E-Print Archive

There are 4354 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
Microwave observations of a large-scale coronal wave with the Nobeyama radioheliograph View all abstracts by submitter

Alexander Warmuth   Submitted: 2016-10-13 01:08

Context. Large-scale globally propagating waves in the solar corona have been studied extensively, mainly using extreme ultraviolet (EUV) observations. In a few events, corresponding wave signatures have been detected in microwave radioheliograms provided by the Nobeyama radioheliograph (NoRH). Several aspects of these observations seem to contradict the conclusions drawn from EUV observations. Aims. We investigate whether the microwave observations of global waves are consistent with previous findings. Methods. We revisited the wave of 1997 Sep 24, which is still the best-defined event in microwaves. We obtained radioheliograms at 17 and 34 GHz from NoRH and studied the morphology, kinematics, perturbation profile evolution, and emission mechanism of the propagating microwave signatures. Results. We find that the NoRH wave signatures are morphologically consistent with both the associated coronal wave as observed by SOHO/EIT and the Moreton wave seen in Hα . The NoRH wave is clearly decelerating, which is typically found for large-amplitude coronal waves associated with Moreton waves, and its kinematical curve is consistent with the EIT wavefronts. The perturbation profile shows a pronounced decrease in amplitude. Based on the derivation of the spectral index of the excess microwave emission, we conclude that the NoRH wave is due to optically thick free-free bremsstrahlung from the chromosphere. Conclusions. The wavefronts seen in microwave radioheliograms are chromospheric signatures of coronal waves, and their characteristics support the interpretation of coronal waves as large-amplitude fast-mode MHD waves or shocks.

Authors: Warmuth, A., Shibasaki, K., Iwai, K., & Mann, G.
Projects: Nobeyama Radioheliograph,SoHO-EIT

Publication Status: Astronomy & Astrophysics (2016), Volume 593, id. A102, 8 pp.
Last Modified: 2016-10-14 09:18
Go to main E-Print page  Suprathermal electron distributions in the solar transition region  The Contribution of Coronal Jets To The Solar Wind  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
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)
Mixed properties of slow magnetoacoustic and entropy waves in a plasma with heating/cooling misbalance
The morphology of average solar flare time profiles from observations of the Sun's lower atmosphere
Indications of stellar coronal mass ejections through coronal dimmings
Could switchbacks originate in the lower solar atmosphere? II. Propagation of switchbacks in the solar corona
Solar large-scale magnetic field and cycle patterns in solar dynamo
Three-dimensional magnetic reconnection in astrophysical plasmas
Energy partition in a confined flare with an extreme-ultraviolet late phase
Alfvén wave heating in partially ionized thin threads of solar prominences
He I 10830 Dimming During Solar Flares, I: The Crucial Role of Non-Thermal Collisional Ionisations
Separating aa-index into Solar and Hale Cycle Related Components Using Principal Component Analysis
Inward Propagating Plasma Parcels in the Solar Corona: Models with Aerodynamic Drag, Ablation, and Snowplow Accretion
Energetics and 3-D Structure of Elementary Events in Solar Coronal Heating
Stellar Superflares Observed Simultaneously with Kepler and XMM-Newton
Medium-term predictions of F10.7 and F30 cm solar radio flux with the adaptive Kalman filter
Resonances in a Coronal Loop Driven by Torsional Alfvén Waves Propagating from the Photosphere
Effects of external flow on resonant absorption of coronal loop kink oscillations driven by an external fast wave: Selective excitation problem
Emerging Dimming as Coronal Heating Episodes
Proxy-Based Prediction of Solar Extreme Ultraviolet Emission using Deep Learning

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