scholarly journals CIELO-RGS: a catalog of soft X-ray ionized emission lines

2019 ◽  
Vol 625 ◽  
pp. A122
Author(s):  
Junjie Mao ◽  
Jelle S. Kaastra ◽  
Matteo Guainazzi ◽  
Rosario González-Riestra ◽  
Maria Santos-Lleó ◽  
...  
Keyword(s):  
Detection Algorithm ◽  
Emission Lines ◽  
Quality Data ◽  
Photon Flux ◽  
Astrophysical Plasmas ◽  
High Quality ◽  
X Ray ◽  
Spectral Diagnostics ◽  
Starting Point ◽  
Automated Line

Context. High-resolution X-ray spectroscopy has advanced our understanding of the hot Universe by revealing physical properties like kinematics, temperature, and abundances of the astrophysical plasmas. Despite technical and scientific achievements, the lack of scientific products at a level higher than count spectra is hampering complete scientific exploitation of high-quality data. This paper introduces the Catalog of Ionized Emission Lines Observed by the Reflection Grating Spectrometer (CIELO-RGS) onboard the XMM-Newton space observatory. Aims. The CIELO-RGS catalog aims to facilitate the exploitation of emission features in the public RGS spectra archive. In particular, we aim to analyze the relationship between X-ray spectral diagnostics parameters and measurements at other wavelengths. This paper focuses on the methodology of catalog generation, describing the automated line-detection algorithm. Methods. A moderate sample (∼2400 observations) of high-quality RGS spectra available at XMM-Newton Science Archive is used as our starting point. A list of potential emission lines is selected based on a multi-scale peak-detection algorithm in a uniform and automated way without prior assumption on the underlying astrophysical model. The candidate line list is validated via spectral fitting with simple continuum and line profile models. We also compare the catalog content with published literature results on a small number of exemplary sources. Results. We generate a catalog of emission lines (1.2 × 104) detected in ∼1600 observations toward stars, X-ray binaries, supernovae remnants, active galactic nuclei, and groups and clusters of galaxies. For each line, we report the observed wavelength, broadening, energy and photon flux, equivalent width, and so on.

scholarly journals X-ray Variability of the Flare Star CC Eri

1995 ◽  
Vol 151 ◽  
pp. 170-170
Author(s):  
H.C. Pan ◽  
C. Jordan
Keyword(s):  
Binary Star ◽  
Emission Measure ◽  
Quality Data ◽  
Spectral Variability ◽  
High Quality ◽  
High Quality Data ◽  
X Ray ◽  
Spectroscopic Binary ◽  
Two Temperature ◽  
Continuous Temperature

The flare/spotted spectroscopic binary star CC Eri (HD 16157) was observed in the periods 1990 July 9-11 and 1992 January 26-27 with the ROSAT PSPC detector (Pan and Jordan 1995). These high quality data give the first information on the temporal and spectral variability of CC Eri in the X-ray energy band.During the ROSAT observations the X-ray intensity of the source is variable on timescales from a few minutes to several hours. The X-ray luminosity is in the range 2.5 – 6.8 × 1029 erg s−1, which is similar to values found from previous measurements with the Einstein IPC and EXOSAT LE. On 1990 July 10 an X-ray flare-like event was detected with an exponential rise time of about one hour and a decay time of about two hours. The X-ray spectrum of CC Eri can be described by current thermal plasma codes with two temperature components or with a continuous temperature distribution. The spectral results show that plasma at Te ∼ 107 K exists in the corona of CC Eri. We find that the X-ray spectrum is also variable and the variations of the emission measure, and to a lesser extent of the temperature, are correlated with the source intensity.

The Fabrication and Performance of CVD Diamond-Based X-Ray Detectors

2005 ◽  
Vol 475-479 ◽  
pp. 3605-3610 ◽  
Author(s):  
S.G. Wang ◽  
P.J. Sellin ◽  
Q. Zhang ◽  
Fan Xiu Lu ◽  
Wei Zhong Tang ◽  
...  
Keyword(s):  
Diamond Film ◽  
Chemical Vapour ◽  
Cvd Diamond ◽  
Electrical Contacts ◽  
Electrode Spacing ◽  
Photon Flux ◽  
High Quality ◽  
X Ray ◽  
Increase With Increase ◽  
Lift Off

In this study, X-ray detectors with coplanar metal-semiconductor-metal structure, were fabricated employing high quality chemical vapour deposited (CVD) diamond film grown by a direct current arc jet plasma system. In which the electrical contacts with dimension of 25 µm in width with a 25 µm inter-electrode spacing, were patterned on the growth side of the diamond film using lift-off technology. The performance of the fabricated detectors was evaluated by steady-state X-ray illumination. The photoconductivity of the diamond detectors was found to linearly increase with increase in the X-ray photon flux. This demonstrates that high quality CVD diamond can be used for X-ray detectors.

scholarly journals IVAN PULUJ AND THE DISCOVERY OF X-RAYS

2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Ulyana Pidvalna ◽  
◽  
Roman Plyatsko ◽  
Vassyl Lonchyna ◽  
◽  
...  
Keyword(s):  
International Exhibition ◽  
Bone Lesions ◽  
X Rays ◽  
High Quality ◽  
X Ray ◽  
Exact Date ◽  
Starting Point ◽  
The World ◽  
New Type ◽  
The Given

On January 5, 1896, the Austrian newspaper Die Presse published an article entitled “A Sensational Discovery”. It was dedicated to the discovery of X-rays made on November 8, 1895 by the German physicist Wilhelm Conrad Röntgen. Having taken into account the contribution of other scientists, the precondition of the given epochal, yet unexpected, discovery was, first and foremost, the work of the Ukrainian scientist Ivan Puluj. It was Puluj who laid the foundation for X-ray science. He explained the nature of X-rays, discovered that they can ionize atoms and molecules, and defined the place of X-ray emergence and their distribution in space. In 1881, Puluj constructed a cathode lamp (“Puluj’s tube”) which was fundamentally a new type of light source. In the same year, in recognition of this discovery, Puluj received an award at the International Exhibition in Paris. Investigating the processes in cathode-ray tubes, Ivan Puluj set the stage for two ground-breaking discoveries in physics, namely X-rays and electrons. Puluj used his cathode lamp in medicine as a source of intense X-rays which proved to be highly efficient. The exact date of the first X-ray images received by Puluj remains unknown. High-quality photographs of the hand of an eleven-year-old girl, taken on January 18, 1896, are preserved. Multiple X-ray images clearly visualized pathological changes in the examined structures (fractures, calluses, tuberculous bone lesions). High-quality images were obtained by means of the anticathode in the design of Puluj’s lamp, which was the first in the world. The image of the whole skeleton of a stillborn child (published on April 3, 1896 in The Photogram) is considered to be the starting point of using X-rays in anatomy.

scholarly journals An Archival Study of HST Observations of Her X-1/HZ Her

1996 ◽  
Vol 158 ◽  
pp. 381-382
Author(s):  
F. H. Cheng ◽  
S. D. Vrtilek ◽  
J. C. Raymond
Keyword(s):  
Accretion Disk ◽  
Model Fitting ◽  
Rotation Period ◽  
Emission Lines ◽  
High Quality ◽  
Detailed Model ◽  
Companion Star ◽  
X Ray ◽  
First Time ◽  
Archival Study

Her X-1 is an X-ray pulsar with a rotation period of 1.24 s and a binary period of 1.7d (Tananbaum et al. 1972). The 1.7 d variations in optical and ultraviolet flux are attributed to X-ray heating of the companion star and disk (e.g. Howarth & Wilson 1983, hereafter HW83). The system displays a 35 d period, attributed to the effects of a tilted, precessing, accretion disk. Optical and ultraviolet flux variations continue unchanged throughout. This work is motivated by the following reasons:• The observed IUE spectra have significantly flatter slopes than those predicted by previous models (e.g. HW83).• The observed strength of the Balmer jump is anomalously low compared to that expected for a normal B star (Anderson et al. 1994).• HST observations obtained by Anderson et al. (1994) in order to study emission lines have yielded high quality spectra of the continuum emission from HZ Her, enabling for the first time detailed model fitting efforts.

Adaptive surface geometry determination in multi-material x-ray computed tomography using fringe projection

2021 ◽  
Author(s):  
Jonas Großeheide ◽  
Kilian Geiger ◽  
Ânderson Schmidt ◽  
Calvin Bütow ◽  
Benjamin Montavon ◽  
...  
Keyword(s):  
Measurement Data ◽  
Internal Surface ◽  
Detection Algorithm ◽  
Fringe Projection ◽  
X Rays ◽  
Surface Geometry ◽  
Data Set ◽  
X Ray ◽  
Starting Point ◽  
X Ray Computed

Abstract One of the main challenges during digital post-processing of x-ray computed tomographic (XCT) measurement data is the reconstruction of the surface geometry of the measured objects. Conventionally, the surface geometry is defined as an isosurface of identical greyscale values, i.e. the x-ray absorbance of the material, based on a linear interpolation between neighboring voxels. Due to the complex surface geometry and rough surface, XCT measurements of additively manufactured (AM) parts are particularly prone to measurement artefacts caused by various physical effects when the x-rays penetrate the material. The irregular greyscale values at the measured surface geometry render commonly used single threshold greyscale value based isosurfaces as insufficient for representing the external and internal surface of the measured objects. This issue becomes particularly apparent when measuring multi-material objects, such as additively manufactured objects with integrated RFID tags. To address this challenge, this study presents a methodology for reliable surface geometry determination of XCT data based on previously acquired fringe projection (FP) data. For this purpose, the conventionally acquired surfaces geometries from the XCT and FP measurements are extracted, pre-processed and registered to each other before being merged into a single mesh. This merged data set is subsequently used as a starting point or reference for a locally adaptive threshold surface detection algorithm, which is able to capture the surface geometry at a sub-voxel resolution. In order to validate the methodology and confirm the envisaged benefits, selected geometry elements of the resulting surface geometry from measurements samples manufactured by additive manufacturing with integrated RIFD tags are compared to coordinate measurement machine (CMM) reference measurements. The results indicate a more robust surface geometry detection against artifacts especially for multi-material applications.

scholarly journals Prisma the Instruments

1993 ◽  
Vol 137 ◽  
pp. 672-674
Author(s):  
Andrew Jones
Keyword(s):  
High Resolution ◽  
Stellar Structure ◽  
Quality Data ◽  
The Sun ◽  
Calibration Point ◽  
High Quality ◽  
High Quality Data ◽  
X Ray ◽  
Very High ◽  
Selection Of

Our understanding of Solar structure has increased dramatically in the last couple of decades thanks mainly to the opening of new windows of observation providing high quality data to theoreticians with access to powerful computing facilities. Two of the new windows were UV and X-ray images of the Sun, allowing a detailed view of the upper solar atmosphere, and the development of very high resolution spectrometers allowing us to exploit the solar oscillations to probe the internal structure of the Sun. It is the goal of PRISMA to extend these techniques to other stars, which using the Sun as a calibration point will allow us to explore stellar structure and evolution in ways not possible now.In this poster I will present a possible selection of instruments able to achieve this goal, and explain some of the rationale in their design. A more general overview is presented by T. Appouchaux also in these proceedings. It must be stressed that these are not the definitive instruments to be flown on PRISMA, but rather result from a study to show the feasibility of such a mission. Should PRISMA be chosen as the next ESA medium sized mission, an ‘Announcement of Opportunity’ wiH be issued by ESA and the responses of all people interested in constructing the instrument will be considered.

scholarly journals Application of an edge detection algorithm for surface determination in industrial X-ray computed tomography

2022 ◽  
Author(s):  
Matthias Busch ◽  
Tino Hausotte
Keyword(s):  
Computed Tomography ◽  
Edge Detection ◽  
Detection Algorithm ◽  
Measurement Process ◽  
Initial Contour ◽  
Process Step ◽  
Edge Detection Algorithm ◽  
X Ray ◽  
Starting Point ◽  
X Ray Computed

AbstractSurface determination is an essential step of the measurement process in industrial X-ray computed tomography (XCT). The starting point of the surface determination process step is a single grey value threshold within a voxel volume in conventional surface determination methods. However, this value is not always found in the reconstructed volume in the local environment of the surface of the measurement object due to various artefacts, so that none or incorrect surfaces are determined. In order to find surfaces independently of a single grey value, a three-dimensional approach of the initial contour determination based on a Prewitt edge detection algorithm is presented in this work. This method is applied to different test specimens and specimen compositions which, due to their material or material constellation, their geometric properties with regard to surfaces and interfaces as well as their calibrated size and length dimensions, embody relevant properties in the examination of joining connections. It is shown that by using the surface determination method in the measurement process, both a higher metrological structure resolution and interface structure resolution can be achieved. Surface artefacts can be reduced by the application and it is also an approach to improved surface finding for the multi-material components that are challenging for XCT.

A fibre-based crystal mounting technique for protein cryocrystallography

2012 ◽  
Vol 45 (2) ◽  
pp. 362-366 ◽  
Author(s):  
Michihiro Sugahara
Keyword(s):  
Data Collection ◽  
Success Rate ◽  
Single Crystals ◽  
Conventional Technique ◽  
Synthetic Zeolite ◽  
Quality Data ◽  
High Quality ◽  
High Quality Data ◽  
X Ray ◽  
Loop Technique

The CryoFibre, a crystal mounting tool, has been developed for protein cryocrystallography. The technique attaches single crystals to the tips of polyester fibres, allowing removal of excess liquid around each crystal. Single-wavelength anomalous dispersion phasing using a Cu Kα X-ray source (Cu SAD) was applied to crystals from five proteins without any derivatization, demonstrating a clear improvement in the success rate of Cu SAD compared with the conventional loop technique. In addition, a xylanase crystal on the surface of a synthetic zeolite as a hetero-epitaxic nucleant was directly mounted on the CryoFibre without separation treatment of the crystal from the zeolite. The crystal had a lower mosaicity than that observed using the conventional technique, indicating that the fibre technique is suitable for high-quality data collection from zeolite-mediated crystals.

scholarly journals New Results in Laboratory X-ray Astrophysics

2005 ◽  
Vol 13 ◽  
pp. 633-639 ◽  
Author(s):  
P. Beiersdorfer ◽  
H. Chen ◽  
K. R. Boyce ◽  
G. V. Brown ◽  
R. L. Kelley ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Ion Trap ◽  
Laboratory Astrophysics ◽  
Emission Lines ◽  
Laboratory Simulation ◽  
X Ray ◽  
Spectral Diagnostics ◽  
Electron Beam Ion Trap ◽  
Full Complement ◽  
Measuring Magnetic Field

AbstractA multi-faceted, multi-institutional laboratory astrophysics program is carried out at the Livermore electron beam ion trap facility, which is a mature spectroscopic source with unsurpassed controls and capabilities, and an unparalleled assortment of spectroscopic equipment, including a full complement of grating and crystal spectrometers and a 6x6 micro-calorimeter array. Recent results range from the calibration of x-ray diagnostics, including the Fe XVII and Fe XXV emission lines, extensive lists of L-shell ions, the first laboratory simulation and fit of a cometary x-ray emission spectrum, and the discovery of new spectral diagnostics for measuring magnetic field strengths.

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