Narrow energy band X-rays via mosaic crystal for mammography application

ABSTRACT The discovery of optical/UV (ultraviolet) tidal disruption events (TDEs) was surprising. The expectation was that, upon returning to the pericentre, the stellar-debris stream will form a compact disc that will emit soft X-rays. Indeed, the first TDEs were discovered in this energy band. A common explanation for the optical/UV events is that surrounding optically thick matter reprocesses the disc’s X-ray emission and emits it from a large photosphere. If accretion follows the super-Eddington mass infall rate, it would inevitably result in an energetic outflow, providing naturally the reprocessing matter. We describe here a new method to estimate, using the observed luminosity and temperature, the mass and energy of outflows from optical transients. When applying this method to a sample of supernovae, our estimates are consistent with a more detailed hydrodynamic modelling. For the current sample of a few dozen optical TDEs, the observed luminosity and temperature imply outflows that are significantly more massive than typical stellar masses, posing a problem to this common reprocessing picture.

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Study of recent outburst in the Be/X-ray binary RX J0209.6−7427 with AstroSat: a new ultraluminous X-ray pulsar in the Magellanic Bridge?

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1041 ◽

2020 ◽

Vol 495 (3) ◽

pp. 2664-2672 ◽

Cited By ~ 4

Author(s):

Amar Deo Chandra ◽

Jayashree Roy ◽

P C Agrawal ◽

Manojendu Choudhury

Keyword(s):

Energy Band ◽

Spectral Characteristics ◽

Spectral Studies ◽

X Rays ◽

Energy Bands ◽

Large Area ◽

Pulse Profile ◽

X Ray ◽

Outburst Energy ◽

Area X

ABSTRACT We present the timing and spectral studies of RX J0209.6–7427 during its rare 2019 outburst using observations with the Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counter (LAXPC) instruments on the AstroSat satellite. Pulsations having a periodicity of 9.29 s were detected for the first time by the NICER mission in the 0.2–10 keV energy band and, as reported here, by AstroSat over a broad energy band covering 0.3–80 keV. The pulsar exhibits a rapid spin-up during the outburst. Energy resolved folded pulse profiles are generated in several energy bands in 3–80 keV. To the best of our knowledge this is the first report of the timing and spectral characteristics of this Be binary pulsar in hard X-rays. There is suggestion of evolution of the pulse profile with energy. The energy spectrum of the pulsar is determined and from the best-fitting spectral values, the X-ray luminosity of RX J0209.6−7427 is inferred to be 1.6 × 1039 erg s−1. Our timing and spectral studies suggest that this source has features of an ultraluminous X-ray pulsar in the Magellanic Bridge. Details of the results are presented and discussed in terms of the current ideas.

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Galactic plane structure in hard X-rays

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310011877 ◽

2009 ◽

Vol 5 (H15) ◽

pp. 809-809

Author(s):

A. Lutovinov ◽

M. Revnivtsev ◽

R. Krivonos

Keyword(s):

Energy Band ◽

Galactic Plane ◽

Galactic Disk ◽

X Rays ◽

X Ray ◽

The Galaxy ◽

Increased Sensitivity ◽

Using Data

AbstractWe study the structure of the Galaxy in the hard X-ray energy band (¿20 keV) using data from the INTEGRAL observatory. The increased sensitivity of the survey and the very deep observations performed during six years of the observatory operation allow us to detect about a hundred new sources. This significantly enlarges the sample of hard X-ray sources in the Galactic disk and bulge in a comparison with the previous studies.

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Diffraction of Thermally Scattered X-Rays in Mosaic Crystal

Journal of the Physical Society of Japan ◽

10.1143/jpsj.57.2026 ◽

1988 ◽

Vol 57 (6) ◽

pp. 2026-2039 ◽

Cited By ~ 1

Author(s):

Yasuhiro Oya ◽

Yasuji Kashiwase

Keyword(s):

X Rays ◽

Mosaic Crystal

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Structure, Magnetic Property and Energy Band Gap of Fe-Doped NiO Nanoparticles Prepared by Co-Precipitation Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.751.379 ◽

2017 ◽

Vol 751 ◽

pp. 379-383 ◽

Cited By ~ 1

Author(s):

Buppachat Toboonsung

Keyword(s):

Crystal Structure ◽

Band Gap ◽

Energy Band ◽

Precipitation Method ◽

Precipitation Process ◽

X Rays ◽

Nio Nanoparticles ◽

Energy Band Gap ◽

Air Atmosphere ◽

Co Precipitation

Fe-doped NiO nanoparticles was prepared by the co-precipitation method. The precipitation solution were used the concentration of FeSO4 mixing NiCl2 for 0.5 M. The precipitation process was used a magnetic stirrer of 1100 rpm, a temperature of 30-60 OC for 0.5 h and the dropping a NaOH of 0.5 M in the mixing solution. The precipitate product was dried at the temperature of 120 OC for 9 h and calcined in a furnace at the temperature of 400 OC for 4 h in air atmosphere. The powder product was analyzed a crystal structure by a x-rays diffractometer, calculated an energy band gap by UV-VIS spectrophotometer, measured a magnetic properties by a vibrating sample magnetometer and explained morphology by a scanning electron microscope. It was found that the crystal structure was shown face center cubic. The nanoparticles in the range of 30-100 nm was observed the morphology of the optimum product. However, the coercive, the magnetic moment and the energy band gap was found the optimum at the doping Fe of 8 wt% at the precipitation temperature of 40 OC.

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Ultrasoft X-Ray Background Observations of the Local Interstellar Medium

International Astronomical Union Colloquium ◽

10.1017/s0252921100098237 ◽

1984 ◽

Vol 81 ◽

pp. 222-225 ◽

Cited By ~ 1

Author(s):

W.T. Sanders ◽

S.L. Snowden ◽

J.J. Bloch ◽

M. Juda ◽

K.M. Jahoda ◽

...

Keyword(s):

Interstellar Medium ◽

Energy Band ◽

Mean Free Path ◽

Sounding Rocket ◽

X Rays ◽

Local Interstellar Medium ◽

Peak Response ◽

X Ray ◽

Band Emission ◽

X Ray Background

Preliminary results from a May 8, 1984 sounding rocket survey of the soft X-ray background are presented. The X-ray detectors are sensitive to X-rays in three soft X-ray bandpasses: 80-110 eV, 90-188 eV, and 284-532 eV (at 20% of peak response). The lowest energy X-rays in this range have a mean free path of order 1019 cm-2 and provide information about the local interstellar medium. The count rate in the 80-110 eV energy band (the Be band) tracks the 90-188 eV band (the B band) very well, indicating that the same ~1 million degree gas that is responsible for the B band emission may be responsible for the bulk of the Be band X-rays as well. We estimate for the flux in the Be band ~1 photon cm-2 s-1 sr-1 eV-1 , about a factor of four lower than that found by Stern and Bowyer (1979) and Paresce and Stern (1981) over a similar energy band.

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Edge-enhanced imaging obtained with very broad energy band x-rays

Applied Physics Letters ◽

10.1063/1.3380641 ◽

2010 ◽

Vol 96 (14) ◽

pp. 144102 ◽

Cited By ~ 5

Author(s):

A. Taibi ◽

P. Cardarelli ◽

G. Di Domenico ◽

M. Marziani ◽

M. Gambaccini ◽

...

Keyword(s):

Energy Band ◽

X Rays ◽

Enhanced Imaging ◽

Broad Energy

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Rapid X-Ray Variability and The FE II Problem in I Zw 1 Objects

Symposium - International Astronomical Union ◽

10.1017/s0074180900048312 ◽

1994 ◽

Vol 161 ◽

pp. 660-661

Author(s):

Th. Boller ◽

J. Trümper ◽

S. Molendi ◽

S. Schaeidt ◽

H. Fink

Keyword(s):

Spectral Analysis ◽

Accretion Disk ◽

Energy Band ◽

Optical Spectrum ◽

Seyfert Galaxies ◽

X Rays ◽

Narrow Line ◽

X Ray ◽

Compact Region ◽

First Time

X-ray variability in the 0.1–2.4 keV ROSAT energy band with a doubling timescale of 800 s and a factor of 4 within a few hours has been detected in a 20 ksec pointing on the IRAS AGN 13224-3809. The optical spectrum indicates that IRAS 13224-3809 is a narrow-line Seyfert 1 galaxy with strong permitted Fe II emission, a member of the unusual I Zw 1 class objects. IRAS 13224-3809 appears to be one of the most rapidly variable AGN known so far. This is the first time that variability on a timescale smaller than 1000 s is reported at such high L (0.1–2.4 keV) = 3·1044 erg · s−1 X-ray luminosity in Seyfert galaxies. It is also the first reported X-ray variability in I Zw 1 class objects. The δt = 800 s variation indicates that the X-rays come from a compact region of about 17 light minutes in size. Our results from the X-ray spectral analysis favour a scenario in which a hard X-ray source irradiates the accretion disk which reemits at soft X-ray energies. The absence of broad H I wings can be explained if only a part of the BLR, far from the centre, is observed and the bulk of the region, which emits the wings, is hidden. We want to draw attention to the fact that rapid X-ray variability could also be connected with the absence of broad H I lines in IRAS 13224-3809.

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High-efficiency diffraction and focusing of X-rays through asymmetric bent crystalline planes

Journal of Applied Crystallography ◽

10.1107/s1600576714024960 ◽

2015 ◽

Vol 48 (1) ◽

pp. 297-300 ◽

Cited By ~ 4

Author(s):

Valerio Bellucci ◽

Gianfranco Paternò ◽

Riccardo Camattari ◽

Vincenzo Guidi ◽

Michael Jentschel ◽

...

Keyword(s):

High Efficiency ◽

X Rays ◽

X Ray ◽

Symmetric Configuration ◽

Mosaic Crystal ◽

Fine Focus ◽

Γ Ray ◽

Lattice Planes ◽

Laue Geometry ◽

Better Than

The grooving technique was employed for manufacturing a self-standing curved Ge crystal. The crystal focuses hard X-rays with high efficiency by diffraction in Laue geometry through asymmetric bent planes. The sample was tested at the Institut Laue–Langevin (Grenoble, France), undergoing two types of characterization. A monochromatic and low-divergence γ-ray beam was used to test the curvature of asymmetric planes, showing a diffraction performance better than for any mosaic crystal under equal conditions. Then, the focusing capability of the crystal was probed through a polychromatic and fine-focus hard X-ray beam. Asymmetric (220) planes were chosen for analysis because of the impossibility of obtaining a curvature along this family of planesviaany symmetric configuration in focusing crystals. A method for calculating the curvatures induced in any family of lattice planes is also presented.

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White-Light Coronal Structures: Streamers and CMEs

International Astronomical Union Colloquium ◽

10.1017/s0252921100025045 ◽

1994 ◽

Vol 144 ◽

pp. 82

Author(s):

E. Hildner

Keyword(s):

Emission Line ◽

Electron Density ◽

White Light ◽

Coronal Mass Ejections ◽

X Rays ◽

Solar Cycles ◽

Temperature Function ◽

X Ray ◽

Eclipse Observations ◽

Coronal Structures

AbstractOver the last twenty years, orbiting coronagraphs have vastly increased the amount of observational material for the whitelight corona. Spanning almost two solar cycles, and augmented by ground-based K-coronameter, emission-line, and eclipse observations, these data allow us to assess,inter alia: the typical and atypical behavior of the corona; how the corona evolves on time scales from minutes to a decade; and (in some respects) the relation between photospheric, coronal, and interplanetary features. This talk will review recent results on these three topics. A remark or two will attempt to relate the whitelight corona between 1.5 and 6 R⊙to the corona seen at lower altitudes in soft X-rays (e.g., with Yohkoh). The whitelight emission depends only on integrated electron density independent of temperature, whereas the soft X-ray emission depends upon the integral of electron density squared times a temperature function. The properties of coronal mass ejections (CMEs) will be reviewed briefly and their relationships to other solar and interplanetary phenomena will be noted.

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