances of bulk materials at the nanoscale. In the high-resolution ptychography-EXAFS method, it is necessary to use high-intense coherent X-rays with a uniform wavefront in a wide energy range, hence a ptychographic measurement system installed with advanced Kirkpatrick–Baez mirror focusing optics is developed and its performance is evaluated. Ptychographic diffraction patterns of micrometre-size MnO particles are collected by using this system at 139 energies between 6.504 keV and 7.114 keV including the Mn K absorption edge, and then the EXAFS of MnO is derived from the reconstructed images. By analyzing the EXAFS spectra obtained from a 48 nm × 48 nm region, the nanoscale bond lengths of the first and second coordination shells of MnO are determined. The present approach has great potential to elucidate the unclarified relationship among the morphology, electronic state and atomic arrangement of inhomogeneous bulk materials with high spatial resolution.

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