Radial velocities of the photospheric matter in a solar flare with matter ejection
Tóm tắt
We present results of a study of photospheric horizontal motions at the initial and main phases of the solar flare which happened on September 4, 1990, near the solar limb. The flare was accompanied by matter ejection. Spectra of the flare were obtained using the AZU-26 horizontal solar telescope at the MAO NAS (Terskol observatory). We found variations of the matter motion velocity’s value and direction at different stages of the photosphere during the flare development. The velocity changed in a range from −4 to 2 km/s. Comparisons of the obtained data with variations of the chromospheric radial velocities showed that the horizontal matter motions in the photosphere and chromosphere are mostly directed toward the observer but at particular time moments their direction changed. At two different knots, the time shift of the photospheric velocities is different. The highest velocities were observed at the main phase of the flare. At the initial phase of the flare, in the matter ejection region, we note a velocity increase compared with its preflare value and at the flare knots.
Tài liệu tham khảo
K. V. Alikaeva, K. A. Burlov-Vasil’ev, I. E. Vasil’eva, et al., “Horisontal Solar Telescope ATsU-26 on Caucasus,” Kinem. Fiz. Nebesn. Tel 12(6), 65–74 (1996).
A. S. Gadun and V. A. Sheminova, SRANSAT: Calculation Program of Profiles of Spectral Absorbtion Lines in Stellar Atmospheric in LTE Approach (Kiev, 1988) [in Russian].
E. A. Gurtovenko and R. I. Kostyk, Fraungofer Spectrum and the System of Solar Forces of Oscillators (Nauk. Dumka, Kiev, 1989) [in Russian].
V. O. Danilevs’kii, S. S. Er’omin, and O. O. Rozhilo, “Instrumentation for Spectral Observations of Active Regions on the Sun,” Visn. Kiiv. Univ., Ser. Fiz. Mat. Nauki, No. 6, 96–100 (1992).
V. G. Parusimov, “Automatic Digital Two-Coordinate Microphotometer for Input of Photographic Images Into Computer,” Astrom. Astrofiz., No. 45, 86–99 (1981).
M. M. Pasechnik, “Motion of Chromospheric Matter in Active Region During Flare with Ejection,” Visn. Kiiv. Nats. Univ., Astron., Nos. 39–40, 13–16 (2003).
R. C. Canfield, T. A. Gunkler, and P. J. Ricchiazzi, “The Hα Spectral Signatures of Solar Flare Nonthermal Electrons, Conductive Flux, and Coronal Pressure,” Astrophys. J. 282, 296–307 (1984).
R. C. Canfield, K. P. Reardon, K. D. Leka, et al., “Hα Surges and X-Ray Jets in AR 7260,” Astrophys. J. 464, 1016–1029 (1996).
G. Cauzzi, A. Falchi, R. Falciani, and L. A. Smaldone, “Coordinated Observations of Solar Activity Phenomena II. The Velocity Field Pattern in An Elementary Flare,” Astron. Astrophys. 306, 625–637 (1996).
H. D. Chen, Y. C. Jiang, and S. L. Ma, “Observations of Hα Surges and Ultraviolet Jets Above Satellite Sunspots,” Astron. Astrophys. 478, 907–913 (2008).
C. Fang, J. C. Henoux, and W. Q. Gan, “Diagnostics of Non-Thermal Processes in Chromospheric Flares. I. Hα and Ca II K Line Profiles of An Atmosphere Bombarded by Hecta KeV Electrons,” Astron. Astrophys. 274, 917–922 (1993).
V. S. Gorbachev and B. V. Somov, “Photospheric Vortex Flows As a Cause for Two-Ribbon Flares. A Topological Model,” Solar Phys. 117, 77–88 (1988).
K. L. Harvey and J. W. Harvey, “A Study of the Magnetic and Velocity Fields in An Active Region,” Solar Phys. J. 47, 233–246 (1976).
S. L. Keil, K. S. Balasubramanian, P. Bernasconi, et al., “Observations of Active Region Dynamics: Preflare Flows and Field Observations,” in Solar Active Region Evolution: Comparing Models with Observations, Ed. by K. S. Balasubramaniam and G. W. Simon, ASP Conf. Ser. 68, 265–281 (1994).
N. N. Kondrashova, “Line-Of-Sight Velocities in a Flaring Active Region,” Kinem. Phys. Celest. Bodies, Suppl. No. 5, 179–182 (2005).
A. G. Kosovichev, “The Cause of the Photospheric and Helioseismic Responses To Solar Flares: High-Energy Electrons Or Protons?,” Astrophys. J. 670, L65–L68 (2007).
H. Kurokawa and G. Kawai, “Hα Surge Activity at the First Stage of Magnetic Flux Emergence,” in The Magnetic and Velocity Fields of Solar Active Regions, Ed. by H. Zirin, G. Ai, and H. Wang, ASP Conf. Ser. 46, 507 (1993).
H. Kurokawa, Y. Liu, S. Sano, and T. T. Ishii, “Observation of Magnetic Field Reconnection at the Base of EFR Surges,” ASP Conf. Ser. 369, 347 (2007).
Y.-J. Moon, J. Chae, G. S. Choe, et al., “Flare Activity and Magnetic Helicity Injection by Photospheric Horizontal Motions,” Astrophys. J. 574, 1066–1073 (2002).
Y.-J. Moon, J. Chae, H. Wang, et al., “Impulsive Variations of the Magnetic Helicity Change Rate Associated with Eruptive Flares,” Astrophys. J. 580, 528–537 (2002).
Y.-J. Moon, J. Chae, and Y. D. Park, “Magnetic Helicity Changes of Solar Active Regions by Photospheric Horizontal Motions,” J. Korean Astron. Soc. 36, 37–44 (2003).
C. E. Moore, M. G. J. Minnaert, and J. Houtgast, The Solar Spectrum 2935 to 8770 A (National Bureau of Standards, Washigton, 1966).
N. E. Piskunov, F. Kupka, T. A. Ryabchikova, et al., “VALD: The Vienna Atomic Line Data Base,” Astron. Astrophys. Suppl. Ser. 112, 525–535 (1995).
G. Roumeliotis and R. L. Moore, “A Linear Solution for Magnetic Reconnection Driven by Converging Or Diverging Footpoint Motions,” Astrophys. J. 416, 386–391 (1993).
Solar Geophys. Data (1991), p. II.
B. V. Somov, T. Kosugi, H. S. Hudson, et al., “Magnetic Reconnection Scenario of the Bastile Day 2000 Flare,” Astrophys. J. 579, 863–873 (2002).