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Astrophysical Plasmas

  • R. Casini
  • E. Landi Degl'Innocenti
Part of the Atomic, Optical, and Plasma Physics book series (SSAOPP, volume 44)

In this chapter, we discuss the application of spectro-polarimetry diagnostics to the investigation of astrophysical plasmas. We first present an overview of why polarization is expected in the spectral-line radiation that we receive from a large variety of cosmic objects, and then treat in some detail specific atomic models (e.g., the 0–1 and 1–0 two-level atoms), which illustrate how physical and electro-dynamical properties of the emitting plasma can be inferred by studying the polarized radiation in the corresponding spectral lines. The practical applications described in this chapter are taken exclusively from the realm of solar physics, mainly for two reasons: (a) from a historical point of view, the Sun was the first cosmic object to which polarization analysis of radiation was successfully applied, proving the existence of solar magnetic fields, and demonstrating the diagnostic potential of radiation phenomena involving resonance polarization, and (b) because spectro-polarimetric signals are generally very weak, their detection with a sufficient signal-to-noise ratio is possible only for strong radiation sources. In particular, a plethora of atomicpolarization effects (magnetic and collisional depolarization, alignment-toorientation conversion, level crossing and anti-crossing interferences) could be detected in the polarized light from the Sun only because of the high sensitivity that can be attained in solar observations. As the light-collecting capabilities of night-time astronomical instrumentation keep growing, it is expected that the diagnostic techniques illustrated in this chapter will become increasingly available for the investigation of plasma properties all over the universe.

Keywords

Solar Phys Scattered Radiation Stokes Parameter Atomic Polarization Astrophysical Plasma 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    J.O. Stenflo, C.U. Keller, Nature 321, 927 1997Google Scholar
  2. 2.
    M. Born, Atomic Physics (Blackie, London, 1958)Google Scholar
  3. 3.
    U. Fano, Rev. Mod. Phys. 29, 73 1957CrossRefMathSciNetADSGoogle Scholar
  4. 4.
    F. Mandl, G. Shaw, Quantum Field Theory (Wiley, New York, 1984)Google Scholar
  5. 5.
    E. Landi Degl’Innocenti, Solar Phys. 85, 3 1983CrossRefADSGoogle Scholar
  6. 6.
    E. Landi Degl’Innocenti, M. Landolfi, Polarization in Spectral Lines (Kluwer, Dordrecht, 2004)Google Scholar
  7. 7.
    J. Trujillo Bueno, R. Manso Sainz, Astrophys. J. 516, 436 1999CrossRefADSGoogle Scholar
  8. 8.
    L.D. Landau, E.V. Lifshitz, Classical Theory of Fields (Pergamon, New York, 1975)Google Scholar
  9. 9.
    W. Hanle, Z. Phys. 30, 93 1924CrossRefADSGoogle Scholar
  10. 10.
    W. Happer, Rev. Mod. Phys. 44, 169 1972CrossRefADSGoogle Scholar
  11. 11.
    R. Loudon, The Quantum Theory of Light (Clarendon, Oxford, 1983)Google Scholar
  12. 12.
    C. Cohen-Tannoudji, J. Dupont-Roc, G. Grynberg, Atom-Photon Interactions (Wiley, New York, 1992)Google Scholar
  13. 13.
    R. Manso Sainz, E. Landi Degl’Innocenti, Astron. Astrophys. 394, 1093 2002CrossRefADSGoogle Scholar
  14. 14.
    R. Manso Sainz, J. Trujillo Bueno, Phys. Rev. Lett. 91, 1102 2003Google Scholar
  15. 15.
    D.M. Brink, G.R. Satchler, Angular Momentum (Clarendon, Oxford, 1993)Google Scholar
  16. 16.
    R. Becker, Electromagnetic Fields and Interactions (Dover, New York, 1982)Google Scholar
  17. 17.
    E. Landi Degl’Innocenti, Solar Phys. 91, 1 1984CrossRefADSGoogle Scholar
  18. 18.
    R. Casini, P.G. Judge, Astrophys. J. 522, 524 1999CrossRefADSGoogle Scholar
  19. 19.
    . S. Tomcyzk, Multi-Channel Polarimeter for Coronal Magnetic Field Measurements, American Geophysical Union, Fall Meeting 2003 (2003)Google Scholar
  20. 20.
    J. Trujillo Bueno, E. Landi Degl’Innocenti, M. Collados, L. Merenda, R. Manso Sainz, Nature 415, 403 2002CrossRefADSGoogle Scholar
  21. 21.
    H. Lin, M. Penn, J. Kuhn, Astrophys. J. 493, 978 1998CrossRefADSGoogle Scholar
  22. 22.
    J. Trujillo Bueno, L. Merenda, R. Centeno, M. Collados, E. Landi Degl’Innocenti, Astrophys. J. 619, 191 2005CrossRefADSGoogle Scholar
  23. 23.
    R. Casini, R. Bevilacqua, A. López Ariste, Astrophys. J. 622, 1265 2005CrossRefADSGoogle Scholar
  24. 24.
    J.C. Lehmann, J. Physique 25, 809 1964CrossRefGoogle Scholar
  25. 25.
    J.C. Kemp, J.H. Macek, F.W. Nehring, Astrophys. J. 278, 863 1984CrossRefADSGoogle Scholar
  26. 26.
    H.R. Griem, Spectral Line Broadening by Plasmas (Academic, New York, 1974)Google Scholar
  27. 27.
    V. Bommier, S. Sahal-Bréchot, Astron. Astrophys. 69, 57 1978ADSGoogle Scholar
  28. 28.
    E. Landi Degl’Innocenti, Solar Phys. 79, 291 1982CrossRefADSGoogle Scholar
  29. 29.
    R. Casini, A. López Ariste, S. Tomczyk, B.W. Lites, Astrophys. J. 598, L67 2003CrossRefADSGoogle Scholar
  30. 30.
    A. López Ariste, R. Casini, Astrophys. J. 575, 529 2002CrossRefADSGoogle Scholar
  31. 31.
    Nguyen-Hoe, H.-W. Drawin, L. Herman, J. Quant. Spectrosc. Radiat. Transfer 7,429 1967Google Scholar
  32. 32.
    C.A. Moore, G.P. Davis, R.A. Gottscho, Phys. Rev. Lett. 52, 538 1984CrossRefADSGoogle Scholar
  33. 33.
    F.M. Levinton, G.M. Gammel, R. Kaita, H.W. Kugel, D.W. Roberts, Rev. Sci. Instr. 61, 2914 1990CrossRefADSGoogle Scholar
  34. 34.
    R. Casini, Phys. Rev. A 71, 062505 2005CrossRefADSGoogle Scholar
  35. 35.
    R. Casini, E. Landi Degl’Innocenti, Astron. Astrophys. 276, 289 1993ADSGoogle Scholar
  36. 36.
    R. Casini, E. Landi Degl’Innocenti, Astron. Astrophys. 291, 668 1994ADSGoogle Scholar
  37. 37.
    R. Casini, E. Landi Degl’Innocenti, Astron. Astrophys. 300, 309 1995ADSGoogle Scholar
  38. 38.
    R. Casini, Astron. Astrophys. Suppl. Ser. 114, 363 1995ADSGoogle Scholar
  39. 39.
    P.V. Foukal, B.B. Behr, Solar Phys. 156, 293 1995CrossRefADSGoogle Scholar
  40. 40.
    R. Casini, P.V. Foukal, Solar Phys. 163, 65 1996CrossRefADSGoogle Scholar
  41. 41.
    V. Bommier, S. Sahal-Bréchot, Solar Phys. 78, 157 1982CrossRefADSGoogle Scholar
  42. 42.
    B. Favati, E. Landi Degl’Innocenti, M. Landolfi, Astron. Astrophys. 179, 329 1987ADSGoogle Scholar
  43. 43.
    A. López Ariste, R. Casini, F. Paletou, S. Tomczyk, B.W. Lites, M. Semel, E. Landi Degl’Innocenti, J. Trujillo Bueno, K.S. Balasubramaniam, Astrophys. J. 621, 145L 2005CrossRefADSGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • R. Casini
    • 1
  • E. Landi Degl'Innocenti
    • 2
  1. 1.High Altitude ObservatoryNational Center for Atmospheric ResearchBoulderUSA
  2. 2.Dipartimento di Astronomia e Scienze dello SpazioUniversitá di FirenzeFirenzeItaly

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