E-Print Archive

There are 4553 abstracts currently viewable.


Advanced Search
Main Page Add New E-Print Submitter
News Help/FAQ About Preferences
Manage Key Phrase
Statistics, Morphology, and Energetics of Ellerman Bombs View all abstracts by submitter

Manolis K. Georgoulis   Submitted: 2002-04-08 16:42

We investigate the statistical properties of Ellerman bombs in the dynamic emerging flux region NOAA 8844, underneath an expanding arch filament system. High-resolution chromospheric Hα filtergrams (spatial resolution 0.8arcsec), as well as photospheric vector magnetograms (spatial resolution 0.5arcsec), and Dopplergrams, have been acquired by the balloon-borne Flare Genesis Experiment. Hα observations reveal the first ``seeing-free'' data set on Ellerbombs and one of the largest samples of these events. We find that Ellerman bombs occur and recur in preferential locations in the low chromosphere, either above, or in the absence of, photospheric neutral magnetic lines. Ellerman bombs are associated with photospheric downflows and their loci follow the transverse mass flows on the photosphere. They are small-scale events, with typical size 1.8 imes 1.1;arcsec^2, but this size depends on the instrumental resolution. A large number of Ellerman bombs are probably undetected, due to limited spatial resolution. Ellerman bombs occur in clusters which exhibit fractal properties. The fractal dimension, with an average value sim 1.4, does not change significantly in the course of time. Typical parameters of Ellerman bombs are interrelated and obey power-law distribution functions, as in case of flaring and sub-flaring activity. We find that Ellerman bombs may occur on separatrix, or quasi-separatrix, layers, in the low chromosphere. A plausible triggering mechanism of Ellerman bombs is stochastic magnetic reconnection caused by the turbulent evolution of the low-lying magnetic fields and the continuous re-shaping of separatrix layers. The total energies of Ellerman bombs are estimated in the range (1027,1028);erg, the temperature enhancement in the radiating volume is sim 2 imes 103;K and the timescale of radiative cooling is short, of the order of a few seconds. The distribution function of the energies of Ellerman bombs exhibits a power-law shape with an index sim -2.1. This suggests that Ellerman bombs may contribute significantly to the heating of the low chromosphere in emerging flux regions.

Authors: M. K. Georgoulis, D. M. Rust, P. N. Bernasconi, and B. Schmieder

Publication Status: ApJ (in press)
Last Modified: 2002-04-08 16:42
Go to main E-Print page  Coronal mass ejections and their association to active region flaring.  OSCILLATING HOT LOOPS OBSERVED BY SUMER  Edit Entry  Download Preprint  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
Stability of slow magnetoacoustic and entropy waves in the solar coronal plasma with thermal misbalance
The chromosphere underneath a Coronal Bright Point
Characterising fast-time variations in the hard X-ray time profiles of solar flares using Solar Orbiter's STIX
The quiet sun at mm wavelengths as seen by ALMA
Explosive Events in the Quiet Sun Near and Beyond the Solar Limb Observed with the Interface Region Imaging Spectrograph (IRIS)
Multi-stage reconnection powering a solar coronal jet
A Statistical Analysis of Magnetic Field Changes in the Photosphere during Solar Flares Using High-cadence Vector Magnetograms and Their Association with Flare Ribbons
Numerical Study on Excitation of Turbulence and Oscillation in Above-the-loop-top Region of a Solar Flare
Oscillatory reconnection as a plasma diagnostic in the solar corona
The independence of oscillatory reconnection periodicity from the initial pulse
Oscillatory Reconnection of a 2D X-point in a hot coronal plasma
Formation Of The Lyman Continuum During Solar Flares
MHD simulation of Solar Eruption from Active Region 11429 Driven by Photospheric Velocity Field
Unfolding Drift Effects for Cosmic Rays over the Period of the Sun's Magnetic Field Reversal
Problems in Observation and Identification of Torsional Waves in the Lower Solar Atmosphere
Solar Orbiter and SDO Observations, and Bifrost MHD Simulations of Small-scale Coronal Jets
Dominance of Bursty over Steady Heating of the 48 MK Coronal Plasma in a Solar Active Region: Quantification Using Maps of Minimum, Maximum, and Average Brightness
Solar flare hard X-rays from the anchor points of an eruptive filament
Plasmoids, Flows, and Jets During Magnetic Reconnection in a Failed Solar Eruption
Connecting Chromospheric Condensation Signatures to Reconnection-driven Heating Rates in an Observed Flare

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