X-Ray and Extreme Ultraviolet Emission from Comets

Comets II ◽  
2004 ◽  
pp. 631-644
Author(s):  
C. M. Lisse ◽  
T. E. Cravens ◽  
K. Dennerl
Keyword(s):  
Extreme Ultraviolet ◽  
Ultraviolet Emission ◽  
X Ray

scholarly journals Extreme Ultraviolet Spectroscopy of Magnetic Cataclysmic Variables

1996 ◽  
Vol 152 ◽  
pp. 309-316
Author(s):  
Frits Paerels ◽  
Min Young Hur ◽  
Christopher W. Mauche
Keyword(s):  
High Resolution ◽  
White Dwarf ◽  
Extreme Ultraviolet ◽  
Cataclysmic Variables ◽  
Ultraviolet Spectroscopy ◽  
Temperature Structure ◽  
Polar Cap ◽  
Ultraviolet Emission ◽  
X Ray ◽  
Magnetic Cataclysmic Variables

A longstanding problem in the interpretation of the X-ray and extreme ultraviolet emission from strongly magnetic cataclysmic variables can be addressed definitively with high resolution EUV spectroscopy. A detailed photospheric spectrum of the accretion-heated polar cap of the white dwarf is sensitive in principle to the temperature structure of the atmosphere. This may allow us to determine where and how the bulk of the accretion energy is thermalized. The EUVE data on AM Herculis and EF Eridani are presented and discussed in this context.

scholarly journals X-ray and extreme-ultraviolet emission from the coronae of Capella

2001 ◽  
Vol 325 (4) ◽  
pp. 1500-1510 ◽  
Author(s):  
K. J. H. Phillips ◽  
M. Mathioudakis ◽  
D. P. Huenemoerder ◽  
D. R. Williams ◽  
M. E. Phillips ◽  
...  
Keyword(s):  
Extreme Ultraviolet ◽  
Ultraviolet Emission ◽  
X Ray

scholarly journals Influence of Pre-Ionized Plasma on the Dynamics of a Tin Laser-Triggered Discharge-Plasma

2019 ◽  
Vol 9 (23) ◽  
pp. 4981
Author(s):  
Xu ◽  
Deng ◽  
Tian ◽  
Zhao ◽  
Wang
Keyword(s):  
Steady State ◽  
Discharge Plasma ◽  
Extreme Ultraviolet ◽  
Spectral Purity ◽  
Ultraviolet Emission ◽  
X Ray ◽  
Euv Emission ◽  
Current Voltage ◽  
Steady State Time ◽  
Temperature Ranges

The effect of laser-current delay on extreme ultraviolet emission by laser-triggered discharge-plasma has been investigated. Typical waveforms for current, voltage, laser signals, and X-ray signals have been compared. Theoretical tin spectra were simulated among the electron temperature ranges from 10 to 50 eV to compare with the experimental results. The results show that longer laser-current delay time is propitious to increase the steady-state time of plasma at high temperatures, and it increases the intensity and spectral purity of 13.5 nm emission in 2% band. The 13.5 nm radiation intensity increases about 120% with the delay increasing from 0.7 to 5 μs, and the extreme ultraviolet (EUV) emission conversion efficiency (CE) increases from 0.5% to 1.1%.

A Discussion on solar studies with special reference to space observations - Extreme ultraviolet emission during flares

1971 ◽  
Vol 270 (1202) ◽  
pp. 117-125 ◽  
Keyword(s):  
Extreme Ultraviolet ◽  
Suitable Model ◽  
X Rays ◽  
Radio Waves ◽  
Ultraviolet Emission ◽  
Magnetic Instability ◽  
X Ray ◽  
Time Profiles ◽  
Peak Flux ◽  
Cool Plasma

A number of time profiles are presented which show how the flux of radiation in the wavelength bands 0.1 to 0.3 nm, 0.3 to 0.9 nm, 0.8 to 1.6 nm and at 30.4 nm change during flares. The first sign of a flare is often a decrease of flux at 30.4 nm followed by an increase in the X-ray emission. In general, the higher the photon energy, the earlier the peak flux is reached, although any increase observed at 30.4 nm seems to peak before the X -ray flux. It is concluded that a model in which a mass of gas in the upper chromosphere is heated by shock waves or incident energetic particles does not explain the observations. What appears to be a more suitable model is suggested. Cool plasma from low in the chromosphere passes through a region of magnetic instability and is heated during the passage. In this way the material of the X -ray emitting region is heated to a high tem perature a little at a time. The intensity of X-rays observed in each waveband is proportional to the volume of gas produced up to that time at the corresponding tem perature. As the instability decays the gas passing through it can no longer be heated to the temperatures reached earlier and the emission of longer wavelength X-rays becomes dominant. The emission of y -rays and radio waves can also be explained

scholarly journals Discovery of X-ray and Extreme Ultraviolet Emission from Comet C/Hyakutake 1996 B2

Science ◽  
1996 ◽  
Vol 274 (5285) ◽  
pp. 205-209 ◽  
Author(s):  
C. M. Lisse ◽  
K. Dennerl ◽  
J. Englhauser ◽  
M. Harden ◽  
F. E. Marshall ◽  
...  
Keyword(s):  
Extreme Ultraviolet ◽  
Ultraviolet Emission ◽  
X Ray

scholarly journals SPH Simulations of Galaxy Cluster Mergers

2003 ◽  
Vol 208 ◽  
pp. 453-454
Author(s):  
Motokazu Takizawa
Keyword(s):  
Thermal Emission ◽  
Extreme Ultraviolet ◽  
Galaxy Cluster ◽  
The Other ◽  
Relativistic Electrons ◽  
Ultraviolet Emission ◽  
X Ray ◽  
Temperature Distributions ◽  
Cluster Mergers ◽  
Shock Fronts

We present our results of SPH simulations of cluster mergers. We investigate the temperature evolution explicitly considering the relaxation process between ions and electrons. The electron temperature distributions are significantly different than those of ions in the later stages of mergers. We also investigate evolution of non-thermal emission from relativistic electrons accelerated around shock fronts. Hard X-ray is luminous only while signatures of merging events are clearly seen in the thermal intracluster medium. On the other hand, extreme ultraviolet emission is still luminous after the system has relaxed.

A possible heating mechanism for the X-ray-emitting plasma within clusters of galaxies

2013 ◽  
Vol 79 (4) ◽  
pp. 447-450
Author(s):  
R. BINGHAM ◽  
B. J. KELLETT ◽  
U. DE ANGELIS ◽  
V. N. TSYTOVICH ◽  
P. K. SHUKLA
Keyword(s):  
Thermal Emission ◽  
Extreme Ultraviolet ◽  
Energy Content ◽  
Self Organization ◽  
Clusters Of Galaxies ◽  
Ultraviolet Emission ◽  
X Ray ◽  
Heating Mechanism ◽  
Hot Plasma ◽  
Thermal Energy Content

AbstractX-ray and extreme ultraviolet emission from galaxy clusters can be interpreted as thermal emission from a hot plasma gravitationally bound to the cluster and constituting a significant amount of the mass of the cluster. The origin of this plasma and its thermal energy content can be linked to the formation process through the theory of self-organization of these structures.

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