Upcoming
Friday 16:00 @ Nordita 6th floor
Accurate projections of mass loss from the Antarctic Ice Sheet depend on precise modelling of ice flow. Ice flow is routinely modelled as a non-Newtonian fluid using a power law called Glen’s flow law, but this approach neglects the inherent direction-dependent viscosity of ice. This simplification leads to a discretised ice-sheet model that is both computationally efficient and numerically stable, capable of modelling entire ice sheets. However, model intercomparison projects have revealed large discrepancies between ice-sheet models and uncertainty in future sea level projections. In this talk, I will present an overview of model developments in the area of anisotropic ice-flow modelling, an alternative to Glen’s flow law that accounts for the evolution of the crystal orientation of ice, offering a more accurate representation of ice dynamics. I will present 3D simulations of coastal regions of Antarctica, comparing modelled crystal orientation with observations of ice crystal structure obtained from quad-polarimetric radar data.
Imagine trying to follow two voices in a crowded room—your brain naturally separates them, but what if you had to do it mathematically? This is exactly the challenge we face with X-ray pulsars. These cosmic lighthouses beam powerful X-rays into space as they spin, but their light doesn’t come from just one source—it comes from two magnetic poles, blending together in a way that’s almost impossible to untangle.
In this talk, I’ll take you on a journey through the strange world of X-ray pulsars, showing how we observe their flickering light and why their pulse profiles hold hidden secrets. The big mystery? We still don’t know exactly how each pole contributes to what we see. Enter blind source separation—a clever mathematical trick inspired by the “cocktail party problem,” where we try to isolate individual signals from a messy mix. I’ll explain how this technique can help us decode pulsar emission, what its limitations are, and what we’ve learned from applying it to the pulsar Cen X-3.
By the end, you’ll see why these rapidly spinning neutron stars remain one of the most intriguing puzzles in astrophysics—and why solving them is far from simple.