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Unformatted text preview: Central velocity dispersions of elliptical galaxies - the Faber-Jackson relation (1976 ApJ 204, 668) otherwise known as the L - σ 4 relation (a manifestation of the fundamental plane, as we've discussed). As shown in their Fig. 16, the correlation is reasonable; a rough theoretical argument has been applied, assuming the L measures total mass in some scaled way. A refinement, including a second parameter related to surface brightness, has been used by the Seven Samurai to compile a large set of redshift-independent distances for mapping the local velocity field (Dressler et al. 1987 ApJ 313, 42; data in Faber et al. 1989 ApJSuppl 69, 763). Global galaxy properties : These must be used for more and more distant systems, requiring extensive calibration from the techniques above. Specific indicators include: "Sosies" : from the French for lookalikes. The idea here is to find galaxies that look as much like our own or a very nearby one as possible, assuming then that lookalikes have the same size...
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