International Ultraviolet Explorer observations of M 87.

Abstract

A spectrum of M87 obtained in the 1150-2000 A spectral range by the IUE is discussed. The visual and UV energy distribution of the nucleus of M87 reveals an essentially continuous curve from 1300 to 10,500 A, and a turnup in flux below 2200 A. It is shown that this turnup is not a consequence of scattered light in the instrument, while a plot of the deconvolved M87 UV profile and the visual profile shows that the radiation in the 1300-2200 A spectral region is distributed in the same way as the visual radiation; it is not a point source. In addition, there is evidence in the UV for an emission line of C IV; the relative strengths of C IV, H beta, and the forbidden O III lines at 4959 and 5007 A are consistent with those seen in planetary nebulae, but the forbidden O II line at 3727 A is much too strong.