A Quadruple Magnetic Source Model for Arcade Flares and X‐Ray Arcade Formations outside Active Regions. II. Dark Filament Eruption and the Associated Arcade Flare

2001 ◽  
Vol 551 (1) ◽  
pp. 586-596 ◽  
Author(s):  
S. Hirose ◽  
Y. Uchida ◽  
S. Uemura ◽  
T. Yamaguchi ◽  
S. B. Cable
Keyword(s):  
Active Regions ◽  
Source Model ◽  
X Ray ◽  
Filament Eruption ◽  
Magnetic Source ◽  
Dark Filament

scholarly journals MHD Simulation of Dark Filament Eruption in the Quadrupole Source Model

1998 ◽  
Vol 167 ◽  
pp. 384-387 ◽  
Author(s):  
Y. Uchida ◽  
S. Hirose ◽  
S. Cable ◽  
S. Uemura ◽  
K. Fujisaki ◽  
...  
Keyword(s):  
Classical Model ◽  
Source Model ◽  
Mhd Simulation ◽  
Filament Eruption ◽  
Magnetohydrodynamic Simulation ◽  
Characteristic Features ◽  
Dark Filament

AbstractA magnetohydrodynamic simulation in a 2.5D approximation is performed for the quadrupole source model for arcade flares treated years ago by Uchida (1980), and recently supported by the observations from Yohkoh. It is shown that this model can explain several key characteristic features of arcade flares found by Yohkoh, and can avoid some of the paradoxes existing in the “classical model”.

scholarly journals Interpretation of the X-Ray Spectra of Solar Active Regions

1975 ◽  
Vol 68 ◽  
pp. 73-100 ◽  
Author(s):  
Arthur B. C. Walker
Keyword(s):  
Transition Region ◽  
Rate Constant ◽  
Active Regions ◽  
Temperature Structure ◽  
Spectroscopic Techniques ◽  
Density Structure ◽  
Coronal Temperature ◽  
X Ray ◽  
Euv Spectrum

This paper presents a review of recent analytical studies of the coronal X-ray spectrum below 25 Å. The techniques used to compute the theoretical coronal spectrum, and the currently available atomic rate constant data are reviewed first. Spectroscopic techniques which have been proposed for the determination of coronal temperature and density structure, and the results derived from their application to coronal spectra are also reviewed.A number of coronal models based on X-ray observations have been developed recently, and the coronal temperature structure and composition predicted by these models is discussed, and compared with models of the corona and transition region derived from studies of the solar EUV spectrum.

scholarly journals Testing a double AGN hypothesis for Mrk 273

2018 ◽  
Vol 611 ◽  
pp. A71 ◽  
Author(s):  
K. Iwasawa ◽  
V. U ◽  
J. M. Mazzarella ◽  
A. M. Medling ◽  
D. B. Sanders ◽  
...  
Keyword(s):  
Alternative Explanation ◽  
Source Model ◽  
Spectral Slope ◽  
Line Flux ◽  
Ionized Gas ◽  
X Ray ◽  
Gas Kinematics ◽  
N Source ◽  
Seyfert Nucleus ◽  
Luminous Infrared Galaxy

The ultra-luminous infrared galaxy (ULIRG) Mrk 273 contains two infrared nuclei, N and SW, separated by 1 arcsecond. A Chandra observation has identified the SW nucleus as an absorbed X-ray source with NH ~ 4 × 1023 cm−2 but also hinted at the possible presence of a Compton-thick AGN in the N nucleus, where a black hole of ~109 M⊙ is inferred from the ionized gas kinematics. The intrinsic X-ray spectral slope recently measured by NuSTAR is unusually hard (Γ ~ 1.3) for a Seyfert nucleus, for which we seek an alternative explanation. We hypothesize a strongly absorbed X-ray source in N, of which X-ray emission rises steeply above 10 keV, in addition to the known X-ray source in SW, and test it against the NuSTAR data, assuming the standard spectral slope (Γ = 1.9). This double X-ray source model gives a good explanation of the hard continuum spectrum, deep Fe K absorption edge, and strong Fe K line observed in this ULIRG, without invoking the unusual spectral slope required for a single source interpretation. The putative X-ray source in N is found to be absorbed by NH = 1.4+0.7−0.4 × 1024 cm−2. The estimated 2−10 keV luminosity of the N source is 1.3 × 1043 erg s−1, about a factor of 2 larger than that of SW during the NuSTAR observation. Uncorrelated variability above and below 10 keV between the Suzaku and NuSTAR observations appears to support the double source interpretation. Variability in spectral hardness and Fe K line flux between the previous X-ray observations is also consistent with this picture.

scholarly journals X-Ray Spectra of Solar Active Regions

1975 ◽  
Vol 68 ◽  
pp. 45-64 ◽  
Author(s):  
John H. Parkinson
Keyword(s):  
Spectral Resolution ◽  
Active Regions ◽  
X Ray ◽  
Quantitative Theory ◽  
Great Progress ◽  
Solar Active Regions ◽  
Cascading Processes ◽  
Weak Satellite

The last few years have seen great progress in our understanding of X-ray spectra of solar active regions. This paper demonstrates both the usefulness and the limitations of the techniques, both scientific and instrumental, that have recently become available. Improvements in spectral resolution led to the discovery of weak satellite lines to helium-like ions; the quantitative theory for these lines is also discussed. The observed intensities of the Fe XVII lines are also investigated and found to be in agreement with calculations that allow for cascading processes.

scholarly journals Statistical Properties of Magnetic Separators in Model Active Regions

2000 ◽  
Vol 195 ◽  
pp. 443-444
Author(s):  
B. T. Welsch ◽  
D. W. Longcope
Keyword(s):  
Active Region ◽  
Solar Corona ◽  
Magnetic Reconnection ◽  
First Principles ◽  
Magnetic Charge ◽  
Active Regions ◽  
Heating Rates ◽  
X Ray ◽  
Field Lines ◽  
Charge Topology

“Transient brightenings” (or “microflares”) regularly deposit 1027 ergs of energy in the solar corona, and account for perhaps 20% of the active corona's power (Shimizu 1995). We assume these events correspond to episodes of magnetic reconnection along magnetic separators in the solar corona. Using the techniques of magnetic charge topology, we model active region fields as arising from normally distributed collections of “magnetic charges”, point-like sources/sinks of flux (or field lines). Here, we present statistically determined separator (X-ray loop) lengths, derived from first principles. We are in the process of statistical calculations of heating rates due to reconnection events along many separators.

X-Ray and microwave observations of active regions

Solar Physics ◽  
1983 ◽  
Vol 85 (2) ◽  
pp. 267-283 ◽  
Author(s):  
D. F. Webb ◽  
J. M. Davis ◽  
M. R. Kundu ◽  
T. Velusamy
Keyword(s):  
Active Regions ◽  
X Ray
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