An eccentric disk model for the nucleus of M31 SCOTT TREMAINE
نویسنده
چکیده
The nucleus of M31 may be a thick eccentric disk, composed of stars traveling on nearly Keplerian orbits around a black hole or other dark compact object. This hypothesis reproduces most of the features seen in HST photometry of the center of M31; in particular the bright o center source P1 is the apoapsis of the disk. An eccentric disk can also explain the rotation curve and asymmetric dispersion pro le revealed by ground-based observations. The central object must be smaller than 1 pc so that the potential felt by the disk is nearly Keplerian. The disk eccentricity may be excited by a secular instability driven by dynamical friction from the bulge.
منابع مشابه
ar X iv : a st ro - p h / 03 07 41 2 v 1 2 3 Ju l 2 00 3 Eccentric - disk models for the nucleus of M 31
We construct dynamical models of the “double” nucleus of M31 in which the nucleus consists of an eccentric disk of stars orbiting a central black hole. The principal approximation in these models is that the disk stars travel in a Kepler potential, i.e., we neglect the mass of the disk relative to the black hole. We consider both “aligned” models, in which the eccentric disk lies in the plane o...
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