What mechanisms allow the 5-minute oscillations in the active regions of the solar surface to penetrate from the photosphere into the chromosphere?
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| 1Kostyk, RI 1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine |
| Kinemat. fiz. nebesnyh tel (Online) 2015, 31(4):45-53 |
| Start Page: Solar Physics |
| Language: Russian |
Abstract: Using some results of filter (line center of Ca II λ 396.8 nm) spectral (in Ba II λ 455.4 nm) and spectropolarimetric (in Fe I λλ 1564.3—1565.8 nm) observations of an active region (isolated faculae near the solar disk center) with the German Vacuum Tower Telescope (VTT) at the Canaries Institute of Astrophysics, we investigated some properties of the propagation of five-minute oscillations from the bottom of the photosphere (h = 0 km) to the bottom of the chromosphere (h = 1600 km). Maximum oscillation power in the lower photosphere, in the transition region, and in the middle chromosphere falls at a period close to P ≈ 5 min. At the height h = 1600 km is well seen even one oscillation period P ≈ 700 sec. Penetration of 5-min oscillations from the photosphere into the chromosphere is allowed by two factors: the inclination of the magnetic field lines and the deviation of wave propagation process from adiabatic. Maximal power of 5-minute oscillations at the height h=1600 km to fit on the inclination angles of the magnetic field in the range of 11°—13° and the phase shift between the oscillations of temperature and velocity of 40—50 degrees. |
| Keywords: 5-minute oscillations, Sun, VTT telescope |
References:
1.N. Bel and B. Leroy, “Analytical study of magneto-acoustic gravity waves,” Astron. Astrophys. 55, 239–243 (1977).
2.M. Blondel, “Statistical compared studies of velocity-fields in a facular region and in two quiet regions of the photosphere,” Astron. Astrophys. 10, 342–353 (1971).
3.R. Centeno, M. Collados, and J. Trujillo Bueno, “Oscillations and wave propagation in different solar magnetic features,” Astron. Soc. Pac. Conf. Ser. 358, 465–470 (2006).
4.R. Centeno, M. Collados, and J. Trujillo Buen, “Wave propagation and shock formation in different magnetic structures,” Astrophys. J. 692, 1211–1220 (2009).
https://doi.org/10.1088/0004-637X/692/2/1211
5.F.-L. Deubner, “Some properties of velocity fields in the solar photosphere,” Sol. Phys. 2, 133–149 (1967).
https://doi.org/10.1007/BF00155914
6.F.-L. Deubner, “Waves and oscillations in the non-magnetic photosphere,” Int. Astron. Union, Symp. (IAUS) 138, 217–228 (1990).
7.A. G. de Wijn, S. W. McIntosh, and B. de Pontieu, “On the propagation of p-modes into the solar chromospheres,” Astrophys. J., Lett. 702, 168–171 (2009).
https://doi.org/10.1088/0004-637X/702/2/L168
8.L. Heggland, B. de Pontieu, and V. H. Hansteen, “Numerical simulations of shock wave-driven chromospheric jets,” Astrophys. J. 666, 1277–1283 (2007).
https://doi.org/10.1086/518828
9.L. Heggland, V. H. Hansteen, B. de Pontieu, and M. Carlsson, “Wave propagation and jet formation in the chromospheres,” Astrophys. J. 743, 142–171 (2011).
https://doi.org/10.1088/0004-637X/743/2/142
10.H. Holweger and L. Testerman, “Five-minute oscillations of solar equivalent width,” Sol. Phys. 43, 271–284 (1975).
https://doi.org/10.1007/BF00152351
11.R. Howard, “Velocity field in the solar atmosphere,” Sol. Phys. 2, 3–33 (1967).
https://doi.org/10.1007/BF00155889
12.E. Khomenko, R. Centeno, M. Collados, and J. Trujillo Bueno, “Channeling 5 minute photospheric oscillations into the solar outer atmosphere through small-scale vertical magnetic flux tubes,” Astrophys. J., Lett. 676, 85–88 (2008).
https://doi.org/10.1086/587057
13.N. I. Kobanov and V. V. Pulyaev, “Photospheric and chromospheric oscillations in solar faculae,” Sol. Phys. 246, 273–279 (2007).
https://doi.org/10.1007/s11207-007-0391-7
14.R. Kostik and E. Khomenko, “Properties of convective motions in facular regions,” Astron. Astrophys. 545, 1–9 (2012).
https://doi.org/10.1051/0004-6361/201219534
15.R. Kostic and E. Khomenko, “Properties of oscillatory motions in a facular region,” Astron. Astrophys. 559, 1–10 (2013).
16.R. Kostik, E. Khomenko, and N. Shchukina, “Solar granulation from photosphere to low chromosphere observed in Ba II 4554 A line,” Astron. Astrophys. 506, 1405–1415 (2009).
https://doi.org/10.1051/0004-6361/200912441
17.R. I. Kostyk and E. V. Khomenko, “The effect of acoustic waves on spectral-line profiles in the solar atmosphere: observations and theory,” Astron. Rep. 46, 925–931 (2002).
https://doi.org/10.1134/1.1522081
18.J. M. Krijger, R. J. Rutten, B. W. Lites, et al., “Dynamics of the solar chromosphere. III. Ultraviolet brightness oscillations from TRACE,” Astron. Astrophys. 379, 1052–1082 (2001).
https://doi.org/10.1051/0004-6361:20011320
19.B. W. Lites, R. J. Rutten, and W. Kalkofen, “Dynamics of the solar chromosphere. I. Long-period oscillations,” Astrophys. J. 414, 345–356 (1993).
https://doi.org/10.1086/173081
20.A. G. Michalitsanos, “The five-minutes period oscillations in magnetically active regions,” Sol. Phys. 30, 47–61 (1973).
https://doi.org/10.1007/BF00156172
21.R. W. Noyes and R. B. Leighton, “Velocity field in the solar atmosphere. II. The oscillatory field,” Astrophys. J. 138, 631–647 (1963).
https://doi.org/10.1086/147675
22.F. W. Orral, “Observational study of macroscopic inhomogeneities in the solar atmosphere. VIII. Vertical chromospheric oscillations measured in K3,” Astrophys. J. 143, 917–927 (1966).
https://doi.org/10.1086/148567
23.B. Roberts, “Wave propagation in intense flux tubes,” Sol. Phys. 87, 77–93 (1983).
https://doi.org/10.1007/BF00151162
24.N. R. Sheeley and A. Bhatnagar, “Measurements of the oscillatory and slowly-varying components of the solar velocity field,” Sol. Phys. 18, 379–384 (1971).
https://doi.org/10.1007/BF00149059
25.M. Stangalini, D. Del Moro, F. Berrilli, and S. M. Jefferies, “MHD wave transmission in the Sun’s atmosphere,” Astron. Astrophys. 534, 1–7 (2011).
https://doi.org/10.1051/0004-6361/201117356
26.I. P. Turova, “Peculiarities of the mode of oscillations in a floccule and its neighborhoods at different chromospheric levels,” Astron. Lett. 37, 799–816 (2011).
https://doi.org/10.1134/S1063773711110065
27.C. A. Whitney, “Granulation and oscillation of the solar atmosphere,” Smithson. Contrib. Astrophys. 2, 365–376 (1958).
https://doi.org/10.5479/si.00810231.2-12.365
28.D. T. Woods and L. E. Cram, “High resolution spectroscopy of the disk chromospheres,” Sol. Phys. 6, 233–238 (1981).
https://doi.org/10.1007/BF00149991
29.Y. D. Zhugzhda and N. S. Dzhalilov, “Magneto-acoustic-gravity waves on the Sun. I. Exact solution for an oblique magnetic field,” Astron. Astrophys. 132, 45–51 (1984).