Some galaxies have an active black hole in their center driving powerful outflows of gas, unlike our Milky Way. We know very little about their impact and origin. ESA’s future X-ray mission Athena will change this. Astronomers from SRON and UvA have now developed a new method to use Athena to study these outflows, in preparation for the launch in the 2030s.
Astronomical pictures are often full of stars from the Milky Way. But some of them are imposters. Some dots are in fact centers of entire galaxies, instead of simple stars. They are so far away that they appear as a faint dot and blend in with the stars. This trick has fooled astronomers for decades, until the 1950s. This is why we call them quasi-stellar objects or quasars for short. Astronomers discovered that the spectrum of some dots was highly redshifted. It is indicating a large distance at which a star would be invisible from Earth.
Astronomers realized that the light from quasars must come from the centers of galaxies. It is called active galactic nuclei (AGN). This is probably powered by a supermassive black hole. Cosmological models predict that these AGN are the powerhouses altering the evolution of galaxies. These attract and eject massive amounts of material from their vicinity.
Scientists are studying these outflows from AGN using X-ray space telescopes, in preparation for the launch of ESA’s new X-ray mission Athena. It is to be launched in the early 2030s and with a substantial contribution of SRON. Researchers develop a new method to study AGN outflows. AGN brightness can be highly variable in time. Scientists will use Athena’s X-ray spectra to see how the outflows respond to these brightness variations.
Scientists used frequency analysis to identify the outflows by their behavior.