Category Astronomy/Space

Picture of the GRS 1758-258 microquasar, obtained with the Jansky Very Large Array radiotelescope at 5 GHz frequency radio waves. The white line shows the Z-shape path formed by the relativistic plasma produced in the core region, where the black hole is located. Credit: Image courtesy of University of Barcelona

The results of a study allow researchers progressing in the study of the distribution of gravitational waves from distant sources. Researchers from the Institute of Cosmos Sciences of the University of Barcelona (ICCUB) and the University of Jaén have described, for the first time, the structure of a Z-shaped galactic microquasar...

Surface, ocean and core of Saturn’s moon Enceladus. The illustration shows the ice shell, which is thinner at the polar regions, with the ocean underneath. The core of Enceladus is assumed to be porous and thus permeable to ocean water. The graphic is based on a new model used to produce a three-dimensional simulation of these processes under the influence of Saturn’s tidal forces. The orange “glowing” parts of the core represent the areas that reach temperatures of at least 90 degrees Celsius. Credit: Surface – NASA/JPL-Caltech/Space Science Institute; Core – Choblet et al (2017); Graphic composition – ESA

A computer simulation shows how icy moon heats water in a porous rock core...

Neutron star mass and radius measurements from atmospheric model fits to X-ray burst cooling tail spectra. Astronomy & Astrophysics, 2017; DOI: 10.1051/0004-6361/201731082

Neutron stars are made out of cold ultra-dense matter. How this matter behaves is one of the biggest mysteries in modern nuclear physics. Researchers developed a new method for measuring the radius of neutron stars which helps them to understand what happens to the matter inside the star under extreme pressure. A new method for measuring neutron star size was developed in a study led by a high-energy astrophysics research group at the University of Turku, Finland. The method relies on modelling how thermonuclear explosions taking place in the uppermost layers of the star emit X-rays to us...

A Kyoto University-based team has unraveled the mystery of gamma-ray emission cascades caused by lightning strikes. Credit: Kyoto University/Teruaki Enoto

Researchers find that lightning strikes causes photonuclear reactions in the atmosphere, creating antimatter. Researchers from Japan describe how gamma rays from lightning react with the air to produce radioisotopes and even positrons – the antimatter equivalent of electrons. “We already knew that thunderclouds and lightning emit gamma rays, and hypothesized that they would react in some way with the nuclei of environmental elements in the atmosphere,” explains Teruaki Enoto from Kyoto University.

“In winter, Japan’s western coastal area is ideal for observing powerful lightning and thunderstorms...