BEIJING, Dec. 1 (Xinhuanet) -- Astronomers have long wondered which came first, the black hole or the galaxy around it.

    The leading theory holds that the two co-evolve, starting small and building over time, according to U.S. media report Tuesday.     

    Astronomers recently observed a peculiar large black hole that does not belong to a surrounding galaxy as expected.

    The black hole, designated HE0450-2958, is located about 5 billion light-years away from Earth. It is a type of supermassive black hole known as a quasar, which releases extremely bright jets of high-energy light.    

    Astronomers think that this black hole's host galaxy is merely shrouded in dust and rendered invisible to us. They used the European Southern Observatory's Very Large Telescope to capture new observations of the quasar targeted to search for dust in long-wavelength infrared light.     

    "However, we did not find any dust. Instead we discovered that an apparently unrelated galaxy in the quasar's immediate neighborhood is producing stars at a frantic rate," said Knud Jahnke of the Max Planck Institute for Astronomy in Heidelberg, Germany, who led the observations.    

    The astronomers think the black hole is powering star formation in the nearby galaxy by spraying its jets of high-energy particles toward it. In fact, the quasar could have triggered the galaxy's formation in the first place when its energetic jets hit nearby clouds of gas. And as time goes on, the neighboring galaxy will likely grow to encompass the black hole at last.

    (Source: Agencies)