E-Print Archive

There are 4282 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
* News 04/04/20 * The archive is using a new backend database. This has thrown up a few SQL errors in the last few days. If you have any issues please email adavey@nso.edu with either the number of eprint you are trying to edit or a link to your preprint.

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 

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
Propagation Effects in Quiet Sun Observations at Meter Wavelengths
Twin Null-Point-Associated Major Eruptive Three-Ribbon Flares with Unusual Microwave Spectra
Trajectory Determination for Coronal Ejecta Observed by WISPR/Parker Solar Probe
Recurring Homologous Solar Eruptions in NOAA AR 11429
Resonant absorption: transformation of compressive motions into vortical motion
The depth and the vertical extent of the energy deposition layer in a medium-class solar flare
Helicity proxies from linear polarisation of solar active regions
The Submillimeter Active Region Excess Brightness Temperature during Solar Cycles 23 and 24
Nanoflare Diagnostics from Magnetohydrodynamic Heating Profiles
The Solar Orbiter mission - Science Overview
Time Series Analysis of Photospheric Magnetic Parameters of Flare-quiet versus Flaring Active Regions: Scaling Properties of Fluctuations
Image Quality Assessment for Full-Disk Solar Observations with Generative Adversarial Networks
Identifying and Tracking Solar Magnetic Flux Elements with Deep Learning
Active Region Irradiance During Quiescent Periods: New Insights from Sun-as-a-star Spectra
Probing solar flare accelerated electron distributions with prospective X-ray polarimetry missions
Accelerating and Supersonic Density Fluctuations in Coronal Hole Plumes: Signature of Nascent Solar Winds
Sequential Lid Removal in a Triple-Decker Chain of CME-Producing Solar Eruptions
RESIK and RHESSI observations of the 20 September 2002 flare
Starspot mapping with adaptive parallel tempering I: Implementation of computational code
Heating and Eruption of a Solar Circular Ribbon Flare

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