This is less a physical question than a moral one. Should we feed a black hole? If we do, will it ever learn to feed and fend for itself independently? Will it ever truly be able to return to the wild, or will it ever after be chained to the yoke of domestic comfort?
The XXL Survey is here as the rightful successor to the XMM-Newton survey that gave us a unique and extravagant look into the high-energy universe. Here, we look at some of the observations that the XXL has to offer!
Active galactic nuclei (AGN) and star-formation processes ionize gases around galaxies and the Universe. How can we separate the two to pin down the dominant ionizing sources in the early Universe?
Counting the number of galaxies at a given mass in a region of space gives you the number density – something that can be really easily compared to simulations. But do our observations and theory match up? And how does looking out to higher and higher redshifts help us to better understand our Universe…
What makes up the innards of the brightest galaxy in the universe?
These hot galaxies show signs of AGN and starburst activity occurring within their dusty interiors.