We report on observations of the CO (2→1) transition of a complete subset of 11/39 of the Piccinotti (1982) hard X-ray selected AGN sample. All of the 11 galaxies were clearly detected. All the galaxies in our sample are strong hard-X ray sources and thus the sample is unbiased with respect to obscuring material. Six of the galaxies are Seyfert 1 type objects with the rest five being reddened S...

We assume that the gravitational instability of standard thin accretion disks leads to the Broad Line Regions (BLRs), the B band luminosity comes from standard thin disk and the motion of BLRs is virial. The central black hole masses, the accretion rates and the disk inclinations to the line of sight for 17 Seyfert 1 galaxies and 17 Palomar-Green (PG) quasars have been calculated. Our results a...

High resolution (a few arcseconds) observations of CO(1−0) and HCN(1−0) emission from nearby Seyfert galaxies have been conducted with the NobeyamaMillimeter Array. Based on the observed CO distribution and kinematics, we suggest that a small scale (a few 100 pc a few kpc) distortion of the underlying potential seems to be necessary for Seyfert activity, although it is not a sufficient conditio...

We have used the ROSAT Bright Source Catalogue to extract a complete sample of sources selected in the band from 0.1–0.4 keV. This 1/4 keV-selected sample is comprised of 54 Seyfert galaxies, 25 BL Lacertae objects, 4 clusters and 27 Galactic stars or binaries. Seyfert-type galaxies with “ultrasoft” X-ray spectra can very often be classed optically as Narrow-line Seyfert 1s (NLS1s). Such object...

We present the results of a Hubble Space Telescope (HST) survey of extended [OIII] emission in a sample of 60 nearby Seyfert galaxies (22 Seyfert 1’s and 38 Seyfert 2’s), selected by mostly isotropic properties. The comparison between the semi major axis size of their [OIII] emitting regions (RMaj) shows that Seyfert 1’s and Seyfert 2’s have similar distributions, which seems to contradict Unif...

We use the CO band at 2.3μm to constrain the populations of young stars in the central regions of Seyfert galaxies. We report new CO band spectroscopy of 46 Seyfert galaxies. In most cases, the observed CO indices appear diluted by the presence of a non-stellar component (most likely, warm dust surrounding the active nucleus). We used JHKL aperture photometry to estimate the non-stellar contrib...

The relationship of an AGN to its host galaxy is one crucial question in the study of galaxy evolution. We present a method to estimate the stellar contribution in active galactic nuclei. We perform stellar population synthesis in the central regions of a sample of 12 galaxies of different levels of activity: normal galaxies, starburst galaxies, LINERs, Seyfert 2 and Seyfert 1 galaxies. Quantif...

We present and analyze ROSAT–PSPC observations of eight Seyfert 2 galaxies, two Seyfert 1/QSOs, and one IR–luminous non–Seyfert. These targets were selected from the Extended 12 μm Galaxy Sample and, therefore, have different multiwavelength properties from most (optically or X–ray selected) Seyferts previously observed in the soft X–rays. The targets were also selected as having atypical X–ray...

We present subarcsecond resolution mid-infrared (mid-IR) photometry in the wavelength range from 8 to 20 μm of eighteen Seyfert galaxies, reporting high spatial resolution nuclear fluxes for the entire sample. We construct spectral energy distributions (SEDs) that the AGN dominates, relatively uncontaminated by starlight, adding near-IR measurements from the literature at similar angular resolu...