Dark matter wind blowing past the Sun

When galaxies collide, and several have merged into our own Milky Way, there are imprints that show as streams of stars, which are all moving in the same direction, but not yet equilibrated into the usual spiral arm rotation.

DMFlow
Artists impression: C. O’Hare; NASA/Jon Lomberg

One such stream, the S1 stream, is of particular interest since it crosses the path of our sun. Thinking about the dark matter from the merged galaxy, this would imply that there is a dark matter “wind” blowing past us at about 500km/s. This could potentially help in our efforts to detect the components of dark matter in earth-bound experiments.

However it is possible that the dark matter from a merger would follow a different trajectory from the stars, since we know that the dark matter in a galaxy does not occupy the same geometric shape as the stars in that galaxy. Indeed dark matter may not have the same equivalence of gravitational and inertial mass.

Phys. Rev. D 98, 103006 (2018)

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s