Image of the Day: Quasar Jet at Near Speed of Light -The Birth of a Galaxy

0131_multi This Chandra image shows a powerful jet shooting from the quasar 3C273, providing an X-ray view into the area between 3C273's core and the beginning of the jet (below).High-powered jets driven from quasars, often at velocities very close to the speed of light, have long been a mystery for scientists. Instead of seeing a smooth stream of material driven from the core of the quasar, most optical, radio, and earlier X-ray observations have revealed inconsistent, "lumpy" clouds of gas. 

The recent Chandra data show a continuous X-ray flow in 3C273 from the core to the jet, which may reveal insight on the physical processes that power these jets. Scientists would like to learn why matter is violently ejected from the quasar's core, then appears to suddenly slow down.

The energy emitted from the jet in 3C273 probably comes from gas that falls toward a supermassive black hole at the center of the quasar, but is redirected by strong electromagnetic fields into a collimated jet. While the black hole itself is not observed directly, scientists can discern properties of the black hole by studying the jet. The formation of the jet from the matter that falls into the black hole is a process that remains poorly understood.

These quasars can now be shown to originate in low redshift, active galaxies which eject them along their minor (rotation) axis. It can be empirically demonstrated that this is how galaxies are born and evolve. 

A single quasar outshines trillions of suns. From Earth-based telescopes, quasars look like stars. But they’re not stars. Modern astronomers believe that quasars are associated with galaxies, and with black holes at the centers of galaxies. A quasar might be a black hole in the center of a young galaxy that actively devours the material around it.

It's believed that quasars might signal the birth of a galaxy. Astronomers now consider quasars to be associated with supermassive black holes that live in the center of galaxies. As materials fall on the black hole – pulled in by the very strong pull of the black hole’s gravity – the material gets very hot. It glows and shines so much that it can outshine the entire galaxy surrounding it. 

Quasars appear to represent a phase when galaxies, at least massive ones, were coming together in the early universe. The materials were falling together to the center. It’s still a mystery of how the central black hole formed, but it’s clearly some process resulting from the collapse of material towards the center of what became a massive galaxy and formed a central black hole. And then as more material fell into it, of course it got greatly heated by the gravitational energy released by falling near the black hole, and thus we could see it, and that’s what made quasars shine so brightly.

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Via Chandra X Ray Observatory

http://earthsky.org/space/quasars-key-to-birth-of-galaxies

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