RT Journal Article T1 The relationship between soft X-rays and the 1640 Å feature fluxes in late-type stars A1 Rego Fernández, Manuel A1 González Riestra, R. A1 Fernández Figueroa, María José AB The λ 1640 feature has been observed in a sample of late­ type stars of different luminosity classes. The intensity was measured from IUE low dispersion spectra, and it has been compared with the observed X-ray fluxes, finding a relationship between both quantities for "solar type" stars. The X-ray fluxes derived from this relationship for a reduced sample of stars are consistent with the observed ones in the case of "solar type" stars. "Non solar type" stars exhibit discrepancies that could be explained assuming that the λ 1640 feature is formed by contri­buters other than He II, which supply an important fraction of this emission in "solar type" stars. The obtained empirical relationship has been used to derive the X-ray flux for some stars that have not been observed in the X-ray range. PB EDP Sciencies SN 0004-6361 YR 1983 FD 1983 LK https://hdl.handle.net/20.500.14352/64989 UL https://hdl.handle.net/20.500.14352/64989 LA eng NO Athay, R.G.: 1965, Astrophys. J. 142, 755Ayres, T.R., Marstad, N.C., Linsky, J.L.: 1981, Astrophys. J. 247, 545Ayres, T.R., Linsky, J.L., Vaiana, G.S., Golub, L., Rosner, R.: 1981, Astrophys. J. 250, 293Barnes, T.G., Evans, D.S.: 1976, Monthly Notices Roy. Astron. Soc. 174, 489Boggess, A., Carr, F.A., Evans, D.C., Fischel, D., Freeman, H.R., Fuechsel, C.F., Klinglesmith, D.A., Krueger, V.L., Longa­necker, G.W., Moore, J.V., Pyle, E.J., Rebar, F., Sizemore, K.O., Sparks, W., Underhill, A.B., Vitagliano, H.D., West, D.K., Macchetto, F., Fitton, B., Parker, P.J., Dunford, E., Gond­halekar, P.M., Hall, J.E., Harrison, V.A.M., Oliver, M.B., Sand­ford, M.C.V., Vaughan, P.A., Ward, A.K., Anderson, B.E., Boksenberg, A., Coleman, C.I., Snijders, M.A.J., Wilson, R.: 1978, Nature 275, 377Bohlin, R.C., Holm, A.V., Lindler, A.J.: 1981, IUE ESA Newsletter 10, 10Boland, B.C. et al.: 1975, Monthly Notices Roy. Astron. Soc. 171, 697Brown, A., Jordan, C.: 1980, Monthly Notices Roy. Astron. Soc. 191, 37PCayrel de Strobel, G., Bentolila, C., Hauck, B., Curchod, A.: 1980, Astron. Astrophys. Suppl. 41, 405Hartmann, L., Davis, R., Dupree, A.K., Raymond, J., Schmidtke, P.C., Wing, R.F.: 1977, Astrophys. J. Letters 233, L69Hartmann, L., Dupree, A.K., Raymond, J.C.: 1980, Astrophys. J. Letters 236, L143Hartmann, L., Dupree, A.K., Raymond, J.C.: 1982, Astrophys. J. 252, 214Hoffleit, D.: 1964, Catalogue of Bright Stars, Yale University Press Johnson, H.L., Mitchell, R.G., Iriarte, B., Wisniewsky, W.Z.: 1966, Comm. Lunar and Planetary Lab. 4, 99Jordan, C.: 1975, Monthly Notices Roy. Astron. Soc. 170, 429Kohl, J.L.: 1977, Astrophys. J. 211, 958Linsky, J.L., Ayres, T.R., Basri, G.S., Morrison, N.D., Boggess, A., Schiffer, F.H. III, Holm, A., Cassatella, A., Heck, A., Macchetto, F., Stickland, D., Wilson, R., Blanco, C., Dupree, A.K., Jordan, C., Wing, R.F.: 1978, Nature 275, 389Linsky, J.L., Haisch, B.W.: 1979, Astrophys. J. Letters 229, L27 Raymond, J.C., Noyes, R.W., Stopa, M.P.: 1979, Solar Phys. 61, 271Raymond, J.C., Smith, B.W.: 1977, Astrophys. J. Suppl. 35, 419 Pallavicini, R., Golub, L., Rosner, R., Vaiana, G.S., Ayres, T., Linsky, J.L.: 1981, Astrophys. J. 248, 279Vaiana, G.S., Cassinelli, J.P., Fabbiano, G., Giacconi, R., Golub, L., Gorenstein, P., Haisch, B.M., Harnden, F.R., Johnson, H.M., Linsky, J.L., Maxson, C.W., Meve,R., Rosner, R., Seward, F., Topka, K., Zwaan, C.:1981, Astrophys. J. 245, 163 Walter, F.M., Cash, W., Charles, P.A., Bowyer, C.S.: 1980, Astrophys. J. 236, 212Wilson, O.C.: 1966, Astrophys. J. 205, 803 Zirin, H.: 1975, Astrophys. J. Letters 199, L63 Zirin, H.: 1976, Astrophys. J. 208, 414 NO © European Southern Observatory (ESO).© EDP Sciencies. DS Docta Complutense RD 5 may 2024