Slow unstable modes of counter-rotating nearly Keplerian stellar discs
Abstract
The nuclei of two nearby galaxies, NGC4486B in the Virgo cluster and M31 our nearest neighbour, both show an unusual double-peak distribution of stellar light. The stars appear to be distributed in a highly anisotropic, lopsided manner about a massive black hole, whose mass could be hundred million solar masses. These nearly Keplerian stellar discs have been explored by many authors since the eccentric disk model proposed by Tremaine (1995). One of the most interesting questions concerns the origins of the high eccentricities and lopsided distribution of stellar orbits about the central black hole. A possible origin of lopsidedness, suggested by Touma (2002), is through an instability off counter-rotating streams of stars. This could occur were a globular cluster to be tidally disrupted and added to the stellar system. This work is an exploration of modes in these nearly Keplerian systems, in particular the nature of the instabilities due to counter-rotation streams of stars.
- Publication:
-
Astronomical Society of India Conference Series
- Pub Date:
- 2013
- Bibcode:
- 2013ASInC...9...91G