ASCA observations have revealed the presence of low-luminosity AGN in ~10 LINERs as a hard point sources at the nucleus. The X-ray continuum shapes (photon indices Γ ≈ 1.8) are very similar to those of Seyfert galaxies (Makishima et al. 1997, Serlemitsos et al. 1996). An iron emission line is observed from heavily absorbed low-luminosity AGNs (Makishima et al. 1997), while M81 is the only object among those with small intrinsic absorption from which an iron line detected (Ishisaki et al. 1996) on account of limited photon statistics for other objects.
We summed up the ASCA spectra of 5 LINERs which host low-luminosity AGN of low intrinsic absorption to search for an iron emission line. We used 7 observations of 5 objects (NGC 1097, NGC 3310, NGC 3998, NGC 4450, and NGC 4594) to make a composite spectrum. All the objects have very similar X-ray characteristics (spectral slope, intrinsic absorption, no short time-scale variability; Iyomoto et al. 1996, Serlemitsos et al. 1996).