Credit: ESO/D. Ribeiro for the MPE GC team

A new view on the heart of our Milky Way is presented in today's Picture of the Week. This stunning snapshot, taken with ESO’s Very Large Telescope (VLT), reveals the stars and gas surrounding an invisible giant — a supermassive black hole, located some 27 000 light-years away. This is a hugely dynamic environment, with stars and gas clouds hurtling by the black hole at dramatic speeds. A team of astronomers at the Max Planck Institute for Extraterrestrial Physics in Germany has detected a new gas cloud, named G2t, orbiting the supermassive black hole. Two gas clouds, G1 and G2, were already known, but their nature and origin were still being debated. In particular, it was unclear whether these clouds were hiding a star inside or consisted purely of gas. However, the discovery of a third gas cloud now helps answer these questions. The observations were done with the Enhanced Resolution Imager and Spectrograph (ERIS), an instrument on ESO’s VLT that can not only take images like the one in this Picture of the Week, but also spectra. Thanks to this, astronomers were able to measure the 3D orbits of the clouds around the black hole. The clouds move within a very small region at the centre of this wide-field image. It was revealed that G1, G2 and G2t are actually on almost identical orbits, only rotated a bit with respect to each other. This rules out the possibility that each cloud hides a star in their core, as the odds of different stars having almost identical orbits are slim. The similarity of the orbits suggests that the three clouds probably share the same origin, most likely IRS16SW, a pair of massive stars expelling an enormous amount of gas. As IRS16SW moves around the black hole, each cloud of gas is ejected in a slightly different orbit, explaining the small differences in the trajectories of the ‘G-triplet’. This discovery shows that, despite decades of monitoring our Milky Way centre, new unanswered curiosities still arise. But what could be more exciting than mysteries waiting to be solved? Links Research paper in Astronomy & Astrophysics

Provider: European Southern Observatory

Image Source: https://www.eso.org/public/images/potw2610a/

Curator: European Southern Observatory, Garching bei München, None, Germany

Image Use Policy: Creative Commons Attribution 4.0 International License