When a star comes too close to the intense gravity of black hole, the resulting tidal forces can rip the star apart. In these so-called tidal disruptions, some of the stellar debris is flung outward at high speeds, while the rest falls toward the black hole, causing a distinct X-ray flare that can last for years. A team of astronomers has observed a tidal disruption event in galaxy PGC 043234 that lies about 290 million light-years from Earth.
Nearly all black holes come in one of two sizes: stellar mass black holes that weigh up to a few dozen times the mass of our Sun, or supermassive black holes ranging from a million to several billion times the Sun’s mass. A team led by astronomers at the University of Maryland and NASA’s Goddard Space Flight Center has found evidence for a new intermediate-mass black hole about 5,000 times the mass of our star.
Many galaxies blast huge, wide-angled flows of material outward from their centres, pushing to their outer edges enough dust and gas each year that otherwise would have formed more than a thousand stars the size of our Sun. A team led by University of Maryland scientists has found the driving force behind these massive molecular outflows.