Ray Carlberg, University of Toronto
When
Abstract: The small-scale structure of galactic halos depends on dark matter physics. For instance, the numbers of visible Milky Way dwarf galaxies requires that dark matter particles are fairly cold. The Galaxy’s thin stellar streams are beginning to provide complimentary information. Streams begin as stars are pulled away from the outskirts of globular clusters to create thin, low velocity dispersion, streams. Subsequent encounters with dark matter sub-halos orbiting in the halo perturb the streams, creating gaps, and gradually increasing the width and velocity spread of the streams. Sub-halos less massive than 108 M_sun dominate the gap creation and heating, providing an avenue to test for the numbers of lower mass and essentially completely dark sub-halos in the Galaxy.
Zoom: https://arizona.zoom.us/j/4470189357
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https://docs.google.com/spreadsheets/d/1JL2K9EwNbBlBEnUEukGPBKoSzt3Mlr8cKTnlQAz5cfg/edit?usp=sharing