Today was the first day of the 2019 Santa Barbara Gaia Sprint at KITP. My goal for the week is to write a paper with Christina Eilers (MPIA), Hans-Walter Rix (MPIA), Sarah Pearson (Flatiron) and others on non-axi-symmetries in the Milky Way disk, possibly including spiral arms and the bar. I'd like to say we made a lot of progress today! Maybe we did, but it was progress in the form of making very complex code changes to improve visualization and plotting and then deciding that they only made the figures less good. Grr.
The Sprint has no required program and very few plenary activities. However, each day of the Sprint ends with a check-in in which people show a few results. Kareem El-Badry (Berkeley) showed some incredible stuff he has been doing with Rix on wide-separation binaries (identified as co-moving stars). He shows an excess population of wide binaries with near identical (few percent level!) masses. This is not surprising in that such populations are known at small separations. But it is surprising given that none of the explanations for the small-separation equal-mass binaries work at large separations. He did a lot of work today showing that these results are real and not something spurious in the Gaia data.
At that same check-in, Kathryn Johnston (Columbia) showed a beautiful visualization of how the local phase spiral in the Milky Way disk varies with azimuthal action. For her, the azimuthal action is a proxy for a vertical frequency; her picture is that the disk was impulsed at some time in the past, and that impulse has been winding up at different frequencies on different orbits. Beautiful.
No comments:
Post a Comment