E-Print Archive

There are 4371 abstracts currently viewable.


Search:

Advanced Search
Options
Main Page Add New E-Print Submitter
Information
Feedback
News Help/FAQ About Preferences
Manage Key Phrase
Notification
Comparison of Enhanced Absorption in He I 10830 ┼ in Observations and Modeling During the Early Phase of a Solar Flare View all abstracts by submitter

Nengyi Huang   Submitted: 2020-07-30 11:47

The He I 10830 ┼ triplet is a very informative indicator of chromospheric activities as the helium is the second most abundant element in the solar atmosphere. Taking advantage of the high resolution of the 1.6 m Goode Solar Telescope (GST) at Big Bear Solar Observatory (BBSO), previous observations have shown clear evidence of the enhanced absorption, instead of typically-observed emission, for two M-class flares. In this study, we analyze the evolution of the He I 10830 ┼ emission in numerical models and compare it with observations. The models represent the RADYN simulation results obtained from the F-CHROMA database. We consider the models with the injected electron spectra parameters close to observational estimates for the 2013-August-17 flare event (δ =8, Ec=15,20 keV, F = 1e11, 3e11 erg cm-2) in detail, as well as other available models. The modeling results agree well with observations, in the sense of both the maximum intensity decrease (-17.1%, compared to the observed value of -13.7%) and the trend of temporal variation (initial absorption phase followed by the emission). All models demonstrate the increased number densities and decreased ratio of the upper and lower level populations of He I 10830 ┼ transition in the initial phase, which enhances the opacity and forms an absorption feature. Models suggest that the temperatures and free-electron densities at heights of 1.3-1.5 Mm should be larger than ~10,000 K and 6e11 cm-3 thresholds for the line to start being in emission.

Authors: Nengyi Huang, Viacheslav M. Sadykov, Yan Xu, Ju Jing, Haimin Wang
Projects: None

Publication Status: ApJ Letter (published)
Last Modified: 2020-08-03 19:21
Go to main E-Print page  Heating Rates for Protons and Electrons in Polar Coronal Holes: Empirical Constraints from the Ultraviolet Coronagraph Spectrometer  Radio Echo in the Turbulent Corona and Simulations of Solar Drift-Pair Radio Bursts  Edit Entry  Download Preprint  Delete Entry 

Key
Go to main E-Print pageGo to main E-Print page.
Previous AbstractPrevious Abstract.
Next AbstractNext Abstract.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
View All Abstracts By SubmitterView all abstracts by submitter.
Delete AbstractDelete abstract.

Latest Entries
The Poissonian origin of power laws in solar flare waiting time distributions
Correlation of the sunspot number and the waiting time distribution of solar flares, coronal mass ejections, and solar wind switchback events observed with the Parker Solar Probe
Self-organized criticality in stellar flares
Finite system-size effectrs in self-organizing criticality systems
Global energetics of solar flares. XII. Energy scaling laws
Global energetics of solar flares. XI. Flare magnitude predictions of the GOES class
Are the Magnetic Fields Radial in the Solar Polar Region?
Fast magnetoacoustic wave trains: from tadpoles to boomerangs
Multi-channel coronal hole detection with convolutional neural networks
FOXSI-2 Solar Microflares. II. Hard X-ray Imaging Spectroscopy and Flare Energetics
Structure and Evolution of an InterľActive Region Large-scale Magnetic Flux Rope
Variation of Magnetic Flux Ropes through Major Solar Flares
MHD Modeling of Solar Coronal Magnetic Evolution Driven by Photospheric Flow
The Causes of Peripheral Coronal Loop Contraction and Disappearance Revealed in a Magnetohydrodynamic Simulation of Solar Eruption
The Sun's Dynamic Extended Corona Observed in Extreme Ultraviolet
Magnetohydrodynamic Simulations of Spicular Jet Propagation Applied to Lower Solar Atmosphere Model
Thermal Trigger for Solar Flares II: Effect of the Guide Magnetic Field
The role of non-axisymmetry of magnetic flux rope in constraining solar eruptions
Energy budget of plasma motions, heating, and electron acceleration in a three-loop solar flare
Space weather: the solar perspective - an update to Schwenn (2006)

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey



© 2000-2020 Solar Physics Group - Montana State University