Date: Friday 13th October | Time: 1.00pm – 2.00pm
Dr Denis Erkal
Denis Erkal is currently a postdoc at the Institute of Astronomy,
University of Cambridge and will be a Lecturer at the University of
Surrey starting in August, 2017. He studies galaxy formation, and in
particular what we can learn from detailed studies of the Milky Way and
nearby galaxies. His work is primarily theoretical with an emphasis on
comparing to data. He has a keen interest in public outreach and has
been interviewed by the BBC for Sky at Night.
Dark Matter ?
Dark matter is pervasive and mysterious. Although it is five times asprevalent as regular matter, we still know very little about it. After overviewing the evidence for dark matter, I will explain how we think galaxies form and what role dark matter plays. I will then talk about recent efforts to map out the dark matter in our Galaxy using tidal streams. These tidal streams form as globular clusters are torn apart by tidal forces, forming long and thin “streams”. The way these streams curve tells us about the large scale distribution of dark matter in our Galaxy and hence about how our Galaxy was formed. In addition, small
wiggles in the stream tell us about how lumpy dark matter is on small scales, allowing us to test our understanding of galaxy formation and constrain the mass of the dark matter particle.
Images below show Galaxy dark matter, and dark matter with stream.