E-Print Archive

There are 4524 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
Soft X-ray coronal spectra at low activity levels observed by RESIK View all abstracts by submitter

Barbara Sylwester   Submitted: 2010-03-15 13:13

The quiet-Sun X-ray emission is important for deducing coronal heating mechanisms, but it has not been studied in detail since the Orbiting Solar Observatory (OSO) spacecraft era. Bragg crystal spectrometer X-ray observations have generally concentrated on flares and active regions. The high sensitivity of the RESIK (REntgenovsky Spectrometer s Izognutymi Kristalami) instrument on the CORONAS-F solar mission has enabled the X-ray emission from the quiet corona to be studied in a systematic way for the first time. Our aim is to deduce the physical conditions of the non-flaring corona from RESIK line intensities in several spectral ranges using both isothermal and multithermal assumptions. We selected and analyzed spectra in 312 quiet-Sun intervals in January and February 2003, sorting them into 5 groups according to activity level. For each group, the fluxes in selected spectral bands have been used to calculate values parameters for the best-fit that lead to a intensities characteristic of each group. We used both isothermal and multitemperature assumptions, the latter described by differential emission measure (DEM) distributions. RESIK spectra cover the wavelength range (3.3-6.1 A). This includes emission lines of highly ionized Si, S, Cl, Ar, and K, which are suitable for evaluating temperature and emission measure, were used. The RESIK spectra during these intervals of very low solar activity for the first time provide information on the temperature structure of the quiet corona. Although most of the emission seems to arise from plasma with a temperature between 2MK and 3MK, there is also evidence of a hotter plasma (T approx. 10MK) with an emission measure 3 orders smaller than the cooler component. Neither coronal nor photospheric element abundances appear to describe the observed spectra satisfactorily.

Authors: B. Sylwester, J. Sylwester, K. J. H. Phillips
Projects: CORONAS-F/SPIRIT

Publication Status: Accepted by Astronomy and Astrophysics
Last Modified: 2010-03-16 08:28
Go to main E-Print page  Independent Signals from the Influence of Internal Magnetic Layers on the Frequencies of Solar P-modes  Formation Heights of Extreme Ultraviolet Lines in an Active Region Derived by Correlation of Doppler Velocity and Magnetic Field  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
Coronal seismology by slow waves in non-adiabatic conditions
Exploring the Ideal MHD Quasi-Modes of a Plasma Interface with a Thick Nonuniform Transition
Changes of Magnetic Energy and Helicity in Solar Active Regions from Major Flares
Spectroscopic and Imaging Observations of Spatially Extended Magnetic Reconnection in the Splitting of a Solar Filament Structure
The Universality of Power Law Slopes in the Solar Photosphere and Transition Region Observed with HMI and IRIS
Turbulence and Anomalous Resistivity inside Near-Earth Magnetic Clouds
On the specific energy and pressure in near-Earth magnetic clouds
Solar Energetic Particle Event Associated with the 2012 July 23 Extreme Solar Storm
Investigation of Energetic Particle Release Using Multi-point Imaging and In Situ Observations
Shock Properties and Associated Characteristics of Solar Energetic Particles in the 2017 September 10 GLE event
Dimensionality of Solar Magnetic Reconnection
Microwave Perspective on Magnetic Breakout Eruption
Effects of Coronal Density and Magnetic Field Distributions on a Global Solar EUV Wave
Multi-spacecraft Observations of the Coronal and Interplanetary Evolution of a Solar Eruption Associated with Two Active Regions
Sun-to-Earth Characteristics of the 2012 July 12 Coronal Mass Ejection and Associated Geo-effectiveness
The effect of nanoflare flows on EUV spectral lines
On some features of the solar proton event on 2021 October 28 GLE73
The role and contribution of magnetic fields, characterized via their magnetic flux, to the statistical structuring of the solar atmosphere
Do periods of decayless kink oscillations of solar coronal loops depend on noise?
Automatic detection technique for solar filament oscillations in GONG data

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