Abstract
Intensity distributions of the EUV network and the cell interior in the solar atmosphere have been obtained in fourteen emission lines from Solar and Heliospheric Observatory (SOHO)/Coronal Diagnostic Spectrometer (CDS) observations. The formation temperature of the observed lines is in the range log T=4.90 – 6.06 (T in Kelvin), and hence they represent increasing heights in the solar atmosphere from the upper chromosphere and the transition region to the low corona. Intensity distributions of the cell interior have been found to be different in the quiet Sun and the coronal hole even at the lower transition region, which is at variance with some earlier results. The intensity contrast of the network with respect to the cell interior has been obtained for each line, and differences in the quiet Sun and the coronal hole have been examined. The network contrast, in general, is lower for the coronal hole as compared to the quiet Sun, but becomes equal to it in the upper transition region. The maximum contrast for both the regions is at about log T=5.3. Also obtained are the relative contributions of the network and the cell interior to the total intensity. The implications of the results for models of the transition region are briefly mentioned.
Similar content being viewed by others
References
Athay, R.: 1982, Astrophys. J. 263, 982.
Bohlin, J.D.: 1977, In: Zirker, J.B. (ed.) Coronal Holes and High Speed Wind Streams, Colorado Associated Press, Boulder, 27.
Bromage, B.J.J., Alexander, D., Breen, A., Clegg, J.R., Del Zanna, G., DeForest, C., Dobrzycka, D., Gopalswamy, N., Thompson, B., Browning, P.K.: 2000, Solar Phys. 193, 181.
Brueckner, G., Bartoe, J.-D.: 1974, Solar Phys. 38, 133.
Dere, K.P., Landi, E., Mason, H.E., Monsignori Fossi, B.C., Young, P.R.: 1997, Astron. Astrophys. Suppl. 125, 149.
Deslandres, H.: 1899, Comptes Rendus 129, 1225.
Dowdy, J.F., Jr., Rabin, D., Moore, R.L.: 1986, Solar Phys. 105, 35.
Gabriel, A.H.: 1976, Phil. Trans. Roy. Soc. Lond. A 281, 339.
Gallagher, P.T., Phillips, K.J.H., Harra-Murnion, L.K., Keenan, F.P.: 1999, Astron. Astrophys. 335, 733.
Huber, M.C.E., Foukal, P.V., Noyes, R.W., Reeves, E.M., Schmahl, E.J., Timothy, J.G., Vernazza, J.E., Withbroe, G.L.: 1974, Astrophys. J. Lett. 194, 115.
Jordan, C., Macpherson, K.P., Smith, G.R.: 2001, Mon. Not. Roy. Astron. Soc. 328, 1098.
Landi, E., Del Zanna, G., Young, P.R., Dere, K.P., Mason, H.E., Landini, M.: 2006, Astrophys. J. Suppl. 162, 261.
Munro, R.H., Withbroe, G.L.: 1972, Astrophys. J. 176, 511.
Ortiz, A., Solanki, S.K., Domingo, V., Fligge, M., Sanahuja, B.: 2002, Astron. Astrophys. 388, 1036.
Patsourakos, S., Vial, J.-C., Gabriel, A.H., Bellamine, N.: 1999, Astrophys. J. 522, 540.
Peter, H.: 2001, Astron. Astrophys. 374, 1108.
Raju, K.P.: 2009, Solar Phys. 255, 119.
Raju, K.P., Bromage, B.J.I.: 2006, Astron. Astrophys. 446, 295.
Raju, K.P., Bromage, B.J.I., Chapman, S.A., Del Zanna, G.: 2005, Astron. Astrophys. 432, 341.
Reeves, E.M., Foukal, P.V., Huber, M.C.E., Noyes, R.W., Schmahl, E.J., Timothy, J.G., Vernazza, J.E., Withbroe, G.L.: 1974, Astrophys. J. Lett. 188, 27.
Reeves, E.M.: 1976, Solar Phys. 46, 53.
Simon, G.W., Leighton, R.B.: 1964, Astrophys. J. 140, 1120.
Stucki, K., Solanki, S.K., Schühle, U., Rüedi, I., Wilhelm, K., Stenflo, J.O., Brković, A., Huber, M.C.E.: 2000, Astron. Astrophys. 363, 1145.
Tian, H., Xia, L., He, J., Tan, B., Yao, S.: 2008a, Chin. J. Astron. Astrophys. 8, 732.
Tian, H., Marsch, E., Tu, C.-Y., Xia, L.-D., He, J.-S.: 2008b, Astron. Astrophys. 482, 267.
Tian, H., Teriaca, L., Curdt, W., Vial, J.-C.: 2009, Astrophys. J. Lett. 703, 152.
Wiegelmann, T., Solanki, S.K.: 2004, Solar Phys. 225, 227.
Withbroe, G.L.: 1970, Solar Phys. 11, 42.
Withbroe, G.L.: 1977, In: Zirker, J.B. (ed.) Coronal Holes and High Speed Wind Streams, Colorado Associated Press, Boulder, 145.
Withbroe, G.L., Noyes, R.W.: 1977, Annu. Rev. Astron. Astrophys. 15, 363.
Zirker, J.B.: 1977, In: Zirker, J.B. (ed.) Coronal Holes and High Speed Wind Streams, Colorado Associated Press, Boulder, 1.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Raju, K.P. Intensity Distribution and Contrast of the Solar EUV Network. Sol Phys 262, 61–69 (2010). https://doi.org/10.1007/s11207-010-9514-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11207-010-9514-7