Skip to main content

2019 03 13 : Particle Physics Seminar : The Gaia Sausage and the Dark Matter Hurricane

Particle Physics Seminar

  • Date 13 Mar 2019
  • Time 3.30-4.30pm
  • Category Seminar

This event has been archived

Prof Wyn Evans (University of Cambridge)

The talk discusses discoveries in data from the Gaia satellite, which is scanning the sky right now. Gaia provides distances, velocities and chemical information on all stars brighter than 20th magnitude. With such precise chemistry and kinematics, we can uncover the accretion history of the Galaxy, including the build-up of stars and dark matter in the halo. This has led to two important discoveries with implications for dark matter detection experiments. First, a dark matter hurricane is blowing past the Solar system right now, associated with the newly-found S1 stellar stream. It offers new prospects of identifying the nature of the elusive dark matter particle, especially for detectors with directional sensitivity. Second,  a substantial fraction of the stellar and dark halo lies in an elongated structure called the Gaia Sausage. This head-on merger with a massive dwarf satellite 8 or so billion years ago re-configured the inner Galaxy, with consequences for the velocity distribution of dark matter particles,The Sausage skin has a tell-tale signature in indirect dark matter detection experiments. The Sausage Galaxy itself re-structured the Galactic disk, creating the thick disk, while its black hole scoured out the Galactic centre.


In Tolansky T125.

Related topics

Explore Royal Holloway

Get help paying for your studies at Royal Holloway through a range of scholarships and bursaries.

There are lots of exciting ways to get involved at Royal Holloway. Discover new interests and enjoy existing ones

Heading to university is exciting. Finding the right place to live will get you off to a good start

Whether you need support with your health or practical advice on budgeting or finding part-time work, we can help

Discover more about our 21 departments and schools

Find out why Royal Holloway is in the top 25% of UK universities for research rated ‘world-leading’ or ‘internationally excellent’

Royal Holloway is a research intensive university and our academics collaborate across disciplines to achieve excellence.

Discover world-class research at Royal Holloway

Discover more about who we are today, and our vision for the future

Royal Holloway began as two pioneering colleges for the education of women in the 19th century, and their spirit lives on today

We’ve played a role in thousands of careers, some of them particularly remarkable

Find about our decision-making processes and the people who lead and manage Royal Holloway today