ASP Observations on 2001 October 16 & 17 at NSO/SP

Welcome! Let’s work on polarimetric spectrum.

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Webpage established on 2007/03/20 updated on: 2007/09/24

Contact: na.deng@csun.edu

Related Paper:

Multiheight Properties of Moving Magnetic Features 2007 ApJ 664. 1228 By D. P. Choudhary and K. S. Balasubramaniam

Observations:

AR NOAA 9661, Stokes profiles (I, Q, U, V)

Photospheric line: FeI 6301.5 Å, 6302.5 Å line pair dispersion 0.012 Å/pixel  ;     5171Å, 5173Å

Lower-chromospheric line: Mgb2 5172 Å , dispersion 0.01 Å/pixel

80 micron wide slit => 0.6 arcsec spatial resolution

1.6 arcmin long slit, 0.36 arcsec/pixel

Scanned 280 steps => FOV 1.6 × 2.8 arcmin

Data Info:

2007/10/17

sets = ['01', '02', '04', '05', '06', '18']

lines = ['5172', '6300']

; big_arr_i [255, 229, 280]

; big_arr_q [255, 229, 280]

; big_arr_u [255, 229, 280]

; big_arr_v [255, 229, 280]

; | | |___ scan sequence, spatial x, time t

; | |___ along slit, spatial y

; |___ wavelength lambda

sx = 280 ; size of spatial x, scan steps

sy = 229 ; size of spatial y, along slit

sw = 255 ; size of wavelength range

Data Cube of Mgb2 Stokes I Data Cube of FeI Line Pair Stokes I

(Click on the img. to see movie: solar image at dif. wavelength) (Click on the img. to see movie: slit image at dif. solar position)

The Sun on 2001/10/17

Solar Activities between 2001/10/16 and 2001/10/17

SEC Events

:Product: 20011016events.txt
:Created: 2001 Oct 19 0302 UT
:Date: 2001 10 16
#Event Begin Max End Obs Q Type Loc/Frq Particulars Reg#
#-------------------------------------------------------------------------------
 
3640 1632 1644 1654 GO8 5 XRA 1-8A C2.8 3.6E-03 
3570 1758 1807 1907 HOL 3 FLA N16E11 SF  9661
3570 + 1809 1814 1821 GO8 5 XRA 1-8A C3.5 2.3E-03 9661
3590 + 1919 1926 1943 GO8 5 XRA 1-8A C6.0 6.8E-03 9661
3590 1920 1928 2009 HOL 3 FLA N14E08 SF ERU 9661
3650 2158 2202 2207 GO8 5 XRA 1-8A C2.2 1.2E-03 
 
:Product: 20011017events.txt
:Created: 2001 Oct 20 0302 UT
:Date: 2001 10 17
#Event Begin Max End Obs Q Type Loc/Frq Particulars Reg#
#-------------------------------------------------------------------------------
 
3750 + 0714 0721 0730 GO8 5 XRA 1-8A C3.5 2.8E-03 9661
3750 + 0716 0719 0747 LEA 3 FLA N13W03 SF ERU 9661
3750 0730 ////  0731 LEA C RSP 025-180 III/1 9661
3770 0835 0847 0850 GO8 5 XRA 1-8A C2.33 1.9E-03 
3790 0930 0943 0956 GO8 5 XRA 1-8A C2.51  3.4E-03 
3910 + 1717 1721 1724 GO8 5 XRA 1-8A C2.5 9.0E-04 9661
3910 1719 1720 1731 HOL 3 FLA N15W02 SF ERU 9661
4200 A2309 //// B1513 HOL 3 DSF N01W19 07 B.0A 9661

BBSO Solar Activity Report 16-OCT-2001 22:18:30 UT

NOAA 9661, N15E04. Very large and magnetically complex sunspot (beta-gamma-delta) with bright H-alpha plage along the magnetic inversion line. 9661 continues in growth phase. C- and M-class events expected with a chance of a hi-level M-class or even an X-class event.

BBSO Solar Activity Report 17-OCT-2001 22:28:38 UT

NOAA 9661, N16W09. Very large and magnetically complex sunspot. Beta-gamma-delta magnetic configuration. 9661 has been slowly developing over the past several days. The potential for a major flare has increased.

BBSO Solar Activity Report 19-OCT-2001 21:03:43 UT

NOAA 9661, N16W35. Beta-gamma region. Region has decayed from yesterday in sunspot area and is breaking up. The delta configuration has decayed. Region produced a X1.6@0105UT and a X1.6@1630UT. Expect M-class events and a chance for another X-class event.

NOAA 9661 on 2001 October 16
Number	Location	Hale	McIntosh	Area	NSpots	Events

09661

N15E03 (-47",153")

/

Eki/Dko

0720/0670

16/18

C3.5(18:09) C6.0(19:19) /C3.7(16:11)

NOAA 9661 on 2001 October 17
Number	Location	Hale	McIntosh	Area	NSpots	Events

09661

N16W10 (158",172")

/

Ekc/Eki

0800/0720

34/16

C3.5(07:14) C2.5(17:17) /C3.5(18:09) C6.0(19:19)

Stokes Profile Analysis: (as suggested by Dr. Sami Solanki)

1. First determine the following parameters:

Stokes I: (1) Line core λ₀

(2) dI/dλ

Stokes V: (3) Zero Crossing Wavelength λ_zc of (a) Mgb2 line, (b) two lines at Mgb2 wings, (c) FeI line pair

(4) Amplitudes V_{amp_ma} & V_{amp_mi} at two sides of Stokes V => amplitude asymmetry

(5) Absolute areas A_ma & A_mi at two sides of Stokes V => area asymmetry

Stokes Q, U: (6) the shifts, shifts in Blue & Red wings

(7) ratio of Stokes Q to Stokes U, or Q/sqrt(Q^2+U^2) & U/sqrt(Q^2+U^2) (reflect “shear”)

2. Then check the following relationships:

(8) normalized dI/dλ with Stokes V (By increasing filling factor, they may be similar.)

(9) plot (a) λ_zc shift VS λ₀ shift and or A

(b) V_amp VS A

(10) Amplitudes and areas of Mgb2 VS those of FeI, also with those of the lines at Mgb2 wings

(11) δλ (distance between V_{amp_ma} & V_{amp_mi}) of all the profiles. Dependence of δλ VS V_amp

(12) δλ of Mgb2 VS δλ of FeI

(13) δλ in different regions: pores, spot, plage, quiet sun

(14) compare the shapes of FeI with Mgb2, Stokes-V mainly

(15) compare Q/U ratio between photospheric and chromospheric lines

Results:

Figure 1 is a solar image (280 × 229 pixels) constructed with continuum intensity. At each point on the image, there is a set of Stokes-I,Q,U,V profiles. Therefore, we can derive the parameters: lamda_0 (λ₀), lamda_zc (λ_zc), v_amp_ma (V_{amp_ma}), v_amp_mi (V_{amp_mi}), v_area_ma (A_ma), v_area_mi (A_mi), delta_lambda (δλ), and Q/U, at each point. Finally save them into 280 × 229 pixels size images.

Figure 1. Continuum image. The red crossing marks one of points on the image.

The Stokes profiles and analysis of Mgb2 5172 line corresponding to the red crossing point are presented in Figure 2.

Figure 2. The white curves are observed profiles. Red curves are their polynomial or smooth fits.

Yellow crossings mark the fitted λ₀. Green crossings mark the fitted λ_zc, Blue crossings mark the fitted V_{amp_ma}, V_{amp_mi}

Shaded areas show A_ma & A_mi and magnitude of Stokes-Q & U signals

Figure 3. Images constructed with derived parameters from FeI 6301.5 Å stokes profiles. The neutral line shows anomalous profile. In particular, there are 6 discrete and confined points showing highly red asymmetry (amplitude and area asymmetry) of Stokes-V signal, representing probably down flows there. Q/U ratio is also very high along the neutral line, representing probably high magnetic shear there. The dopplergram (lambda_0 shift) illustrates the down flows along the neutral line. 

Figure 4. Scatter plots among derived parameters of the 5 lines.

Red: Neutral line areas with anomalous profiles. Yellow: penumbra areas. Green: pore areas. Blue: umbra areas.

First row shows that in the photosphere (lines 6301.5, 6302.5, 5171 and 5173), the neutral line has large shift in λ₀ and λ_zc, while in the lower chromosphere (line 5172), the neutral line does not show prominent larger shifts than other areas.

Second and third rows indicate that the lines are broader in the neutral line area in the photosphere.

Forth row shows that in the photosphere, the lines become broader in the neutral line area. δλ slowly decrease with increasing amplitude of Stokes-V signal in the neutral line area, which is in contrast to cases in other regions. In the chromosphere, both of the phenomena are not prominent.

Figure 5. Scatter plots of parameters between different lines.

The Resulting parameters IDL save files are listed in the following table.

Line Set	'01'	'02'	'04'	'05'	'06'	'18'
5172 (Mgb2)	line5172_set01_parameters.sav
5171 (Mgb2 left)
5173 (Mgb2 right)
6301.5 (FeI)
6302.5 (FeI)