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> Galaxies NGC 1316 and NGC 1317 in Fornax
Galaxies NGC 1316 and NGC 1317 in Fornax
author: Anglo-Australian Observatory/David Malin Images/Novapix
reference: a-gax13-16003
Image Size 300 DPI: 40 * 51 cm
NGC 1316-17 are on the outskirts of a nearby cluster of galaxies in the southern constellation of Fornax, at a distance of about 60 million light years. At first glance, the optical image of these galaxies does not seem to be very unusual. However, closer inspection shows that the larger galaxy, the elliptical NGC 1316, has distinct dust lanes in its inner regions, and NGC 1317 is a strangely distorted spiral. The dust lanes strongly suggest that NGC 1316 has recently absorbed a dusty spiral galaxy, and that the merger is not yet complete. The colour picture also hints at faint arcs or shells of stars in the outer parts of the galaxy, another strong indication of recent merger activity. A much deeper picture reveals enormous loops and shell-like structures extending far beyond this photograph, again supporting the merger hypothesis. If any more evidence were needed, it is provided by radio astronomers, who see Fornax A as one of the strongest and largest sources in the sky, with radio lobes extending over several degrees of sky. However, unlike the faint optical extensions, the radio lobes extend roughly E-W across the sky. There is another southern galaxy with many of these characteristics -- dusty elliptical, faint outer shells and somewhat detached from a cluster of galaxies. This is NGC 5128, Centaurus A, a confimed merger remnant.
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