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
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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
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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
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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.
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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.
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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
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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
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30 frames/second
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30 frames/second
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Image_i(i=1~50) – Image_a(20:38:08UT)
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Image_i (I = 2~50) – Image_1
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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
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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
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C_halo ~ 1/3 C_core = 8%
Most recent numerical simulation ~13% (Cheng et al. 2009), electron flux ~ 1011 erg cm-2 s-1
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GLOBAL Hα NETWORK (GHN)
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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
2010 August 042010 August 04
GLOBAL Hα NETWORK (GHN)
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.
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