WFPC2 Images of Multiple Nuclei in Nearby Active Galactic Nuclei

Abstract

High-resolution images have been made with the Hubble Space Telescope of the cores of three active galaxies: Mrk 348, Mrk 516, and Mrk 789. The 500 s images were taken using the WFPC2 camera with the F606W filter. Each galaxy exhibits structure which may be interpreted as multiple nuclei. Mrk 348 appears to have two nuclei, although it is possible that they may be bipolar ejecta from the core. The optical image was compared to a VLBI image showing a linear triple source. Though there are similarities between the two images, there is no direct one-to-one correspondence between the sources. The optical polarization angle for Mrk 348 (168 deg) is almost perpendicular to the position angle of its nuclei (84 deg). Mrk 516 is a spiral with a warped disk which may be evidence of a recent merger. One of its two nuclei is resolved. Mrk 789 was identified as a double nucleus galaxy from the ground and is a merger in which three sources were detected within one of the previously identified nuclei. However, it is possible that the knots may be very bright H II regions.