2010 August 04

2010 August 042010 August 04

High resolution observations of solar flares using the ground-based telescopes

Yan Xu

SWRL/NJIT

1010thth RHESSI Workshop RHESSI WorkshopWorking Group 4Working Group 4

What is unique of our data sets:

High Order AO correction (AO-76)

Highest spatial/temporal resolution

First NIR continuum observation


Origin of the White-Light Emission:

Direct Heating of Non-thermal Particle Beam: Najita & Orrall 1970, Aboundarham & Hénoux 1986a

Chromospheric Back-warming: Hudson 1972, Metcalf et al., 1990a&b, Ding et al. 2003

H- emission: Ding et al. 2003

Review by Metcalf et al., 1990b

Prediction of NIR Continuum Radiation:

Hudson 1972, Far-Infrared > 20 mm

Ohki & Hudson 1975, IR > 1 mm


NIR: 1560 nm 2.5 nm 91.2" x 91.2 " October 29 122.2 " x 122.2 " November 2 Exposure = 13 ms Cadence = 30 frames/second, October 29 Cadence = 2 seconds, November 2

Visible: 520 nm 26 nm

81" x 81 " Exposure = 4 ms Cadence = 30 frames/second 100 frames/minute

G-band: 430.5 nm 0.5 nm

72" x 72 " Exposure = 2 ms Cadence = 2 seconds


RHESSI HXR contours (blue) correspond to the 50 – 100 keV channel with 60-second integration. The local NIR intensity maxima are shown in red. Two flare ribbons are correlated with strong HXR kernels. HXR contour levels are drawn at 0.17, 0.25, 0.60, and 0.80 of the maximum intensity, except for the first two frames, where they correspond to 0.7 and 0.8 for the first frame and 0.4, 0.6, and 0.8 for the second, when the HXR kernels were weaker.


Color-encoded NIR difference images showing the temporal evolution of the flare ribbons from 20:40~UT to 20:47~UT. The background is an MDI line-of-sight magnetogram.


Event October 29 November 2

Disk Location S17W10 S17W63

GOES X-ray Class X10 X8

Start Time 20:39 UT 17:15 UT

Peak Time 20:42 UT 17:17 UT

NIR Peak 25% 66%

V_5200 Peak 37% 76%

G-band Peak 75% 230%

V (km/s) 29 24

E (V/cm) 23 22


MLC: Core emissionALC: Halo emission

1. Delay of ALC relative to MLC

2. MLC HXR

3. HXR up to 800keV

Oct. 29, 2003

Nov. 02, 2003


30 frames/second


Image_i(i=1~50) – Image_a(20:38:08UT)


Image_i (I = 2~50) – Image_1


1. G-band kernel: >100* aresec2 for an X9 flare (Wang 2009)

2. A typical UV area ~ 100 arcsec2 (Fletcher et al. 2007)

3. Dennis and Pernak, 2009

2003 Mar 18 X1.5 50-100


C_halo ~ 1/3 C_core = 8%

Most recent numerical simulation ~13% (Cheng et al. 2009), electron flux ~ 1011 erg cm-2 s-1



GLOBAL Hα NETWORK (GHN)



Provide daily images from all nine stations

Provide 1 min & 1" images from BBSO, KSO and YNAO Database (1.1 million imgs ~ 9TB ): 1. BBSO 2001/03/08 ~ 2009/05/29 total 307,066 frames 2. KSO 2000/07/20 ~ 2009/01/10 total 601,989 frames 3. YNAO 2002/01/01 ~ 2008/12/10 total 207,164 frames

http://swrl.njit.edu/ghn_web/data_request/data_request.htm



http://swrl.njit.edu/ghn_web/data_request/data_request.htm

Summary:

1. Different mechanisms for core and halo WL emission;

2. WL source sizes indicating 3D magnetic configuration;

3. More observations in optical wavelengths are scheduled, especially with high spatial/temporal resolution.

Prospective to RHESSI:

Images or LCs <1s

New imaging tech.


2010 August 04

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