Abstract
The Fast Imaging Solar Spectrograph (FISS) is being operated on the New Solar Telescope of the Big Bear Solar Observatory. It simultaneously records spectra of Hα and Ca ii 8542 Å lines, and this dual-spectra measurement provides an estimate of the temperature and nonthermal speed components. We observed a loop structure in AR 11305 using the FISS, SDO/AIA, and STEREO/EUVI in 304 Å, and found plasma material falling along the loop from a coronal height into the umbra of a sunspot, which accelerated up to 80 km s−1. We also observed C2 and C7 flare events near the loop. The temperature of the downflows was in the range of 10 000 – 33 000 K, increasing toward the umbra. The temperature of the flow varied with time, and the temperature near the footpoint rose immediately after the C7 flare, but the temperature toward the umbra remained the same. There seemed to be a temporal correlation between the amount of downflow material and the observed C-class flares. The downflows decreased gradually soon after the flares and then increased after a few hours. These high-speed red-shift events occurred continuously during the observations. The flows observed on-disk in Hα and Ca ii 8542 Å appeared as fragmented, fuzzy condensed material falling from the coronal heights when seen off-limb with STEREO/EUVI at 304 Å. Based on these observations, we propose that these flows were an on-disk signature of coronal rain.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ahn, K., Chae, J., Park, H.-M., Nah, J., Park, Y.-D., Jang, B.-H., Moon, Y.-J.: 2008, J. Korean Astron. Soc. 41, 31.
Antiochos, S.K., MacNeice, P.J., Spicer, P.J., Klimchuk, J.A.: 1999, Astrophys. J. 512, 985.
Antolin, P., Rouppe van der Voort, L.: 2012, Astrophys. J. 745, 152.
Antolin, P., Shibata, K., Vissers, G.: 2010, Astrophys. J. 716, 154.
Antolin, P., Vissers, G., Rouppe van der Voort, L.: 2012, Solar Phys. 280, 457.
Beckers, J.M.: 1962, Aust. J. Phys. 15, 327.
Beckers, J.M.: 1964, A study of the fine structures in the solar chromosphere, Ph.D. thesis, Univ. Utrecht.
Cao, W., Gorceix, N., Coulter, R., Ahn, K., Rimmele, T.R., Goode, P.R.: 2010, Astron. Nachr. 331, 636.
Chae, J., Park, H.-M., Ahn, K., Yang, H., Park, Y.-D., Nah, J., Jang, B.-H., Cho, K.-S., Cao, W., Goode, P.R.: 2013, Solar Phys. 288, 1.
de Groof, A., Bastiaensen, C., Müller, D.A.N., Berghmans, D., Poedts, S.: 2005, Astron. Astrophys. 443, 319.
del Toro Iniesta, J.C., Bellot Rubio, L.R., Collados, M.: 2001, Astrophys. J. Lett. 549, L139.
Dialetis, D., Mein, P., Alissandrakis, C.E.: 1985, Astron. Astrophys. 147, 93.
Field, G.B.: 1965, Astrophys. J. 142, 531.
Foukal, P.: 1978, Astrophys. J. 223, 1046.
Georgakilas, A.A., Christopoulou, E.B., Skodras, A., Koutchmy, S.: 2003, Astron. Astrophys. 403, 1123.
Goldsmith, D.W.: 1971, Solar Phys. 19, 86.
Goode, P.R., Denker, C.J., Didkovsky, L.I., Kuhn, J.R., Wang, H.: 2003, J. Korean Astron. Soc. 36, 125.
Habbal, S.R., Ronan, R., Withbroe, G.L.: 1985, Solar Phys. 98, 323.
Hasan, S.S., Schuessler, M.: 1985, Astron. Astrophys. 151, 69.
Heinzel, P., Anzer, U.: 2006, Astrophys. J. Lett. 643, L65.
Heinzel, P., Gouttebroze, P., Vial, J.-C.: 1994, Astron. Astrophys. 292, 656.
Ichimoto, K., Shine, R.A., Lites, B., Kubo, M., Shimizu, T., Suematsu, Y., et al.: 2007, Publ. Astron. Soc. Japan 59, 593.
Kawaguchi, I.: 1970, Publ. Astron. Soc. Japan 22, 405.
Lemen, J.R., Title, A.M., Akin, D.J., Boerner, P.F., Chou, C., Drake, J.F., et al.: 2012, Solar Phys. 275, 17.
Leroy, J.-L.: 1972, Solar Phys. 25, 413.
Louis, R.E., Bellot Rubio, L.R., Mathew, S.K., Venkatakrishnan, P.: 2011, Astrophys. J. 727, 49.
Mein, P., Briand, C., Heinzel, P., Mein, N.: 2000, Astron. Astrophys. 355, 1146.
Müller, D.A.N., Hansteen, V.H., Peter, H.: 2003, Astron. Astrophys. 411, 605.
Müller, D.A.N., Peter, H., Hansteen, V.H.: 2004, Astron. Astrophys. 424, 289.
Narain, U., Ulmschneider, P.: 1990, Space Sci. Rev. 54, 377.
Nicolas, K.R., Kjeldseth-Moe, O.: 1981, In: Cram, L.E., Thomas, J.H. (eds.) The Physics of Sunspots, National Solar Observatory, Sunspot, 336.
Parker, E.N.: 1953, Astrophys. J. 117, 431.
Schrijver, C.J.: 2001, Solar Phys. 198, 325.
Tziotziou, K., Heinzel, P., Mein, P., Mein, N.: 2001, Astron. Astrophys. 366, 686.
Vardavas, I.M., Cram, L.E.: 1974, Solar Phys. 38, 367.
Vissers, G., Rouppe van der Voort, L.: 2012, Astrophys. J. 750, 22.
Wallace, L., Hinkle, K., Livingston, W.C.: 1993, An Atlas of the Photospheric Spectrum from 8900 to 13 600 cm−1 (7350 to 11 230 Å), National Solar Observatory, Tucson.
Wallace, L., Hinkle, K., Livingston, W.: 1998, An Atlas of the Spectrum of the Solar Photosphere from 13 500 to 28 000 cm−1 (3570 to 7405 Å). National Optical Astronomy Observatories, Tucson.
Wang, H., Chae, J., Gurman, J.B., Kucera, T.A.: 1998, Solar Phys. 183, 91.
Acknowledgements
I would like to thank the referee for many critical comments, which improved this manuscript considerably. This research was supported by the National Research Foundation of Korea (355-2012-1-2012R1A6A3A03039815 and 2012R1A2A1A03670387). K. Ahn and W. Cao gratefully acknowledge the support of NSF-CAREER through ATM-0847126.
Author information
Authors and Affiliations
Corresponding author
Additional information
Initial Results from FISS
Topical Issue Coordinator: Jongchul Chae
Electronic Supplementary Material
Below are the links to the electronic supplementary material.
Movie 1 (MP4 4.2 MB)
Movie 2 (MP4 9.7 MB)
Rights and permissions
About this article
Cite this article
Ahn, K., Chae, J., Cho, KS. et al. Active Region Coronal Rain Event Observed by the Fast Imaging Solar Spectrograph on the NST. Sol Phys 289, 4117–4136 (2014). https://doi.org/10.1007/s11207-014-0559-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11207-014-0559-x