“We wanted a census of all the black holes and we wanted to know what they are like. We also wanted to measure how black holes have grown over the history of the Universe.”
“We find active super massive black holes at the centers of massive galaxies. Our galaxy also has its own black hole at its center measuring 2.6 million solar masses. Our black hole is not active today, but we presume it was active in the past.”
“We designed (the Chandra surveys) carefully to complement each other, to be sure that we would get consistent results from two different fields. Otherwise, we'd be worried that what we got wouldn't be consistent overall - and they're quite consistent, within about 20 percent.”
“We would like to know if active galactic nuclei change over cosmic time. Do black holes feed and grow in the same way over the history of the Universe?”
