The Chromospheric Field Probed by the He I 10830 Line
Some Recent Developments
Andreas Lagg
Max-Planck-Institut fur
¨ Sonnensystemforschung
¨
Gottingen,
Germany
Coupling and Dynamics of the Solar Atmosphere
Pune, India
Nov-11 2014
1
The He I 10830 line
He I Formation
The He I atom (Centeno et al., 2008)
3
The He I 10830 line
He I Formation
Coronal Illumination - Ionization - Recombination (Centeno et al., 2008)
4
The He I 10830 line
He I Formation
He I – What can be observed?
5
The He I 10830 line
He I Formation
He I – Formation Height
Avrett et al. (1994)
5
The He I 10830 line
He I Formation
He I – Formation Height
Avrett et al. (1994)
5
The He I 10830 line
He I Formation
He I – Formation Height
Poster on He D3 results:
T. E. L. Libbrecht et al.:
Spectrographic Helium D3
observations with SST/TRIPPEL
Avrett et al. (1994)
5
The He I 10830 line
Chromospheric B-Field with He I
B-Field and He I 10830 A˚
Zeeman + PB effect
reliable magnetic field information for
B> 200 G
0.90
0.80
Paschen-Back effect for stronger fields
saturated regime (8–100 G): directional
information
Tr2
Tr3
0.85
three (blended) HeI lines:
(”blue” line + 2 ”red” lines)
0.005
V/IC
Hanle effect
sensitive regime: ≈0.1–8 G
Tr1
0.95
I
simultaneous observation of photosphere
(Si, Ca) and chromosphere (He)
27aug03.004_he_2comp_str_bin1_1_profile_zoom3comp
1.00
0.000
−0.005
10826
10828
10830
Wavelength [Å]
10832
./ps/27aug03.004.pikaia_he_2comp_str_bin1_1_profile_zoom3comp.x0094.y
6
He I Observatories
Full-disk and hi-res instruments
He I Observatories
He I 10830 full disk instruments
SOLIS VSM and FDP
He I 10830 at high resolution
TIP-1
(NSO; until 2014: Kitt Peak, 2014:
Tucson: 2015: ???; Keller et al.,
2003)
(IAC; Tenerife; Mart´ınez Pillet et al., 1999;
Collados et al., 1999)
Chrotel
(IAC/MPS; Tenerife; Collados et al., 2007)
(KIS; Tenerife; Bethge et al., 2011)
ProMag (prominences)
CHIP
(NSO; Sunspot; Elmore et al., 2008)
TIP-2
(MacQueen et al., 1998)
NAOJ Solar Flare Telescope
(NAOJ; Hanaoka et al., 2011)
Recent hi-res Spectropolarimeters
FIRS, SPINOR, NIRIS, GRIS
7
He I Observatories
Hi-Res Spectropolarimeters
Recent Hi-Res Spectropolarimeters
SPINOR @ DST (Sac Peak)
NIRIS @ 1.6m NST (Big Bear)
Socas-Navarro et al. (2006)
Cao et al. (2012)
full Stokes simultaneous obs. of
several VIS + IR regions
attached to 1.6 m NST at Big Bear
´
dual Fabry-Perot
Interferometers
virtually any combination of
spectral line
imaging polarimetry @ 0.′′ 25
GRIS @ 1.5m GREGOR (Tenerife)
FIRS @ DST (Sac Peak)
Jaeggli et al. (2010); Schad (2013)
Collados et al. (2012)
4-slit, dual-beam spectropol.
attached to 1.5 m GREGOR
telescope (Tenerife)
Fe I 630.2 & He I 1083
standard Czerny-Turner config.
simultaneous with IBIS
spectro-polarimetry @ 0.′′ 25
8
Some Recent results
VTT - TIP-2
The magnetic field configuration of a solar prominence inferred from
´
spectropolarimetric observations in the He I 10830 A˚ triplet (Orozco Suarez
et al., 2014)
quasi-horizontal solution
quasi-vertical solution
Field strength [Gauss]
30
25
30
[arcsec]
20
20
15
10
10
5
0
0
0
20
40
[arcsec]
60
0
20
40
[arcsec]
HAZEL inversions (Asensio Ramos et al., 2008)
60
70 s/slit pos
Ambiguities (unresolved, plausibility argument: use quasi-horizontal solution):
Zeeman effect: 180◦ ambiguity
Hanle effect: 90◦ and 180◦ ambiguity
9
Some Recent results
VTT - TIP-2
The magnetic field configuration of a solar prominence inferred from
´
spectropolarimetric observations in the He I 10830 A˚ triplet (Orozco Suarez
et al., 2014)
quasi-horizontal solution
quasi-vertical solution
Field strength [Gauss]
30
25
30
[arcsec]
20
20
15
10
10
5
0
0
0
20
40
[arcsec]
60
0
20
40
[arcsec]
60
Magnetic field strength
quiescent prominence, on average 7 G
up to 30 G at prominence feet (coinciding with high opacity)
9
Some Recent results
VTT - TIP-2
The magnetic field configuration of a solar prominence inferred from
´
spectropolarimetric observations in the He I 10830 A˚ triplet (Orozco Suarez
et al., 2014)
quasi-horizontal solution
quasi-vertical solution
[arcsec]
Field inclination [degree]
140
130
30
120
110
20
100
90
10
80
0
70
60
0
20
40
[arcsec]
60
0
20
40
[arcsec]
60
Magnetic field inclination
inclined ≈77◦ to solar vertical;
in between previous results: 60◦ (e.g., Bommier et al., 1994) and horizontal
(Casini et al., 2003)
9
Some Recent results
VTT - TIP-2
The magnetic field configuration of a solar prominence inferred from
´
spectropolarimetric observations in the He I 10830 A˚ triplet (Orozco Suarez
et al., 2014)
quasi-horizontal solution
quasi-vertical solution
Field azimuth [degree]
70
60
50
40
30
20
10
0
-10
-20
[arcsec]
30
20
10
0
0
20
40
[arcsec]
60
0
20
40
[arcsec]
60
Magnetic field orientation wrt. prominence axis
inclined ≈58◦ / ≈156◦ to prominence long axis
(unresolved ambiguity), both solutions: inverse polarity prominence
9
Some Recent results
DST - FIRS
He I Vector Magnetometry of Field-aligned Superpenumbral Fibrils (Schad et al., 2013)
(a) SPECKLE Cont.
(d) He I/IC 1082.999 Å
(c) Ca II 8541.873 Å
(b) Hα 6562.46 Å
(e) He I VLOS [km/s]
10
TO DISK CENTER
240
5
θSPOT
= 180
Y [Arcsec]
220
0
200
−5
θSPOT = 90
180
−10
550
560
570
X [Arcsec]
580
550
560
570
X [Arcsec]
580
550
560
570
X [Arcsec]
580
550
560
570
X [Arcsec]
580
550
560
570
X [Arcsec]
580
IBIS & FIRS Observations, NOAA AR 11408, Jan 29 2012, µ = 0.8
10
Some Recent results
DST - FIRS
He I Vector Magnetometry of Field-aligned Superpenumbral Fibrils (Schad et al., 2013)
0
(a) Magnetic Field Strength [G]
500
1000
1500
2000
0
(b) Inclination, θB (SOLAR) [deg]
45
90
135
180
−180
(c) Azimuth, χB (SOLAR) [deg]
−90
0
90
180
240
220
220
220
200
200
180
530
Y [arcsec]
240
Y [arcsec]
Y [arcsec]
IBIS FOV
240
200
180
540
550
560
X [arcsec]
570
580
530
180
540
550
560
X [arcsec]
570
580
530
540
550
560
X [arcsec]
570
580
Photospheric field from Si I ME-inversions (H E LI X+ Lagg et al., 2009)
10
Some Recent results
DST - FIRS
He I Vector Magnetometry of Field-aligned Superpenumbral Fibrils (Schad et al., 2013)
(a) Magnetic Field Strength [G]
100
200
300
400
500
600
0
(b) Inclination, θB (SOLAR) [deg]
45
90
135
180
−180
240
240
220
220
220
200
200
180
530
Y [arcsec]
240
Y [arcsec]
Y [arcsec]
0
550
560
X [arcsec]
570
580
530
180
200
180
540
(c) Azimuth, χB (SOLAR) [deg]
−90
0
90
180
540
550
560
X [arcsec]
570
580
530
540
550
560
X [arcsec]
Fibril tracing (CRISPEX, Vissers & Rouppe van der Voort, 2012), careful
disambiguation (Hanle & Zeeman), assumption on fibril height (1.75 Mm)
570
580
10
Some Recent results
DST - FIRS
He I Vector Magnetometry of Field-aligned Superpenumbral Fibrils (Schad et al., 2013)
(a) Magnetic Field Strength [G]
100
200
300
400
500
600
0
(b) Inclination, θB (SOLAR) [deg]
45
90
135
180
−180
240
240
220
220
220
200
200
180
530
Y [arcsec]
240
Y [arcsec]
Y [arcsec]
0
550
560
X [arcsec]
570
580
530
180
200
180
540
(c) Azimuth, χB (SOLAR) [deg]
−90
0
90
180
540
550
560
X [arcsec]
570
580
530
540
550
560
X [arcsec]
570
580
B-strength: rise in strength towards inner endpoints
10
Some Recent results
DST - FIRS
He I Vector Magnetometry of Field-aligned Superpenumbral Fibrils (Schad et al., 2013)
(a) Magnetic Field Strength [G]
100
200
300
400
500
600
0
(b) Inclination, θB (SOLAR) [deg]
45
90
135
180
−180
240
240
220
220
220
200
200
180
530
Y [arcsec]
240
Y [arcsec]
Y [arcsec]
0
550
560
X [arcsec]
570
580
530
180
200
180
540
(c) Azimuth, χB (SOLAR) [deg]
−90
0
90
180
540
550
560
X [arcsec]
570
580
530
540
550
560
X [arcsec]
570
580
B-inclination: change at inner endpoint towards sunspot
10
Some Recent results
DST - FIRS
He I Vector Magnetometry of Field-aligned Superpenumbral Fibrils (Schad et al., 2013)
(a) Magnetic Field Strength [G]
100
200
300
400
500
600
0
(b) Inclination, θB (SOLAR) [deg]
45
90
135
180
−180
240
240
220
220
220
200
200
180
530
Y [arcsec]
240
Y [arcsec]
Y [arcsec]
0
550
560
X [arcsec]
570
580
530
180
200
180
540
(c) Azimuth, χB (SOLAR) [deg]
−90
0
90
180
540
550
560
X [arcsec]
570
580
530
540
550
560
X [arcsec]
570
580
B-inclination: remain horizontal until outer endpoint
few fibrils: turn over again, connect in regions of opposite polarity photosphere
10
Some Recent results
DST - FIRS
He I Vector Magnetometry of Field-aligned Superpenumbral Fibrils (Schad et al., 2013)
(a) Magnetic Field Strength [G]
100
200
300
400
500
600
(b) Inclination, θB (SOLAR) [deg]
45
90
135
0
180
−180
240
240
220
220
220
200
200
180
530
Y [arcsec]
240
Y [arcsec]
Y [arcsec]
0
550
560
X [arcsec]
570
580
530
180
200
180
540
(c) Azimuth, χB (SOLAR) [deg]
−90
0
90
180
540
550
560
X [arcsec]
570
580
530
540
550
560
X [arcsec]
570
580
B-azimuth: aligned ±10◦ with fibrils
10
Some Recent results
NST - NIRIS/IRIM
Multi-wavelength High-resolution Observations of a Small-scale Emerging Magnetic
Flux Event and the Chromospheric and Coronal Response (Vargas Dom´ınguez et al., 2014)
11
Some Recent results
NST - NIRIS/IRIM
Multi-wavelength High-resolution Observations of a Small-scale Emerging Magnetic
Flux Event and the Chromospheric and Coronal Response (Vargas Dom´ınguez et al., 2014)
11
Some Recent results
NST - NIRIS/IRIM
Multi-wavelength High-resolution Observations of a Small-scale Emerging Magnetic
Flux Event and the Chromospheric and Coronal Response (Vargas Dom´ınguez et al., 2014)
Ubiquitous small-scale reconnection
scenario (Shibata et al., 2007)?
11
Some Recent results
GREGOR - GRIS
GREGOR/GRIS Data & First Results (June 2014)
IC, 10824.17−10824.75 Å
I, 10829.88−10830.70 Å (/Ic)
V, 10827.13−10828.38 Å
V, 10830.30−10830.79 Å
1.00
0.03
0.015
1.05•104
50
50
50
50
0.02
0.010
0.95
1.00•104
40
40
40
40
0.01
0.005
0.90
30
30
0.00
Arcsec
Arcsec
Arcsec
Arcsec
9.50•103
30
30
0.000
0.85
9.00•103
20
20
20
−0.01
20
−0.005
10
−0.02
10
−0.010
−0.03
−0
0.80
8.50•103
10
8.00•103
−0
0
5
10
15
Arcsec
20
Stokes Ic
25
10
0
0.75
0
5
10
15
Arcsec
20
Stokes IHe
25
0
0
5
10
15
Arcsec
20
Stokes VSi
25
−0.015
0
5
10
15
20
25
Arcsec
Stokes VHe
12
Some Recent results
GREGOR - GRIS
GREGOR/GRIS Data & First Results (June 2014)
IC, 10824.17−10824.75 Å
I, 10829.88−10830.70 Å (/Ic)
V, 10827.13−10828.38 Å
V, 10830.30−10830.79 Å
1.00
0.03
0.015
1.05•104
50
50
50
50
0.02
0.010
0.95
1.00•104
40
40
40
40
0.01
0.005
0.90
30
30
0.00
Arcsec
Arcsec
Arcsec
Arcsec
9.50•103
30
30
0.000
0.85
9.00•103
20
20
20
−0.01
20
−0.005
10
−0.02
10
−0.010
−0.03
−0
0.80
8.50•103
10
8.00•103
−0
0
5
10
15
Arcsec
20
Stokes Ic
25
10
0
0.75
0
5
10
15
Arcsec
20
Stokes IHe
25
0
0
5
10
15
Arcsec
20
Stokes VSi
25
−0.015
0
5
10
15
20
25
Arcsec
Stokes VHe
12
Some Recent results
GREGOR - GRIS
GREGOR/GRIS Data & First Results (June 2014)
≈0.′′ 40
(diff. limit:
pol. noise level in 5 s:
Arcsec
spatial resolution:
9.50•103
0.′′ 25)
30 −4
5·10 IC
9.00•103
20
12
Some Recent results
GREGOR - GRIS
GREGOR/GRIS Data & First Results (June 2014)
I
0.02
0.01
0.00
−0.01
−0.02
U
Q
x=79 y=210, PR0
9000
8000
7000
6000
5000
4000
0.04
0.02
0.00
−0.02
−0.04
0.04
V
0.02
0.00
−0.02
−0.04
1.0825•104
fitted
observed
1.0830•104
1.0835•104
Wavelength [Å]
1.0840•104
12
Some Recent results
GREGOR - GRIS
GREGOR/GRIS Data & First Results (June 2014)
IC, 10824.17−10824.75 Å
I, 10829.88−10830.70 Å (/Ic)
V, 10827.13−10828.38 Å
V, 10830.30−10830.79 Å
1.00
0.03
0.015
1.05•104
50
50
50
50
0.02
0.010
0.95
1.00•104
40
40
40
40
0.01
0.005
0.90
30
30
0.00
Arcsec
Arcsec
Arcsec
Arcsec
9.50•103
30
30
0.000
0.85
9.00•103
20
20
20
−0.01
20
−0.005
10
−0.02
10
−0.010
−0.03
−0
0.80
8.50•103
10
8.00•103
−0
0
5
10
15
Arcsec
20
Stokes Ic
25
10
0
0.75
0
5
10
15
Arcsec
20
Stokes IHe
25
0
0
5
10
15
Arcsec
20
Stokes VSi
25
−0.015
0
5
10
15
20
25
Arcsec
Stokes VHe
12
Some Recent results
GREGOR - GRIS
GREGOR/GRIS Data & First Results (June 2014)
Ca I – deep photosphere
magnetic field strength, Comp: 5
azimuth angle, Comp: 5
inclination angle, Comp: 5
line−of−sight velocity, Comp: 5
2000
2
-90◦ ,+90◦
0,2000 G
50
0◦ ,180◦
50
-2,+2
50
km s−1
50
150
50
1500
1
40
40
40
40
20
20
20
30
0
[km/s]
[o]
30
Arcsec
0
[o]
30
Arcsec
[G]
1000
Arcsec
Arcsec
100
30
20
50
500
−1
−50
10
10
−0
0
0
5
10
15
Arcsec
20
B-strength
25
10
0
10
0
0
5
10
15
Arcsec
20
Azimuth
25
0
0
5
10
15
Arcsec
20
Inclination
25
0
−2
0
5
10
15
20
25
Arcsec
LOS-velocity
12
Some Recent results
GREGOR - GRIS
GREGOR/GRIS Data & First Results (June 2014)
Si I – mid/upper photosphere
magnetic field strength, Comp: 3
azimuth angle, Comp: 3
inclination angle, Comp: 3
line−of−sight velocity, Comp: 3
2000
2
-90◦ ,+90◦
0,2000 G
50
0◦ ,180◦
50
-2,+2
50
km s−1
50
150
50
1500
1
40
40
40
40
20
20
20
30
0
[km/s]
[o]
30
Arcsec
0
[o]
30
Arcsec
[G]
1000
Arcsec
Arcsec
100
30
20
50
500
−1
−50
10
10
−0
0
0
5
10
15
Arcsec
20
B-strength
25
10
0
10
0
0
5
10
15
Arcsec
20
Azimuth
25
0
0
5
10
15
Arcsec
20
Inclination
25
0
−2
0
5
10
15
20
25
Arcsec
LOS-velocity
12
Some Recent results
GREGOR - GRIS
GREGOR/GRIS Data & First Results (June 2014)
He I – upper chromosphere
magnetic field strength, Comp: 1
azimuth angle, Comp: 1
inclination angle, Comp: 1
line−of−sight velocity, Comp: 1
2500
-90◦ ,+90◦
0,2000 G
50
0◦ ,180◦
50
-5,+7 km s−1
50
6
50
150
2000
50
4
1000
20
20
30
20
2
[km/s]
0
100
[o]
30
40
Arcsec (0.15 <= ALPHA C1 <= 1.00)
[G]
30
[o]
1500
40
Arcsec (0.15 <= ALPHA C1 <= 1.00)
40
Arcsec (0.15 <= ALPHA C1 <= 1.00)
Arcsec (0.15 <= ALPHA C1 <= 1.00)
40
30
0
20
50
−2
−50
500
10
10
10
0
0
10
−4
−0
0
0
5
10
15
Arcsec
20
B-strength
25
0
5
10
15
Arcsec
20
Azimuth
25
0
0
5
10
15
Arcsec
20
Inclination
25
−0
0
5
10
15
20
25
Arcsec
LOS-velocity
12
Some Recent results
GREGOR - GRIS
GREGOR/GRIS Data & First Results (June 2014)
He I – upper chromosphere
magnetic field strength, Comp: 1
azimuth angle, Comp: 1
inclination angle, Comp: 1
line−of−sight velocity, Comp: 1
800
-90◦ ,+90◦
0,800 G
50
0◦ ,180◦
50
-5,+7 km s−1
50
6
50
150
50
4
600
20
20
30
20
2
[km/s]
100
[o]
0
40
Arcsec (0.15 <= ALPHA C1 <= 1.00)
30
[o]
400
40
Arcsec (0.15 <= ALPHA C1 <= 1.00)
30
[G]
40
Arcsec (0.15 <= ALPHA C1 <= 1.00)
Arcsec (0.15 <= ALPHA C1 <= 1.00)
40
30
0
20
50
−2
200
−50
10
10
10
0
0
10
−4
−0
0
0
5
10
15
Arcsec
20
B-strength
25
0
5
10
15
Arcsec
20
Azimuth
25
0
0
5
10
15
Arcsec
20
Inclination
25
−0
0
5
10
15
20
25
Arcsec
LOS-velocity
12
Some Recent results
GREGOR - GRIS
Chromospheric Fine Structure: Summary
Fine structure in the He I spectral region
fine structure mainly He I intensity:
almost absent in Stokes images / B-vector
outlines velocity and density/temp. structure
continuous decrease of fine structure in B with height:
Ca I (deep photosphere):
Si I (mid/upper photosphere):
He I (chromosphere):
0.′′ 40
0.′′ 70
1.′′ 00
13
Outlook
Instrumentation: What’s Next?
Ground-based: DKIST & NLST
DL-NIRSP (The Diffraction
Limited Near-Infrared
Spectropolarimeter, DKIST;
Haosheng Lin)
Spectral Range:
500 nm to 1800 nm
Spectral resolution:
up to 250000
˚
Spatial resolution: 0.07′′ @10830A
Target polarimetric accuracy:
> 5 · 10−4 Ic
NLST @ Hanle, India
Spectropolarimeter:
Based on SPINOR design
Spectral Range:
500 nm to 1600 (5000) nm
14
Outlook
Instrumentation: What’s Next?
Space-borne: Solar-C
SOLAR
Magnetic elements
(concentrated magnetic
f eld region)
2000km
15
Outlook
Science: What’s Next?
Scientific future of He I 10830
To-Do list for He I 10830 Science
obtain measurements at highest possible spatial
resolution, S/N in the low 10−4 range (ideal: 2D FOV)
reliable disambiguation methods (Van Vleck
ambiguity, 180◦ Hanle & Zeeman ambiguity):
→ combination with other chromospheric line?
reliable anisotropy determination (take into account
coronal illumination, symmetry breaking due to, e.g.,
sunspots):
→ determine population imbalances
reliable height determination: → high S/N,
stereoscopy
16
Outlook
Science: What’s Next?
Bibliography
Asensio Ramos, A., Trujillo Bueno, J., & Landi
Degl’Innocenti, E. 2008, ApJ, 683, 542
Collados, M., et al. 1999, in Astronomische
Gesellschaft Meeting Abstracts, 13–+
Avrett, E. H., Fontenla, J. M., & Loeser, R.
1994, in IAU Symp. 154: Infrared Solar
Physics, ed. Rabin, D. M. (Kluwer
Academic Publishers, Dordrecht, 1994),
35–47
Elmore, D. F., et al. 2008, in Society of
Photo-Optical Instrumentation Engineers
(SPIE) Conference Series, Vol. 7014,
Society of Photo-Optical Instrumentation
Engineers (SPIE) Conference Series, 16
Bethge, C., et al. 2011, A&A, 534, A105
Hanaoka, Y., et al. 2011, in Astronomical
Society of the Pacific Conference Series,
Vol. 437, Solar Polarization 6, ed. Kuhn,
J. R., et al., 371
Bommier, V., et al. 1994, Sol. Phys., 154, 231
Cao, W., et al. 2012, in Astronomical Society of
the Pacific Conference Series, Vol. 463,
Second ATST-EAST Meeting: Magnetic
Fields from the Photosphere to the
Corona., ed. Rimmele, T. R., et al., 291
Casini, R., et al. 2003, ApJL, 598, L67
Centeno, R., et al. 2008, ApJ, 677, 742
Collados, M., et al. 2007, in Astronomical
Society of the Pacific Conference Series,
Vol. 368, The Physics of Chromospheric
Plasmas, ed. Heinzel, P., Dorotoviˇc, I., &
Rutten, R. J., 611
Collados, M., et al. 2012, Astronomische
Nachrichten, 333, 872
Jaeggli, S. A., et al. 2010, Memorie della
Societa Astronomica Italiana, 81, 763
Ji, H., Cao, W., & Goode, P. R. 2012, ApJL,
750, L25
Keller, C. U., Harvey, J. W., & Giampapa, M. S.
2003, in Society of Photo-Optical
Instrumentation Engineers (SPIE)
Conference Series, Vol. 4853, Innovative
Telescopes and Instrumentation for Solar
Astrophysics, ed. Keil, S. L. & Avakyan,
S. V., 194–204
Lagg, A., et al. 2009, in Astronomical Society of
the Pacific Conference Series, Vol. 415,
The Second Hinode Science Meeting:
Beyond Discovery-Toward Understanding,
ed. Lites, B., et al., 327
MacQueen, R. M., et al. 1998, Sol. Phys., 182,
97
Mart´ınez Pillet, V., et al. 1999, in
Astronomische Gesellschaft Meeting
Abstracts, 5–+
´
Orozco Suarez,
D., Asensio Ramos, A., &
Trujillo Bueno, J. 2014, A&A, 566, A46
Schad, T. A. 2013, PhD thesis, The University
of Arizona
Schad, T. A., Penn, M. J., & Lin, H. 2013, ApJ,
768, 111
Shibata, K., et al. 2007, Science, 318, 1591
Socas-Navarro, H., et al. 2006, Sol. Phys., 235,
55
Trujillo Bueno, J. 2001, in ASP Conf. Ser. 236:
Advanced Solar Polarimetry – Theory,
Observation, and Instrumentation, 161
Vargas Dom´ınguez, S., Kosovichev, A., &
Yurchyshyn, V. 2014, ApJ, 794, 140
Vissers, G. & Rouppe van der Voort, L. 2012,
ApJ, 750, 22
17
Outlook
Science: What’s Next?
18
Atomic Polarization (Trujillo Bueno, 2001)
Case 1: Jlower = 0 −→ Jupper = 1
“normal” (scattering) case: upper level atomic polarization
→ polarization only in emission (1) (90◦ scattering)
→ no polarization in absorption (2) (forward scattering)
19
Atomic Polarization (Trujillo Bueno, 2001)
Case 2: Jlower = 1 −→ Jupper = 0
degenerate lower level: upper level cannot carry atomic polarization
→ emitted beam (1) unpolarized
→ polarization of transmitted beam (2) depends on “uneven” population of lower
level
19
Atomic Polarization (Trujillo Bueno, 2001)
Case 2: Jlower = 1 −→ Jupper = 0
degenerate lower level: upper level cannot carry atomic polarization
→ emitted beam (1) unpolarized
→ polarization of transmitted beam (2) depends on “uneven” population of lower
level
blue component of He I line
lower level carries atomic polarization
red components of He I line
both levels carry atomic polarization
19
Atomic Polarization: Emission Profiles (Trujillo Bueno, 2001)
1.0
2.0
0.8
1.5
Q/Imax (%)
I/Imax (%)
0.6
0.4
0.2
1.0
0.5
0
–0.2
–1.0
2.0
2.0
1.5
1.5
V/Imax (%)
–0.5
U/Imax (%)
0.0
1.0
0.5
1.0
0.5
0
0
–0.5
–0.5
–1.0
–3
–2
–1
0
–
0
1
(Å)
2
3
–1.0
–3
–2
–1
0
–
0
1
2
3
(Å)
20
Atomic Polarization: Absorption Profiles (Trujillo Bueno, 2001)
1.0
2.0
0.8
He I (blue)
0.4
1.5
Q/Imax (%)
I/Ic (%)
0.6
He I (red)
0.2
Si I
0.0
1.0
0.5
0
–0.5
–0.2
2.0
1.5
1.5
V/Imax (%)
U/Imax (%)
–1.0
2.0
1.0
0.5
0
–0.5
–1.0
1.0
0.5
0
–0.5
–3
–2
–1
0
1
λ – ȕ0 (Å)
2
3
–1.0
–3
–2
–1
0
1
λ – ȕ0 (Å)
2
3
21
He I: From milli-Gauss to kilo-Gauss
2
magnetic field direction
around B = 10−2 G, the density matrix
elements start to be affected by the
magnetic field caused by a feedback
effect that the alteration of the
lower-level polarization has on the
upper levels
Application: very weak fields
(high S/N required!)
↓ Regime: 8 – 100 G ↓
magnetic field strength
Regime: 0 – 8 G
1
↑
linear polarization signal
depends on:
↑
Hanle sensitive region
Zeeman:
≥70 G
Hanle saturation regime
linear polarization signal
depends on
1
magnetic field direction
coherences are negligible and the
atomic alignment values of the lower
and upper levels are insensitive to the
strength of the magnetic field
Application:
disk center, horizontal field:
tan(2φ) = Q/U
22
Atomic Polarization Causes Linear Polarization
H=5.00’’, γ=60.0, χ=0.0, vDopp=6.5, ds=0.50, dir=(0.0, 0.0, 0.0)
1.0
Tr1
B=1G
B=25G
B=100G
0.8
I
0.6
Tr2
Tr3
0.4
0.2
0.0
0.0015
0.0010
Q/IC
0.0005
0.0000
−0.0005
−0.0010
−0.0015
0.0015
0.0010
U/IC
0.0005
0.0000
−0.0005
−0.0010
−0.0015
0.004
V/IC
0.002
0.000
−0.002
−0.004
10828
10829
10830
10831
10832
23
Atomic Polarization Causes Linear Polarization
0.2
0.0
0.0015
0.0010
Q/IC
0.0005
0.0000
−0.0005
−0.0010
−0.0015
0.0015
0.0010
U/IC
0.0005
0.0000
−0.0005
−0.0010
−0.0015
0.004
23
DST - SPINOR
SPINOR @ DST (Sac Peak)
Spectro-POlarimeter for
INfrared and Optical Regions
SPINOR (Socas-Navarro et al.,
2006)
full Stokes simultaneous
observation of several VIS
+ IR regions
virtually any combination
of spectral line
Detector:
slit length:
Rockwell TCM 8600
120′′
24
DST - FIRS
FIRS @ DST (Sac Peak)
Facility Infrared
Spectrapolarimeter FIRS
(Jaeggli et al., 2010; Schad,
2013)
G
rating
S it U nit
old Mirror
F
drical Lens
4-slit, dual-beam
spectropolarimeter
Cy in
IR Pick-off Mirror
drical Lens
Cy in
e
IS Pick-off M irror
L ns
ible rm
V
old M irror
F
Fe I 630.2 & He I 1083
LCVR
LCVR
D
simultaneous with IBIS
WDM
0
1
er
Fi t
e
e
L ns
L ns
LCVR
Wollaston Prism
0
Fi ter
1
LCVR
ocalplane
D
F
WDM
I rared rm
Det: Raytheon Virgo 1k×1k HgCdTe
@He I:
λ/∆λ > 3.5 · 105 , 0.′′ 36
FOV:
174′′ ×75′′ in 18 min
S/N:
1000 in 7.5 s
e
L ns
x
arabolic Mirror
Off-A is P
Wollaston Prism
ocalplane
F
25
NST - NIRIS
NIRIS @ 1.6m NST (Big Bear)
Near-InfraRed Imaging Spectropolarimeter NIRIS (Cao
et al., 2012)
attached to 1.6 m NST at Big Bear
´
dual Fabry-Perot
Interferometers
2x×2k HgCdTe HAWAII-2RG
Wavelength range:
1000–1700 nm
Spectral resolving power:
λ/∆λ = 1.0–1.5 · 105
FOV:
85 arcsec
Parasitic light:
< 10−3
Spatial sampling:
0.083 arcsec/pixel−1
Exposure time:
20 ms for S/N ≥ 400
Strehl ratio:
≥ 0.7
Zeeman sensitivity:
≈ 10−4 Ic
Spectroscopy:
< 1 s cadence
Vector spectro-polarimetry:
< 10 s cadence
26
GREGOR / GRIS
GRIS @ 1.5m GREGOR (Tenerife)
GREGOR Infrared Spectrograph (Collados
et al., 2012)
attached to 1.5 m GREGOR
telescope (Tenerife)
standard Czerny-Turner configuration
1x×1k HgCdTe Rockwell TCM 8600
Wavelength range:
Spectral resolving power:
FOV:
Spatial sampling:
Zeeman sensitivity:
Spectroscopy:
Vector spectro-polarimetry:
1000–2300 nm
λ/∆λ = 1.9 · 105
65 arcsec
0.126 arcsec/pixel−1
≈ 10−4 Ic
< .1 s cadence
< 2 s cadence
27
GREGOR / GRIS
Observation of Ultrafine Channels of Solar Corona Heating (Ji et al., 2012)
NST IRIM in He I 10830
unexpected complexes of ultrafine
loops (100 km) reaching from
photosphere to base of corona
origin: intense, compact magnetic
field elements in intergranular
lanes
He I absorbing material injections
with subsequent coronal
brightening (observed in AIA/SDO
loops)
52 Mm
28
GREGOR / GRIS
Observation of Ultrafine Channels of Solar Corona Heating (Ji et al., 2012)
5
S-N (Mm)
4
3
2
1
0
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
5
˚
TiO 7057 A
29
GREGOR / GRIS
Observation of Ultrafine Channels of Solar Corona Heating (Ji et al., 2012)
5
S-N (Mm)
4
3
2
1
0
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
5
˚
He I 10830 A
29
GREGOR / GRIS
Observation of Ultrafine Channels of Solar Corona Heating (Ji et al., 2012)
5
S-N (Mm)
4
3
2
1
0
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
5
AIA 171 A˚
29
GREGOR / GRIS
Observation of Ultrafine Channels of Solar Corona Heating (Ji et al., 2012)
5
S-N (Mm)
4
3
Why does the cool He I
material coincide with the hot
coronal material?
2
1
0
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
5
AIA 171 A˚
29
GREGOR / GRIS
Observation of Ultrafine Channels of Solar Corona Heating (Ji et al., 2012)
5
S-N (Mm)
4
3
Could the coronal
brightening be the cause for
the enhanced He I
absorption?
2
1
0
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
5
AIA 171 A˚
29
GREGOR / GRIS
Observation of Ultrafine Channels of Solar Corona Heating (Ji et al., 2012)
5
S-N (Mm)
4
3
Missing:
Stokes signal
(interpretation of Hanle &
Zeeman)
2
1
0
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
0
1
2
3
E-W (Mm)
4
5
AIA 171 A˚
29

1 Aebischer Ivan 2 Aebischer Sonia 3 Aerne Maria Pia 4 Agustoni

NPC Course Application Form

一般演題プログラム - 日本コンベンションサービス

SYNAPSE PENDANT P 1185

スライド 1