Astrophysics News & Events

Gr@v member João Rosa was one of the recipients of the 2018 Alberto prize, awarded by the Portuguese Society of Relativity and Gravitation (SPRG). The prize was given for his work on the phenomenon of superradiance and its physical and astrophysical implications. The prize was shared by Richard Brito, a researcher of the Max Planck Institute for Gravitational Physics, in Berlin, Germany. The prize was delivered at the General Assembly of the SPRG, on 19th December 2018, during the XI Black Holes Workshop.

Gr@v member Pedro Cunha was one of the invited lecturers of the V Amazonia Workshop on Black Holes and Analogue Models of Gravity, that took place at the Federal University of Pará, in Belém, Brazil, from December 3rd to 7th, 2018. Cunha gave five lectures on "Geodesics and Shadows of Kerr black holes".

Gr@v member Tjarda Boekholt recently travelled to the University of Concepcion in Chile. He was invited by the Theory and Starformation Group (TSG), which is led by a team of professors including Mike Fellhauer, Dominik Schleicher, Amelia Stutz and Stefano Bovino. In the first week Tjarda lectured students on the Astrophysical Multi-purpose Software Environment (AMUSE). In particular, they discussed the coupling between N-body and hydrodynamics.

João Rosa was interviewed for Porto Canal's "Mentes que brilham" about his work on stimulated axion decay around primordial black holes as a possible origin for fast radio bursts, recently published in Physical Review Letters. He also gave a related interview to the radio programme "Click" on Antena 1.

The CIDMA Young Doctor Award is a prize for a researcher within 5 years after the PhD, who has made important contributions to his or her research field. The 2018 award is granted to Gr@v member Tjarda Boekholt for his recent achievements in the field of dynamical chaos in astronomical systems. During the annual meeting of CIDMA 2018, Tjarda presented his new numerical N-body code and the ability to obtain reversible solutions to highly chaotic systems.

In a recent paper "Head on collisions of Proca Stars", [arXiv:1806.07779], by N. Sanchis-Gual et al., head-on collisions of exotic compact objects known as "Proca stars" were studied via fully non linear numerical simulations, with the goal of extracting the gravitational wave templates that such exotic objects could produce.

Watch the presentation movie of the COST Action CA16104 Gravitational waves, black holes and fundamental physics (GWverse), in which Gr@v is involved as part of the core group.

The movie was created at the University of Aveiro (Portugal), written and directed by Carlos Herdeiro, with Design and Graphics by Joana Reis and Ana Sousa and Edited by Pedro Henriques.

The article "Stimulated axion decay in superradiant  clouds around astrophysical black holes" (arXiv:1709.06581), co-authored by Gr@v member João Rosa and Tom Kephart (Vanderbilt University, USA), has been accepted for publication in Physical Review Letters and will be highlighted as one of the PRL Editors' Suggestions (a distinction attributed to about one in six Letters).

Black hole (BH) shadows in dynamical binary BHs have been produced via ray-tracing techniques on top of computationally expensive fully non-linear numerical relativity simulations.

On arXiv:1805.03798 [gr-qc], it is illustrated (as a proof of concept) that the main features of these shadows can be captured by a simple quasi-static evolution of the photon orbits on top of a static double-Schwarzschild family of solutions, which is exact.

A team of Gr@v members (P. Cunha, J. Delgado, C. Herdeiro and J. Oliveira) is visiting the Universidad Nacional Autónoma de México, at its Cuernava Campus, in April-May 2018 hosted by Professor Juan Carlos Degollado. The visit occurs within a Marie Curie RISE action, of which both UNAM and Aveiro Universities are partners.