Secondary ribbons found in the flare Hα filtergrams

Transcription

1 Secondary ribbons found in the flare Hα filtergrams Pavel Kotrč and Miroslav Bárta, Astronomical institute AS ČR, Ondřejov Václav Šebelík, University of South Bohemia, České Budějovice Jiří Žák, Gymnázium Jarošova, Brno Wolfgang Poetzi, Kanzelhohe Solar Observatory, Austria Abstract. Recent models of solar flares deal with high resolution MHD simulations. Energy transfer from large to small scales can be explained by a cascade reconnection model (Bárta et al, 2011a). The model also describes an origin and movement of plasmoids during flare development and predicts a specific structures and behavior of flare kernels that can become evident in the observation. It concerns particularly the secondary ribbons occurring temporarily in solar flares. A first indication of such observation was published recently (Bárta et al, 2011b). Here we report on results of a more extensive analysis of H-alpha filtegrams of solar flares. We studied H-alpha filtergrams of the Kanzelhohe Solar Observatory for the most energetic solar flares in the period 1973 till We analyzed flare images in all flare phases with emphasize on the intensity profile put perpendicularly to the axes of ribbons. We report on several cases of possible secondary flare ribbons and on the study of their kinematic parameters. Bairisch Koeldorf, Workshop April

2 Solar flare models A standard scenario reconnection A good agreement of models and observations for large scales Flare model scheme: (K. Shibata, P. Gallagher) Bairisch Koeldorf, Workshop April

3 Solar flare mechanism magnetic field reconnection X point & current sheet Bairisch Koeldorf, Workshop April

4 Numerical modelling of reconnection: Bairisch Koeldorf, Workshop April

5 Flare modelling: Reconection of magnetic field Shibata, K. & Tanuma, S. 2001, Bairisch Koeldorf, Workshop April

6 Spontaneous Current-layer Fragmentation and Cascading Reconnection in Solar Flares. I. Model and Analysis Bárta et al., ApJ (2011a), Bairisch Koeldorf, Workshop April

7 Bárta et al., ApJ (2011b), Bairisch Koeldorf, Workshop April

8 A solar flare See the absorption features in Ha) Bairisch Koeldorf, Workshop April

9 Numerical modelling of flares: Relation to observation Structuring of chromospheric flare ribbons Bairisch Koeldorf, Workshop April

10 Numerical modelling of flares: Relation to observation Structuring of chromospheric flare ribbons Plasmoid? Ondrejov MCF Spectrograph, Kotrč, 2009 Bairisch Koeldorf, Workshop April

11 Diagnostics in optical region four-ribbon flare: A rare and specific effect predicted by a reconnection model based on plasmoids Bairisch Koeldorf, Workshop April

12 A search in existing archives (Ondrejov, Catania, Hvar NO) List of observed flares 1 B + (source digitized films & CCD) Since 1988 till 2013, full disk H-alpha images with flares Films data converted from densities to relative intensities A simple code for photometric scans across the ribbons :30:00 12:54:00 15:52:00 D S24 E07 4B :57:00 14:11:00 16:14:00 D N32 E67 3B :24:00 7:40:00 11:05:00 D N29 E06 3B :05:00 9:05:00 9:37:00 S16 E22 2B :49:00 15:10:00 15:35:00 D S27 W17 2B :42:00 11:34:00 12:12:00 D N35 E27 2B :53:00 E 0:00:00 16:44:00 D S15 W41 2B :36:00 12:44:00 13:44:00 S28 W41 2B :19:00 12:51:00 13:25:00 N19 E73 2B :23:00 14:58:00 15:28:00 S08 E69 1B :56:00 9:00:00 9:24:00 S07 E32 1B :46:00 12:50:00 13:11:00 D S11 E16 1B :53:00 14:11:00 16:03:00 D S08 E07 1B :58:00 10:05:00 10:57:00 S27 W36 1B :40:00 13:44:00 14:06:00 N25 W77 1B :54:00 11:58:00 13:58:00 D S22 W15 1B :20:00 13:24:00 13:47:00 N29 E66 1B :32:00 7:31:00 8:10:00 D N18 E44 3B :23:00 9:57:00 U 13:59:00 N07 W02 3B :35:00 E 13:47:00 14:45:00 D S15 W14 3B :44:00 7:02:00 7:57:00 D N18 E10 3B :19:00 E 13:19:00 U 14:00:00 S11 W13 3B :56:00 12:00:00 12:41:00 N06 E17 2B :43:00 10:01:00 10:27:00 N12 W73 2B :50:00 9:02:00 10:18:00 S09 W35 2B :31:00 12:35:00 13:14:00 N10 W48 2B :38:00 E 8:46:00 9:01:00 D N26 E28 2B :35:00 10:20:00 13:21:00 D S15 W07 2B :47:00 12:55:00 13:23:00 S21 E74 2B :01:00 13:17:00 13:37:00 N15 E63 2B :31:00 8:18:00 8:44:00 D S15 W60 1B :49:00 10:53:00 11:28:00 S11 E05 1B :29:00 10:33:00 10:48:00 S23 E48 1B :43:00 13:55:00 15:11:00 S12 E16 1B :02:00 15:18:00 15:40:00 D N08 E57 1B :14:00 16:26:00 16:44:00 N07 E54 1B :45:00 12:53:00 13:49:00 N10 E04 1B :54:00 9:10:00 9:56:00 N15 W25 1B :43:00 E 13:50:00 U 13:50:00 D S25 E16 1B :32:00 E 11:23:00 U 14:20:00 S16 E07 4B :46:00 E 6:46:00 E 9:17:00 S14 E41 3B :50:00 13:57:00 14:31:00 D S09 E29 3B :26:00 12:31:00 13:30:00 N10 E32 3B :16:00 E 9:51:00 11:57:00 N14 W24 3B :26:00 E 10:36:00 10:40:00 D N17 E25 2B :35:00 7:42:00 8:43:00 N01 W08 2B :28:00 7:34:00 8:57:00 N12 E28 2B :28:00 E 6:30:00 U 8:05:00 N11 E57 2B :21:00 9:43:00 10:17:00 S17 W47 1B :56:00 7:08:00 9:15:00 N08 E14 3B :19:00 E 7:19:00 E 9:25:00 S18 W17 2B :16:00 13:52:00 13:56:00 D N17 W28 2B :54:00 8:14:00 U 9:03:00 U N17 W69 2B :23:00 U 8:39:00 9:52:00 S21 W13 1B :26:00 14:32:00 14:52:00 S21 W30 1B :26:00 8:55:00 9:20:00 S11 W23 1B :18:00 9:21:00 10:26:00 S09 E54 1B Selection of a sub image, making a photometric profile In positive cases fitting by 4 gaussians deriving the positions of ribbons :23:00 9:25:00 9:43:00 N07 W49 1B :03:00 9:06:00 9:12:00 S17 W62 1B :22:00 E 14:22:00 E 14:25:00 D N13 E30 1B :09:00 U 16:12:00 16:21:00 U N16 E47 1B :14:00 9:21:00 9:31:00 N16 E37 1B :41:00 9:55:00 10:56:00 S18 W17 1B :38:00 11:44:00 12:10:00 S18 W33 1B Bairisch Koeldorf, Workshop April

13 Flare on 05th May 1989, 3B, N29, E06, 7:24-11;05 UT, 07:32:04 UT Bairisch Koeldorf, Workshop April

14 Flare on 20th April 1990, 3N, N10, W48, 08:30-09:51 UT, 08:38:14 UT Bairisch Koeldorf, Workshop April

15 Flare on 15th May 1990, 3N, N38, E36, 14:11-15:29 UT, 14:13:00 UT Bairisch Koeldorf, Workshop April

16 Flare on 15th May 1990, 3N, N38, E36, 14:11-15:29 UT, 14:49:04 UT Bairisch Koeldorf, Workshop April

17 Discussion Recent models of reconnection in flares expect that plasmoids play a significant role. One of the key prediction of the model is a possibility of temporal existence of the multifold flare ribbons during the interaction of the plasmoid with the flare-loop arcade. Thus, finding the multiple pairs of the flare ribbons would represent a significant evidence in favor of the plasmoid-dominated magnetic reconnection in solar flares. For search of 4-ribbon flares we found no ribbon flare catalogue. Existing archives do not provide information about two ribbon flares. Thus the search for flares was more difficult than we expected. Bairisch Koeldorf, Workshop April

18 Summary 3 examples of the model-predicted phenomena were probably found Flare secondary ribbons can be well separated from the main ones Studied phenomena occurred in all phases of flares on solar disk Study of fine structures in flare ribbons (H-alpha emission/absorption) is important for specification structures in chromosphere and lower corona and for testing of existing flare models Further observation with a better spatial resolution is highly recommended UV, EUV and Radio data provide more complementary infomation Bairisch Koeldorf, Workshop April

19 Thank you for attention The research leading to these results has received funding from the European Community s Seventh Framework Programme (FP7/ ) under grant agreement No (F-CHROMA). Bairisch Koeldorf, Workshop April