Abstract
We present the results of a continuous 18 hour observation of 4U1755-33 made with the European Space Agency's EXOSAT Observatory. Four 50 min dips in X-ray intensity were observed equally spaced with a period of 4.4 hrs, confirming the periodicity first suggested in White et al. (1984). The dips are spectrally independent. We examine the properties of 4U1755-33 and conclude that the source is most probably point-like and that the metallicity of the absorbing material is at least 600 times less than cosmic values.
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References
Bradt, H., and McClintock, 1983. Ann.Rev.Astr.Astrophys, 21
Cominsky, L., Ossmann, W., and Lewin, W.H.G. 1983. Ap.J., 270, 226.
Courvoisier, T.J.-L., Parmar, A.N., & Peacock, A. 1985. This volume.
de Korte, P.A.J. et al. 1981. Space.Sci.Rev., 30, 495.
Frank, J., and Sztajno, M. 1984. Astr.Astrophys, 138, L15.
Kraft, R.P. 1979. Ann.Rev.Astr.Astrophys., 17, 309.
Parmar, A.N. et al. 1985. Accepted for publication in Nature.
Peacock, A. et al. 1981. Space. Sci.Rev., 30, 525.
Turner, M.J.L., Smith, A., and Zimmermann, H.U. 1981. Space.Sci. Rev., 30, 513.
Verbunt, F., van Paradijs, J., & Elson, R. 1984. M.N.R.A.S. 210, 899
Watson, et al. 1985. This volume.
White, N.E. et al. 1981. Ap.J., 247, 994.
White, N.E. et al. 1984. Ap.J., 283, L9.
White, N.E., and Swank, J.H. 1982. Ap.J., 253, L61.
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Parmar, A.N., Whitel, N.E., Sztajno, M. et al. An investigation into the nature of the 4.4 hr periodic source 4U1755-33. Space Sci Rev 40, 213–217 (1985). https://doi.org/10.1007/BF00212887
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DOI: https://doi.org/10.1007/BF00212887