Upcoming JBCA and Schuster Colloquia
JBCA Colloquia begin at 3 pm every Wednesday in the Sir Bernard Lovell Seminar Room (3.225) in the Alan Turing Building, unless otherwise stated. Tea, coffee and biscuits are served from 2,45pm . The post-colloquium social starts at 4,30 pm in the tea room.
Schuster Colloquia normally start at 2,30 pm and take place in the Rutherford Lecture Theatre in the Schuster Building.
Extra seminars, which can be organised by anyone in the group separately from the colloquium series, are also included on this page for convenience.
To view a talk abstract, click on the talk title. Click again on the talk title to hide the abstract.
|7 Oct||Mattia Fornasa
(GRAPPA, Amsterdam, The Netherlands)
Dissecting the Diffuse Gamma-Ray Background
|The Diffuse Gamma-Ray Background (DGRB) is the radiation that remains after the Galactic gamma-ray emission and extragalactic resolved sources are subtracted from the total gamma-ray flux. The DGRB collects the radiation produced by all those sources that are not bright enough to be resolved individually. Therefore, it represents an essential tool to study faint gamma-ray emitters, like star-forming galaxies or Dark Matter halos and subhalos. I will review our current knowledge of the nature of the DGRB, presenting the strategies that have been proposed to study it. I will focus, in particular, on how it is possible to derive some constraints on the emission associated with Dark Matter, by reconstructing the composition of the DGRB.|
|14 Oct||Caroline D'Angelo
(Leiden, The Netherlands)
|21 Oct||Jonathan Marshall
(New South Wales U., Australia)
|11 Nov||Thomas Kitching
(MSSL, UCL, UK)
|18 Nov||Marta Alves
(IRAP, Toulouse, France)
|25 Nov||Giorgia Busso
(IoA, Cambridge, UK)
|9 Dec||Judith Croston
(Southampton U., UK)
|16 Dec||Lionel Wilson
(Lancaster U., UK)
The Bizarre Nature of Volcanism on Early-Forming Asteroids
|Meteorite evidence shows that asteroids that accreted within ~1 Ma of the origin of the Solar System incorporated significant amounts of the short-half-life isotope 26Al, a major energy source that allowed them to be heated beyond the onset of silicate melting and hence to differentiate. The resulting almost completely uniform heating below an ~8 km thick conductively-defined crustal shell contrasts dramatically with how pressure release melting driven by mantle convection has occurred in the larger silicate planets, including Earth. The consequence for many early-forming asteroids was efficient core formation followed by a period of vigorous volcanic activity. I shall outline the key processes involved and show how the low acceleration due to gravity and absence of atmosphere on these small bodies should have led to potentially bizarre volcanic landforms and to unexpected styles of activity, including, for some small asteroids, the explosive eruption of magma at greater than escape speed from the body, so that no basaltic crust ever formed.|
|27 Apr||Francesco Shankar
(Southampton U., UK)