Physical conditions in the chromosphere of a solar two-ribbon flare, accompanied by a surge. II
Heading:
| 1Baranovskii, EA, 2Kondrashova, NN, 2Pasechnik, MN, 1Tarashchuk, VP 1Crimean Astrophysical Observatory, Nauchny, Ukraine 2Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine |
| Kinemat. fiz. nebesnyh tel (Online) 2014, 30(6):14-26 |
| Start Page: Solar Physics |
| Language: Russian |
Abstract: The modeling of the chromosphere of the two-ribbon flare which took place on 4 September 1990 and was accompanied by a surge is performed on the basis of spectral observations obtained at the solar horizontal telescope ATsU-26 at the Terskol Peak Observatory. Semiempirical models were calculated for three moments of the flare at the phase of soft X-ray radiation intensity gradual increase. The changes in the plasma physical parameters in different parts of the surge (in the center and on the edge) and flare kernels to which it was projected were studied. The modeling was carried out using two- or three-component models chromosphere by matching the observed and calculated line profiles. Additional components of the models with filling factors from 2 to 15 % were necessary for explanation of the significant emission in the line wings. Our calculations showed that the temperature of these components in the lower layers of the chromosphere was increased by 1000—3500 K as compared to the temperature in the quiet Sun (VAL-C model). Line-of-sight velocities are determined which explain the pattern of the profile asymmetries. In most of the obtained models matter motion bulk in the upper and lower chromosphere is directed towards the observer. The velocities in the upper chromosphere varied from –100 km/s to –15 km/s, and in the lower one they did not exceed –40 km/ s. In some periods in the middle chromosphere of the surge central part the velocity from the observer was 15 km/s. Additional components showed the presence of oppositely directed flows with velocities to –100 km/s towards the observer and 50—160 km/s from the observer. |
| Keywords: chromosphere, solar flare, Sun |
References:
1.E. A. Baranovskii, N. N. Kondrashova, M. N. Pasechnik, and V. P. Tarashchuk, “Physical conditions in the chromosphere of a two-ribbon solar flare accompanied by a surge: 1,” Kinemat. Phys. Celest. Bodies 29(4), 167–175 (2013).
https://doi.org/10.3103/S0884591313040028
2.N. N. Kondrashova and M. N. Pasechnik, “Radial velocities of the photospheric matter in a solar flare with matter ejection,” Kinemat. Phys. Celest. Bodies 26(1), 26–35 (2010).
https://doi.org/10.3103/S0884591310010034
3.N. N. Kondrashova and M. N. Pasechnik, “Radial velocity field in the lower atmosphere of the solar active region during a flare with an ejection. The initial phase of the flare,” Kinemat. Phys. Celest. Bodies 27(5), 224–232 (2011).
https://doi.org/10.3103/S0884591311050059
4.M. N. Pasechnik, “Chromosperic matter motion in active region during a flare with an ejection,” Visn. Kiyv. Nats. Un. Im. Shevchenka, Astronomiya, Nos. 39–40, 13–16 (2003).
5.E. R. Priest, Solar Magnetohydrodynamics (Reidel, Dordrecht, 1982; Mir, Moskow, 1985).
https://doi.org/10.1007/978-94-009-7958-1
6.E. H. Avrett and R. Loeser, “Formation of line and continuous spectra. I. Source-function calculations,” Spec. Report SAO, No. 303 (1969).
7.J. Y. Ding, M. S. Madjarska, J. G. Doyle, et al., “Magnetic reconnection resulting from flux emergence: implications for jet formation in the lower solar atmosphere ?,” Astron. Astrophys. 535, A95 (2011).
https://doi.org/10.1051/0004-6361/201117515
8.X. M. Gu, J. Lin, K. J. Li, et al., “Kinematic characteristics of the surge on March 19, 1989,” Astron. Astrophys. 282, 240–251 (1994).
9.P. Kayshap, A. K. Srivastava, and K. Murawski, “The kinematics and plasma properties of a solar surge triggered by chromospheric activity in AR11271,” Astrophys. J. 763(1) (2013).
10.K. Li, J. Li, X. Gu, and S. H. Zhong, “A quantitative analysis of the surge on March 19, 1989,” Solar Phys. 168(1), 91–103 (1996).
https://doi.org/10.1007/BF00145827
11.N. Nishizuka, M. Shimizu, T. Nakamura, et al., “Giant chromospheric anemone jet observed with Hinode and comparison with magnetohydrodynamic simulations: evidence of propagating Alfven waves and magnetic reconnection,” Astrophys. J. 683(1), L83–L86 (2008).
https://doi.org/10.1086/591445
12.K. Tziotziou, G. Tsiropoula, and P. Sitterlin, “DOT tomography of the solar atmosphere. V. Analysis of a surge from AR 10489,” Astron. Astrophys. 444, 265–274 (2005).
https://doi.org/10.1051/0004-6361:20053604
13.J. E. Vernazza, E. H. Avrett, and R. Loeser, “Structure of the solar chromosphere. III. Models of the EUV brightness components of the quiet Sun,” Astrophys. J., Suppl. Ser. 45(4), 635–725 (1981).
https://doi.org/10.1086/190731