View Full Version : Quasar induced galaxy formation: a new paradigm?

2010-May-04, 10:15 PM
Quasar induced galaxy formation: a new paradigm?

This is curious. A naked Quasar is somehow creating a jet that is striking a cloud of gas that is in the vicinity of the naked quasar. The interaction between the naked quasar and the cloud of gas that is in the vicinity of the naked quasar is causing a massive increase in new young stars in the cloud of gas.

Quasar jets are currently thought to be short periods of activity in the life of the super massive object's life. How a quasar jet could be produced by a Naked quasar is not known. It is curious that this jet is aimed at the cloud of gas.

The Naked quasar and the cloud of gas are moving towards each other. The resultant then they meet will be an AGN.


We conclude that the starburst event in the companion galaxy of HE0450−2958 is most probably triggered by the radio jets emitted by the neighboringQSO.We consider that although possible, it is highly improbable that such configuration happened by chance during a merger process. Several examples of jetinduced star formation are discussed and compared to this system in Sect. 6.1. In the next Section, we discuss a formation scenario where the whole galaxy formation was induced by the radio jet of the QSO.

We therefore propose that we are witnessing a process that we call “quasar-induced galaxy formation” through which the companion galaxy was triggered by the radio jets of the QSO HE0450−2958.We note the presence of three structures in the close vicinity of the quasar which may represent three successive steps in the process: (1) a blob of photoionized gas, adjacent to the quasar, deprived of stars (Magain et al. 2005); (2) an elongated gas + stars (see with HST-NICMOS imaging) structure extending toward the N-E from the position of the quasar (Jahnke et al. 2009); (3) the companion galaxy itself dominated by a ∼40–200 Myr-old stellar population with distorted morphology. The presence of ionized gas moving from the quasar in the direction of the companion galaxy (Letawe et al. 2008b), along the radio jet, strengthens the idea that matter is being transported from the quasar to the companion galaxy.


This a simplified explanation from the news release.

The naked quasar's enigma
The team's conclusions are based on careful observation of a very peculiar object, the quasar HE0450-2958, located at a redshift distance of about 3,2 billion light-years from the Earth. The term "Quasar", or "Quasi-star" (also known as "QSO" or "Quasi-Stellar Objects"), refers to the core of a galaxy formed by a supermassive black hole. Its center is intensely bright, eclipsing the galaxy that surrounds it. But to date, no host galaxy has ever been detected for the quasar, HE0450-2958, commonly known as "the naked quasar" for this reason. Believing that the host galaxy might be hidden behind large amounts of dust, the astrophysicists used the mid-infrared camera VISIR built by the CEA-Irfu and installed on the ESO's Very Large Telescope (VLT). What they actually observed is far different from their original expectations, but something much more surprising: they did not detect any dust clouds. Instead, they discovered that the nearest galaxy to the quasar has been producing stars at an astounding rate.

"The ‘naked quasar’ and its companion galaxy are bound to merge in the future," David Elbaz explains: "the quasar is moving at a speed of only a few tens of thousands of km/hour with respect to the galaxy and the two objects are only about 22,000 light-years away from each other. Whether or not the quasar is 'naked', it will eventually be "dressed" when it merges with its companion galaxy, the stars in which have mostly been formed by the quasar."

These observations change our understanding of this type of system and allow us to develop a new paradigm. The quasars may help to build the galaxy that will later host them. Perhaps this is the missing link that will explain why the mass of black holes is always larger in galaxies that contain the highest number of stars.

2010-May-04, 10:46 PM
The galaxy in question that the Naked Quasar is activating by a stream of matter that is moving from the quasar to the galaxy is 22,000 lights years from the naked quasar. It is odd that the quasar jet would point at the galaxy for 22,000 years.


The Quasar That Built a Galaxy

Even more remarkable, the astronomers observed a small companion galaxy, only about 22,000 light-years away, whose new stars are being formed at an extremely rapid clip. One of the quasar's jets is aimed directly at the galaxy, and the team thinks it's likely that the jet is driving the star-making process by blasting matter into the galaxy. The astronomers also found that HE0450-2958 and this companion are slowly moving toward each other. Within a few million years, both quasar and galaxy will have merged. That may explain why some quasars are surrounded by galaxies: the galaxy didn't form the quasar; rather the quasar pulled in the galaxy. The team reports its findings online this week in Astronomy & Astrophysics.

2010-May-05, 12:33 AM
Where does it say that it is 22,000 years continuously? Even if it said so, why would that be odd?

2010-May-05, 01:46 AM
Where does it say that it is 22,000 years continuously? Even if it said so, why would that be odd?


The massive black hole spins which resists changes in direction like a top.(i.e. The quasar will keep pointing in one direction.)

The quasar on time is estimated to be around 10 million years, to explain how the number of observed quasars changes with redshift (there is a massive peak in the number of quasars at z=2.3). The estimate time for the jet to travel from the naked quasar to the galaxy is 1 million years assuming the jet travels at 0.02C (from the paper.) The time for jet one time is less than the lifetime of the quasar.

There is no time for the quasar to align with the galaxy. i.e. There is only one galaxy that is 22,000 light years from the quasar. The galaxy in question must be over the quasar's pole which does not change direction for the quasar to affect it.

Now if the gas for the galaxy came from the quasar, then the observation would make sense.

The quasar in question is a naked quasar. There is no evidence of an associated galaxy with this quasar. Roughly 10% of all quasars are naked quasars. There are two puzzles then. What powers the naked quasar as there is no gas for the black hole's accretion disk and in this case where is the gas for the quasar's jets.

The paper proposes intergalactic filaments as the solution. They want something that could feed the quasar but not create a cloud about the quasar. That does seem possible to me. The quasar's gravitational field would pull the intergalactic filament about it creating a gas cloud about a massive black hole.

There are commonly gas clouds in the vicinity of quasars, hence the question posed what came first the gas clouds or the quasar?

2010-May-05, 03:20 AM
galaxies regurgitating themselves? Causality for the well documented but totally unexplicable size/luminosity/central mass relationship?

wow. just wow.