Evidence of Chromospheric Evaporation in a Neupert-type F

lare

NING Zongjun

ningzongjun@pmo.ac.cn

Purple Mountain Observatory, China

Flare Model

corona

chromosphere

HXRHXR

Eva

pora

tion

Eva

pora

tion

SXR

Neupert

Effect

It is necessary to see the evidence of chromospheric evaporation in a Neupert-type event.

Based on this concept, we try:

1. To prove that the flare does follow the Neupert effect;

2. To look for the evidence of evaporation.

Hot Hot

The event we select

• 2004. Oct. 30

• M3.3

• 03:23 — 03:37 UT (GOES)

• N14W15 (disk event)

10691

2004 Oct.30 solar flare

RHESSI_HXR GOES_SXR TemperatureEMLow cutoffElectron spectra

l indexThermal ENonthermal E

1. How to test the Neupert effect from these parameters?

Methods to test the Neupert effect1. Comparison: the maximum of the SXR derivative with the HXR

maximum (e.g. Dennis et al. 1985)

2. Comparison: time difference between the SXR maximum and the HX

R end (e.g. Veronig et al. 2002)

3. Correlation: I. Between the SXR derivative and HXR light curve (e.g. Ning et al.

2009)

II. Between the thermal energy derivative and HXR light curve (e.g. Ning et al. 2008)

III. Between thermal energy derivative and nonthermal energy profiles (e.g. Ning 2009, submitted)

Correlation

HXR

SXR derivative Thermal E derivative

No

nth

erm

al e

ner

gy

0.71 0.74

This event does follow the Neupert effect!

2. Then we look for the evidence of chromospheric evaporation in this flare.

Evidence of evaporation1. Seen on radio dynamics high frequency cutoff and positively drifting (e.g. Aschwanden & Benz 1995)

II. HXR footpoints move close and finally merge together (disk event, e.g. Ning et al. 2009)

2. Seen by EUV and Ha I. EUV red-shift on the edge of ribbons (e.g. Czaykowska

et al. 1999) II. broad Ha width on the edge of ribbons(e.g. Li & Ding 2

004)

3. Seen by HXR I. HXR footpoint sources tend to rise up and finally

merge together (limb event, e.g. Liu et al. 2006)

Evidence of evaporation

1. Seen on radio dynamics high frequency cutoff and positively drifting

2. Seen by EUV and Ha I. EUV red-shift on the edge of ribbons

II. broad Ha width on the edge of ribbons 3. Seen by HXR I. HXR footpoint sources tend to rise up and finally

merge together (limb event, e.g. Liu et al. 2006)

Evidence of evaporation

1. Seen on radio dynamics high frequency cutoff and positively drifting

2. Seen by EUV and Ha I. EUV red-shift on the edge of ribbons

II. broad Ha width on the edge of ribbons 3. Seen by HXR I. HXR footpoint sources tend to rise up and finally

merge together (limb event, e.g. Liu etal. 2006) II. HXR footpoints move close and finally merge toget

her (disk event, e.g. Ning et al. 2009)

2004 Oct. 30

Projection correction

Assumption: semi-circular loop

Evaporation speed: (S)632 km/s & (N)397 km/s

Summary

2004. Oct. 30 solar flare:

1. This event shows the Neupert effect.

2. This event exhibits the double footpoints movement close together and finally mergence into a single source at the same position of the loop-top source, which is thought to be the evidence of the chromospheric evaporation at HXR.

(Ning et al. 2009 submitted)

Thanks!