E-Print Archive

There are 4353 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
Elementary Loop Structures in the Solar Corona Analyzed from TRACE Triple-Filter Images View all abstracts by submitter

Markus J. Aschwanden   Submitted: 2005-06-06 11:55

This study represents the first quantitative analysis of the multi-thread structure of coronal loops. We analyzed a set of 234 fine loop threads observed with TRACE triple-filter images at wavelengths of 171, 195, and 284 A. The cross-sectional flux profiles are simultaneously forward-fitted in all three filters with the superposition of a cospatial gaussian and linear background functions. We fit a general multi-temperature differential emission measure (DEM) distribution to each cross-section, as well as the special case of a single-temperature or isothermal DEM. We perform these forward-fits at ~ 18,000 loop positions and find that this geometric model could be fitted in ~ 3500 cases (within a chi_red < 1.5), while all other cases require more complex geometric models of the loop cross-section, secondary loops, and background. The major result of this study is that the vast majority (84%) of the acceptable DEM fits are isothermal. Temperatures are measured over the whole sensitivity range of 0.7-2.8 MK, but with a higher probability near the peak sensitivities of the three filters. We conclude that we indeed resolve ``elementary'' or ``monolithic'' loop strands with TRACE, in terms of isothermal homogeneity. Virtually all earlier studies detected ensembles of multiple strands, while our detected loop strands exhibit much smaller widths (w ~ 1.4 ± 0.3 Mm) and also smaller signal-to-background ratios (14% ± 10%). We suggest that the temperature homogeneity of coronal loops up to widths of w ~ 2000 km is related to their magnetic mapping to photospheric granulation (convection) cells.

Authors: Markus J. Aschwanden & Richard W. Nightingale
Projects: TRACE

Publication Status: ApJ, Vol 633 (2005 Nov 1 issue, in press)
Last Modified: 2005-07-18 11:51
Go to main E-Print page  Magnetic Flux Cancellation and Coronal Magnetic Energy  All Coronal Loops are the Same: Evidence to the Contrary  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
The role of non-axisymmetry of magnetic flux rope in constraining solar eruptions
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

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