LONDON: The best observations so far of the dusty gas cloud G2 confirm that it made its closest approach to the supermassive black hole at the center of the Milky Way in May 2014 and has survived the experience. The new result from the European Southern Observatory’s (ESO) Very Large Telescope (VLT) shows that the object appears not to have been significantly stretched and that it is very compact. It is most likely to be a young star with a massive core that is still accreting material. The black hole itself has not yet shown any increase in activity.
A supermassive black hole with a mass 4 million times that of the Sun lies at the heart of the Milky Way Galaxy. It is orbited by a small group of bright stars and, in addition, an enigmatic dusty cloud, known as G2, which has been tracked on its fall toward the black hole over the last few years. Closest approach, known as peribothron, was predicted to be in May 2014.
The great tidal forces in this region of strong gravity were expected to tear the cloud apart and disperse it along its orbit. Some of this material would feed the black hole and lead to sudden flaring and other evidence of the monster enjoying a rare meal. To study these unique events, the region at the galactic center has been very carefully observed over the last few years by many teams using large telescopes around the world.
A team led by Andreas Eckart from the University of Cologne in Germany has observed the region using ESO’s VLT over many years, including new observations during the critical period from February to September 2014, just before and after the peribothron event in May 2014. These new observations are consistent with earlier ones made using the Keck Telescope on Hawaii.
The images of infrared light coming from glowing hydrogen show that the cloud was compact both before and after its closest approach as it swung around the black hole.
