E-Print Archive

There are 3914 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
A statistical study of the inferred transverse density profile of coronal loop threads observed with SDO/AIA View all abstracts by submitter

Christopher Goddard   Submitted: 2017-08-24 03:16

Aims. We carry out a statistical study of the inferred coronal loop cross-sectional density profiles using extreme ultraviolet (EUV) imaging data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). Methods. We analysed 233 coronal loops observed during 2015/2016. We consider three models for the density profile; the step function (model S ), the linear transition region profile (model L), and a Gaussian profile (model G). Bayesian inference is used to compare the three corresponding forward modelled intensity profiles for each loop. These are constructed by integrating the square of the density from a cylindrical loop cross section along the line of sight, assuming an isothermal cross section, and applying the instrumental point spread function. Results. Calculating the Bayes factors for comparisons between the models, it was found that in 47 % of cases there is very strong evidence for model L over model S and in 45 % of cases very strong evidence for model G over S . Using multiple permutations of the Bayes factor the favoured density profile for each loop was determined for multiple evidence thresholds. There were a similar number of cases where model L or G are favoured, showing evidence for inhomogeneous layers and constantly varying density cross sections, subject to our assumptions and simplifications. Conclusions. For sufficiently well resolved loop threads with no visible substructure it has been shown that using Bayesian inference and the observed intensity profile we can distinguish between the proposed density profiles at a given AIA wavelength and spatial resolution. We have found very strong evidence for inhomogeneous layers, with model L being the most general, and a tendency towards thicker or even continuous layers.

Authors: C. R. Goddard , D. J. Pascoe , S. Anfinogentov, and V. M. Nakariakov
Projects: None

Publication Status: In press
Last Modified: 2017-08-25 10:16
Go to main E-Print page  Solar Open Flux Migration from Pole to Pole: Magnetic Field Reversal  Seismology of contracting and expanding coronal loops using damping of kink oscillations by mode coupling  Edit Entry  Download Preprint  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
Linear Polarization Features in the Quiet-Sun Photosphere: Structure and Dynamics
Solar Microflares Observed by SphinX and RHESSI
Two Kinds of Dynamic Behavior in a Quiescent Prominence Observed by the NVST
Resistively-limited current sheet implosions in planar anti-parallel (1D) and null-point containing (2D) magnetic field geometries
Is It Small-scale Weak Magnetic Activity That Effectively Heats the Upper Solar Atmosphere?
Self-Similar Approach for Rotating Magnetohydrodynamic Solar and Astrophysical Structures
Spectroscopic and imaging observations of small-scale reconnection events
A Study of Magnetic Field Characteristics of Flaring Active Region Based on Nonlinear Force-free Field Extrapolation
A Study of a Compound Solar Eruption with Two Consecutive Erupting Magnetic Structures
Non-potential magnetic helicity ratios at the onset of eruptions
Solar Cycle Observations of the Neon Abundance in the Sun-as-a-star
Subresolution Activity in Solar and Stellar Coronae from Magnetic Field Line Tangling
A Model of Zebra Patterns in Solar Radio Emission
Three-dimensional magnetic reconnection in a collapsing coronal loop system
On the Synthesis of GOES Light Curves from Numerical Models
Efficient Calculation of Non-Local Thermodynamic Equilibrium Effects in Multithreaded Hydrodynamic Simulations of Solar Flares
2D solar wind speeds from 6 to 26 solar radii in solar cycle 24 by using Fourier filtering
Non-damping oscillations at flaring loops
An Event-Based Verification Scheme for the Real-Time Flare Detection System at Kanzelhöhe Observatory
Computation of Relative Magnetic Helicity in Spherical Coordinates

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



© 2003 Solar Physics Group - Montana State University