| This week: Galaxy Interactions | |
| Tides | |
| Simulations | |
| Warps | |
| Dynamical Friction | |
| Shells | |
| (Ch. 7, Combes et al., parts) | |
| Unless noted, all figs and eqs from Combes et al or Longair. | |
| Tidal forces experienced by an object of diameter d in gravitational interaction with galaxy mass M a distance D away: | ||
| Ftide ~ GMd/D3 (differentiating Newton) | ||
| (Why not exactly equal?) | ||
| Therefore tidal forces very sensitive to D | ||
| The text goes into some detail about an analytical approach under a number of simplifying assumptions (p. 183-186). | |
| I’m not going to go through it in class, but do look at it. It is similar to some items in Chapter 6 we skipped. | |
| The real way to do this anyway is through numeric simulation. |
| M51 and simulation (Toomre & Toomre 1972) |
| Antennae Galaxies: http://www.cita.utoronto.ca/~dubinski/antennae/antennae.html |
| Gas and simulation in text (TT72). |
| Simulation of “The Mice” in text. | |
| Redone more recently by Barnes. |
| Joshua Barnes: http://www.ifa.hawaii.edu/faculty/barnes/transform.html | |
| John Dubinksi: | |
| http://www.cita.utoronto.ca/~dubinski/nbody/ | |
| Chris Mihos: | |
| http://burro.astr.cwru.edu/models/models.html | |
| Bob Berrington (yes, our Bob): | |
| http://physics.uwyo.edu/~rberring/ | |
| There are others… |
| More on interactions, distortions, and dynamical friction. | |
| Chapter 8 in Combes et al. on radio sources. | |
| Continue on Data Reduction and Analysis | |
| New problem set, old homework returned. |