ASCA Observation of the Low-Luminosity Seyfert 1.5 Galaxy NGC 5033

We present the results of an ASCA observation of the low-luminosity Seyfert 1.5 galaxy NGC 5033. A point-likeX-ray sourcewith a luminosity of 2 .3 × 10 41 erg s −1 in the2–10 ke V band (at 18.7 Mpc; Tully 1988, AAA 045.002.054) was detected at the nucleus. The X-ray light curve shows variability on a timescale of ∼ 10 4 s with an amplitudeof ∼ 20%. The X-ray continuum is represented by a weakly absorbed (NH ≈ 9 × 10 20 cm −2 ) power-law with a photon index of 1.72 ± 0.04, which is quitesimilar to Seyfert 1 galaxies with higher luminosities. An Fe Kα emission line is detected at 6.40 +0.08 −0.06 keV (redshift corrected) and the equivalent width is 290 ± 100 eV. The line width is unresolved. The narrower line width and larger equivalent width compared to Seyfert 1s imply that fluorescent Fe Kα emission from matter further out from the center than the accretion disk significantly contributes to the observed Fe Kα line. We suggest that fluorescent Fe Kα emission from the putative torus contributes to the observed Fe Kα line.