EXOSAT observations of a strong soft X-ray excess in MKN 841
Open Access
- 1 November 1985
- journal article
- research article
- Published by Oxford University Press (OUP) in Monthly Notices of the Royal Astronomical Society
- Vol. 217 (1) , 105-113
- https://doi.org/10.1093/mnras/217.1.105
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.