1 / 38

Introduction to Solar EUV Emission Line Imaging Spectroscopy

Introduction to Solar EUV Emission Line Imaging Spectroscopy. 国立天文台 渡 邊 鉄 哉. 目次 1a. Coronal Condition と輻射・衝突モデル 1b. Ionization Equilibrium Line Intensity 2. 温度診断 (Temperature Diagnostics) 3. 密度診断 (Density Diagnostics) Line Profile 1c.  スリットレス・輝線撮像分光 (overlappograph)

hinda
Télécharger la présentation

Introduction to Solar EUV Emission Line Imaging Spectroscopy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Introduction to Solar EUV Emission Line Imaging Spectroscopy 国立天文台 渡 邊 鉄 哉

  2. 目次 • 1a. Coronal Conditionと輻射・衝突モデル • 1b. Ionization Equilibrium • Line Intensity • 2. 温度診断 (Temperature Diagnostics) • 3. 密度診断 (Density Diagnostics) • Line Profile • 1c. スリットレス・輝線撮像分光 (overlappograph) • 4. 速度診断 (Velocity Diagnostics) • Combining both? • 5. Non (Ionization) Equilibrium

  3. 太陽外層大気の一次元モデル CIV 1550Å

  4. Spectroscopic Solar Atmospheres • Photosphere; radiative transfer (LTE) • continuum, weak (photospheric) lines absorption → optically thin • Chromosphere; radiative transfer (non-LTE) • strong (chromospheric) lines (NaID, CaIIH&K, MgIIh&k, HIC=Hα, CI/II, Lyα...) → optically thin, temperature inversion → emission lines • Transitioin region/Corona; statistical equilibrium • all lines → optically thin, emission lines • -------------------------- • Optical depth; “optically thin” • CIVλ1548Å: τ0 ~ 10-2 • →Statistical Equilibrium • (collisional-radiative model)

  5. 連続光のopacity

  6. Yohkoh/BCS SUMER spectra SXV 5.04Å Solar transition region &corona

  7. Statistical Equilibrium → collisional-radiative model • dni/dt = (∫j + Σj) Pijni - (∫j + Σj) Pjinj ~ 0 • (∫j + Σj) nj = N (N; total no. of particles) • Pij = Cij + Rij Pji = Cji + Rji • Coronal Condition • ○Collisional excitation – Radiative decay • ○Collisional (auto) ionization • – Radiative (dielectronic) recombination • →Pij~ Cij Pji ~ Rji (+Cji)

  8. Coronal Condition • Rate (cm-3s-1) Characteristic time (s) opt.thin low n • Collisional excitation nineCij 2×10-3 • Radiative excitation (absorption) niBij4πJ × • Collisional deexcitation nj*neCji 2×10-3× • Spontaneous radiative decay njAji 4×10-9 • Collisional ionization nenionqcoll 107 • Autoionization nenionqauto • Phtoionization nionαrad4πJ × • Total ionization nenionqtot 107 • Radiative recombination nenionαrad 88 • Dielectronic recombination nenionαdiel • Three-body recombination (collisional recombination) × • Total recombination rate nenionαtot 88

  9. Dielectronic recombination/Autoionization • X+z(nl) + e (E, l”+1)↔ X+(z-1)(n’l+1; n”l”) • X+(z-1)(n’l+1; n”l”) → X+(z-1)(nl; n”l”) + hν • ← X+(z-1)(nl; n”l”) + e

  10. Ionization Equilibrium; Relaxation Time Scales Neτequil ~ 1012 cm-3sec Brooks et al. (1999)

  11. Line intensity of a permitted line (j → i) (Emissivity /volume) ←radiative-collisional model excited state << ground state

  12. ↓element abundance ↑ion fraction G(T); contribution function

  13. ←emission measure ←differential emission measure

  14. Temperature diagnostics •  ← Intensity ratio of two permitted lines at the same ionization stage • Li-like; (2s-3p, 2s-3s, 2p-3d) / (2s-2p) • OVI, NeVIII, MgX, … • He-like; Gabriel (1972) • resonance/dielectronic satellites • inner-shell excitation lines

  15. j, k w SXVI 1s z SXV 1P 1s2p x, y 3S 1s2s 3P 1s2p q 1s2p2 1s2s2p x y j, k q z w 1S 1s2 SXIV 1s22s 1s22p (He-like) (Li-like)

  16. w • SXV temperatature diagnostics

  17. Temperature Sensitive Line Pairs (CDSn,g/SUMER) • ION Wavelength (λ) • OIII 702.98g/599.59n • OV 172.17g/629.73n • OVI 184g/1032s • NeV 359n/572.20n 365n/572.20n • 416.20g/569.20n or 572.20n • MgIX 705.80g/749g • SiXI 604n/580.90n

  18. Differential Emission Measure • FeVIII(log T=5.6), IX, X, XI, XII, XIII, XIV, XV, XV, XVI, XVII (log T=6.5) • MgVI(log T=5.6), VII, VIII, IX (log T=6.0) • SiVII(log T=5.8), VIII, IX, X (log T=6.0) • NeV (log T=5.5), VI, VII, VIII (log T=5.8) • NeI (log T=4.4), III (log T=4.9)

  19. Density diagnostics • ← collisional deexcitation ~ radiative decay • Allowed line excited from the ground state • vs. • 2a. Forbidden line originating from metastable levels • 2b. Allowed lines excited from metastable levels

  20. Helium-like ion • resonance line (w) ; 1s21S – 1s2p 1P • forbidden line (z); 1s21S – 1s2s 3S • intersystem line (x,y); 1s21S – 1s2p 3P

  21. j, k w SXVI 1s z SXV 1P 1s2p x, y 3S 1s2s 3P 1s2p q 1s2p2 1s2s2p x y j, k q z w 1S 1s2 SXIV 1s22s 1s22p (He-like)

  22. SXV density diagnostics • Te = 9×106 K

  23. C14 <<C13~C24 4 3 2 1 A31 C13 A32 C14 C24 A42 C23 C21 A21 C12 • Four level case • R=(n4A42)/(n3A31) • n4(A42+A41)=n1neC14+n2neC24 • n3(A32+A31)=n1neC13+n2neC23 • n1ne(C12+C13+C14)=n4A41+n3A31+n2(A21+neC21)

  24. αji≡Aji/(Aj1+Aj2) • R={α42[C14+(n2/n1)C24]}/{α31[C13+(n2/n1)C23]} • n2/n1=(C12+C13α32+C14α42)/ • (A21/ne+C21+C23α31+C24α41) • ∴ R = (α42C14)/(α31C13) for low density (n2/n1 << 1) • (neC12 ≒ A21;density sensitive) • ~ const for high density (n2/n1 ~ const)

  25. FeXIV density sensitive line ratio λ 274.21Å 3s23p 2P1/2 (1) – 3s3p22S1/2 (3) λ 264.79Å 3s23p 2P3/2 (2) – 3s3p22P3/2 (4) λ5303Å

  26. Iron ion density sensitive line pairs (CDS) • Ion Wavelength (λ) • FeX 175.27/174.53g • FeXI 180.41,184.70/181.14g • FeXII 186.87,196.64/193.51g • 338.27/364.47n • FeXIII 202.04, 201.12/200.02g, 203.79g • 318.12, 348.18/320.80,359.64n • FeXIV 219.12/211.32g • 264.80/274.20g

  27. Line profile (intrinsic) • Voigt (Gaussian + Lorenzian) • Gaussian • thermal Doppler (+ microturbulence) • Lorenzian • natural damping • Others • pressure (van der Waals) broadening • Stark broadening (Holtsmark)

  28. Slitless emission line spectroscopy Overlappograph 凹面回折格子

  29. Velocity (line of sight velocity) diagnostics • Microturbulence • correlation length • …small • Macroturbulence; • correlation length • …small (transverse) • …long (line of sight) • Systematic motion • (blue/red shifts) • correlation length…long

  30. Strong & isolated lines for dynamic studies • (CDS/NIS) • Ion Wavelength(Å) log T • HeI 584.33 4.3 • OIII 599.59 4.9 • OIV 554.52 5.3 • NeVI 562.83 5.6 • MgVIII 313.73 5.9 • MgIX 368.06 6.0 • FeXII 364.47 6.2 • FeXIII 320.80 6.2 • FeXIV 334.17 6.3 • FeXV 327.02 6.3 • FeXVI 335.40 6.4

  31. Non-Equilibrium

  32. Dynamic Transition Region and Corona (CDS)

  33. Hydrodynamical Simulations (Teriaca et al. 1999) Nano flare at the OVI forming layer

  34. References: • Mariska J. T.: Solar Transition Region, 1992, Cambridge University Press. • Jefferies, J. T.: Spectral Line Formation, 1968, Blaisdell Publ. Co. • Harrison, R. A. & Fludra, A.: CDS for SoHO Scientific Report, 199x, RAL • SUMER Red Book; 199y, Max-Planck Institute für Aeronomie

More Related