Coronal plasma parameters in a long-duration X-ray event observed by SKYLAB

1977 ◽  
Vol 212 ◽  
pp. 550 ◽  
Author(s):  
J. A. Vorpahl ◽  
E. Tandberg-Hanssen ◽  
J. B., Jr. Smith
Keyword(s):  
Coronal Plasma ◽  
Plasma Parameters ◽  
X Ray ◽  
Long Duration

scholarly journals Plasma Parameters and Structures of the X4 Flare of 19 May 1984 as Observed by SMM-XRP

1989 ◽  
Vol 104 (2) ◽  
pp. 165-168
Author(s):  
J.T. Schmelz ◽  
J.L.R. Saba ◽  
K.T. Strong
Keyword(s):  
Solar Maximum ◽  
Coronal Plasma ◽  
The Sun ◽  
Plasma Parameters ◽  
Crystal Spectrometer ◽  
Solar Maximum Mission ◽  
X Ray ◽  
Bent Crystal ◽  
East Limb ◽  
Large Flare

AbstractThe eruption of a large flare on the east limb of the Sun was observed by the X-Ray Polychromator (XRP) on board the Solar Maximum Mission (SMM) on 19 May 1984. The XRP Flat Crystal Spectrometer (FCS) made polychromatic soft X-ray images during the preflare, flare and postflare phases. The XRP Bent Crystal Spectrometer (BCS) provided information on the temperature and dynamics of the hot (Te > 8 x 106K) coronal plasma from spectra integrated spatially over the whole region.

ASCAObservation of a Long‐Duration X‐Ray Flare from the W UMa–Type Binary VW Cephei

1998 ◽  
Vol 492 (2) ◽  
pp. 761-766 ◽  
Author(s):  
C. S. Choi ◽  
T. Dotani
Keyword(s):  
X Ray ◽  
Long Duration

Long duration X-ray flash from low mass population III stars

2012 ◽  
Author(s):  
Daisuke Nakauchi ◽  
Yudai Suwa ◽  
Kazumi Kashiyama ◽  
Takashi Nakamura
Keyword(s):  
X Ray ◽  
Long Duration ◽  
Low Mass ◽  
Population Iii Stars ◽  
Population Iii

Determination of the plasma parameters in the PF-3 facility by the methods of X-ray spectroscopy

2011 ◽  
Vol 37 (11) ◽  
pp. 935-947 ◽  
Author(s):  
E. O. Baronova ◽  
V. P. Vinogradov ◽  
V. I. Krauz ◽  
V. V. Myalton ◽  
A. M. Stepanenko ◽  
...  
Keyword(s):  
Plasma Parameters ◽  
X Ray

Isolated Sunspot with a Dark Patch in the Coronal Emission

2012 ◽  
Vol 21 (4) ◽  
Author(s):  
D. A. Bezrukov ◽  
B. I. Ryabov ◽  
K. Shibasaki
Keyword(s):  
Active Region ◽  
Normal Mode ◽  
Plasma Density ◽  
Specific Region ◽  
The Sun ◽  
Coronal Emission ◽  
Plasma Parameters ◽  
X Ray ◽  
Dark Patch ◽  
Chromospheric Line

AbstractOn the base of the 17 GHz radio maps of the Sun taken with the Nobeyama Radio Heliograph we estimate plasma parameters in the specific region of the sunspot atmosphere in the active region AR 11312. This region of the sunspot atmosphere is characterized by the depletion in coronal emission (soft X-ray and EUV lines) and the reduced absorption in the a chromospheric line (He I 1.083 μm). In the ordinary normal mode of 17 GHz emission the corresponding dark patch has the largest visibility near the central solar meridian. We infer that the reduced coronal plasma density of about ~ 5 × 10

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 Early neutron star evolution in high-mass X-ray binaries

2020 ◽  
Vol 494 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Wynn C G Ho ◽  
M J P Wijngaarden ◽  
Nils Andersson ◽  
Thomas M Tauris ◽  
F Haberl
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Thermal Emission ◽  
Equilibrium Phase ◽  
High Mass ◽  
X Ray ◽  
Spin Period ◽  
Long Duration ◽  
X Ray Binaries ◽  
The Magnetic Field

ABSTRACT The application of standard accretion theory to observations of X-ray binaries provides valuable insights into neutron star (NS) properties, such as their spin period and magnetic field. However, most studies concentrate on relatively old systems, where the NS is in its late propeller, accretor, or nearly spin equilibrium phase. Here, we use an analytic model from standard accretion theory to illustrate the evolution of high-mass X-ray binaries (HMXBs) early in their life. We show that a young NS is unlikely to be an accretor because of the long duration of ejector and propeller phases. We apply the model to the recently discovered ∼4000 yr old HMXB XMMU J051342.6−672412 and find that the system’s NS, with a tentative spin period of 4.4 s, cannot be in the accretor phase and has a magnetic field B > a few × 1013 G, which is comparable to the magnetic field of many older HMXBs and is much higher than the spin equilibrium inferred value of a few × 1011 G. The observed X-ray luminosity could be the result of thermal emission from a young cooling magnetic NS or a small amount of accretion that can occur in the propeller phase.

scholarly journals Study of pure and mixed clustered noble gas puffs irradiated with a high intensity (7 × 1019 W/cm2) sub-ps laser beam and achievement of a strong X-ray flash in a laser-generated debris-free X-ray source

2019 ◽  
Vol 37 (03) ◽  
pp. 276-287
Author(s):  
K. A. Schultz ◽  
V. L. Kantsyrev ◽  
A. S. Safronova ◽  
V. V. Shlyaptseva ◽  
E. E. Petkov ◽  
...  
Keyword(s):  
Laser Beam ◽  
Noble Gas ◽  
Lawrence Livermore National Laboratory ◽  
National Laboratory ◽  
Experimental Parameter ◽  
Mixed Gas ◽  
Plasma Parameters ◽  
X Ray ◽  
Drastic Increase ◽  
Degree Of Anisotropy

AbstractWe present a broad study of linear, clustered, noble gas puffs irradiated with the frequency doubled (527 nm) Titan laser at Lawrence Livermore National Laboratory. Pure Ar, Kr, and Xe clustered gas puffs, as well as two mixed-gas puffs consisting of KrAr and XeKrAr gases, make up the targets. Characterization experiments to determine gas-puff density show that varying the experimental parameter gas-delay timing (the delay between gas puff initialization and laser-gas-puff interaction) provides a simple control over the gas-puff density. X-ray emission (>1.4 keV) is studied as a function of gas composition, density, and delay timing. Xe gas puffs produce the strongest peak radiation in the several keV spectral region. The emitted radiation was found to be anisotropic, with smaller X-ray flux observed in the direction perpendicular to both laser beam propagation and polarization directions. The degree of anisotropy is independent of gas target type but increases with photon energy. X-ray spectroscopic measurements estimate plasma parameters and highlight their difference with previous studies. Electron beams with energy in excess of 72 keV are present in the noble gas-puff plasmas and results indicate that Ar plays a key role in their production. A drastic increase in harder X-ray emissions (X-ray flash effect) and multi-MeV electron-beam generation from Xe gas-puff plasma occurred when the laser beam was focused on the front edge of the linear gas puff.

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