X-Ray Evidence for Seyfert Activity Buried in the Infrared Galaxy NGC 4945

We have observed the infrared galaxy NGC 4945 using the Japanese X-ray astronomy satellite, Ginga. The X-ray spectrum is found to be composed of three components: hard X-ray emission which is heavily absorbed by cold material with column density of about 10 24.7 cm −2 ; a soft X-ray component seen in the 2-10 keV band; and an iron emission line. The hard component exhibits a power-law spectrum with photon index of about 1.7. The mean X-ray luminosity in the 2-20 keV band, after correction for absorption is 3×10 42 ergs s −1 with significant intensity variation on a time scale of several hours. These results are thought to be evidence for an AGN (active galactic nucleus) in the galaxy