Abstract
We consider the scattering of cyclotron radiation in a plasma moving along a homogeneous magnetic field. The equation of radiation transfer in a co-moving frame is derived and two limiting cases are pointed out. In the first case of a “small” velocity gradient, the total Doppler frequency shift due to variations in the plasma velocity over the flow is much smaller than the width of the line. The second, opposite, case of a “large” velocity gradient is analogous to the Sobolev approximation in the theory of moving stellar envelopes. The solution of the transfer equation for a wind-type flow illuminated by radiation of a given intensity is obtained in the latter case, when the influence of the plasma motion on cyclotron scattering is most important. It is shown that cyclotron scattering in a moving plasma differs from the known (and qualitatively similar) problems of resonance scattering in moving stellar envelopes and cyclotron scattering in a motionless plasma permeated by an inhomogeneous magnetic field. In particular, a symmetric absorption band with residual intensity proportional to the velocity gradient appears in the spectrum of the outgoing radiation, while in these two other problems, the depth of the corresponding spectral features cannot exceed half the continuum level. Detailed qualitative analysis reveals that this difference is due to the particular form of the frequency redistribution for cyclotron scattering.
Similar content being viewed by others
References
G. W. Clark, J. W. Woo, F. Nagase, et al., Astrophys. J. 353, 274 (1990).
M. Cropper, Space Sci. Rev. 54, 195 (1990).
W. H. G. Lewin, J. van Paradijs, and R. E. Taam, Space Sci. Rev. 62, 223 (1993).
V. V. Zheleznyakov and A. A. Litvinchuk, Astron. Zh. 64, 306 (1987) [Sov. Astron. 31, 159 (1987)].
G. S. Miller, R. I. Epstein, J. P. Nolta, and E. E. Fenimore, Phys. Rev. Lett. 66, 1395 (1991).
V. V. Zheleznyakov and A. V. Serber, Pis’ma Astron. Zh. 17(5), 419 (1991) [Sov. Astron. Lett. 17, 179 (1991)].
V. V. Zheleznyakov and A. V. Serber, Space Sci. Rev. 68, 275 (1994).
V. V. Sobolev, Moving Stellar Envelopes [in Russian] (Leningrad. Gos. Univ., Leningrad, 1947).
D. Mihalas, Stellar Atmospheres (Freeman, San Francisco, 1978; Mir, Moscow, 1982).
V. V. Zheleznyakov, Astrophys. Space Sci. 97, 229 (1983).
V. V. Zheleznyakov and A. A. Litvinchuk, Astrophys. Space Sci. 105, 73 (1984).
A. V. Serber, Astron. Zh. 67, 582 (1990) [Sov. Astron. 34, 291 (1990)].
V. V. Zheleznyakov and A. A. Litvinchuk, in Proceedings of the Joint Varenna-Abastumani International School and Workshop on Plasma Astrophysics (ESA, Noordwijk, 1986), ESA SP-251, p. 375.
A. A. Litvinchuk, Astron. Zh. 65, 488 (1988) [Sov. Astron. 32, 249 (1988)].
G. Schmidt, in IAU Coll. 114: White Dwarfs (Springer, Berlin, 1989), p. 305.
G. W. Clark, J. W. Woo, F. Nagase, et al., Astrophys. J. 353, 274 (1990).
T. Mihara, K. Makishima, T. Ohashi, et al., Nature 346, 250 (1990).
V. V. Sobolev, Course of Theoretical Astrophysics (Nauka, Moscow, 1985).
V. V. Zheleznyakov, Astrofizika 16, 539 (1980).
A. V. Serber, Cand. Sci. Dissertation (Phys.-Math.), Nizhni\(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l}\) Novgorod, 1998.
S. Chandrasekhar, Rev. Mod. Phys. 17, 138 (1945).
L. B. Lucy, Astrophys. J. 163, 95 (1971).
V. V. Zheleznyakov, Radiation in Astrophysical Plasma (Yanus-K, Moscow, 1997).
Author information
Authors and Affiliations
Additional information
__________
Translated from Astronomicheski\(\overset{\lower0.5em\hbox{$\smash{\scriptscriptstyle\smile}$}}{l}\) Zhurnal, Vol. 77, No. 12, 2000, pp. 922–933
Original Russian Text Copyright © 2000 by Serber.
Rights and permissions
About this article
Cite this article
Serber, A.V. Scattering of cyclotron radiation in a moving plasma. Astron. Rep. 44, 815–824 (2000). https://doi.org/10.1134/1.1327639
Received:
Issue Date:
DOI: https://doi.org/10.1134/1.1327639