NEW X-RAY SPECTRAL OBSERVATIONS OF NGC-4151 WITH ASCA

We present new X-ray spectral data for the well-studied Seyfert galaxy NGC 4151, which was observed twice for about 20 ks each during the AS CA performance verification phase, once on 1993 May 25 and again on 19 93 November 5. The source underwent complex spectral variability, and the observed 2-10 keV flux increased by a factor of 2 while the intrin sic 2-10 keV flux increased by no more than 20%. The data can be model ed with either a dual cold absorber plus a soft X-ray excess consistin g of scattered continuum flux and an additional ''ultrasoft'' X-ray ex cess component, or a warm absorber plus scattered continuum flux. Ther e is evidence for variability at <1 keV energies that is unrelated to the 2-10 keV continuum. For an ionized-absorber description of NGC 415 1, changes in the ionization state of the absorber appear to be unrela ted to changes in the ionizing continuum.