E-Print Archive

There are 4354 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
Yohkoh SXT Full-Resolution Observations of Sigmoids: Structure, Formation, and Eruption View all abstracts by submitter

Richard Canfield   Submitted: 2007-08-01 09:23

We study the structure of 107 bright sigmoids using full-resolution (2 farcs 5 pixels) images from the Yohkoh Soft X-Ray Telescope obtained between December 1991 and December 2001. We find that none of these sigmoids are made of single loops of S or inverse-S shape - all comprise a pattern of multiple loops. We also find that all S-shaped sigmoids are made of right-bearing loops, and all S-1-shaped sigmoids, left-bearing loops, without exception. We co-align the SXT images with Kitt Peak magnetograms to determine the magnetic field directions in each sigmoid. We use a potential-field source surface model to determine the direction of the overlying magnetic field. We find that sigmoids for which the relative orientation of these two fields has a parallel component outnumber anti-parallel ones by more than an order of magnitude. We find that the number of sigmoids per AR region varies with the solar cycle in a manner that is consistent with this finding. Finally, those few sigmoids that are anti-parallel erupt roughly twice as often as those that are parallel. We briefly discuss the implications of these results in terms of formation and eruption mechanisms of flux tubes and sigmoids.

Authors: Richard C. Canfield, Maria D. Kazachenko, Loren W. Acton, D. H. Mackay, Ji Son, Tanya L. Freeman
Projects: None

Publication Status: ApJ Letters, submitted
Last Modified: 2007-08-01 09:24
Go to main E-Print page  Helioseismic Holography of Simulated Solar Convection and
Prospects for the Detection of Small-Scale Subsurface Flows  Segmentation of loops from coronal EUV images  Edit Entry  Download Preprint  Submitter's Homepage 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
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