First ever observation of a cloud ripped apart by a black hole
Astronomers have shown, for the first time, the tearing apart of the gas clouds by the supermassive black hole at the center of the galaxy with the help of ESO’s Very Large Telescope (VLT).
Astronomers have observed that the front part of the cloud is moving away from the black hole at a speed of over 10 million km/h while the tail is still falling towards the black hole.
“The most exciting thing we now see in the new observations is the head of the cloud coming back towards us at more than 10 million km/h along the orbit — about 1% of the speed of light,” Reinhard Genzel, leader of the research group that has been studied this region for nearly twenty years, said in a statement. “This means that the front end of the cloud has already made its closest approach to the black hole.”
“The gas at the head of the cloud is now stretched over more than 160 billion kilometres around the closest point of the orbit to the black hole. And the closest approach is only a bit more than 25 billion kilometres from the black hole itself — barely escaping falling right in,” Stefan Gillessen (Max Planck Institute for Extraterrestrial Physics, Garching, Germany) who led the observing team, explained in a statement. “The cloud is so stretched that the close approach is not a single event but rather a process that extends over a period of at least one year.”
Scientists took the observations of the region close to the black hole for more than 20 hours of total exposure time with the SINFONI instrument on the VLT, thereby measured the velocities of the different parts of the cloud.
“Like an unfortunate astronaut in a science fiction film, we see that the cloud is now being stretched so much that it resembles spaghetti. This means that it probably doesn’t have a star in it,” Gillessen concluded. “At the moment we think that the gas probably came from the stars we see orbiting the black hole.”
Stefan Gillessen, Reinhard Genzel, Tobias K Fritz, Frank Eisenhauer, Oliver Pfuhl, Thomas Ott, Marc Schartmann, Alessandro Ballone, & Andreas Burkert (2013). Pericenter passage of the gas cloud G2 in the Galactic Center Astrophysical Journal arXiv: 1306.1374v1