Skip to main content
SpringerLink
Log in

Search for Microflaring Activity in the Magnetic Network

  • Published:
Solar Physics Aims and scope Submit manuscript

Abstract

We analyze the temporal behavior of network bright points (NBPs) searching for low-atmosphere signatures of flares occurring on the magnetic network. We make use of a set of data acquired during coordinated observations between ground-based observatories (NSO/Sacramento Peak) and the MDI instrument on board SOHO. Light curves in chromospheric spectral lines show only small-amplitude temporal variations, without any sudden intensity enhancement that could suggest the presence of a transient phenomenon such as a (micro)flare. Only one NBP shows spikes of downward velocity, of the order of 2–4 km s−1, considered as signals of compression associated with a (micro)flare occurrence. For this same NBP, we also find a peculiar relationship between the magnetic and velocity fields fluctuations, as measured by MDI. Only for this point the B−V fluctuations are well correlated, suggesting the presence of magneto-acoustic waves propagating along the magnetic structure. This correlation is lost during the compression episodes and resumes afterward. An A6 GOES soft X-ray burst is temporally associated with the downward velocity episodes, suggesting that this NBP is the footpoint of a flaring loop. This event has a total thermal energy content of about 1028 erg, and, hence, belongs to the microflare class.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Benz, A. O. and Krucker, A.: 1999, Astron. Astrophys. 341, 286.

    Google Scholar 

  • Canfield, R. C. and Metcalf, T. R.: 1987, Astrophys. J. 321, 586.

    Google Scholar 

  • Cauzzi, G., Falchi, A., and Falciani, R.: 2000, Astron. Astrophys. 357, 1093.

    Google Scholar 

  • Cauzzi, G., Vial, J. C., Falciani, R., and Falchi, A.: 1997, in B. Schmieder, J. C. del Toro Iniesta, M. Vázquez (eds.), ASP Conf. Ser. 118, p. 309.

  • Cauzzi, G., Falchi, A., Falciani, R., and Vial, J. C.: 1999, in A. Wilson (ed.), Magnetic Fields and Solar Processes, 9th EPS Solar Meeting, Florence, ESA SP-448, p. 685.

  • Chae, J., Lee, C.-Y., Wang, H., Goode, P. R., and Schühle, U.: 1998, Astrophys. J. 497, L109.

    Google Scholar 

  • Chae, J., Wang, H., Goode, P. R., Fludra, A., and Schühle, U.: 2000, Astrophys. J. 528, L119.

    Google Scholar 

  • Dere, K. P.: 1994, Adv. Space Res. 14, 13.

    Google Scholar 

  • Edmonds, F. N., Jr. and Webb, C. J.: 1972, Solar Phys. 22, 276.

    Google Scholar 

  • Feldman, U., Doschek, G. A., and Behring, W. E.: 1996, Astrophys. J. 461, 465.

    Google Scholar 

  • Golub, L., Krieger, A. S., Silk, J. K., Timothy, A. F., and Vaiana, G. S.: 1974, Astrophys. J. 189, L93.

    Google Scholar 

  • Hansteen, V.: 1997, in A. Wilson (ed.), The Corona and Solar Wind Near Minimum Activity, Fifth SOHO Workshop, Oslo, 17–20 June dy1997, ESA SP-404, p. 45.

  • Harrison, R. A.: 1997, Solar Phys. 175, 457.

    Google Scholar 

  • Harrison, R. A., Lang, J., Brooks, D. H., and Innes, D. E: 1999, Astron. Astrophys. 351, 1115.

    Google Scholar 

  • Hasan, S. S. and Kalkofen, W.: 1999, Astrophys. J. 519, 899.

    Google Scholar 

  • Ichimoto, K. and Kurokawa, K.: 1984, Solar Phys. 93, 105.

    Google Scholar 

  • Innes, D. E., Brekke, P., Germerott, D., and Wilhelm, K.: 1997, Solar Phys. 175, 341.

    Google Scholar 

  • Krucker, S. and Benz, A. O.: 2000, Solar Phys. 191, 341.

    Google Scholar 

  • Krucker, S., Benz, A. O., Bastian, T. S., and Acton, L. W.: 1997, Astrophys. J. 488, 499.

    Google Scholar 

  • Lites, B. W., Rutten, R. J., and Kalkofen, W.: 1993, Astrophys. J. 414, 345.

    Google Scholar 

  • Porter, J. G., Moore, R. L., Reichmann, E. J., Engvold, O., and Harvey, K. L.: 1987, Astrophys. J. 323, 380.

    Google Scholar 

  • Scherrer, P. H. et al.: 1995, Solar Phys. 162, 129.

    Google Scholar 

  • Schrijver, C. J., Title, A. M., van Ballegooijen, A. A., Hagenaar, H. J., and Shine, R. A.: 1997, Astrophys. J. 487, 424.

    Google Scholar 

  • Shimizu, T.: 1995, Publ. Astron. Soc. Japan 47, 251.

    Google Scholar 

  • Thomas, R. J., Starr, R., and Crannell, C. J.: 1985, Solar Phys. 95, 323.

    Google Scholar 

  • Ulmschneider, P., Rosner, R., Priest, E. R. (eds.): 1991, Mechanisms of Chromospheric and Coronal Heating, Springer-Velag, Berlin.

    Google Scholar 

  • Ulrich, R. K.: 1996, Astrophys. J. 465, 436.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Osservatorio Astrofisico di Arcetri, L. Fermi 5, I-50125, Firenze, Italy

    G. Cauzzi & A. Falchi

  2. Dipartimento di Astronomia e Scienza dello Spazio, L. Fermi 5, I-50125, Firenze, Italy

    R. Falciani

Authors
  1. G. Cauzzi
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A. Falchi
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. R. Falciani
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Cauzzi, G., Falchi, A. & Falciani, R. Search for Microflaring Activity in the Magnetic Network. Solar Physics 199, 47–60 (2001). https://doi.org/10.1023/A:1010390911221

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/A:1010390911221

Keywords

Search

Navigation