The Astrophysical Journal
We report the detection of intense EUV radiation from the Seyfert 1 galaxy Ton S180. The source EUVE J0057-223, discovered in the Extreme-Ultraviolet Explorer all-sky survey, is only 25'' away from its optical counterpart, well within the position error circle. We present a complete broadband energy distribution of Ton S180 using infrared (IRAS), optical, ultraviolet (IUE) and X-ray (ROSAT) flux measurements, and we find that the measured EUV flux, corrected for neutral hydrogen and helium absorption in the Galaxy, suggests the presence of a strong EUV to soft X-ray flux excess. We briefly discuss the implications for models of active galaxies.
Vennes, Stéphane; Polomski, Elisha; Bowyer, Stuart; and Thorstensen, John R., "Discovery of Extreme-Ultraviolet Radiation from the Seyfert Galaxy Ton S180 (=EUVE J0057−223)" (1995). Open Dartmouth: Faculty Open Access Articles. 2296.