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22 ASTRO PUBLISHING JULY-AUGUST 2022 Unknown structure in the host galaxy of 3C273 A s a result of achieving high imaging dynamic range, a team of astronomers in Japan has discovered for the first time a faint radio emission covering a giant galaxy with an energetic black hole at its center. The radio emission is released from gas cre- ated directly by the central black hole. The team expects to under- stand how a black hole interacts with its host galaxy by applying the same technique to other quasars. 3C273, which lies at a distance of 2.4 billion light-years from Earth, is a quasar. A quasar is the nucleus of a galaxy believed to house a massive black hole at its center, which swal- lows its surrounding material, giving off enormous radiation. Contrary to its bland name, 3C273 is the first quasar ever discovered, the bright- est, and the best studied. It is one of the most frequently observed sources with telescopes because it can be used as a standard of position in the sky: in other words, 3C273 is a radio lighthouse. by ALMA Observatory Bárbara Ferreira