Spiral and Bar Instabilities Provoked by Dark Matter Satellites
| dc.creator | Dubinski, John | |
| dc.creator | Gauthier, Jean-Rene | |
| dc.creator | Widrow, Larry | |
| dc.creator | Nickerson, Sarah | |
| dc.date | 2008-02-27 | |
| dc.date.accessioned | 2026-07-07T09:23:34Z | |
| dc.date.available | 2026-07-07T09:23:34Z | |
| dc.description | We explore the secular dynamical evolution of an N-body model of M31 in the presence of a population of 100 dark matter satellites over 10 Gyr. The satellite population has structural and kinematic characteristics modelled to follow the predictions of Lambda-CDM cosmological simulations. Vertical disk heating is a small effect despite many interactions with the satellite population with only a 20% increase in vertical velocity dispersion sigma_z and the disk scale height z_d at the equivalent solar radius R = 2.5R_d . However, the stellar disk is noticeably flared after 10 Gyr with z_d nearly doubling at the disk edge. Azimuthal disk heating is much larger with sigma_R and sigma_z both increasing by 1.7x. However, in a control experiment without satellites dispersion increases by 1.5x suggesting that most of the effect is due to heating through scattering off of spiral structure excited by swing-amplified noise. Surprisingly, direct impacts of satellites on the disk can excite spiral structure with a significant amplitude and in some cases impacts close to the disk center also induce the bar instability. The large number of dark matter satellite impacts expected over a galaxy's lifetime may be a significant source of external perturbations for driving disk secular evolution. | |
| dc.description | 4 pages, 1 figure, 4 movies at http://www.cita.utoronto.ca/~dubinski/Rome2007, to appear in the proceedings of the ASP, Formation and Evolution of Galaxy Disks - Rome, Pontifical Gregorian University, 1-5 October 2007, ed. J.G Funes and E.M Corsini | |
| dc.identifier | https://arxiv.org/abs/0802.3997 | |
| dc.identifier | http://arxiv.org/abs/0802.3997 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/155776 | |
| dc.subject | Astrophysics | |
| dc.title | Spiral and Bar Instabilities Provoked by Dark Matter Satellites | |
| dc.type | text |