Group Blog

Summary of the GRAPPA retreat – April 3-4 2019 Sera has organized several retreats for her group in the past. We usually bike to this picturesque farm in Weesp and spend the day in a meeting room surrounded by sheep. We use this meeting to focus and plan our research efforts, practice giving elevator/grant pitches, […]

In today’s post I will talk about Compton scattering – a physical process by which light and matter interact. Interestingly, this process is responsible for colouring our sky and also for generating electromagnetic radiation from the most energetic phenomena in the universe. A Brief History This phenomenon was first discovered by Arthur H. Compton in

With the Event Horizon Telescope results just a few days away, I thought it would be great to discuss how exactly a jet is launched from a black hole. The thought is counter-intuitive. Black holes are depicted as these giant “vacuum cleaners” in the centre of galaxies, eating up anything that has the misfortune of

In this post I thought I’d write a bit about my Master’s thesis, which eventually (thanks to a good bit of luck, as you will see) led to my very first paper. During my master’s thesis I worked (together with Fabrizio Tavecchio and Gabriele Ghisellini at the Merate Observatory, near Milan) on understanding the properties

Hi all, Over January and February, we had an exchange student, Wanga Mulaudzi from the University of Cape Town, come to Amsterdam to work with us on a new project. This project uses multiwavelength data from an outbursting black hole X-ray binary to model how the jet physics evolved during the outburst. With Wanga, we

With my post, I would like to summarize work that my colleagues and I published recently (Beuchert et al. 2019, A&A, 610, 32). Let me start with a general introduction to provide the necessary context needed to understand what “jets” are. One of the major open questions in astrophysics deals with the most powerful objects in

Hi all, Firstly, I hope you all had a great holiday period! Over the Christmas break, I had a paper published in ApJ letters (links at the bottom of the page) that I thought I might summarise here. This paper was focused on the radio emission from a newly discovered X-ray transient called IGR J17591-2342.

This morning I came into work to read some super exciting news in my email! A gamma-ray burst (GRB) has been detected by ground based TeV facility MAGIC for the very first time, with extremely high significance! There has been an impressive multi-wavelength campaign to try to constrain more details of the source, and it

Fantastic Beasts (and where to find them) Most galaxies on our universe seem to harbor, at their center, the amazing beast known as a supermassive black hole (to know more about black holes see my previous post here). What do we mean by word supermassive? Astronomers compare the mass of most objects in the universe

As one of fundamental forces, gravity works its magic on the physics of the largest scales, helping us understand how celestial objects form and move. Sir Isaac Newton in the 17th century formulated a mathematical equation depicting the effect two objects have on each other by virtue of their mass. Newton’s theory successfully predicted the