Abstract
We consider the flare oscillations from the active red dwarf AT Mic detected with the XMM-Newton space observatory in the soft X-ray energy range (0.2–12 keV). Following Mitra-Kraev et al. (2005a), we associate the observed oscillations with a period of ≈750 s with the excitation of a standing slow magnetoacoustic (SMA) wave in a coronal loop. The damping of flare loop SMA oscillations is shown to be governed by electron thermal conduction. We have estimated the plasma density (≈3 × 1010 cm−3) and the minimum magnetic field strength (≈100 G) in the region of flare energy release. The adopted model is consistent with the results of a spectral analysis of the soft X-ray emission. The piston mechanism is assumed to be responsible for the excitation of loop SMA oscillations.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
M. J. Aschwanden, presented at Proceedings of the Royal Society Discussion Meeting “MHD Waves and Oscillations in the Solar Plasma,” Ed. by J. M. T. Thompson (2005) (in press).
S. I. Braginskii, Vopr. Teor. Plazmy 1, 183 (1963).
B. De Pontieu, R. Erdélyi, and I. De Moortel, Astrophys. J. 624, L61 (2005).
R. E. Gershberg, Solar-Type Activity in Main-Sequence Stars (Astroprint, Odessa, 2002; Springer, Berlin, 2005).
B. E. Gordon and J. V. Hollweg, Astrophys. J. 266, 373 (1983).
M. Mathioudacis, J. H. Seiradakis, D. R. Williams, et al., Astron. Astrophys. 403, 1101 (2003).
U. Mitra-Kraev, L. K. Harra, D. R. Williams, and E. Kraev, Astron. Astrophys. 436, 1041 (2005a).
U. Mitra-Kraev, L. K. Harra, M. Güdel, et al., Astron. Astrophys. 431, 679 (2005b).
D. J. Mullan, Astrophys. J. 282, 603 (1984).
D. J. Mullan, R. B. Herr, and S. Bhattacharyya, Astrophys. J. 391, 265 (1992).
Z. E. Musielak and P. Ulmschneider, Astron. Astrophys. 400, 1057 (2003).
V. M. Nakariakov, L. Ofman, E. E. Deluca, et al., Science 285, 862 (1999).
V. M. Nakariakov, D. Tsiklauri, A. Kelly, et al., Astron. Astrophys. 414, L25 (2004).
V. M. Nakariakov, E. Verwichte, D. Berghmans, and E. R. Robbrecht, Astron. Astrophys. 362, 1151 (2000).
E. R. Priest, Solar Magnetohydrodynamics (Reidel, Dordrecht, 1982; Mir, Moscow, 1985).
E. Priest and T. Forbes, Magnetic Reconnection (Cambridge Univ. Press, Cambridge, 2000).
A. J. J. Raassen, R. Mewe, M. Audard, and M. Güdel, Astron. Astrophys. 411, 509 (2003).
V. Roberts, Advances in Solar System Magnetohydrodynamics, Ed. by E. R. Priest and A. W. Wood (Cambridge Univ. Press, Cambridge, 1991; Mir, Moscow, 1995), p. 112.
L. M. Sarro, R. Erdélyi, J. G. Doyle, and M. E. Pérez, Astron. Astrophys. 351, 721 (1999).
M. Selwa, K. Murawski, and S.K. Solanki, Astron. Astrophys. 436, 701 (2005).
A. V. Stepanov, Yu. G. Kopylova, Yu. T. Tsap, and E. G. Kupriyanova, Pis’ma Astron. Zh. 31, 684 (2005) [Astron. Lett. 31, 612 (2005)].
S. I. Syrovatskii, Usp. Fiz. Nauk LXII, 247 (1957).
Y. Taroyan, R. Erdély, J. G. Doyle, and S. J. Bradshaw, Astron. Astrophys. 438, 713 (2005).
Yu. T. Tsap, and Yu. G. Kopylova, Pis’ma Astron. Zh. 27, 859 (2001) [Astron. Lett. 27, 737 (2001)].
D. Tsiklauri, V. M. Nakariakov, T. Arber, and M. J. Aschwanden, Astron. Astrophys. 422, 351 (2004).
T. J. Wang, S. K. Solanki, D. E. Innes, and W. Curdt, Astron. Astrophys. 435, 753 (2005).
V. V. Zaitsev, A. G. Kislyakov, and A. V. Stepanov, Pis’ma Astron. Zh. 30, 362 (2004) [Astron. Lett. 30, 319 (2004)].
V. V. Zaitsev and A. V. Stepanov, Pis’ma Astron. Zh. 15, 154 (1989) [Sov. Astron. Lett. 15, 66 (1989)].
V. V. Zaitsev, A. V. Stepanov, S. Urpo, and S. Pohjolainen, Astron. Astrophys. 337, 887 (1998).
Author information
Authors and Affiliations
Additional information
Original Russian Text © A.V. Stepanov, Yu.T. Tsap, Yu.G. Kopylova, 2006, published in Pis’ma v Astronomicheskiĭ Zhurnal, 2006, Vol. 32, No. 8, pp. 631–636.
Rights and permissions
About this article
Cite this article
Stepanov, A.V., Tsap, Y.T. & Kopylova, Y.G. Soft X-ray oscillations from AT Mic: Flare plasma diagnostics. Astron. Lett. 32, 569–573 (2006). https://doi.org/10.1134/S1063773706080081
Received:
Issue Date:
DOI: https://doi.org/10.1134/S1063773706080081