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Hubble Space Telescope has captured new images of eight massive green clouds of gas which is tens of thousands of light years away.
Quasars are bright masses of light and energy in the universe.
Theses gas clouds indicates the existence of quasars, and they glow by the beams of radiation emitted by the quasars.
ESA and NASA are partners in the Hubble project.
Photoionisation is the process by which once invisible filaments in the deep space are glowing by the beam of radiation of quasar.
“However, the quasars are not bright enough now to account for what we’re seeing; this is a record of something that happened in the past. The glowing filaments are telling us that the quasars were once emitting more energy, or they are changing very rapidly, which they were not supposed to do,” said lead author of the study Bill Keel, researcher from the University of Alabama.
He added, “We see these twisting dust lanes connecting to the gas, and there’s a mathematical model for how that material wraps around in the galaxy. Potentially, you can say we’re seeing it 1.5 billion years after a smaller gas-rich galaxy fell into a bigger galaxy.”
The filaments contains oxygen, nitrogen, sulphur, helium and neon which absorb light from the quasar and slowly re-emit the light over thousands of years.
The green color of the gas clouds is due to ionized oxygen.
Quasars are powered by black holes. Black hole is surrounded by the disk of gasses and due to its gravitational pull gas and dust from the surroundings disk fall into the black hole, these materials are heated to high temperature and then it blasts off resulting in a quasar radiating high amount of energy, light and particles into space.
The gas clouds are lit up by a radiation from quasars and it is believed that the quasar is dead and since the gas clouds are thousands of light years away from the center of galaxy the quasar beam has taken thousands of years to reach the clouds.
Scientists believe that the gas clouds resulted from merging of galaxies.
