Astronomers have observed gigantic tornadoes emerging from a supermassive black hole. The intense winds blow with such force that they shape the surrounding galaxy. The find could contribute new insights to theories about the evolution of galaxies in the early universe. A team of astronomers from the Rochester Institute of Technology in New York state, along with colleagues at the University of Hertfordshire in the United Kingdom, studied the active centre of galaxy PG 1700+158, located about 3 billion light-years away, using polarised light. Superheated gas from Black holes accretion disks rapidly spiral out --at such temperatures that the resulting light can outshine entire galaxies. To study the galaxy, astronomers broke down the light into its constituent colours, which revealed subtle shifts in its wavelengths, because interstellar dust can polarise the light. The team interpreted those shifts as the effect of cyclonic winds moving above and below the black hole at speeds of about 4000 kilometres per second. According to the astronomer and lead author Stuart Young, who along with colleagues reports the findings in the 1 November issue of Nature, the influence of such winds can extend well beyond the galaxy. The winds may heat the surrounding intergalactic medium enough to prevent it from condensing, which halts the growth of the galaxy. If so, then winds from black holes could have restricted the size of galaxies in the early universe. But astronomers will need to spot more such cyclones in order to be sure that they were common back then.
"This critical observation is the first time astronomers have been able to 'zoom in' on a black hole and watch the actual source of such power. It's amazing new proof that the technique of simply splitting white light into different colours can be used like puzzle pieces to reconstruct speeds, directions, and shapes of material surrounding black holes--places we still cannot photograph with our telescopes" - astronomer Kimberly Weaver of NASA's Goddard Space Flight Centre in Greenbelt, Maryland.
