scholarly journals High-resolution measurements of X-ray emission from dense quasi-1D plasma: Line merging and profile modification

1999 ◽  
Vol 17 (3) ◽  
pp. 365-375 ◽  
Author(s):  
O. RENNER ◽  
P. SONDHAUSS ◽  
O. PEYRUSSE ◽  
E. KROUSKÝ ◽  
R. RAMIS ◽  
...  
Keyword(s):  
Theoretical Data ◽  
Theoretical Models ◽  
Spectral Lines ◽  
Line Profiles ◽  
Plasma Parameters ◽  
X Ray ◽  
Profile Modification ◽  
Spatially Resolved ◽  
Plasma Line ◽  
Band Spectra

The precise measurements of the spectral line profiles near the short-wavelength limit of the Lyman series of Al are reported. The spatially resolved narrow-band spectra were attributed to macroscopic plasma parameters by using the results of 1D and 2D hydrodynamic plasma modeling. The gradual merging and broadening of the spectral lines Al Lyε–θ was compared to the synthetic spectra produced by atomic physics codes. The discrepancies between the experimental and theoretical data indicate the limits for applicability of standard theoretical models.

scholarly journals Investigations concerning plasma parameters and population inversion in laser-produced counterstreaming plasmas

1991 ◽  
Vol 9 (2) ◽  
pp. 501-515 ◽  
Author(s):  
P. Glas ◽  
M. Schnürer
Keyword(s):  
Computational Analysis ◽  
Nuclear Charge ◽  
Gain Coefficient ◽  
Spectral Lines ◽  
Interaction Zone ◽  
Electron Number ◽  
Plasma Parameters ◽  
X Ray ◽  
Spatial Intensity Distribution ◽  
Resonance Transitions

We investigated the case where two laser-produced plasmas collide nearly head on. Special attention was devoted to the fundamentals necessary to realize a coherent X-ray source. A gas-dynamic computational analysis was performed to understand the evolution of the density, the temperature, and the velocity of merging plasmas. The spatial intensity distribution of selected spectral lines reveals that the interaction of plasmas of different nuclear charge and charge state is not strictly collision dominated. Using spectral line intensity ratios, we determined electron temperatures and electron number densities, as well as the intensity inversion on the 4–1 to 3–1 resonance transitions of [He]-like Al. Inversion occurs in the vicinity of the targets if identical materials are used (Al–Al) and is possibly indicated in the interaction zone for different ones (Al–Cu), too. The inversion factors (and the gain coefficient) for the 4–3 transition of [He]-like Al at about 130 Å were estimated.

scholarly journals High-precision measurement of velocity profiles in laser-created chlorine plasma

1995 ◽  
Vol 13 (4) ◽  
pp. 503-510 ◽  
Author(s):  
O. Renner ◽  
E. Krouský ◽  
T. Mißalla ◽  
E. Förster ◽  
G. Hölzer
Keyword(s):  
Spectral Lines ◽  
Plasma Parameters ◽  
High Precision Measurement ◽  
One Dimensional ◽  
Electron Temperature Gradient ◽  
Spatially Resolved ◽  
Doppler Shifts ◽  
Velocity Gradients ◽  
Marquardt Algorithm ◽  
The One

A vertical dispersion variant of the Johann spectrometer has been used to record the highresolution X-ray spectra of the chlorine He-like resonance line group emitted from lowradiance plasma. The emission profiles were measured at two observation angles and decomposed into single spectral lines by using a fit based on the Levenberg-Marquardt algorithm. The results of computerized analysis of the one-dimensional (1-D) spatially resolved spectra were used to evaluate the distribution of the main plasma parameters. The electron temperature gradient 7.5·104 eV cm-1 was computed by modeling the measured spectra with the collisional-radiative package RATION. The blowoff maximum velocities 4.2–6.1·107 cm s-1 and the velocity gradients 0.9–1.6·109 s-1 were determined from the Doppler shifts of individual spectral lines within their different spatial extent.

scholarly journals X-raying winds in distant quasars: The first high-redshift wind duty cycle

2020 ◽  
Vol 638 ◽  
pp. A136
Author(s):  
E. Bertola ◽  
M. Dadina ◽  
M. Cappi ◽  
C. Vignali ◽  
G. Chartas ◽  
...  
Keyword(s):  
Duty Cycle ◽  
High Redshift ◽  
Cosmic Time ◽  
Theoretical Models ◽  
Host Galaxy ◽  
Time Interval ◽  
Absorption Column ◽  
X Ray ◽  
Spatially Resolved ◽  
First Time

Aims. Theoretical models of wind-driven feedback from active galactic nuclei (AGN) often identify ultra-fast outflows as being the main agent in the generation of galaxy-sized outflows, which are possibly the main actors in establishing so-called AGN-galaxy co-evolution. Ultra-fast outflows are well characterized in local AGN but much less is known in quasars at the cosmic time when star formation and AGN activity peaked (z ≃ 1–3). It is therefore necessary to search for evidence of ultra-fast outflows in high-z sources to test wind-driven AGN feedback models. Methods. Here we present a study of Q2237+030, the Einstein Cross, a quadruply-imaged radio-quiet lensed quasar located at z = 1.695. We performed a systematic and comprehensive temporally and spatially resolved X-ray spectral analysis of all the available Chandra and XMM-Newton data (as of September 2019). Results. We find clear evidence for spectral variability, possibly due to absorption column density (or covering fraction) variability intrinsic to the source. For the first time in this quasar, we detect a fast X-ray wind outflowing at vout ≃ 0.1c that would be powerful enough (Ėkin ≃ 0.1 Lbol) to significantly affect the evolution of the host galaxy. We report also on the possible presence of an even faster component of the wind (vout ∼ 0.5c). For the first time in a high-z quasar, given the large sample and long time interval spanned by the analyzed X-ray data, we are able to roughly estimate the wind duty cycle as ≃0.46 (0.31) at 90% (95%) confidence level. Finally, we also confirm the presence of a Fe Kα emission line with variable energy, which we discuss in the light of microlensing effects as well as considering our findings on the source.

scholarly journals Spatially resolved spectroscopy across stellar surfaces

2018 ◽  
Vol 616 ◽  
pp. A144 ◽  
Author(s):  
Dainis Dravins ◽  
Martin Gustavsson ◽  
Hans-Günter Ludwig
Keyword(s):  
Fine Structure ◽  
Disk Center ◽  
Spectral Lines ◽  
Line Profiles ◽  
Small Surface ◽  
Hydrodynamic Simulations ◽  
Link Type ◽  
Spatially Resolved ◽  
Future Potential ◽  
Spatially Resolved Spectroscopy

Context. Spectroscopy across spatially resolved stellar surfaces reveals spectral line profiles free from rotational broadening, whose gradual changes from disk center toward the stellar limb reflect an atmospheric fine structure that is possible to model by 3D hydrodynamics. Aims. Previous studies of photospheric spectral lines across stellar disks exist for the Sun and HD 209458 (G0 V) and are now extended to the planet-hosting HD 189733A to sample a cooler K-type star and explore the future potential of the method. Methods. During exoplanet transit, stellar surface portions successively become hidden and differential spectroscopy between various transit phases uncovers spectra of small surface segments temporarily hidden behind the planet. The method was elaborated in Paper I, in which observable signatures were predicted quantitatively from hydrodynamic simulations. Results. From observations of HD 189733A with the ESO HARPS spectrometer at λ/Δλ~ 115 000, profiles for stronger and weaker Fe I lines are retrieved at several center-to-limb positions, reaching adequate S/N after averaging over numerous similar lines. Conclusions. Retrieved line profile widths and depths are compared to synthetic ones from models with parameters bracketing those of the target star and are found to be consistent with 3D simulations. Center-to-limb changes strongly depend on the surface granulation structure and much greater line-width variation is predicted in hotter F-type stars with vigorous granulation than in cooler K-types. Such parameters, obtained from fits to full line profiles, are realistic to retrieve for brighter planet-hosting stars, while their hydrodynamic modeling offers previously unexplored diagnostics for stellar atmospheric fine structure and 3D line formation. Precise modeling may be required in searches for Earth-analog exoplanets around K-type stars, whose more tranquil surface granulation and lower ensuing microvariability may enable such detections.

scholarly journals A Separation of Systematic and Turbulent Motions in the Narrow-Line Region of NGC 4151

1989 ◽  
Vol 134 ◽  
pp. 352-354
Author(s):  
Hartmut Schulz ◽  
Berto Boer
Keyword(s):  
Radio Source ◽  
Galactic Disk ◽  
Narrow Line ◽  
Line Profiles ◽  
X Ray ◽  
Ngc 4151 ◽  
Spatially Resolved ◽  
Line Region ◽  
Bulk Motion ◽  
Narrow Line Region

Line profiles from the spatially resolved narrow-line region of NGC 4151 are separated into several bulk-motion components which show velocity dispersions two to three times larger than starburst nuclei with similar luminosity. The components are suggested to arise within the galactic disk and by filaments entrained in or situated along the shells of two super-bubbles. The large cone-like SW bubble is able to account for the SW soft-X ray excess and the hole in the NLR disk through which a UV-radiation cone emerges. The bubbles appear to be related to the nuclear radio source.

scholarly journals Density diagnostic of highly ionized samarium laser produced plasma using Ni-like spatially resolved spectra

2011 ◽  
Vol 29 (1) ◽  
pp. 61-67 ◽  
Author(s):  
E. Louzon ◽  
Z. Henis ◽  
I. Levy ◽  
G. Hurvitz ◽  
Y. Ehrlich ◽  
...  
Keyword(s):  
Electron Density ◽  
Ionization State ◽  
Plasma Parameters ◽  
Hydrodynamic Simulations ◽  
X Ray ◽  
Spatially Resolved ◽  
Laser Produced Plasma ◽  
Hebrew University ◽  
Spectroscopic Identification ◽  
Measured Line

AbstractDetailed spectroscopic identification and analysis of lines emitted by Ni-like ions may infer on plasma parameters, such as electron density, temperature, and ionization state. Spatially, resolved X-ray spectra of samarium laser produced plasma were recorded in the 7 to10 Å wavelength range. Measured line intensity ratios of Ni-like 3d-5f, 3p-4d, 3p-4s, and 3s-4p transitions were used for electron density diagnostic as a function of the distance from the target. Calculations using Hebrew University Lawrence Livermore Atomic Code show that these ratios are not very sensitive to the electron temperature in the range from 500 to 1000 eV. Self-absorption of some lines is found to be important at electron densities higher than 1021cm−3. The inferred ranges of electron density and temperature are found to be consistent with results of hydrodynamic simulations and models of ionization in plasma.

scholarly journals Spectroscopic study of plasma produced with a heavy ion maxilac beam

1992 ◽  
Vol 10 (4) ◽  
pp. 737-742 ◽  
Author(s):  
G. E. Belyaev ◽  
B. A. Bryunetkin ◽  
A. A. Golubev ◽  
K. Mahrt-Olt ◽  
I. Y. Skobelev ◽  
...  
Keyword(s):  
Spectroscopic Study ◽  
Electron Impact ◽  
Ionic Composition ◽  
Heavy Ion ◽  
Spectral Lines ◽  
Visible Range ◽  
Plasma Parameters ◽  
X Ray ◽  
Characteristic Emission

Spectroscopic study of plasma produced through bombardment of the 1 × 3 mm2 area on the surface of a solid Mg target with Kr+ ions is carried out. Spectral lines of Mg I and Mg II ions were observed in the visible range (200–600 nm). The plasma parameters Ne = 1.4.1017 cm−3 and Te = 0.8 eV are calculated from electron impact broadening of the 4f–3d line of Mg II and from the ratio of intensities for the 4f–3d and 4s–3p lines of Mg II. The ionic composition of the plasma is determined. The detected X-ray emission is shown to be the characteristic emission of the target.

scholarly journals A New Procedure to Determine the Plasma Parameters from a Genetic Algorithm Coupled with the Spectral Line-Shape Code PPP

Atoms ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 55 ◽  
Author(s):  
Caroline Mossé ◽  
Paul Génésio ◽  
Nelly Bonifaci ◽  
Annette Calisti
Keyword(s):  
Genetic Algorithm ◽  
Spectral Line ◽  
Line Shape ◽  
Stark Effect ◽  
Theoretical Models ◽  
Spectral Lines ◽  
Genetic Operators ◽  
Plasma Parameters ◽  
Spectra Analysis ◽  
Spectral Line Shape

A method of analysis of experimental spectra for obtaining the plasma parameters is presented and discussed. Based on the coupling of the spectral line-shape code PPP with the genetic algorithm PIKAIA, the proposed method is inspired by natural selection mechanisms resulting in the development of basic genetic operators. The spectra analysis is performed by fitting experimental spectra with synthetic spectral line profiles obtained by using theoretical models and a set of plasma parameters, such as its temperature and electron density. In the present paper, the diagnostic procedure based on a genetic algorithm coupled with the PPP code has been used for the analysis of both hydrogen Balmer-β and He I 492.2 nm lines in the helium plasma created by corona discharge. The broadening of these spectral lines due to the Stark effect has been considered, together with the Van der Waals and instrumental broadening.

The Interpretation of Line Profiles

1977 ◽  
Vol 36 ◽  
pp. 191-215
Author(s):  
G.B. Rybicki
Keyword(s):  
Magnetic Fields ◽  
Atomic Physics ◽  
Velocity Fields ◽  
Spectral Lines ◽  
Inhomogeneous Structure ◽  
The Sun ◽  
Line Profiles ◽  
Physical Phenomena

Observations of the shapes and intensities of spectral lines provide a bounty of information about the outer layers of the sun. In order to utilize this information, however, one is faced with a seemingly monumental task. The sun’s chromosphere and corona are extremely complex, and the underlying physical phenomena are far from being understood. Velocity fields, magnetic fields, Inhomogeneous structure, hydromagnetic phenomena – these are some of the complications that must be faced. Other uncertainties involve the atomic physics upon which all of the deductions depend.

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