Fast radio bursts (FRBs) are millisecond flashes of radio waves so bright that they can be seen across the Universe. Many are thought to come from magnetars, neutron stars with ultra-strong magnetic fields. Our work tests a new idea: shear fluctuations in a magnetar wind can hit a shock and activate a plasma wave mode… Read more: Superluminal Wave Activation at Relativistic Magnetized Shocks

Magnetars, highly magnetized neutron stars, can experience crustal quakes that disrupt their magnetic fields and cause X-ray and fast radio bursts (FRBs). This study uses simulations to model plasma waves in magnetar magnetospheres and to understand how magnetic energy is transported. We find that Alfvén waves can transform into fast magnetosonic (FMS) waves, especially when… Read more: Force-free wave interaction in magnetar magnetospheres: Computational modeling in axisymmetry

When binary neutron stars merge, they produce remarkable signals that help astrophysicists understand their composition and magnetized environments. The strong magnetic fields of two neutron stars orbiting each other interact vigorously. Astronomers hope to detect electromagnetic signals before the merger, which would announce a neutron star collision before it happens and allow it to be… Read more: How ultra-magnetized Kelvin-Helmholtz drag impacts precursor emission in neutron star binaries

Columns and other structures of twisted magnetic field lines with footpoints anchored to a surface at both ends exist in many astrophysical settings. Current loops shining in X-rays during the growth of plasma instabilities are observed in the corona of the Sun. They probably also exist around other compact astrophysical objects, such as in highly… Read more: Safety first: Stability and dissipation of line-tied force-free flux tubes in magnetized coronae

Citation cartels formed by journals are a well-known thread to scientific publishing. But this text is not about journals pushing authors to cite certain other journals to hack the journal impact factor (see Smith, 2006; for a comment on the journal impact factor). Here, I discuss my opinion about a strategic possibility for researchers to polish… Read more: Should junior scientists fall for peer-citation-cartels?

The origin of hard X-ray outbursts from magnetars, highly magnetized neutron stars, is still unknown. These outbursts range from frequent faint events to the most energetic Giant Flares and span several orders of magnitude in energy. Our work explores how different instabilities of the magnetar magnetosphere can release energy that shines in X-rays. They can… Read more: Kinking flux tubes and global eruptions: The 3D dynamics of strongly twisted magnetar magnetospheres

Fast radio bursts (FRBs) are millisecond flashes of GHz radio waves that carry a complex spectral imprint of their cosmic origin. Highly magnetized neutron stars, so-called magnetars, are leading candidates for their sources, and in 2020 an FRB was detected from a magnetar in our own galaxy. The exact origin of FRBs is still unknown,… Read more: Electromagnetic fireworks in the striped magnetar wind

Alfvén waves travel along magnetic fields in a plasma as variations of the electromagnetic fields and currents. When two such waves interact, they produce a plasma fluctuation that starts reacting with the primary waves. Mediated by this fluctuation, new plasma waves emerge: Alfvén waves with shorter oscillations than the initial waves, and fast waves that… Read more: Current sheets in Alfvén wave interactions

Magnetic field lines entering the event horizon of a rapidly spinning black hole can slow down its rotation, acting like rubber bands that are dragged along with it. This theoretical concept is well known as the Blandford/Znajek process. While the model is appealing for its clarity in simple equilibrium solutions of magnetic fields around black… Read more: Black hole variability by magnetic loop accretion

Neutron stars, black holes and the plasma around them cannot be studied in a laboratory, so we build virtual laboratories in computers. Modeling physics in computers requires discretizing continuous quantities in space. Approximations are key to simplify systems with millions of particles, waves and their interactions across scales. One such approximation is to treat a… Read more: Astrophysics in computers: Building virtual laboratories