IMAGING SPECTROPHOTOMETRY OF MARKARIAN 573

Abstract

Narrow-band emission-line and continuum images obtained in subarcsecond seeing conditions are presented for the Seyfert~2 galaxy, Markarian 573. Images in the emission-lines of [\oi], [\oii], [\oiii], [\sii], and \halpha+[\nii] are used to measure the structure and excitation in the extended emission regions surrounding the active nucleus. The biconical region contains a variety of complex features, including two arc-like structures within $\sim 2\arcsec$ of the active nucleus that appear to be associated with the extended radio continuum emission in the sense that the radio lobes lie just inside the centroids of the emission-line arcs. These arcs probably arise from an interaction between the ISM and the radio plasma from the active nucleus. Two other emission-line features lie $\sim3-4\arcsec$ on either side of the nucleus, and appear to be elongated nearly perpendicular to the symmetry axis of the inner radio and optical structures. The existence of multiple emission-line components could be evidence for episodic ejection of radio plasma from the active nucleus.

Accepted by ApJ. 24 pages, uuencoded compressed PostScript. 11 Figures (compressed PostScript) available from anonymous ftp at ftp://bessel.mps.ohio-state.edu/pub/rwp/m573/prefigs.ps.Z A complete (text+figs) compressed PostScript preprint is also available at ftp://bessel.mps.ohio-state.edu/pub/rwp/m573/mrk573pre.ps.Z