scholarly journals White-light continuum emission from a solar flare and plage

2015 ◽  
Vol 11 (S320) ◽  
pp. 268-277
Author(s):  
Arkadiusz Berlicki ◽  
Arun Kumar Awasthi ◽  
Petr Heinzel ◽  
Michal Sobotka
Keyword(s):  
Active Region ◽  
Solar Flare ◽  
White Light ◽  
Temporal Evolution ◽  
Continuum Emission ◽  
White Light Continuum ◽  
Multi Wavelength ◽  
Optical Continuum ◽  
The Continuum ◽  
Morphological Correlation

AbstractObservations of flare emissions in the optical continuum are very rare. Therefore, the analysis of such observations is useful and may contribute to our understanding of the flaring chromosphere and photosphere. We study the white light continuum emission observed during the X6.9 flare. This emission comes not only from the flare ribbons but also form the nearby plage area. The main aim of this work is to disentangle the flare and plage (facula) emission. We analyzed the spatial, spectral and temporal evolution of the flare and plage properties by analyzing multi-wavelength observations. We study the morphological correlation of the white-light continuum emission observed with different instruments. We found that some active region areas which produce the continuum emission correspond rather to plages than to the flare kernels. We showed that in some cases the continuum emission from the WL flare kernels is very similar to the continuum emission of faculae.

scholarly journals White-light continuum in stellar flares

2015 ◽  
Vol 11 (S320) ◽  
pp. 259-267 ◽  
Author(s):  
Adam F. Kowalski
Keyword(s):  
White Light ◽  
High Energy ◽  
Continuum Emission ◽  
Nonthermal Electrons ◽  
White Light Continuum ◽  
Optical Wavelength ◽  
Near Ultraviolet ◽  
Stellar Flares ◽  
Optical Continuum ◽  
M Dwarf

AbstractIn this talk, we discuss the formation of the near-ultraviolet and optical continuum emission in M dwarf flares through the formation of a dense, heated chromospheric condensation. Results are used from a recent radiative-hydrodynamic model of the response of an M dwarf atmosphere to a high energy flux of nonthermal electrons. These models are used to infer the charge density and optical depth in continuum emitting flare layers from spectra covering the Balmer jump and optical wavelength regimes. Future modeling and observational directions are discussed.

Gamma-ray observational constraints on the origin of the optical continuum emission from the white-light flare of 1980 July 1

1983 ◽  
Vol 272 ◽  
pp. L61 ◽  
Author(s):  
J. M. Ryan ◽  
E. L. Chupp ◽  
D. J. Forrest ◽  
S. M. Matz ◽  
E. Rieger ◽  
...  
Keyword(s):  
White Light ◽  
Gamma Ray ◽  
Continuum Emission ◽  
Observational Constraints ◽  
Optical Continuum

scholarly journals Spectral Analysis of a White Light Flare

1989 ◽  
Vol 104 (2) ◽  
pp. 247-250
Author(s):  
Boyer R. ◽  
Sotirovski P.
Keyword(s):  
Spectral Analysis ◽  
Solar Flare ◽  
Electron Density ◽  
White Light ◽  
Time Profile ◽  
Crimean Astrophysical Observatory ◽  
Stark Broadening ◽  
Emission Mechanism ◽  
Measured Time ◽  
The Continuum

AbstractWe discuss observations of a solar flare located close to the limb (N15, W75) at 07 00 UT on 26 September 1963 from the Crimean Astrophysical observatory.Stark broadening and hence electron density have been obtained from measured time profile and half-width of the Baliner series lines from Hα to H M.The emission mechanism has been deduced from a study of the continuum intensity as a function of wavelength.

scholarly journals State-of-the-Art Observations and Modeling of Stellar Flares

2012 ◽  
Vol 10 (H16) ◽  
pp. 99-100
Author(s):  
Adam F. Kowalski ◽  
Suzanne L. Hawley
Keyword(s):  
White Light ◽  
Binary Systems ◽  
Light Emission ◽  
Continuum Emission ◽  
M Dwarfs ◽  
Time Resolved ◽  
Color Distribution ◽  
Nonthermal Electrons ◽  
White Light Continuum ◽  
Stellar Flares

Flares are observed on a wide variety of stellar types, ranging from closely orbiting binary systems consisting of an evolved member (RS CVn's) and young, nearby super-active M dwarfs (dMe's). The timescales and energies of flares span many orders of magnitude and typically far exceed the scales of even the largest solar flares observed. In particular, the active M dwarfs produce an energetic signature in the near-UV and optical continuum, which is often referred to as the white-light continuum. White-light emission has been studied in Johnson UBVR filters during a few large-amplitude flares, and the best emission mechanism that fits the broadband color distribution is a T~104 K blackbody (Hawley & Fisher 1992). Time-resolved blue spectra have revealed a consistent picture, with little or no Balmer jump and a smoothly rising continuum toward the near-UV (Hawley & Pettersen 1991). However, the most recent self-consistent radiative-hydrodynamic (RHD) models, which use a solar-type flare heating function from accelerated, nonthermal electrons, do not reproduce this emission spectrum. Instead, these models predict that the white-light is dominated by Balmer continuum emission from Hydrogen recombination in the chromosphere (Allred et al. 2006). Moreover, Allred et al. (2006) showed that the Johnson colors of the model prediction exhibit a broadband distribution similar to a blackbody with T~9000 K.

scholarly journals TEMPORAL EVOLUTION AND SPATIAL DISTRIBUTION OF WHITE-LIGHT FLARE KERNELS IN A SOLAR FLARE

2016 ◽  
Vol 833 (1) ◽  
pp. 50 ◽  
Author(s):  
T. Kawate ◽  
T. T. Ishii ◽  
Y. Nakatani ◽  
K. Ichimoto ◽  
A. Asai ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Solar Flare ◽  
White Light ◽  
Temporal Evolution

The role of chromospheric condensations in the continuum emission of white-light flares

1992 ◽  
Vol 397 ◽  
pp. 694 ◽  
Author(s):  
W. Q. Gan ◽  
E. Rieger ◽  
H. Q. Zhang ◽  
C. Fang
Keyword(s):  
White Light ◽  
Continuum Emission ◽  
The Continuum

A Discussion on solar studies with special reference to space observations - Solar flare X-ray spectra

1971 ◽  
Vol 270 (1202) ◽  
pp. 143-155 ◽  
Keyword(s):  
Solar Flare ◽  
Line Emission ◽  
Continuum Emission ◽  
Solar Abundance ◽  
Lower Corona ◽  
Steady State Condition ◽  
X Ray ◽  
Physical Conditions ◽  
High Energies ◽  
The Continuum

The solar X -ray spectrum provides a versatile method for determining physical conditions in the lower corona and corona—chromosphere interface which are associated with the chromospheric (Hα) flare phenomenon. Information is contained both in the continuum and line emission which exists at these wavelengths. Continuum emission is predominant below 0.13 nm because of the relatively low solar abundance of heavy elements capable of producing line emission at these wavelengths. During the initial phase of an X-ray event this continuum frequently appears in short, often quasi-periodic bursts whose spectrum is best described by a power law to 100 keV and decreasing more rapidly at high energies. The electron spectrum apparently responsible for these bursts has many similarities to that required for the production of type III radio bursts. The emission of flare-associated soft X-ray radiation (both line and continuum radiation) begins at the time of hard X-ray bursts but reaches maximum one to several minutes later. Line emission from ions up to Ni xxvii in the helium-like ion sequence and up to Fe xxvi in the hydrogen-like ion sequence has been observed during large flares. The evolution of the plasma in which this radiation originates can be studied by comparing emission lines in the same or adjacent stages of ionization of an element. From such observations we conclude that a steady-state condition rarely if ever exists in the X-ray emitting regions associated with a solar flare.

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