EVIDENCE FOR BIOCONICAL CORONAL-LINE REGION IN NGC-3516

We present new narrow-band images of the Extended Emission-Line Region (EELR) in NGC 3516. Our [O III]lambda4959 and Halpha + [N II]lambdala mbda6548,6584 images confirm previously reported EELR features. In con trast, the image in the high-excitation [Fe VII] + [Ca V]lambda6087 li ne shows a different structure. We identify a biconical morphology ove r a kiloparsec scale with peak intensities 5.9 x 10(-16) ergs cm-2s-1 arsec-2 and 3.5 x 10(-16) erp cm-2 s-1arcsec-2 to north and south of t he nucleus, respectively, and a total flux of F(tot)([FeVII]+[CaV]) al most-equal-to 1.53 x 10(-13) ergs cm-2s-1 in 24-arcsec circular apertu re. These observations support the model of the Coronal-Line Region pr oposed by Korista and Ferland (1989). The coronal emission in NGC 3516 may arise in a low-density (N(e) approximately 1 cm-3) interstellar m edium exposed to and photoionized by the bare active nucleus.