scholarly journals The chameleon on the branches: spectral state transition and dips in NGC 247 ULX-1

2021 ◽  
Author(s):  
A D’Aí ◽  
C Pinto ◽  
M Del Santo ◽  
F Pintore ◽  
R Soria ◽  
...  
Keyword(s):  
High Resolution ◽  
State Transition ◽  
Black Body ◽  
The Other ◽  
Spectral Parameters ◽  
Data Set ◽  
X Ray ◽  
Monitoring Campaign ◽  
Normal Branch ◽  
Spectral State

Abstract Soft Ultra-Luminous X-ray (ULXs) sources are a sub-class of the ULXs that can switch from a supersoft spectral state, where most of the luminosity is emitted below 1 keV, to a soft spectral state with significant emission above 1 keV. In a few systems, dips have been observed. The mechanism behind this state transition and the dips nature are still debated. To investigate these issues, we obtained a long XMM-Newton monitoring campaign of a member of this class, NGC 247 ULX-1. We computed the hardness-intensity diagram for the whole data-set and identified two different branches: the normal branch and the dipping branch, which we study with four and three hardness-intensity resolved spectra, respectively. All seven spectra are well described by two thermal components: a colder (kTbb ∼ 0.1-0.2 keV) black-body, interpreted as emission from the photo-sphere of a radiatively-driven wind, and a hotter (kTdisk ∼ 0.6 keV) multi-colour disk black-body, likely due to reprocessing of radiation emitted from the innermost regions. In addition, a complex pattern of emission and absorption lines has been taken into account based on previous high-resolution spectroscopic results. We studied the evolution of spectral parameters and flux of the two thermal components along the two branches and discuss two scenarios possibly connecting the state transition and the dipping phenomenon. One is based on geometrical occultation of the emitting regions, the other invokes the onset of a propeller effect.

Refinement of d-AlNico Quasicrystal Structures

2000 ◽  
Vol 643 ◽  
Author(s):  
Hiroyuki Takakura ◽  
Akiji Yamamoto ◽  
An Pang Tsai
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Single Crystal ◽  
Diffraction Data ◽  
The Other ◽  
Structure Model ◽  
X Ray Diffraction ◽  
Data Set ◽  
X Ray ◽  
High Resolution Images

AbstractThe models of decagonal Al72Ni20Co8 quasicrystal with the space group of P105/mmc were refined on the basis of single crystal x-ray diffraction data set using the 5D description. The results of a structure model derived from Al13Fe4-type approximant crystal and Burkov model are compared. The former gives ω R=0.045 and R=0.063 for 449 reflections with 103 parameters and a resonable chemical composition of Al71.2TM28.8 (TM=transition metals). The projected structure in consistent with high resolution images of this material. On the other hand, the latter gives ωR=0.161 and R=0.193 for 55 parameters and a compositon of Al64.6TM35.1.

Characterization of Single- and Multiple-Layer Films by X-Ray Reflectometry

1991 ◽  
Vol 35 (A) ◽  
pp. 137-142 ◽  
Author(s):  
T. C. Huang ◽  
W. Parrish
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
High Resolution ◽  
Single Layer ◽  
The Other ◽  
X Ray ◽  
Buried Interfaces ◽  
Multiple Layer ◽  
Reflectivity Data

AbstractPrecision X-ray reflectivity data were obtained with a high-resolution reflectometer equipped with a rotating anode X-ray source and Ge 220 channel monochromators (one placed before and the other after the specimen). The surfaces and buried interfaces of thin films were characterized by ieast-squares refinement of experimental data. Values of thickness, density, and/or roughness of Pt “single-layer” and Pt/Co based multiple-layer films were determined.

Comparison of total scattering data from various sources: the case of a nanometric spinel

2015 ◽  
Vol 30 (S1) ◽  
pp. S65-S69 ◽  
Author(s):  
Giorgia Confalonieri ◽  
Monica Dapiaggi ◽  
Marco Sommariva ◽  
Milen Gateshki ◽  
Andy N. Fitch ◽  
...  
Keyword(s):  
High Resolution ◽  
High Energy ◽  
European Synchrotron Radiation Facility ◽  
Distribution Functions ◽  
Scattering Data ◽  
Data Set ◽  
Total Scattering ◽  
X Ray ◽  
Fair Comparison ◽  
Pair Distribution Functions

Total scattering data of nanocrystalline gahnite (ZnAl2O4, 2–3 nm) have been collected with three of the most commonly used instruments: (i) ID31 high-resolution diffractometer at the European Synchrotron Radiation Facility (ESRF) (Qmax = 22 Å−1); (ii) ID11 high-energy beamline at the ESRF (Qmax = 26.6 Å−1); and (iii) Empyrean laboratory diffractometer by PANalytical with molybdenum anode X-ray tube (Qmax = 17.1 Å−1). Pair distribution functions (PDFs) for each instrument data-set have been obtained, changing some of the parameters, by PDFgetX3 software, with the aim of testing the software in the treatment of different total scattering data. The material under analysis has been chosen for its nanometric (and possibly disordered) nature, to give rise to a challenge for all the diffractometers involved. None of the latter should have a clear advantage. The PDF and F(Q) functions have been visually compared, and then the three PDF sets have been used for refinements by means of PDFgui suite. All the refinements have been made exactly in the same way for the sake of a fair comparison. Small differences could be observed in the experimental PDFs and the derived results, but none of them seemed to be significant.

scholarly journals Electron density of a new EGFR Tyrokinase-inhibitor at 100 K, consideration of different models

2008 ◽  
Vol 223 (8) ◽  
Author(s):  
Stefan Mebs ◽  
Anja Lüth ◽  
Wolfgang Löwe ◽  
Carsten Paulmann ◽  
Peter Luger
Keyword(s):  
High Resolution ◽  
Synchrotron Radiation ◽  
Electron Density ◽  
Electron Shell ◽  
Cancer Drug ◽  
Outer Electron ◽  
Data Set ◽  
X Ray ◽  
Atomic Properties ◽  
Anti Cancer

AbstractThe electron density (ED) of a substituted 4-(indol-3-yl)-quinazoline, a newly developed anti-cancer drug, was determined from a high resolution X-ray data set measured at 100 K using synchrotron radiation. Because the structure contains a chlorine atom, which has a diffuse outer electron shell and is therefore beyond standard modeling, the influence of the model on the bond topological and atomic properties was studied following Bader's approach of ‘Atoms In Molecules’ (AIM). The expansion/contraction parameters

High Resolution X-Ray Diffraction Analysis of Piezoelectric LiNbO3 Films.

1995 ◽  
Vol 401 ◽  
Author(s):  
Yoshihiko Shibata ◽  
Naohiro Kuze ◽  
Masahiro Matsui ◽  
Masaki Kanal ◽  
Tomoji Kawai
Keyword(s):  
Laser Ablation ◽  
High Resolution ◽  
The Other ◽  
Full Width ◽  
Half Maximum ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Excimer Laser Ablation ◽  
Sapphire Substrates

AbstractThin LINbO3 films are deposited on (001) sapphire and (001) LiTaO3 substrates by using pulsed excimer-laser ablation. These films are evaluated by high-resolution X-ray diffraction (HRXRD) analysis. Strained LiNbO3 films in which the a-axis is longer and the c-axis is shorter than those of LiNbO3 single crystals are deposited on the sapphire substrates. On the other hand, extremely high-quality LiNbO3 films in which the a-axis of the films is the same as that of substrates are grown on the LiTaO substrates. X-ray rocking curves for the (006) reflection showed very narrow full width at half maximum (FWHM) of 208 arcsec for the films on the sapphire substrates, and 9 arcsec for the films on LiTaO3 substrates.

scholarly journals Neutron and high-resolution room-temperature X-ray data collection from crystallized lytic polysaccharide monooxygenase

2015 ◽  
Vol 71 (11) ◽  
pp. 1448-1452 ◽  
Author(s):  
John-Paul Bacik ◽  
Sophanit Mekasha ◽  
Zarah Forsberg ◽  
Andrey Kovalevsky ◽  
Jay C. Nix ◽  
...  
Keyword(s):  
High Resolution ◽  
Diffraction Data ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Lytic Polysaccharide Monooxygenase ◽  
Data Set ◽  
X Ray ◽  
Processing Enzymes ◽  
Bacteria And Fungi ◽  
Polysaccharide Monooxygenase

Bacteria and fungi express lytic polysaccharide monooxgyenase (LPMO) enzymes that act in conjunction with canonical hydrolytic sugar-processing enzymes to rapidly convert polysaccharides such as chitin, cellulose and starch to single monosaccharide products. In order to gain a better understanding of the structure and oxidative mechanism of these enzymes, large crystals (1–3 mm3) of a chitin-processing LPMO from the Gram-positive soil bacteriumJonesia denitrificanswere grown and screened for their ability to diffract neutrons. In addition to the collection of neutron diffraction data, which were processed to 2.1 Å resolution, a high-resolution room-temperature X-ray diffraction data set was collected and processed to 1.1 Å resolution in space groupP212121. To our knowledge, this work marks the first successful neutron crystallographic experiment on an LPMO. Joint X-ray/neutron refinement of the resulting data will reveal new details of the structure and mechanism of this recently discovered class of enzymes.

A First Experimental Electron Density Study on a C70 Fullerene: (C70C2F5)10

2010 ◽  
Vol 65 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Roman Kalinowski ◽  
Manuela Weber ◽  
Sergey I. Troyanov ◽  
Carsten Paulmann ◽  
Peter Luger
Keyword(s):  
High Resolution ◽  
Electron Density ◽  
Theoretical Calculations ◽  
Asymmetric Unit ◽  
Data Set ◽  
X Ray ◽  
Atomic Properties ◽  
Density Methods ◽  
Experimental Electron Density ◽  
Density Study

The electron density of the C70 fullerene C70(C2F5)10 was determined from a high-resolution X-ray data set measured with synchrotron radiation (beamline F1 of Hasylab/DESY, Germany) at a temperature of 100 K. With 140 atoms in the asymmetric unit this fullerene belongs to the largest problems examined until now by electron density methods. Using the QTAIM formalism quantitative bond topological and atomic properties have been derived and compared with the results of theoretical calculations on the title compound and on free C70

Study of Diffuse Scattering by Means of High Resolution Structure Images

1976 ◽  
Vol 34 ◽  
pp. 476-477
Author(s):  
Sumio Iijima ◽  
G. R. Anstis
Keyword(s):  
High Resolution ◽  
Neutron Diffraction ◽  
Diffuse Scattering ◽  
Reciprocal Space ◽  
The Other ◽  
X Ray ◽  
Actual Model ◽  
High Resolution Structure ◽  
Made In ◽  
Resolution Structure

Disorders in crystals with relatively simple structures which gave diffuse scattering have been extensively studied by X-ray or neutron diffraction methods. All these investigations were based on traditional diffraction methods and observations were made in reciprocal space (note observable diffraction intensities can be considered only in terms of interatomic vectors) and therefore the results obtained there leaves considerable ambiguity, particularly when we try to derive an actual model of the disordered crystals. A solution of this problem will be given only by knowing all atom positions in an assembly of atoms and for this case the observable diffracted intensity is given bywhere (xi,yi) and (xj,yj) represent position vectors of the i th and j th atoms with scattering factors fi and fj from an arbitrary origin. On the other hand, a crystal containing imperfections can be defined by

Modeling of dissolution and resolution in contact x-ray microscopy

1994 ◽  
Vol 52 ◽  
pp. 62-63
Author(s):  
Y. Wang ◽  
C. Jacobsen
Keyword(s):  
High Resolution ◽  
Numerical Modelling ◽  
Short Pulse ◽  
Water Layer ◽  
Black Body ◽  
High Resolution Imaging ◽  
Finite Sample ◽  
X Ray ◽  
Resolution Imaging ◽  
Different Diameters

Contact x-ray microscopy or microradiography offers a simple-to-use approach to high resolution imaging of wet, thick biological specimens. One great advantage of the technique is that it can be usedwith short pulse, incoherent x-ray sources such as laser produced plasmas, and polymer replicas or direct AFM viewing are promising new approaches to image readout. However, it has long been pointed outthat issues such as diffraction blurring over finite sample-to-resist spacing, shot noise in the exposure, and sidecutting during development must be considered in evaluating contact x-ray microradiographs.We present here the results of numerical modelling of contact x-ray microscopy using photoresists. We assume a phantom consisting of protein rods and balls of different diameters, all embedded in a water layer. We assume that the x-ray exposure is provided by a black body source with temperature kBT = 100 eV (such as in a laser-produced plasma), and that the black bodyspectrum is then modified by x-ray transmission in 0.1/μm of Al2O3, 0.1μm of Si3N4, and 5μm of water.

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