E-Print Archive

There are 4594 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
Three Criteria to Discriminate Between Elementary and Composite Coronal Loops View all abstracts by submitter

Markus J. Aschwanden   Submitted: 2005-07-13 17:01

In this Letter we establish three simple criteria to discriminate between elementary and composite loop structures, based on observations from high-resolution (TRACE) and low-resolution (EIT) imagers. Both datasets contain triple-filter data with a temperature diagnostic in the range of T=0.7-2.8 MK, which we use for forward-fitting of a differential emission measure (DEM) distribution to constrain the temperature range of each structure. From the TRACE dataset we find for the finest structures a mean width of w=1.4±0.43Mm, a flux-to-background contrast of c=0.18±0.13, and a temperature range of dT=0.07±0.10 MK, which we identify as elementary strands, defined in terms of their thermal homogeneity. The loop structures observed with EIT have loop widths w, flux contrasts c, and temperature ranges dT that are all about an order of magnitude larger, and thus clearly constitute composite structures, consisting of many loop strands. These two contrasting observations resolve previous controversies about the basic thermal structure of coronal loops and yield a simple discrimination rule: Elementary loop strands (1) are near-isothermal (dT < 0.2 MK), (2) have a small width (w < 2 Mm), and (3) have a faint contrast (c < 0.3), while virtually all wider and higher-contrast loop features are most likely to be multi-thermal composites and have a broad DEM.

Authors: Markus J. Aschwanden
Projects: Soho-EIT,TRACE

Publication Status: ApJ Lett. (revised 2005-Oct-05)
Last Modified: 2005-10-05 10:26
Go to main E-Print page  The Localization of Particle Acceleration Sites in Solar Flares and CMEs  Confined and ejective eruptions of kink-unstable flux ropes  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
Repeated Type III Burst Groups Associated with a B-Class Flare and a Narrow-Width CME
Separating the effects of earthside and far side solar events. A case study.
Deciphering The Slow-rise Precursor of a Major Coronal Mass Ejection
Three-dimensional Turbulent Reconnection within Solar Flare Current Sheet
Sequential Remote Brightenings and Co-spatial Fast Downflows during Two Successive Flares
A Model for Confined Solar Eruptions Including External Reconnection
The eruption of a magnetic flux rope observed by Solar Orbiter and Parker Solar Probe
Comprehensive radiative MHD simulations of eruptive flares above collisional polarity inversion lines
An Anisotropic Density Turbulence Model from the Sun to 1 au Derived From Radio Observations
Comparison of damping models for kink oscillations of coronal loops
On the three-dimensional relation between the coronal dimming, erupting filament and CME. Case study of the 28 October 2021 X1.0 event
Polarisation of decayless kink oscillations of solar coronal loops
CME Propagation Through the Heliosphere: Status and Future of Observations and Model Development
30-min Decayless Kink Oscillations in a Very Long Bundle of Solar Coronal Plasma Loops
The Role of High-Frequency Transverse Oscillations in Coronal Heating
ARTop: an open-source tool for measuring Active Region Topology at the solar photosphere
Spectral Observations and Modeling of a Solar White-light Flare Observed by CHASE
New cases of super-flares on slowly rotating solar-type stars and large amplitude super-flares in G- and M-type main-sequence stars
Constraints on the variable nature of the slow solar wind with the Wide-Field Imager on board the Parker Solar Probe
Prediction of short stellar activity cycles using derived and established empirical relations between activity and rotation periods

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