No abstract

Companion galaxy environment for a subset of 78 bright and nearby barred galaxies from the Shapley Ames Catalog is presented. Among the spiral barred galaxies there are Seyfert galaxies, galaxies with circumnuclear structures, galaxies not associated with any large scale galaxy cloud structure, galaxies with peculiar disk morphology (crooked arms) and galaxies with normal disk morphology; the list includes all Hubbles types. The companion galaxy list includes the number of companion galaxies within 20 diameters, their Hubble type and projected separation distance. Additionally, companion environment was searched for four known active spiral galaxies, three of them are Seyfert galaxies, namely, NGC 1068, NGC 1097, NGC 5548 and one is a starburst galaxy, M82. Among the results obtained it is noted that the only spiral barred galaxy classified as Sy 1 in our list has no companions within a projected distance of 20 diameters; 6 out of 10 Sy 2 bar galaxies have no companions within 10 diameters, 6 out of 10 Sy 2 galaxies have one or more companions at projected separation distances between 10 and 20 diameters; 6 out of 12 galaxies with circumnuclear structures have 2 or more companions within 20 diameters.

We studied the spiral pattern in the inner 6>5 (1 00 ¼ 257 pc) central regions of the interacting active nucleus galaxy NGC 1241 using Gemini North Telescope high-resolution K s -and J-band images and Hubble Space Telescope (HST) Pa and H-and ðV þ RÞ-band images with high resolution in the range from $0>1 to $0>3 along with intermediate to large-scale spectroscopy using the Multifunction Spectrograph at the Có rdoba Observatory in Argentina. Our analysis of Pa emission images revealed a faint two-armed leading spiral pattern ending in the 5>6 Â 3>4 clumpy ring discovered by Böker and coworkers, harboring a 1>6 long barlike structure almost perpendicular to the large-scale bar of NGC 1241. When we applied two-dimensional Fourier analysis at circumnuclear scales, we found that a two-arm trailing mode was dominant in K s -and J-band images while the ðV þ RÞ-band images showed more complex structural features with a strong onearmed trailing mode. One-dimensional Fourier analysis showed a corotation (CR) located outward from the edge of the Pa bar. Our kinematics data gave an angular speed CN of 350 AE 50 km s À1 kpc À1 for the trailing mode pattern. The rotation curve showed that the circumnuclear ring is located just inside the large-scale pattern inner Lindblad resonance (ILR), which has a radius of about r $ 1 kpc. We also found, within the uncertainties present in such measurements, that the outer Lindblad resonance (OLR) of the circumnuclear pattern is coincident with the large-scale pattern ILR, indicating a possible connection between circumnuclear and global dynamics. Nevertheless, the estimated high molecular gas fraction (!13%) and the inner pattern high angular speed at the central region of NGC 1241 point to a nuclear bar formation via self-gravitational instability.

No abstract

No abstract