Abstract
Formation of the Hβ λ4861.34 Å line is an important topic related to the diagnosis of the basic configuration of magnetic fields in the solar and stellar chromospheres. Specifically, broadening of the Hβ λ4861.34 Å line occurs due to the magnetic and micro-electric fields in the solar atmosphere. The formation of Hβ in the model umbral atmosphere is presented based on the assumption of non-local thermodynamic equilibrium. It is found that the model umbral chromosphere is transparent to the Stokes parameters of the Hβ line, which implies that the observed signals of magnetic fields at sunspot umbrae via the Hβ line originate from the deep solar atmosphere, where lg τc ≈ −1 (about 300 km in the photospheric layer for our calculations). This is in contrast to the observed Stokes signals from non-sunspot areas, which are thought to primarily form in the solar chromosphere.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
P. Zeeman, Astrophys. J. 5, 332 (1897).
G. E. Hale, J. Geophys. Res. 13, 159 (1908).
G. X. Ai, and Y. F. Hu, Acta Astron. Sin. 27, 173 (1986).
H. Zirin, Astrophysics of the Sun (Cambridge University Press, Cambridge, 1988).
H.-Q. Zhang, and G.-X. Ai, Chin. Astron. Astrophys. 11, 42 (1987).
A. B. Severny, and V. Bumba, Observatory 78, 33 (1958).
T. Tsap, The Magnetic Fields at Different Levels in the Active Regions of the Solar Atmosphere, in Symposium-International Astronomial Union (Cambridge University Press, Cambridge, 1971).
R. G. Giovanelli, Sol. Phys. 68, 49 (1980).
M. K. Georgoulis, A. Nindos, and H. Zhang, Phil. Trans. R. Soc. A. 377, 20180094 (2019).
J. E. Vernazza, E. H. Avrett, and R. Loeser, Astrophys. J. Suppl. Ser. 45, 635 (1981).
M. Ding, and C. Fang, Chin. Astron. Astrophys. 15, 28 (1991).
D. Mihalas, Stellar Atmospheres (W. H. Freeman & Co, San Francisco, 1978).
H. A. Bethe, and E. E. Salpeter, Quantum Mechanics of One-and Two-Electron Atoms (Springer-Verlag, Heidelberg, 1957).
R. Casini, and E. Landi Degl’Innocenti, Astron. Astrophys. 276, 289 (1997).
J. Sanchez Almeida, and B. W. Lites, Astrophys. J. 398, 359 (1992).
W. Unno, Publ. Astron. Soc. Jap. 8, 108 (1956).
D. N. Rachkovsky, Izv. Krymsk. Astrofiz. Obs. 26, 63 (1962).
D. N. Rachkovsky, Izv. Krymsk. Astrofiz. Obs. 28, 259 (1962).
E. Landi Degl’Innocenti, A. Ap. Suppl. 25, 379 (1976).
A. Zelenka, Solar Phys. 40, 39 (1975).
H. Q. Zhang, Sci. China-Phys. Mech. Astron. 62, 999601 (2019), arXiv: 1912.06557.
J. Jin, Chin. Astron. Astrophys. 5, 49 (1981).
J. O. Stenflo, Solar Magnetic Field, Polarized Radiation Diagnostics (Kluwer Academic Publishers, Dordrecht, 1994).
E. Landi Degl’Innocenti, and M. Landolfi, Polarization in Spectral Lines (Kluwer Academic Publishers, New York, 2004).
H. Zhang, Acta Astrophys. Sin. 6, 295 (1986).
H. Zhang, and M. Zhang, Sol. Phys. 196, 269 (2000).
R. J. Bray, and R. E. Loughhead, Sunspots (John Wiley & Sons, Hoboken, 1965).
H. Zhang, Sol. Phys. 146, 75 (1993).
Author information
Authors and Affiliations
Corresponding author
Additional information
This work was supported by the National Natural Science Foundation of China (Grant Nos. 11673033, 11427803, and 11427901), and the Huairou Solar Observing Station, Chinese Academy of Sciences.
Rights and permissions
About this article
Cite this article
Zhang, H. Diagnostic of spectral lines in magnetized solar atmosphere: Formation of the Hβ line in sunspots. Sci. China Phys. Mech. Astron. 63, 119611 (2020). https://doi.org/10.1007/s11433-020-1584-9
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s11433-020-1584-9