The emission from the gas behind the front of a stationary shock wave is calculated for the conditions in the atmospheres of red dwarf stars for velocities u0 from 30 to 100 km/s. Energy exchange between the electron and atom-ion components is taken into account through elastic collisions, free-free, bound-bound, and bound-free collisional and radiative transitions of hydrogen in the radiation field of a star’s photosphere. Cooling by the following chemical elements is included: C, N, O, Mg, Si, S, Ca, and Fe. The following results are obtained: the post-shock gas remains transparent in the optical range of the continuum throughout the emission time; hence, it cannot be a source of the black-body radiation that appears at times during flares. The recombination and bremsstrahlung radiation of the transparent gas, as well as the flux in the Balmer series lines represent a few percent of the energy flux of matter through the viscous jump. The ratio of the fluxes in the spectrum lines and the continuum depends on u0 and on the parameters of the atmosphere. These results are consistent with the idea of multicomponent emission in flares, specifically, line emission is determined by the shock wave in layers above the photosphere, while black-body radiation comes from the photosphere heated by a flux of suprathermal particles.
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References
K. C. Gordon and G. E. Kron, Publ. Astron. Soc. Pacif. 61, 210 (1949).
V. P. Grinin and V. V. Sobolev, Astrophysics 13, 348 (1977).
V. P. Grinin and V. V. Sobolev, Astrophysics 28, 208 (1988); 31, 729 (1989).
V. P. Grinin, V. M. Loskutov, and V. V. Sobolev, Astron. zh. 70, 350 (1993).
A. H. Joy and M. L. Humason, Publ. Astron. Soc. Pacif. 61, 133 (1949).
R. E. Gershberg and P. F. Chugainov, Astron. zh. 1, 934 (1967).
W. E. Kunkel, Astrophys. J. 161, 503 (1970).
S. W. Mochnacki and H. Zirin, Astrophys. J. 239, L27 (1980).
P. F. Chugainov, Izv. KrAO, 44, 3 (1972).
E. P. Abranin, et al., Astrophys. Space Sci. 257, 131 (1998).
E. P. Abranin, et al., Astron. Astrophys. Trans. 17, 221 (1998).
M. N. Lovkaya and B. E. Zhilyaev, Izv. KrAO 103, 158 (2007).
M. N. Lovkaya, Izv. KrAO 108, 157 (2012).
M. N. Lovkaya, Astron. zh. 90, 657 (2013).
A. F. Kowalski, et al., Astrophys. J. Lett. 714, L98 (2010).
I. A. Klimishin, Tsirkulyar ShAO 6, 13 (1970).
B. W. Bopp and T. J. Moffett, Astrophys. J. 185, 239 (1973).
V. V. Sobolev and V. P. Grinin, Astrophysics 38, 15 (1995).
A. F. Kowalski, et al., Astrophys. J. Lett. 837, 125 (2017).
N. D. Kostyuk and S. B. Pikel’ner, Astron. zh. 51, 1002 (1974).
M. M. Katsova, A. G. Kosovichev, and M. M. Livshits, Astrophysics 17, 156 (1981).
M. M. Katsova, A. Ya. Boiko, and M. A. Livshits, Astron. Astrophys. 321, 549 (1997).
E. A. Bruevich and M. A. Livshits, Astron. zh. 70, 1054 (1993).
J. C. Allred, et al., Astrophys. J. 809, 104 (2015).
K. V. Bychkov and E. S. Morchenko, Vestnik MGU Seriya 3 Fizika Astronomiya 66, 298 (2011).
L. C. Johnson, Astron. J. 174, 227 (1972).
J. P. Apruzese, et al., JQSRT, 23, 479 (1981).
L. M. Biberman, V. S. Vorob’ev, and I. T. Yakubov, Nauka, Moscow (1982).
O. M. Belova and K. V. Bychkov, Astrophysics 61, 224 (2018).
V. V. Sobolev and V. V. Ivanov, Trudy astronomicheskoi observatorii 19, 3 (1962).
V. Arnaud and R. Rotheflug, Astron. Astrophys. Suppl. Ser. 60, 425 (1985).
M. J. Shull and M. Van Steenberg, Astron. Astrophys. Suppl. Ser. 55, 15 (1982).
O. M. Belova and K. V. Bychkov, Astrophysics 60, 111 (2017).
S. Narita, Progress of Theoretical Physics 49, 1911 (1973).
L. Spitzer, The Physics of Fully Ionized Gases [Russian translation], Izd. inostr. lit. (1957).
S. A. Kaplan and S. B. Pikel’ner, The Interstellar Medium [in Russian], Fizmatgiz, Moscow (1963).
O. M. Belova and K. V. Bychkov, Astrophysics 60, 200 (2017).
G. Bode, Kontinuerliche Absorption von Sternatmospheren, Kiel (1965).
E. Morchenko, K. Bychkov, and M. Livshits, Astrophys. J. Suppl. Ser. 357, Issue 2, article id. 119 (2015).
E. S. Morchenko, Astrophysics 59, 475 (2016).
A. F. Kowalski, et al., Astrophys. J. Lett. 852, 61 (2018).
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Translated from Astrofizika, Vol. 62, No. 2, pp. 267-284 (May 2019)
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Belova, O.M., Bychkov, K.V. Properties of Radiative Shock Waves in the Atmospheres of Red Dwarf Stars. Astrophysics 62, 234–250 (2019). https://doi.org/10.1007/s10511-019-09577-4
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DOI: https://doi.org/10.1007/s10511-019-09577-4