Small-scale magnetic features in active region NOAA 11024

Heading: 
Solar Physics
1Kondrashova, NN, 2Leiko, UM
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
2Astronomical Observatory of Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2019, 35(2):28-49
https://doi.org/10.15407/kfnt2019.02.028
Start Page: Solar Physics
Language: Russian
Abstract: 

We analyzed spectropolarimetric data obtained for an active region NOAA 11024 with the French-Italian telescope THEMIS on Tenerife (Canary Islands) on 4 July 2009, consisting of the Stokes V measurements of the photospheric lines Fe I 630.15 nm, Fe I 630.25 nm, Fe I 630.35 nm, and Ti I 630.38 nm. The region studied includes two pores of opposite polarity and two plages. One of pores was developing during observation. Eruptive events, such as chromospheric surges, Ellerman bombs were observed in this area. The Stokes V profiles of the photospheric lines vary greatly in different places in the active region. In most cases, they are normal. In pores, their amplitude increases to the outer edges of the pores. The maximal amplitude is noted for the profiles at the boundary between the emerging pore and the Ellerman bomb. It rapidly increased with time. From the analysis of the observed profiles, we have evidence for the presence of two small-scale patches with anomalous Stokes V profiles of the photospheric lines Fe I 630.15 nm and Fe I 630.25 nm in the region studied. The amplitude of the profiles in these places reduced. The amplitude and shape of the profiles changed with time. One of the patches was located between the pores, the other one in the plage area. In these patches the polarity of the photospheric magnetic field changed during the observations. Evidence of new small-scale magnetic fluxes of opposite polarity emergence is obtained. This led to the beginning of magnetic reconnections and the appearance of chromospheric surges and the Ellerman bomb. Strong oscillations of the amplitude of the Stokes V profiles of the photospheric lines Fe I 630.15 nm and Fe I 630.25 nm were found during the Ellerman bombs, which may indicate a pulsed character of energy release.
Keywords: active regions, Ellerman bombs, magnetic fields, photosphere, pores, spectro­polarimetry, Sun

Full text (PDF)

References: 

1. Archontis V., Hood A. W. (2009). Formation of Ellerman bombs due to 3D flux emergence. Astron. and Astrophys. 508. P. 1469—1483.
https://doi.org/10.1051/0004-6361/200912455

2. Beckers J. M. (1969). A table of Zeeman multiplets. Phys. Sci. Res. Papers. 371. 193 p.

3. Bello González N., Danilovic S., Kneer F. (2013). On the structure and dynamics of Ellerman bombs. Detailed study of three events and modelling of Нα. Astron. and Astrophys. 557. id.A102. 16 p.
https://doi.org/10.1051/0004-6361/201321632

4. Bernasconi P. N., Keller C. U., Solanki S. K., Stenflo J. O. (1998). Complex magnetic fields in an active region. Astron. and Astrophys. 329. P. 704—720.

5. Dara H. C., Alissandrakis C. E., Zachariadis T. G., Georgakilas A. A. (1997). Magnetic and velocity field in association with Ellerman bombs. Astron. and Astrophys. 322. P. 653—658.

6. Delbouille L., Roland G., Neven L. (1973). Photometric atlas of the solar spectrum from 3000 to 10000. Liege: Institut d’Astrophysique.

7. Engell A. J., Siarkowski M., Gryciuk M., et al. (2011). Flares and their underlying magnetic complexity. Astrophys. J. 726(1). article id. 12. 8 p.
https://doi.org/10.1088/0004-637X/726/1/12

8. Fischer C. E., Keller C. U., Snik F., et al. (2012). Unusual Stokes V profiles during flaring activity of a delta sunspot. Astron. and Astrophys. 547. id. A34. 12 p.
https://doi.org/10.1051/0004-6361/201219272

9. Franz M., Collados M., Bethge C., et al. (2016). Magnetic fields of opposite polarity in sunspot penumbrae. Astron. and Astrophys. 596. id. A4. 13 p.
https://doi.org/10.1051/0004-6361/201628407

10. Franz M., Schlichenmaier R. (2013). The velocity field of sunspot penumbrae. II. Return flow and magnetic fields of opposite polarity. Astron. and Astrophys. 550. id. A97.
https://doi.org/10.1051/0004-6361/201220708

11. Georgoulis M. K., Rust D. M., Bernasconi P. N., Schmieder B. (2002). Statistics, morphology, and energetics of Ellerman bombs. Astrophys J. 575(1). P. 506—528.
https://doi.org/10.1086/341195

12. Golovko A. A. (1974). The crossover effect in sunspots and the fine structure of penumbra. Solar Phys. 37(1). P. 113—125.
https://doi.org/10.1007/BF00157848

13. Grigorjev V. M., Katz J. M. (1972). The crossover and magneto-optical effects in sunspot spectra. Solar Phys. 22(1). P. 119—128.
https://doi.org/10.1007/BF00145466

14. Joshi N. C., Schmieder B., Magara T., et al. (2016). Chain reconnections observed in sympathetic eruptions. Astrophys. J. 820:126. article id. 126. 20 p.
https://doi.org/10.3847/0004-637X/820/2/126

15. Katsukawa Y., Jurčák J. (2010). A new type of small-scale downflow patches in sunspot penumbrae. Astron. and Astrophys. 524. id. A20. 9 p.
https://doi.org/10.1051/0004-6361/200913898

16. Khomenko E. V., Collados M., Solanki S. K., et al. (2003). Quiet-Sun inter-network magnetic fields observed in the infrared. Astron. and Astrophys. 408(2). P. 1115—1135.
https://doi.org/10.1051/0004-6361:20030604

17. Kjeldseth-Moe O. (1968). On the magnetic-field configuration in sunspots. Structure and development of solar active region. (Symposium IAU N 35 held in Budapest, Hungary, 4—8 September 1967). Ed. Karl Otto Kiepenheuer. Dordrecht, D. Reidel. P. 202.

18. Kondrashova N. N. (2018). Abnormal Stokes profiles of the photospheric lines in the region of chromospheric dual flows in the surroundings of a solar pore. I. Observations. Kinematics and Physics of Celestial Bodies. 34(2). P. 53—67.
https://doi.org/10.3103/S0884591318040049

19. Kondrashova N. N. Pasechnik M. N., Chornogor S. N., Khomenko E. V. (2013). Atmosphere dynamics of the active region NOAA 11024. Solar Phys. 284(2). P. 499— 513.
https://doi.org/10.1007/s11207-012-0212-5

20. Kondrashova N. N. Pasechnik M. N., Leiko U. M. (2017). Manifestation of a new magnetic flux emergence in the active region NOAA 11024. Fourth UK-Ukraine-Spain Meeting on Solar Phys. and Space Sci., 28.08-01.09 2017. Kyiv, Ukraine. Book of abstracts. P. 62.

21. Kubo M., Chye Low B., Lites B. W. (2014). Unresolved mixed polarity magnetic fields at flux cancellation site in solar photosphere at 0.3" spatial resolution. Astrophys. J. Lett. 793(1). article id. L9. 5 p.
https://doi.org/10.1088/2041-8205/793/1/L9

22. Li Z., Fang C., Guo Y., et al. (2015). Diagnostics of Ellerman bombs with high-resolution spectral data. Res. Astron. Astrophys. 15(9). article id. 1513.
https://doi.org/10.1088/1674-4527/15/9/008

23. Matsumoto T., Kitai R., Shibata K., et al. (2008). Height dependence of gas flows in an Ellerman bomb. Publs Astron. Soc. Jap. 60(1). P. 95—102.
https://doi.org/10.1093/pasj/60.1.95

24. Nelson C. J., Scullion E. M., Doyle J. G., et al. (2015). Small-scale structuring of Ellerman bombs at the solar limb. Astrophys. J. 798(1). article id. 19. 9 p.
https://doi.org/10.1088/0004-637X/798/1/19

25. Nelson C. J., Shelyag S., Mathioudakis M., et al. (2013). Ellerman bombs — evidence for magnetic reconnection in the lower solar atmosphere. Astrophys. J. 779(2). article id. 125. 10 p.
https://doi.org/10.1088/0004-637X/779/2/125

26. Palacios J., Balmaceda L. A., Vargas Domínguez S., et al. (2012). Observations of vortex motion in the solar photosphere using Hinode-SP data Hinode-3. The 3rd Hinode Science Meeting ASP Conference Series. 454 / Eds T. Sekii, T. Watanabe, and T. Sakurai. Astronomical Society of the Pacific. P. 51—54.

27. Pariat E., Aulanier G., Schmieder B., et al. (2004). Resistive emergence of undulatory flux tubes. Astrophys. J. 614(2). P. 1099—1112.
https://doi.org/10.1086/423891

28. Pasechnik M. N. (2014). Plasma motions in the solar loop of emerging magnetic flux. Kinematics and Physics of Celestial Bodies. 30(4). P. 161—172.
https://doi.org/10.3103/S0884591314040047

29. Pasechnik M. N. (2016). Spectral study of a pair of Ellerman bombs. Kinematics and Physics of Celestial Bodies. 32(2). P. 55—69.
https://doi.org/10.3103/S0884591316020057

30. Pasechnik M. N. (2018). Spectral study of Ellerman bombs. Photosphere. Kinematics and Physics of Celestial Bodies. 34(2). P. 68—81.
https://doi.org/10.3103/S0884591318020071

31. Pierce A. K., Breckinridge J. B. (1972). The Kitt Peak table of photographic solar spectrum wavelengths. Kitt Peak National Observatory. Contribution N 559.

32. Rueedi I., Solanki S. K., Livingston W., Stenflo J. O. (1992). Infrared lines as probes of solar magnetic features. III. Strong and weak magnetic fields in plages. Astron. and Astrophys. 263(1)/2. P. 323—338.

33. Rutten R. J., Vissers G. J. M., Rouppe van der Voort L. H. M., et al. (2013). Ellerman bombs: fallacies, fads, usage. J. Phys. Conf. Ser. 440(1). article id. 012007.
https://doi.org/10.1088/1742-6596/440/1/012007

34. Sanchez Almeida J., Lites B. W. (1992). Observation and interpretation of the asymmetric Stokes Q, U, and V line profiles in sunspots. Astrophys. J. 398(1). P. 359—374.
https://doi.org/10.1086/171861

35. Sankarasubramanian K., Rimmele T. (2002). Bisector analysis of Stokes profiles: effects due to gradients in the physical parameters. Astrophys. J. 576(2). P. 1048—1063.
https://doi.org/10.1086/341885

36. Scharmer G. B., de la Cruz Rodriguez J., Sutterlin P., Henriques V. M. J. (2013). Opposite polarity field with convective downflow and its relation to magnetic spines in a sunspot penumbra. Astron. and Astrophys. 553. id. A63. 15 p.
https://doi.org/10.1051/0004-6361/201220899

37. Scherrer P. H., Bogart R. S., Bush R. I., et al. (1995). The solar oscillations investigation — Michelson Doppler Imager. Solar Phys. 162(1)-2. P. 129—188.
https://doi.org/10.1007/BF00733429

38. Schlichenmaier R., Collados M. (2002). Spectropolarimetry in a sunspot penumbra. Spatial dependence of Stokes asymmetries in Fe I 1564.8 nm. Astron. and Astrophys. 381. P. 668—682.
https://doi.org/10.1051/0004-6361:20011459

39. Schlichenmaier R., Rezaei R., Gonzalez N. B. (2012). On the formation of penumbrae as observed with the German VTT SOHO/MDI, and SDO/HMI. / 4th Hinode Science Meeting: Unsolved Problems and Recent Insights, ASP Conference series, 455. (Proceedings of a conference held 11-15 October 2010 in Palermo, Italy) / Eds L. R. Bellot Rubio., F. Reale, M. Carlsson. San Francisco: Astronomical Society of the Pacific, P. 61.

40. Shimizu T., Lites B. W., Katsukawa Y., et al. (2008). Frequent occurrence of high-speed local mass downflows on the solar surface. Astrophys. J. 680(2). P. 1467—1476.
https://doi.org/10.1086/588775

41. Sigwarth M. (2001). Properties and origin of asymmetric and unusual Stokes V profiles observed in solar magnetic fields. Astrophys. J. 563(2). P. 1031—1044.
https://doi.org/10.1086/323963

42. Skumanich A., Lites B. (1991). Velocity gradients across a flaring neutral line from Stokes II measureents / Solar Polarimetry (Proceedings of the 11th Sacramento Peak Summer Work shop) / Ed. L. J. November. Sunspot, NM: National Solar Observatory.P. 307—317.

43. Sylwester B., Sylwester J., Siarkowski M., et al. (2011). Physical characteristics of AR 11024 plasma based on SPHINX and XRT Data. Cent. Eur. Astrophys. Bull. 35(1). P. 171—180.

44. Valori G., Green L. M., Démoulin P., et al. (2012). Nonlinear force-free extrapolation of emerging flux with a global twist and serpentine fine structures. Solar Phys. 278(1). P. 73—97.
https://doi.org/10.1007/s11207-011-9865-8

45. Vargas Domínguez S., van Driel-Gesztelyi L., Bellot Rubio L. R. (2012). Granular-scale elementary flux emergence episodes in a solar active region. Solar Phys. 278(1). P. 99—120.
https://doi.org/10.1007/s11207-012-9968-x

46. Vargas Domnguez S., Palacios J., Balmaceda L., et al. (2015). Evolution of small-scale magnetic elements in the vicinity of granular-sized swirl convective motions. Solar Phys. 290(2). P. 301—319.
https://doi.org/10.1007/s11207-014-0626-3

47. Vissers G. J. M., Rouppe van der Voort L. H. M., Rutten R. J. (2013). Ellerman bomb at high resolution. II. Triggering, visibility and effect on upper atmosphere. Astrophys. J. 774(1). article id. 32. 14 p.
https://doi.org/10.1088/0004-637X/774/1/32

48. Viticchie B., Sanchez Almeida J. (2011). Asymmetries of the Stokes V profiles observed by HINODE SOT/SP in the quiet Sun. Astron. and Astrophys. 530. id. A14. 10 p.
https://doi.org/10.1051/0004-6361/201016096

49. Watanabe H., Kitai R., Okamoto K., et al. (2008). Spectropolarimetric observation of an emerging flux region: triggering mechanisms of Ellerman bombs. Astrophys. J. 684(1). P. 736—746.
https://doi.org/10.1086/590234

50. Watanabe H., Vissers G., Kitai R., et al. (2011). Ellerman bombs at high resolution. I. Morphological evidence for photospheric reconnection. Astrophys. J. 736(1). 12 p.
https://doi.org/10.1088/0004-637X/736/1/71