2001ApJ...548L..13T

We present preliminary results from spectral observations of Ton S180 using Chandra and ASCA. The data confirm the presence of the soft excess, but the Chandra Low-Energy Transmission Grating spectrum reveals it to be broad and smooth rather than resolved into individual emission lines. This excess may represent either a primary or reprocessed continuum component or a blend of broad lines from an ionized accretion disk. The occurrence of a similar feature in five other narrow-line Seyfert 1 galaxies leads us to conclude that this soft X-ray component may be a characteristic of sources accreting at a high rate. The X-ray spectrum shows no evidence for absorption lines, indicating that if gas exists in the line of sight then it is in a very high ionization state or has an extreme velocity distribution. The new ASCA data confirm that the narrow component of the Fe Kα line peaks close to a rest energy of 7 keV, indicating the presence of a significant amount of highly ionized material in the nuclear environs.