Prominence-Corona Transition Region

Prominence-Corona Transition Region

T. Kucera,

NASA/GSFC

ISSI Prominence Cavity Team

Jan. 2009

Outline

• Basic structure of the TR• What it looks like in the EUV • Prominence Motions - Models and Observations• ISSI Prominence Group Topics

What is the PCTR?

B

Material between the bulk of the prominence material at T<104 Kand the corona at T>106 K.

What is the PCTR?

Corona

PCTR

PCTR

Prominence

Corona

What is the PCTR?

What is the PCTR?

What is the PCTR?

Other TR Temperature Radiation

What does it actually look like?

Prominences at 304 Å

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

304 Å STEREO/SECCHI/EUVI

304 Å SOHO/EIT

Contributions:He II collisionally excited (50,000-90,000 K)He II scattered (~104 K) (See Labrosse et al.)

Lyman absorption (~104 K)Si XI (~106 K)

SOHO/CDS Chiuderi-Drago & Landi 2002

Coronal Emission?

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

prominence associated jetTRACE Chae 2003

Erupting prominence, EIT 195 ÅCiaravella et al. 2000

Not always. These transient bright features at 171 and 195 Å probably around 250,000 K.

QuickTime™ and a decompressor

are needed to see this picture.

TRACE 171(?) A

Differential Emission Measures

Cirigliano et al. 2004 SOHO/SUMER and CDS

DEMs assume•Ionization equilibrium•Optically thin plasma

QuickTime™ and a decompressor

are needed to see this picture.

Karpen et al. 2008

Prominence Motions

Prominences are dynamic!

Quiescent prominences in H show steady flows, including counter-streaming, up to 20 km/s, and sometimes show faster motions.

Prominences observed in EUV and UV often show faster motions (30-70 km/s)

Prominence Motions

Study prominence motions at different temperatures to understand their properties and how they are related.

Goal: to test theories of prominence formation(which tie into theories of magnetic structure).

Rising Magnetic Field

Priest, van Ballegooijen, Mackay, 1996

Reconnection driven flows

Wang, 1999

Chromospheric Heating/Siphon Flow Models

QuickTime™ and aYUV420 codec decompressor

are needed to see this picture.

Karpen et al.

Studies of Motions in Prominences - Results

Many motions in the EUV seem to be pretty fastSome seem to have detectable H components.

Are there EUV components to slower H motions? Its hard to tell, but this may be a resolution problem.

In general DEMs of motions look rather like DEMs of prominences of a whole.

One difference is the extent to which you can see >300,000 K material in the structure.

QuickTime™ and aCinepak decompressorare needed to see this picture.

TRACE Ly and 1600 Å bands, May 26, 2000

SVST H Integrated Intensity and Doppler, May 26, 2000

QuickTime™ and aCinepak decompressor

are needed to see this picture.

QuickTime™ and aYUV420 codec decompressor

are needed to see this picture.

Activated Prominence and Cool LoopApr. 17, 2003

Kucera & Landi 2006

QuickTime™ and aPhoto - JPEG decompressor

are needed to see this picture.

Prominence between active regionsApr. 29, 2004

QuickTime™ and aPhoto - JPEG decompressor

are needed to see this picture.

Quiet and Activated Prominence Apr. 30 -May 1, 2004

DEMs of Moving Prominence Features

Different from others Promience DEMs because

•Made using as small a piece of a moving feature as possible (in time and space)

•When possible “background” has been estimated or subtracted

Calculated with using method of Landi & Landini 1997

Sample DEMs of Prominence Motions

Loop Differential Emission Measures

Kucera & Landi 2006

Many motions in the EUV seem to be pretty fastSome seem to have detectable H components.

Are there EUV components to slower H motions? Its hard to tell, but this may be a resolution problem.

In general DEMs of moving features look rather like DEMs of prominences of a whole.

One difference is the extent to which you can see >300,000 K material in the structure.

Plans & the Future

•Can Dynamic Equilibrium Model simulate the short times scale DEMs?

•SDO might be able to help understanding of the “high temperature” TR. Does this have any connection to very high temperature emission associated w/ prominences (“Chewy Nougat”)?

ISSI Prominence Group - Some topics

•Prominence Radiative Transfer Observations & Modeling- Lyman Absorption, He lines•PCTR related observations and diagnostics•Flows•Oscillations•Prominence magnetic field, its formations and relationship to the cavity field (Aad)