Explanation for Structure of Faraway Radio Galaxies
University of Barcelona | 2017 Nov 28
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. This astronomical object is considered to be a small-scale version of a winged radio galaxy, so far considered one of the distant sources which are potential emitters of gravitational waves. In this sense, the main conclusion of the study, published in Nature Communications, says that not all winged radio galaxies would be the source of gravitational waves, unlike what was thought so far.
The microquasar is an astronomical object fed by a stellar black hole, which is smaller than the ones at the centre of radio galaxies, and produces a radio jet towards opposite directions. In the study, researchers “could determine that the Z-shaped morphology of the studied microquasar, the GRS 1758-258, can be explained with hydrodynamic interactions with the surrounding medium” says Josep M. Paredes, from ICCUB.
This result can be extrapolated, suggesting that this scenario could work in winged radio galaxies, since these objects follow the same physical laws. So far, it was thought that those radio galaxies were X or Z shaped due the merger of two black holes, a process in which gravitational waves are generated. When these waves are produced at such a long distance from us, it is not possible to distinguish them individually and a gravitational wave background noise is created. ...
A Galactic Microquasar Mimicking Winged Radio Galaxies - Josep Martí et al
- Nature Communications 8:1757 (24 Nov 2017) DOI: 10.1038/s41467-017-01976-5