Theoretical predictions for the polarization of X-ray laser lines in the presence of a directed beam of hot electrons

2001 ◽  
Vol 11 (PR2) ◽  
pp. Pr2-277-Pr2-283 ◽  
Author(s):  
J. Dubau ◽  
M. K. Inal ◽  
D. Benredjem ◽  
M. Cornille
Keyword(s):  
Hot Electrons ◽  
X Ray ◽  
Theoretical Predictions

scholarly journals Hot gaseous atmospheres of rotating galaxies observed with XMM–Newton

2020 ◽  
Vol 499 (4) ◽  
pp. 5163-5174
Author(s):  
A Juráňová ◽  
N Werner ◽  
P E J Nulsen ◽  
M Gaspari ◽  
K Lakhchaura ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Active Galactic Nuclei ◽  
Spiral Galaxy ◽  
Galactic Nuclei ◽  
X Ray ◽  
Hot Gas ◽  
Heating And Cooling ◽  
Theoretical Predictions ◽  
Central Regions ◽  
Gaseous Atmospheres

ABSTRACT X-ray emitting atmospheres of non-rotating early-type galaxies and their connection to central active galactic nuclei have been thoroughly studied over the years. However, in systems with significant angular momentum, processes of heating and cooling are likely to proceed differently. We present an analysis of the hot atmospheres of six lenticulars and a spiral galaxy to study the effects of angular momentum on the hot gas properties. We find an alignment between the hot gas and the stellar distribution, with the ellipticity of the X-ray emission generally lower than that of the optical stellar emission, consistent with theoretical predictions for rotationally supported hot atmospheres. The entropy profiles of NGC 4382 and the massive spiral galaxy NGC 1961 are significantly shallower than the entropy distribution in other galaxies, suggesting the presence of strong heating (via outflows or compressional) in the central regions of these systems. Finally, we investigate the thermal (in)stability of the hot atmospheres via criteria such as the TI- and C-ratio, and discuss the possibility that the discs of cold gas present in these objects have condensed out of the hot atmospheres.

scholarly journals Determination of the Height of Hard X-Ray Sources in the Solar Atmosphere by Measurement of Photospheric Albedo Photons

1975 ◽  
Vol 68 ◽  
pp. 239-241
Author(s):  
John C. Brown ◽  
H. F. Van Beek
Keyword(s):  
Solar Atmosphere ◽  
The Other ◽  
X Ray ◽  
Theoretical Predictions ◽  
Source Models ◽  
The One

SummaryThe importance and difficulties of determining the height of hard X-ray sources in the solar atmosphere, in order to distinguish source models, have been discussed by Brown and McClymont (1974) and also in this Symposium (Brown, 1975; Datlowe, 1975). Theoretical predictions of this height, h, range between and 105 km above the photosphere for different models (Brown and McClymont, 1974; McClymont and Brown, 1974). Equally diverse values have been inferred from observations of synchronous chromospheric EUV bursts (Kane and Donnelly, 1971) on the one hand and from apparently behind-the-limb events (e.g. Datlowe, 1975) on the other.

Polydomain Structure of Epitaxial PbTiO3 films on MgO

1997 ◽  
Vol 493 ◽  
Author(s):  
S. P. Alpay ◽  
A. S. Prakash ◽  
S. Aggarwal ◽  
R. Ramesh ◽  
A. L. Roytburd ◽  
...  
Keyword(s):  
Domain Structure ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Theoretical Predictions ◽  
The Stability ◽  
Increasing Temperature ◽  
Stable Domains ◽  
Domain Stability

ABSTRACTA PbTiO3(001) film grown on MgO(001) by pulsed laser deposition is examined as an example to demonstrate the applications of the domain stability map for epitaxial perovskite films which shows regions of stable domains and fractions of domains in a polydomain structure. X-ray diffraction studies indicate that the film has a …c/a/c/a… domain structure in a temperature range of °C to 400°C with the fraction of c-domains decreasing with increasing temperature. These experimental results are in excellent agreement with theoretical predictions based on the stability map.

Time-dependent X-ray polarization analysis for anisotropic distribution of hot electrons in ultrahigh intensity laser plasmas

2007 ◽  
Vol 3 (1-2) ◽  
pp. 131-135 ◽  
Author(s):  
T. Kai ◽  
T. Kawamura ◽  
Y. Inubushi ◽  
H. Nishimura ◽  
T. Nakamura ◽  
...  
Keyword(s):  
Time Dependent ◽  
Hot Electrons ◽  
Polarization Analysis ◽  
X Ray ◽  
Laser Plasmas ◽  
Intensity Laser

X‐ray tomography of hot electrons in the barrier region of the tandem mirror GAMMA 10

1990 ◽  
Vol 67 (4) ◽  
pp. 1694-1699 ◽  
Author(s):  
T. Kondoh ◽  
T. Cho ◽  
M. Hirata ◽  
N. Yamaguchi ◽  
T. Saito ◽  
...  
Keyword(s):  
Hot Electrons ◽  
X Ray ◽  
Tandem Mirror ◽  
Barrier Region

scholarly journals Influence of hot electrons on the spectra of iron plasma irradiated by femtosecond laser pulses with 1021 W/cm2 intensities

2017 ◽  
Vol 35 (1) ◽  
pp. 92-99 ◽  
Author(s):  
A. Stafford ◽  
A.S. Safronova ◽  
A.Ya. Faenov ◽  
T.A. Pikuz ◽  
R. Kodama ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Time Frame ◽  
Femtosecond Laser Pulses ◽  
Hot Electrons ◽  
Plasma Radiation ◽  
X Ray ◽  
Laser Plasma Interaction ◽  
Multiply Charged ◽  
Interaction Experiment ◽  
Charged Ions

AbstractThe use of laboratory experiments as plasma creating sources is a valuable tool for understanding astrophysical observations. Recently plasma created through irradiation by lasers with relativistic intensities has been used to study effects of hot electrons and X-ray pumping on X-ray formation of multiply charged ions spectra. This paper discusses the formation of K-shell Fe spectra recorded from a plasma irradiated by 35 fs pulses with intensities of 1021 W/cm2. Modeling of the spectra suggests three different regions of plasma radiation including a cold ~10 eV region, a mild ~700 eV region, and a hot ~3500 eV region. The influence of hot electrons and X-ray pumping is discussed and a comparison with K-shell Fe spectra from a 1 MA X-pinch experiment is included to highlight the differences due to the shorter time frame of the laser–plasma interaction experiment.

scholarly journals The Close AGN Reference Survey (CARS)

2018 ◽  
Vol 618 ◽  
pp. A27 ◽  
Author(s):  
M. C. Powell ◽  
B. Husemann ◽  
G. R. Tremblay ◽  
M. Krumpe ◽  
T. Urrutia ◽  
...  
Keyword(s):  
Ambient Medium ◽  
Theoretical Models ◽  
Ionized Gas ◽  
X Ray ◽  
Gas Streams ◽  
Hot Gas ◽  
Upper Limits ◽  
Theoretical Predictions ◽  
Different Origins

Aims. We probe the radiatively-efficient, hot wind feedback mode in two nearby luminous unobscured (type 1) AGN from the Close AGN Reference Survey (CARS), which show intriguing kpc-scale arc-like features of extended [O III]ionized gas as mapped with VLT-MUSE. We aimed to detect hot gas bubbles that would indicate the existence of powerful, galaxy-scale outflows in our targets, HE 0227–0931 and HE 0351+0240, from deep (200 ks) Chandra observations. Methods. By measuring the spatial and spectral properties of the extended X-ray emission and comparing with the sub kpc-scale IFU data, we are able to constrain feedback scenarios and directly test if the ionized gas is due to a shocked wind. Results. No extended hot gas emission on kpc-scales was detected. Unless the ambient medium density is low (n H  ∼  1 cm−3 at 100 pc), the inferred upper limits on the extended X-ray luminosities are well below what is expected from theoretical models at matching AGN luminosities. Conclusions. We conclude that the highly-ionized gas structures on kpc scales are not inflated by a hot outflow in either target, and instead are likely caused by photoionization of pre-existing gas streams of different origins. Our nondetections suggest that extended X-ray emission from an AGN-driven wind is not universal, and may lead to conflicts with current theoretical predictions.

scholarly journals Universal nature of collapsibility in the context of protein folding and evolution

2018 ◽  
Author(s):  
D. Thirumalai ◽  
Himadri S. Samanta ◽  
Hiranmay Maity ◽  
Govardhan Reddy
Keyword(s):  
Single Molecule ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Saxs Data ◽  
X Ray ◽  
Model Free ◽  
X Ray Scattering ◽  
Theoretical Predictions ◽  
Helical Proteins ◽  
Universal Nature

AbstractTheory and simulations predicted sometime ago that the sizes of unfolded states of globular proteins should decrease continuously as the denaturant concentration is shifted from a high to a low value. However, small angle X-ray scattering (SAXS) data were used to assert the opposite, while interpretation of single molecule Forster resonance energy transfer experiments (FRET) supported the theoretical predictions. The disagreement between the two experiments is the SAXS-FRET controversy. By harnessing recent advances in SAXS and FRET experiments and setting these findings in the context of a general theory and simulations, we establish that compaction of unfolded states is universal. The theory also predicts that proteins rich in β-sheets are more collapsible than α-helical proteins. Because the extent of compaction is small, experiments have to be accurate and their interpretations should be as model free as possible. Theory also suggests that collapsibility itself could be a physical restriction on the evolution of foldable sequences, and provides a physical basis for the origin of multi-domain proteins.

scholarly journals Colliding Winds in Symbiotic Systems

1988 ◽  
Vol 103 ◽  
pp. 129-136
Author(s):  
Sun Kwok
Keyword(s):  
Observational Data ◽  
X Ray ◽  
Spectral Behaviour ◽  
Theoretical Predictions ◽  
Colliding Winds

AbstractThe physics of colliding winds in symbiotic systems is reviewed. The theoretical predictions are compared with observational data of symbiotic novae, in particular the recently erupted system HM Sge. It is suggested that the spectral behaviour of HM Sge from X-ray to radio can be explained by the colliding winds process.

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