scholarly journals Spatially resolved X-ray spectroscopy and modeling of the nonthermal emission of the pulsar wind nebula in G0.9+0.1

2012 ◽  
Vol 539 ◽  
pp. A24 ◽  
Author(s):  
M. Holler ◽  
F. M. Schöck ◽  
P. Eger ◽  
D. Kießling ◽  
K. Valerius ◽  
...  
Keyword(s):  
X Ray ◽  
Spatially Resolved ◽  
Nonthermal Emission ◽  
Pulsar Wind

Energy-dependent nebula extent and spatially resolved spectra of the pulsar wind nebula 3C 58

2020 ◽  
Vol 498 (2) ◽  
pp. 1911-1919
Author(s):  
Fang-Wu Lu ◽  
Quan-Gui Gao ◽  
Li Zhang
Keyword(s):  
Surface Brightness ◽  
Spectral Energy Distribution ◽  
High Energy ◽  
Spatial Variations ◽  
Spectral Energy ◽  
X Ray ◽  
Spatially Resolved ◽  
Photon Index ◽  
Pulsar Wind ◽  
Energy Dependent

ABSTRACT 3C 58 is a pulsar wind nebula (PWN) that shows an interesting energy-dependent nebula extent and spatial variations of the photon index and surface brightness in the X-ray band. These observations provide useful information with which to study the spatially dependent radiative cooling of electrons and the energy-dependent transport mechanisms within the nebula. In this paper, the energy-dependent nebula extent and spatially resolved spectra of this PWN are investigated in the framework of a spatially dependent particle transport model. The observations of the nebula, including the photon spectral energy distribution, spatial variations of the X-ray spectrum, and measurements of the nebula extent, can be naturally explained in this model. Our results show that the energy-dependent nebula extent favours an advection–diffusion scenario with advection-dominated transport, and the variations of the nebula extent with energy in the X-ray band can be attributed to the cooling losses of high-energy electrons affected by synchrotron burn-off. Particle diffusion plays an important role in modifying the spatial variations of the photon index and surface brightness in the X-ray band. The radial extents of the nebula at radio, GeV and TeV energies are predicted by the model, indicating that the nebula extent of 3C 58 varies with energy in these bands. The analyses show that the dependence of the adiabatic cooling rate and synchrotron radiation on the spectral index of injected particles is important for changing the nebula extent at different energies.

scholarly journals Discovery of a jet-like structure with overionized plasma in the SNR IC 443

2018 ◽  
Vol 615 ◽  
pp. A157 ◽  
Author(s):  
Emanuele Greco ◽  
Marco Miceli ◽  
Salvatore Orlando ◽  
Giovanni Peres ◽  
Eleonora Troja ◽  
...  
Keyword(s):  
Supernova Remnant ◽  
Supernova Explosion ◽  
Original Position ◽  
Core Collapse ◽  
Complex Environment ◽  
Energy Bands ◽  
X Ray ◽  
Spatially Resolved ◽  
Pulsar Wind ◽  
The Relationship

Context. IC 443 is a supernova remnant (SNR) located in a quite complex environment since it interacts with nearby clouds. Indications for the presence of overionized plasma have been found though the possible physical causes of overionization are still debated. Moreover, because of its peculiar position and proper motion, it is not clear if the pulsar wind nebula (PWN) within the remnant is the relic of the IC 443 progenitor star or just a rambling one seen in projection on the remnant. Aims. Here we address the study of IC 443 plasma in order to clarify the relationship PWN-remnant, the presence of overionization and the origin of the latter. Methods. We analyzed two XMM-Newton observations producing background-subtracted, vignetting-corrected and mosaicked images in two different energy bands and we performed a spatially resolved spectral analysis of the X-ray emission. Results. We identified an elongated (jet-like) structure with Mg-rich plasma in overionization. The head of the jet is interacting with a molecular cloud and the jet is aligned with the position of the PWN at the instant of the supernova explosion. Interestingly, the direction of the jet of ejecta is somehow consistent with the direction of the PWN jet. Conclusions. Our discovery of a jet of ejecta in IC 443 enlarge the sample of core-collapse SNRs with collimated ejecta structures. IC 443’s jet is the first one which shows overionized plasma, possibly associated with the adiabatic expansion of ejecta. The match between the jet’s direction and the original position of the PWN strongly supports the association between the neutron star and IC 443.

scholarly journals X-ray Studies of the Pulsar Wind Nebula Around PSR B0540-69

2004 ◽  
Vol 218 ◽  
pp. 189-192
Author(s):  
R. Petre ◽  
U. Hwang ◽  
S. S. Holt ◽  
R. M. Williams
Keyword(s):  
Particle Flux ◽  
Crab Nebula ◽  
Large Magellanic Cloud ◽  
Thermal Component ◽  
X Ray ◽  
Average Ratio ◽  
Spatially Resolved ◽  
Pulsar Wind ◽  
Spatially Resolved Spectroscopy ◽  
The Crab Nebula

The pulsar wind nebula (PWN) surrounding the 50-ms pulsar B0540-69 in the Large Magellanic Cloud shares many properties with the Crab Nebula, the canonical Galactic PWN. We have used the ACIS instrument on the Chandra X-ray Observatory to perform spatially resolved spectroscopy of the PWN. The spectrum of the inner 10″ is characterized by a simple power law, with a spectral index that steepens strongly with radius. Outside the central 10″ the spectra also require a thermal component. This diameter corresponds to a shell detected in [OIII], suggesting that this shell represents a skin around the PWN, in analogy to the Crab. We infer the value of several key PWN parameters, including σ, the average ratio of electromagnetic to particle flux.

Layered and ion implantation specimens as possible reference materials for the electron-probe microanalysis

1992 ◽  
Vol 50 (2) ◽  
pp. 1652-1653
Author(s):  
G. Remond ◽  
R.H. Packwood ◽  
C. Gilles ◽  
S. Chryssoulis
Keyword(s):  
Ion Implantation ◽  
Reference Materials ◽  
Analytical Techniques ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
X Ray ◽  
Spatially Resolved ◽  
Analytical Expressions ◽  
Original Approach ◽  
Depth Concentration

Merits and limitations of layered and ion implanted specimens as possible reference materials to calibrate spatially resolved analytical techniques are discussed and illustrated for the case of gold analysis in minerals by means of x-ray spectrometry with the EPMA. To overcome the random heterogeneities of minerals, thin film deposition and ion implantation may offer an original approach to the manufacture of controlled concentration/ distribution reference materials for quantification of trace elements with the same matrix as the unknown.In order to evaluate the accuracy of data obtained by EPMA we have compared measured and calculated x-ray intensities for homogeneous and heterogeneous specimens. Au Lα and Au Mα x-ray intensities were recorded at various electron beam energies, and hence at various sampling depths, for gold coated and gold implanted specimens. X-ray intensity calculations are based on the use of analytical expressions for both the depth ionization Φ (ρz) and the depth concentration C (ρz) distributions respectively.

scholarly journals Sample Environment for Operando Hard X-ray Tomography—An Enabling Technology for Multimodal Characterization in Heterogeneous Catalysis

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 459
Author(s):  
Johannes Becher ◽  
Sebastian Weber ◽  
Dario Ferreira Sanchez ◽  
Dmitry E. Doronkin ◽  
Jan Garrevoet ◽  
...  
Keyword(s):  
Heterogeneous Catalysis ◽  
Synchrotron Radiation ◽  
Contrast Imaging ◽  
Co2 Methanation ◽  
Full Field ◽  
X Ray ◽  
Spatially Resolved ◽  
Oxidation Of Methane ◽  
Unique Source ◽  
Sample Environment

Structure–activity relations in heterogeneous catalysis can be revealed through in situ and operando measurements of catalysts in their active state. While hard X-ray tomography is an ideal method for non-invasive, multimodal 3D structural characterization on the micron to nm scale, performing tomography under controlled gas and temperature conditions is challenging. Here, we present a flexible sample environment for operando hard X-ray tomography at synchrotron radiation sources. The setup features are discussed, with demonstrations of operando powder X-ray diffraction tomography (XRD-CT) and energy-dispersive tomographic X-ray absorption spectroscopy (ED-XAS-CT). Catalysts for CO2 methanation and partial oxidation of methane are shown as case studies. The setup can be adapted for different hard X-ray microscopy, spectroscopy, or scattering synchrotron radiation beamlines, is compatible with absorption, diffraction, fluorescence, and phase-contrast imaging, and can operate with scanning focused beam or full-field acquisition mode. We present an accessible methodology for operando hard X-ray tomography studies, which offer a unique source of 3D spatially resolved characterization data unavailable to contemporary methods.

scholarly journals Spatially Resolved Forming Mechanisms Detection in Single Point Incremental Forming Using Synchrotron Based Texture Analysis

2021 ◽  
Author(s):  
Mateus Dobecki ◽  
Alexander Poeche ◽  
Walter Reimers
Keyword(s):  
Texture Analysis ◽  
Incremental Forming ◽  
Single Point ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Forming Mechanism ◽  
Spatially Resolved ◽  
Step Down ◽  
Stress States

AbstractDespite the ongoing success of understanding the deformation states in sheets manufactured by single-point incremental forming (SPIF), the unawareness of the spatially resolved influence of the forming mechanisms on the residual stress states of incrementally formed sheet metal parts impedes their application-optimized use. In this study, a well-founded experimental proof of the occurring forming mechanisms shear, bending and stretching is presented using spatially resolved, high-energy synchrotron x-ray diffraction-based texture analysis in transmission mode. The measuring method allows even near-surface areas to be examined without any impairment of microstructural influences due to tribological reactions. The depth-resolved texture evolution for different sets of forming parameters offers insights into the forming mechanisms acting in SPIF. Therefore, the forming mechanisms are triggered explicitly by adjusting the vertical step-down increment Δz for groove, plate and truncated cone geometries. The texture analysis reveals that the process parameters and the specimen geometries used lead to characteristic changes in the crystallites’ orientation distribution in the formed parts due to plastic deformation. These forming-induced reorientations of the crystallites could be assigned to the forming mechanisms by means of defined reference states. It was found that for groove, plate and truncated cone geometries, a decreasing magnitude of step-down increments leads to a more pronounced shear deformation, which causes an increasing work hardening especially at the tool contact area of the formed parts. Larger step-down increments, on the other hand, induce a greater bending deformation. The plastic deformation by bending leads to a complex stress field that involves alternating residual tensile stresses on the tool and residual compressive stresses on the tool-averted side incrementally formed sheets. The present study demonstrates the potential of high-energy synchrotron x-ray diffraction for the spatially resolved forming mechanism research in SPIF. Controlling the residual stress states by optimizing the process parameters necessitates knowledge of the fundamental forming mechanism action.

Phase composition depth profiles using spatially resolved energy dispersive X-ray diffraction

2004 ◽  
Vol 37 (6) ◽  
pp. 967-976 ◽  
Author(s):  
Andrew C. Jupe ◽  
Stuart R. Stock ◽  
Peter L. Lee ◽  
Nikhila N. Naik ◽  
Kimberly E. Kurtis ◽  
...  
Keyword(s):  
Phase Composition ◽  
Spatial Resolution ◽  
Zinc Coating ◽  
High Energy ◽  
Sulfate Attack ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spatially Resolved ◽  
Composition Profiles

Spatially resolved energy dispersive X-ray diffraction, using high-energy synchrotron radiation (∼35–80 keV), was used nondestructively to obtain phase composition profiles along the radii of cylindrical cement paste samples to characterize the progress of the chemical changes associated with sulfate attack on the cement. Phase distributions were acquired to depths of ∼4 mm below the specimen surface with sufficient spatial resolution to discern features less than 200 µm thick. The experimental and data analysis methods employed to obtain quantitative composition profiles are described. The spatial resolution that could be achieved is illustrated using data obtained from copper cylinders with a thin zinc coating. The measurements demonstrate that this approach is useful for nondestructively visualizing the sometimes complex transformations that take place during sulfate attack on cement-based materials. These transformations can be spatially related to microstructure as seen by computed microtomography.

Spatially Resolved Suprathermal X-Ray Emission from Laser-Fusion Targets

1980 ◽  
Vol 44 (9) ◽  
pp. 579-582 ◽  
Author(s):  
N. M. Ceglio ◽  
J. T. Larsen
Keyword(s):  
Laser Fusion ◽  
X Ray ◽  
Spatially Resolved

scholarly journals Probing nanoscale behavior of magnetic materials with soft X-ray spectromicroscopy

2012 ◽  
Vol 1 (1) ◽  
pp. 5-15 ◽  
Author(s):  
Peter Fischer ◽  
Charles S. Fadley
Keyword(s):  
Magnetic Properties ◽  
Magnetic Materials ◽  
Spin Dynamics ◽  
Magnetic Nanostructures ◽  
Magnetic Behavior ◽  
Research Area ◽  
X Ray ◽  
Spatially Resolved ◽  
Buried Interfaces ◽  
Analytical Tools

AbstractThe magnetic properties of matter continue to be a vibrant research area driven both by scientific curiosity to unravel the basic physical processes which govern magnetism and the vast and diverse utilization of magnetic materials in current and future devices, e.g., in information and sensor technologies. Relevant length and time scales approach fundamental limits of magnetism and with state-of-the-art synthesis approaches we are able to create and tailor unprecedented properties. Novel analytical tools are required to match these advances and soft X-ray probes are among the most promising ones. Strong and element-specific magnetic X-ray dichroism effects as well as the nanometer wavelength of photons and the availability of fsec short and intense X-ray pulses at upcoming X-ray sources enable unique experimental opportunities for the study of magnetic behavior. This article provides an overview of recent achievements and future perspectives in magnetic soft X-ray spectromicroscopies which permit us to gain spatially resolved insight into the ultrafast spin dynamics and the magnetic properties of buried interfaces of advanced magnetic nanostructures.

Sign in / Sign up

Export Citation Format

Share Document