E-Print Archive

There are 4618 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
Observational Analysis of Lyman α Emission in Equivalent Magnitude Solar Flares View all abstracts by submitter

Harry Joseph Greatorex   Submitted: 2023-06-30 09:12

The chromospheric Lyman α line of neutral hydrogen (Lyα; 1216 ) is the most intense emission line in the solar spectrum, yet until recently observations of flare-related Lyα emission have been scarce. Here, we examine the relationship between nonthermal electrons accelerated during the impulsive phase of three M3 flares that were co-observed by RHESSI, GOES, and SDO, and the corresponding response of the chromosphere in Lyα. Despite having identical X-ray magnitudes, these flares show significantly different Lyα responses. The peak Lyα enhancements above quiescent background for these flares were 1.5%, 3.3%, and 6.4%. However, the predicted Lyα enhancements from FISM2 were consistently <2.5%. By comparing the properties of the nonthermal electrons derived from spectral analysis of hard X-ray observations, flares with a harder spectral index were found to produce a greater Lyα enhancement. The percentage of nonthermal energy radiated by the Lyα line during the impulsive phase was found to range from 2.0-7.9%. Comparatively, the radiative losses in He II (304 ) were found to range from 0.6-1.4% of the nonthermal energy while displaying enhancements above the background of 7.3-10.8%. FISM2 was also found to underestimate the level of He II emission in two out of the three flares. These results may have implications for space weather studies and modelling the response of the terrestrial atmosphere to changes in the solar irradiance, and will guide the interpretation of flare-related Lyα observations that will become available during Solar Cycle 25.

Authors: Harry J. Greatorex, Ryan O. Milligan, Phillip C. Chamberlin
Projects: GOES/EUVS,GOES X-rays,RHESSI,SDO-EVE

Publication Status: ApJ (submitted)
Last Modified: 2023-07-05 06:42
Go to main E-Print page  Bayesian evidence for two slow-wave damping models in hot coronal loops  Self-consistent equilibrium models of prominence thin threads heated by Alfvn waves propagating from the photosphere  Edit Entry  Download Preprint  Submitter's Homepage 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
Formation and Dynamics in an Observed Preeruptive Filament
Unveiling the spectacular over 24-hour flare of star CD-36 3202
The centroid speed as a characteristic of the group speed of solar coronal fast magnetoacoustic wave trains
Coronal dimmings as indicators of early CME propagation direction
A Chromatic Treatment of Linear Polarization in the Solar Corona at the 2023 Total Solar Eclipse
MinXSS-2 CubeSat mission overview: Improvements from the successful MinXSS-1 mission
Small Satellite Mission Concepts for Space Weather Research and as Pathfinders for Operations
Study of Time Evolution of Thermal and Nonthermal Emission from an M-class Solar Flare
Achievements and Lessons Learned From Successful Small Satellite Missions for Space Weather-Oriented Research
Scaling of Electron Heating by Magnetization During Reconnection and Applications to Dipolarization Fronts and Super-Hot Solar Flares
Defining the Middle Corona
First Results for Solar Soft X-Ray Irradiance Measurements from the Third-generation Miniature X-Ray Solar Spectrometer
Deciphering the solar coronal heating: Energizing small-scale loops through surface convection
Using Potential Field Extrapolations to Explore the Origin of Type II Spicules
Phase mixed Alfvén waves in partially ionised solar plasmas
Terrestrial temperature, sea levels and ice area links with solar activity and solar orbital motion
A model of failed solar eruption initiated and destructed by magnetic reconnection
Energetics of a solar flare and a coronal mass ejection generated by a hot channel eruption
An Optically Thin View of the Flaring Chromosphere: Nonthermal widths in a chromospheric condensation during an X-class solar flare
A Database of Magnetic and Thermodynamic Properties of Confined And Eruptive Solar Flares

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