Monday, May 05, 2008

Non-liveblogging the 2008 DDA meeting, part 1

This year's Division on Dynamical Astronomy meeting seems to have been a success. Now that the meeting is over, I'm going to free-associate about one talk each day. We'll see how far I get!

Monday, April 28, 2008
Session 1: Stars and Galaxies

Invited Talk: Telling Tales with Tidal Tails

Kathryn V. Johnston, Columbia University

From Kathryn's abstract: In the last decade, the stellar halos of the Milky Way and Andromeda galaxies have been mapped in exquisite detail, revealing that they are actually richly substructured in phase-space due to the presence of debris from tidally disrupted satellites.

The Local Group consists of Andromeda, the Milky Way, and at least 33 smaller galaxies, which is appropriate since M33 is the largest of the nieces and nephews. As the eons pass, Andromeda and the Milky Way are engaging in galactic cannibalism, with the Clash of the Titans likely to occur in about 3 billion years. Until that large meal, we must subsist on snacks such as the Sagittarius stream. Streams are produced by tidal disruption of dwarf galaxies; similar tails are seen in simulations of the Moon-forming impact. The structure of the streams provides a sensitive probe of the Galactic potential at large distances. Ultimately, we will be able to compare aspects of the outer Galaxy, such as the shape of the halo, with that predicted by cosmological N-body simulations, some of which now follow over 1010 particles, i.e., more than one for every man, woman, and child on Earth. One of the key projects of NASA's planned Space Interferometry Mission telescope will be to determine Galactic structure out to hundreds of kiloparsecs, a region containing a number of tidal tails.

astro-ph search for papers about tidal streams and tidal tails

1 Comments:

Anonymous changcho said...

Very cool - One thing I always liked about DDA was the opportunity for solary system 'dynamicists' to interact with the 'galactic/stellar' dynamicists.

Thanks!

1:10 PM  

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