A Dark Matter speedometer


Just how quickly does dark matter zip around in our corner of the Galaxy?  The answer to this basic question is currently unknown, but the result is critical for terrestrial searches for dark matter.   Using a high-resolution simulation of the Milky Way, our group found that the oldest stars in the Galaxy share the same speeds as the dark matter.  Essentially, these old stars act as visible speedometers for the dark matter, measuring its speed distribution near Earth.  The image shows the distribution of these old stars in a simulated Milky Way galaxy.  Our group is currently studying the correlation between dark matter and old stars in further detail using data from the Gaia satellite.

[APS Physics Viewpoint]    [In the Press]