Seminars

We run seminars on Thursdays from 2 - 3pm in the seminar room (30BB03) roughly every other week during the academic year. If you have any queries regarding the seminars then email Stacy Kim.

Spring 2020 Seminars

Dates and abstracts for upcoming seminars can be found below.

Dwarf galaxies are the dominant galaxy population by number in the nearby Universe. Despite their ubiquity, the processes that govern their star formation activity are not well understood. In particular, what causes star formation to cease/quench in these low-mass galaxies? Addressing this question requires spatial information for dwarf galaxies in a range of local environments. Using data from the SDSS-IV MaNGA IFU survey, we identify a sample of quenched dwarf galaxies fainter than Mr = -19, selected independently of morphology and environment.  I will show the majority of quenched dwarfs exhibit coherent rotation in their stellar kinematics, and several host disc or spiral features, inconsistent with a primordial origin. I will also show that a number of bright dwarf galaxies with signatures of gas accretion host active galactic nuclei, which are likely maintaining their quiescence. While they are the "simplest" galaxies in our current models of galaxy formation, quenched dwarf galaxies are a diverse population, with further surveys and modelling needed to understand their origin.

The Galactic Center offers the unique possibility to quantitatively test general relativity in the so-far unexplored regime close to a massive black hole. Here we present the results from the last two years of GRAVITY observations, in particular (1) the detection of the gravitational redshift in the orbit of the star S2, and (2) the orbital motion of matter close to the last stable orbit during a flare. The GRAVITY instrument, which we have developed specifically for the observations of the Galactic Center black hole and its orbiting stars, is now routinely achieving ~3 milli-arcsec imaging interferometry and with a sensitivity several hundred times better than previous instruments. Its astrometric precision of few ten micro-arcseconds corresponds to only few Schwarzschild radii of Galactic Center massive black hole, which opens up the possibility to test the fundamentals of gravity, all the way from the underlying equivalence principles, to considerations on new physics and their characteristic scales and strengths. The Galactic Center is and will remain the Rosetta-stone for deciphering strong gravity around massive black holes.

Abstract TBA.

Abstract TBA.

Abstract TBA.

Abstract TBA.

Abstract TBA.

Past seminars

Speaker: Andres Piatti (Astronomical Observatory of Cordoba)
Date: 3 Oct 2019

Stellar tidal streams outside the local group

Speaker: David Martinez Delgado (University of Heidelberg)
Date: 10 Oct 2019
Find out more.

Spin alignment of stars in old open clusters

Speaker: Enrico Corsaro (University of Catania)
Date: 7 Nov 2019
Find out more.

Runaways from young star-forming regions in simulations and observations

Speaker: Christina Schoettler (University of Sheffield)
Date: 21 Nov 2019
Find out more.

A geometric probe of cosmology: Gravitational lensing time delays and quasar reverberation mapping

Speaker: Angela Ng (University of Sydney)
Date: 12 Dec 2019
Find out more.

Speaker: Else Starkenburg
Date: 26 Oct 2017

Speaker: Mike Shara
Date: 1 Nov 2017

Speaker: Glenn Van de Ven
Date: 3 Nov 2017

Speaker: Chris Evans
Date: 9 Nov 2017

Speaker: Victor Debattista
Date: 23 Nov 2017

Speaker: Sergio Martinez
Date: 14 Dec 2017

Date: 22 Sep 2016
Speaker: Douglas Heggie (Edinburgh)

Date: 6 Oct 2016
Speaker: Luis Aguilar (IAE-UNAM)
Date: 2 Nov 2016

Speaker: Lucio Mayer (University of Zurich)
Date: 3 Nov 2016

Speaker: Rodrigo Ibata (Strasbourg)
Date: 10 Nov 2016

Speaker: Taysun Kimm (Cambridge)
Date: 24 Nov 2016

Speaker: Jackie Hodge (Leiden)
Date: 16 Feb 2017

Speaker: Clare Dobbs (Exeter)
Date: 2 Mar 2017

Speaker: Alis Deason (Durham)
Date: 16 Mar 2017

Speaker: Lia Athanassoula (Marseille)
Date: 18 Apr 2017

Speaker: Glenn van de Ven (MPIA)
Date: 18 May 2017

Speaker: Hans-Walter Rix (MPIA)
Date: 1 Jun 2017

Speaker: Chris Evans (ROE)
Date: 15 Jun 2017

Speaker: Paul Clark (Cardiff)
Date: 22 Jun 2017

Speaker: Jean Brodie
Date: 24 Sep 2015

Speaker: Holger Baumgardt
Date: 15 Oct 2015

Speaker: Peter Jonker
Date: 22 Oct 2015

Speaker: Chris Conselice
Date: 29 Oct 2015

Speaker: Greg Ruchti
Date: 5 Nov 2015

Speaker: Richard Alexander
Date: 19 Nov 2015

Speaker: Pierre-Alain Duc
Date: 26 Nov 2015

Speaker: Filippo Fraternali
Date: 3 Dec 2015

Speaker: Benjamin Moster
Date: 21 Jan 2016

Speaker: Melissa Ness
Date: 4 Feb 2016

Speaker: Stephen Wilkins
Date: 25 Feb 2016

Speaker: Nadine Neumayer
Date: 10 Mar 2016

Speaker: Alberto Sesana
Date: 7 Apr 2016

Speaker: Mark Wilkinson
Date: 21 Apr 2016

Speaker: Rosemary Wyse
Date: 5 May 2016

Speaker: Eugene Vasiliev
Date: 19 May 2016

Speaker: Denis Erkal
Date: 21 Feb 2015

Speaker: Alan Heavens
Date: 6 Mar 2015

Speaker: Monica Valluri
Date: 13 Mar 2015

Speaker: Claudia Maraston
Date: 3 Apr 2015

Speaker: Andrea Maccio
Date: 8 May 2015

Speaker: Jorge Penarrubia
Date: 15 May 2015

Speaker: Michela Mapelli
Date: 22 May 2015

Speaker: Daisuke Kawata
Date: 29 May 2015

Speaker: Laura Greggio
Date: 12 Jun 2015

Speaker: David Bacon
Date: 19 Jun 2015