Katharine K. Reeves1, Terry G. Forbes2, Jon Linker3 & Zoran Mikić3

1Harvard-Smithsonian Center for Astrophysics2University of New Hampshire3Science Applications International Corporation

Theoretical Predictions of Energy Release in

CMEs and Calculations of Flare Emissions

Thanks to the NSF-SHINE program for funding this work!

OverviewMain Goal:

Energy dissipated in the current sheet

Flare emissions

Methods:1. Analytic: loss-of-equilibrium model2. Numerical: 2.5D MHD code (SAIC MAS)

Lin & Forbes, 2000

Equilibrium Curve

Forbes & Priest, 1995

Poynting Flux Thermalized

Energy Release

Effect of MA on Energy

Time (s)

En

erg

y (

x 1

031 e

rgs)

MA = 0.001

MA = 0.006

MA = 0.1

Reeves & Forbes, ApJ,

2005

Soft X-ray Telescope (SXT) Light Curves

Observed

Simulated

Data from Reeves & Warren, ApJ, 2002Simulated light curves from Reeves & Forbes, ApJ 2005

Velocities and Light Curves

Red curves

Blue curves

Background Field: 50 GFlux rope mass: 2.1 x 1016 gm

Background Field: 25 GFlux rope mass: 4.0 x 1015 gm

Densities in the flare loops

QuickTime™ and aTIFF (Uncompressed) decompressor

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Density

Reeves, Warren & Forbes, ApJ, 2007

Simulated Flare Images

TRACE 171Å TRACE 195Å

SXT Al12 SXT Be119Reeves, et

al., ApJ, 2007

Loop-top knots and bars

(e.g. Feldman, et al., 1995)

Yohkoh SXT TRACE 171 TRACE 195(e.g. Doschek & Warren, 2005)

SAIC MAS MHD model

QuickTime™ and aTIFF (Uncompressed) decompressor

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Density

Temperature

Energy over simulation domain

shearing

flux cancellation

current sheetforms

Current sheet

Energy partition

Energy into current sheet

Energy flow at r0

Energy flow at r1

Simulated light curves

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

XRT observations

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Conclusions

• The loss-of-equilibrium model is capable of simulating flare emissions characteristic of observations

• In the SAIC simulations, a higher fraction of the energy leaves the current sheet at the r1 boundary than the r0 boundary.

Conclusions• Conduction, viscous flow

decrease the energy swept in to the current sheet via the Poynting flux.

• The bulk of the energy flow at r0 is conductive flux, which can be used as the input to multi-threaded 1D flare loop simulations, as in Reeves et al. (2007).