A link between black holes and new stars

Oct 23, 2013
This is a composite image of NGC 1068, one of the nearest and brightest galaxies containing both a rapidly growing supermassive black hole and star formation. A new study shows that, on average, both black hole accretion and star formation grow at similar rates, perhaps related to how material flow in to the respective regions. X-ray data from the Chandra X-ray Observatory are shown in red, optical data from the Hubble Space Telescope in green and radio data from the Very Large Array in blue. Credit: NASA and Chandra

Supermassive black holes (those with millions to billions of solar-masses) are thought to reside at the centers of most galaxies. These black holes must have undergone periods of intense accretion activity to grow to their large sizes, during which times they would be observed as active galactic nuclei and especially bright in X-rays. The masses of these black holes have been found to correlate closely with the cumulative mass of the stars that surround the galaxy in its bulge (and which are bound by gravitational forces). In a second discovery, it turns out that the activity of accretion for black holes and of star formation both peaked during a similar cosmic epoch, about three billion years ago, and then declined to the present day. These two results seem to suggest parallel evolutionary paths for the growth of the black holes and stellar mass, but the physical mechanisms that drive this apparent link, if it exists, are poorly understood. To make matters more confusing, some studies of individual objects have concluded that there is little or no correlation, or even an inverse one.

Both and require a supply of gas, and the clues to uncovering any connections between their growth may lie in the gas fueling mechanisms that supply them. CfA astronomers Christine Jones, Bill Forman, and Andy Golding, along with a team of collaborators, reasoned that because star formation occurs over time scales of hundreds of millions of years whereas active black hole accretion can vary rapidly over millions of years, the most appropriate measure to use when comparing these two processes was a long time average.

The scientist studied 121 active galaxies studied by the Chandra X-ray Observatory that were also observed in the infrared by the Spitzer and Herschel space telescopes. The former provided an average measure of accretion activity, while the latter, which detected the dust warmed by young stars, sampled the star formation activity. With this approach the astronomers found an almost linear relationship between the average black hole accretion rate and the star formation rate for galaxies across a wide range of luminosities. The result implies that there are indeed tight links between the two activities in galaxies.

Explore further: Black hole chokes on a swallowed star

More information: Chen, C. et al. A Correlation Between Star Formation Rate and Average Black Hole Accretion in Star-Forming Galaxies, ApJ 773, 3, 2013.

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User comments : 5

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omatwankr
1 / 5 (11) Oct 23, 2013
What does he mean by
"Supermassive black holes (those with millions to billions of solar-masses) are thought to reside at the centers of most galaxies."
hasn't it been proven beyond a doubt, this article is blasphemy

Read more at:
Tuxford
1 / 5 (16) Oct 23, 2013
In front of their noses, and they still don't get it! They 'assume' the active black hole must be accreting. Nonsense. It may be accreting as well, but accretion is unlikely the source of all the new star material. The active black hole is providing the new material forming stars from within. (Heresy! Off with his head.) That is why the relationship is linear. The bigger, and therefore more active the 'grey' hole, the more material that is being produced and ejected from the grey hole mother star. Simple really.

http://phys.org/n...tml#nRlv

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Zephir_fan
Oct 23, 2013
This comment has been removed by a moderator.
maunas
1 / 5 (10) Oct 24, 2013
Motion is an event. Memory of distinct (quantum) events (subjects) gives sense (count) in abstract form of Time and in non-abstract form sense of Space. Unaccumulated space-time gives sense of Vacuum (Dark Energy) and accumulated space-time gives a sense of Matter. Loss of space-time from matter gives sense of Energy. Addition of space-time to matter gives sense of Force or Gravity or Curvature of Space-Time.
theon
1 / 5 (7) Oct 24, 2013
This has been modeled in arXiv:1108.1697:
Model for common growth of supermassive black holes, bulges and globular star clusters: ripping off Jeans clusters. Theo M. Nieuwenhuizen, Europhysics Letters 97, 39001 (2012).
The peak in black hole growth rate and star formation rate occurs at a crossover between
small and large BH's.
Tuxford
1 / 5 (4) Nov 04, 2013
The peak in black hole growth rate and star formation rate occurs at a crossover between
small and large BH's.


This is logical, as once the core star grows too big and therefore active, the extreme winds it produces disrupts the star forming region near the core. Star forming regions would shift further out away from the core, with the clouds becoming more disperse and tenuous, slowing condensation rates.

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