EXOSAT observations of a strong soft X-ray excess in MKN 841

Abstract

EXOSAT observations of the spectrum of the Seyfert 1 galaxy MKN 841 show that it is well-fitted by a power law of photon index 1.6, similar to that of other Seyferts, and a large additional soft component. The X-ray luminosity over the observed band exceeds |$4\times{10}^{44}\,\text{erg}\,\text{s}^{-1}$|⁠. A single-temperature blackbody fit to the soft X-rays and the short-wavelength ultraviolet continuum gives a luminosity of |$2\times{10}^{46}\,\text{erg}\,\text{s}^{-1}$| while an accretion disc spectrum fitted to the same points gives a luminosity of |$4.3\times{10}^{45}\,\text{erg}\,\text{s}^{-1}$|⁠. The flux measured by both the EXOSAT low- and medium-energy instruments exhibits 12 per cent amplitude variability on a time-scale of one day.