Using NASA’s Chandra X-ray Observatory and NSF’s Karl G. Jansky Very Large Array (VLA), astronomers have found that H1821+643 — the nearest quasar hosted by a galaxy cluster, at a distance of about 3.4 billion light-years — is less influential than many giant black holes in other galaxy clusters. This composite image shows the quasar H1821+643. Image credit: NASA / CXC / University of Nottingham / Russell et al. / NSF / NRAO / VLA...
