- Mount Stromlo Observatory, Australian National University, Canberra.On leave from the University of California at San Diego. Work supported by the U.S. National Science Foundation.Mount Wilson and Palomar Observatories, Carnegie Institution of Washington, California Institute of Technology.
THE purpose of this communication is to point out a similarity in the optical continua of several objects, all associated with violent events, but which otherwise have a diverse character. The objects are the nucleus of the Seyfert Galaxy NGC 4151, the galactic, nova-like object Carinae, the Crab Nebula and the quasi-stellar radio source, 3C748. (The term nova-like is to some extent descriptive of the spectrum. In using it, we do not mean to imply a mechanism for the outburst in Carinae. This outburst has involved energies characteristic of supernovae and, unlike either supernovae or novae, has a time scale of the order of a century.) The optical spectrum of NGC 4151 has been discussed by Seyfert1 and Woltjer2, that of Carinae by Thackeray3, that of the Crab Nebula by Woltjer4 and Mayall5, and that of 3C48 by Greenstein and Schmidt6. The emission lines in all of these spectra show, as a common feature, evidence of internal motions as large as a few thousand km/sec. We indicate in Table 1 some of the principal observed features of these objects.
- 1 - general ; 2 - general science & technology ; 3 - general science & technology
- 1 - sciences appliquees, technologies et medecines ; 2 - sciences exactes et technologie ; 3 - terre, ocean, espace ; 4 - astronomie