Spectral study of pair Ellerman bombs

Heading: 
1Pasechnik, MN
1Main Astronomical Observatory of the National Academy of Sciences of Ukraine, Kyiv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2016, 32(2):3-24
Start Page: Solar Physics
Language: Russian
Abstract: 

The results of the spectral observation analysis in the Hα line of two Ellerman bombs (EB-1 and EB-2), which were formed and have developed in the active region NOAA 11024 in the emerging magnetic flux area, are presented. The spectral data, with high temporal and spatial resolution, were obtained with the French-Italian solar telescope THEMIS (the island of Tenerife, Spain) on July 4, 2009. The Hα line profiles, obtained during different periods of the EBs evolution, were asymmetrical with excess emission in the long-wavelength wing. The intensity changes of the line wings indicate that the EBs occurred as a gradual and pulsed release of energy. The temporal variations of the chromospheric line-of-sight velocities (Vlos ) at the heights of the Hα core formation meant that there were two periods of increasing the Vlos consisting of several individual peaks. The maximum Vlos toward and from the observer was –9 km/s and 8 km/s, respectively. During observation there were some moments of upward plasma flows with Vlos up to –80 km/s and downward flows with Vlos up to 50 km/s. Ellerman bombs were accompanied by small chromospheric ejections (surges), lasting about 0.5 — 1.5 minutes. The fine structure of EB found on the Hα line spectra, was obtained during the sharp increase of intensity in the Hα line wings lasting about 4 minutes. Features of intensity change in the line wings and variations of the line-of-sight velocity of chromospheric matter indicate that the two investigated EBs occurred and developed as a physically connected pair. Our results support a model in which the triggering mechanism of formation EBs is a magnetic reconnection in the lower atmosphere.

Keywords: Ellerman bombs, line-of-sight velocities, the Sun
References: 

1.A. N. Babin, “The size and brightness of whiskers,” Bull. Crimean Astrophys. Observatory 58, 5–8 (1978).

2.O. E. Den, G. I. Kornienko, F. M. Makhmutov, and F. A. Mikhalina, “The structure of the chromosphere and radial velocities in the vicinity of “moustaches”,” Sol. Dannye, No. 11, 85–90 (1983).

3.A. N. Koval’, “On the motions related to moustaches,” Izv. Krym. Astrofiz. Obs. 32, 32–37 (1964).

4.M. N. Pasechnik, “Plasma motions in the solar loop of emerging magnetic flux,” Kinematics Phys. Celestial Bodies 30, 161–172 (2014).
https://doi.org/10.3103/S0884591314040047

5.S. B. Pikel’ner, “The nature of point-sources of lined, continuous and X-ray emission on the Sun,” Astron. Zh. 51, 233–242 (1974).

6.A. B. Severnyi, “Some results of investigations of nonstationary processes on the Sun,” Astron. Zh. 34, 684–693 (1957).

7.A. B. Severnyi, “Investigating the fine structure of the emission of active formations and nonstationary processes on the Sun,” Izv. Krym. Astrofiz. Obs. 17, 129–161 (1957).

8.A. B. Severnyi, Some Problems of the Solar Physics (Nauka, Moscow, 1987) [in Russian].

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

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

11.A. Berlicki and P. Heinzel, “Observations and NLTE modeling of Ellerman bombs,” Astron. Astrophys. 567, A110 (2014).
https://doi.org/10.1051/0004-6361/201323244

12.A. Berlicki, P. Heinzel, and E. H. Avrett, “Photometric analysis of Ellerman bombs,” Mem. Soc. Astron. Ital. 81, 646–652 (2010).

13.A. Bruzek, “Some observational results on moustaches,” Sol. Phys. 26, 94–107 (1972).
https://doi.org/10.1007/BF00155110

14.H. C. Dara, C. E. Alissandrakis, T. G. Zachariadis, et al., “Magnetic and velocity field in association with Ellerman bombs,” Astron. Astrophys. 322, 653–658 (1997).

15.L. Delbouille, G. Roland, and L. Neven, Photometric Atlas of the Solar Spectrum from 3000 to 10000 (Univ. de LieÌge, Inst. d'Astrophys., LieÌge, 1973).

16.M. D. Ding, J.-C. Henoux, and C. Fang, “Line profiles in moustaches produced by an impacting energetic particle beam,” Astron. Astrophys. 332, 761–766 (1998).

17.F. Ellerman, “Solar hydrogen "bombs ",” Astrophys. J. 46, 298–300 (1917).
https://doi.org/10.1086/142366

18.C. Fang, Y. H. Tang, Z. Xu, et al., “Spectral analysis of Ellerman bombs,” Astrophys. J. 643, 1325–1336 (2006).
https://doi.org/10.1086/501342

19.M. K. Georgoulis, D. M. Rust, P. N. Bernasconi, et al., “Statistics, morphology, and energetics of Ellerman bomb,” Astrophys. J. 575, 506–528 (2002).
https://doi.org/10.1086/341195

20.Yu. Hashimoto, R. Kitai, K. Ichimoto, et al., “Internal fine structure of Ellerman bombs,” Publ. Astron. Soc. Jpn. 62, 879–891 (2010).
https://doi.org/10.1093/pasj/62.4.879

21.J.-C. Henoux, C. Fang, and M. D. Ding, “A possible mechanism for the Ha broad wings emission of Ellerman bombs,” Astron. Astrophys. 337, 294–298 (1998).

22.M. Herlender and A. Berlicki, “Spectrophotometric analysis of an Ellerman bomb,” Cent. Eur. Astrophys. Bull. 34, 65–72 (2010).

23.M. Herlender and A. Berlicki, “Multi-wavelength analysis of Ellerman bomb light curves,” Cent. Eur. Astrophys. Bull. 35, 181–186 (2011).

24.H. Isobe, D. Tripathi, and V. Archontis, “Ellerman bombs and jets associated with resistive flux emergence,” Astrophys. J., Lett. 657, L53–L56 (2007).
https://doi.org/10.1086/512969

25.D. B. Jess, M. Mathioudakis, P. K. Browning, et al., “Microflare activity driven by forced magnetic reconnection,” Astrophys. J., Lett. 712, L111–L115 (2010).
https://doi.org/10.1088/2041-8205/712/1/L111

26.R. Kitai, “On the mass motions and the atmospheric states of moustaches,” Sol. Phys. 87, 135–154 (1983).
https://doi.org/10.1007/BF00151165

27.R. Kitai and R. Muller, “On the relation between chromospheric and photospheric fine structure in an active region,” Sol. Phys. 90, 303–314 (1984).
https://doi.org/10.1007/BF00173958

28.N. N. Kondrashova, M. N. Pasechnik, S. N. Chornogor, et al., “Atmosphere dynamics of the active region NOAA 11024,” Sol. Phys. 284, 499–513 (2013).
https://doi.org/10.1007/s11207-012-0212-5

29.A. N. Koval and A. B. Severny, “On the asymmetry of moustaches,” Sol. Phys. 11, 276–284 (1970).
https://doi.org/10.1007/BF00155226

30.H. Kurokawa, I. Kawaguchi, Y. Funakoshi, et al., “Morphological and evolutional features of Ellerman bombs,” Sol. Phys. 79, 77–84 (1982).
https://doi.org/10.1007/BF00146974

31.T. Matsumoto, R. Kitai, K. Shibata, et al., “Height dependence of gas flows in an Ellerman bomb,” Publ. Astron. Soc. Jpn. 60, 95–102 (2008).
https://doi.org/10.1093/pasj/60.1.95

32.T. Matsuoto, R. Kitai, K. Shibata, et al., “Cooperative observation of Ellerman bombs between the Solar Optical Telescope aboard Hinode and Hida/Domless Solar Telescope,” Publ. Astron. Soc. Jpn. 60, 577–584 (2008).
https://doi.org/10.1093/pasj/60.3.577

33.C. J. Nelson, J. G. Doyle, R. Erdelyi, et al., “Statistical analysis of small Ellerman bomb events,” Sol. Phys. 283, 307–323 (2013).
https://doi.org/10.1007/s11207-012-0222-3

34.A. Nindos and H. Zirin, “Properties and motions of Ellerman bombs,” Sol. Phys. 182, 381–392 (1998).
https://doi.org/10.1023/A%3A1005041920869

35.E. Pariat, G. Aulanier, B. Schmieder, et al., “Resistive emergence of undulatory flux tubes,” Astrophys. J. 614, 1099–1112 (2004).
https://doi.org/10.1086/423891

36.E. Pariat, B. Schmieder, A. Berlicki, et al., “Spectrophotometric analysis of Ellerman bombs in the Ca II, Ha, and UV range,” Astron. Astrophys. 473, 279–289 (2007).
https://doi.org/10.1051/0004-6361%3A20067011

37.J. Qiu, M. D. Ding, H. Wang, et al., “Ultraviolet and Ha emission in Ellerman bombs,” Astrophys. J., Lett. 544, L157–L161 (2000).
https://doi.org/10.1086/317310

38.A. B. Severny, “Mass motions in flares and moustaches indicated by special spectral features,” in Mass Motions in Solar Flares and Related Phenomena: Proc. 9th Nobel Symp., Anacapri, Italy, June 10–12, 1968, Ed. by Y. Oehman (Almqvist & Wiksell, Stockholm, 1986; Wiley, New York, 1968), p. 71.

39.H. Socas-Navarro, V. Martínez Pillet, D. Elmore, et al., “Spectro-polarimetric observations and non-LTE modeling of Ellerman bombs,” Sol. Phys. 235, 75–86 (2006).
https://doi.org/10.1007/s11207-006-0049-x

40.G. Valori, L. M. Green, P. Demoulin, et al., “Nonlinear force-free extrapolation of emerging flux with a global twist and serpentine fine structures,” Sol. Phys. 278, 73–97 (2012).
https://doi.org/10.1007/s11207-011-9865-8

41.G. J. M. Vissers, L. H. M. Rouppe van der Voort, and R. J. Rutten, “Ellerman bombs at high resolution. II. Triggering, visibility and effect on upper atmosphere,” Astrophys. J. 774, 32–46 (2013).
https://doi.org/10.1088/0004-637X/774/1/32

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

43.H. Watanabe, G. Vissers, R. Kitai, et al., “Ellerman bombs at high resolution. I. Morphological evidence for photospheric reconnection,” Astrophys. J. 736, 71–83 (2011).
https://doi.org/10.1088/0004-637X/736/1/71

44.Th. G. Zachariadis, C. E. Alissandrakis, and G. Banos, “Observations of Ellerman bombs in Ha,” Sol. Phys. 108, 227–236 (1987).
https://doi.org/10.1007/BF00214163