Hengxiao Guo

X-rays from the vicinity of a black hole don't arrive all at once. Some of them first fall onto a disk of scorching gas, get reflected, and only then travel to the telescope. This delay is like an echo in the mountains: first you hear the direct sound, then the response from the cliff.

At the centers of many galaxies lurk supermassive black holes. From time to time they 'scream' — unleashing powerful X-ray flares. Scientists have long puzzled over the nature of these 'quasi-periodic eruptions'.

When a star ventures too close to a supermassive black hole, a cosmic requiem plays out — a tidal disruption event. Thanks to photometry and spectroscopy, astronomers discern every instrument in this orchestra.

The night sky is full of rings and bubbles, but in the radio band they look different. In data from the Australian radio telescope ASKAP, a structure has surfaced that resembles two soap bubbles blown from the same straw.