Final Activity Report Summary - X-RAY PROP GALAXIES (Determining star-formation activity and history in spiral galaxies from their X-ray and multi-wavelength properties)
This project studied the appearance and physical processes inside galaxies which are actively forming new stars. The tell-tale sign of such activity is a stronger emission of X-rays from those galaxies. The X-rays come mainly from two sources: hot gas (a few million degrees) in the star-forming regions, and compact objects (neutron stars and black holes) when gas is falling into them.
The project studied some of those compact objects in more details. In particular, it studied some black holes, and monitored how their luminosity changed over time, probably as a result of a change in the amount of gas falling into them. It investigated what fraction of the gravitational energy released by the infalling gas comes out as radiation, and what fraction as mechanical energy (jets, winds). It studied the effect that such energy has on the region surrounding the black hole. Finally, it used the energy and spectral estimates to constrain the mass of these black holes, suggesting that they are up to 50-100 times the mass of the Sun.
The project studied some of those compact objects in more details. In particular, it studied some black holes, and monitored how their luminosity changed over time, probably as a result of a change in the amount of gas falling into them. It investigated what fraction of the gravitational energy released by the infalling gas comes out as radiation, and what fraction as mechanical energy (jets, winds). It studied the effect that such energy has on the region surrounding the black hole. Finally, it used the energy and spectral estimates to constrain the mass of these black holes, suggesting that they are up to 50-100 times the mass of the Sun.