Black hole came from a shredded galaxy

February 15, 2012, Harvard-Smithsonian Center for Astrophysics
This spectacular edge-on galaxy, called ESO 243-49, is home to an intermediate-mass black hole that may have been stripped off of a cannibalized dwarf galaxy. The estimated 20,000-solar-mass black hole lies above the galactic plane. This is an unlikely place for such a massive back hole to exist, unless it belonged to a small galaxy that was gravitationally torn apart by ESO 243-49. The circle identifies a unique X-ray source that pinpoints the black hole. The X-rays are believed to be radiation from a hot accretion disk around the black hole. The blue light not only comes from the disk, but also from a cluster of hot young stars that formed around the black hole. The galaxy is 290 million light-years from Earth. Hubble can't resolve the stars individually because the suspected cluster is too far away. Their presence is inferred from the color and brightness of the light coming from the black hole's location. Credit: NASA, ESA, and S. Farrell (Sydney Institute for Astronomy, University of Sydney)

( -- Astronomers using NASA's Hubble Space Telescope have found a cluster of young, blue stars encircling the first intermediate-mass black hole ever discovered. The presence of the star cluster suggests that the black hole was once at the core of a now-disintegrated dwarf galaxy. The discovery of the black hole and the star cluster has important implications for understanding the evolution of supermassive black holes and galaxies.

"For the first time, we have evidence on the environment, and thus the origin, of this middle-weight black hole," said Mathieu Servillat, who worked at the Harvard-Smithsonian Center for Astrophysics when this research was conducted.

Astronomers know how collapse to form stellar-mass black holes (which weigh about 10 times the mass of our sun), but it's not clear how (like the four million solar-mass monster at the center of the Milky Way) form in the cores of galaxies. One idea is that supermassive black holes may build up through the merger of smaller, intermediate-mass black holes weighing hundreds to thousands of suns.

Lead author Sean Farrell, of the Sydney Institute for Astronomy in Australia, discovered this unusual black hole in 2009 using the European Space Agency's XMM-Newton X-ray space telescope. Known as HLX-1 (Hyper-Luminous X-ray source 1), the black hole weighs in at 20,000 and lies towards the edge of the galaxy ESO 243-49, which is 290 million light-years from Earth.

Farrell and his team then observed HLX-1 simultaneously with NASA's Swift observatory in X-ray and Hubble in near-infrared, optical, and . The intensity and the color of the light shows a cluster of young , 250 light-years across, encircling the black hole. Hubble can't resolve the stars individually because the suspected cluster is too far away. The brightness and color are consistent with other clusters of young stars seen in other galaxies.

Farrell's team detected blue light from hot gas in the accretion disk swirling around the black hole. However, they also detected red light produced by much cooler gas, which would most likely come from stars. Computer models suggested the presence of a young, massive cluster of stars encircling the black hole.

"What we can definitely say with our Hubble data is that we require both emission from an accretion disk and emission from a stellar population to explain the colors we see," said Farrell.

Such young clusters of stars are commonly seen in nearby galaxies, but not outside the flattened starry disk, as found with HLX-1. The best explanation is that the HLX-1 black hole was the central black hole in a . The larger host galaxy then captured the dwarf. Most of the dwarf's stars were stripped away through the collision between the galaxies. At the same time, new were formed in the encounter. The interaction that compressed the gas around the black hole also triggered star formation.

Farrell and Servillat found that the must be less than 200 million years old. This means that the bulk of the stars were formed following the dwarf's collision with the larger galaxy. The age of the stars tells how long ago the two galaxies crashed into each other.

The future of the black hole is uncertain at this stage. It depends on its trajectory, which is currently unknown. It's possible the black hole may spiral in to the center of the big galaxy and eventually merge with the supermassive black hole there. Alternately, the black hole could settle into a stable orbit around the galaxy. Either way, it's likely to fade away in X-rays as it depletes its supply of gas.

"This black hole is unique in that it's the only intermediate-mass black hole we've found so far. Its rarity suggests that these are only visible for a short time," said Servillat.

More observations are planned this year to track the history of the interaction between the two galaxies.

Explore further: Hubble zooms in on double nucleus in Andromeda galaxy

More information: The new findings are being published in the February 15 issue of the Astrophysical Journal Letters. The journal paper is available online.

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2.1 / 5 (8) Feb 15, 2012

Its rarity suggests that these black holes are only visible for a short time

Either that or the Universe has "moved past" the stage in its evolution that you're going to see a lot of these things. New Galaxy formation might be basically where it's at...

There will be a time in the future where you won't see a single star burning anywhere. It's not because they'll have low visibility, it's because they won't and can't exist anymore.
Feb 15, 2012
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Feb 15, 2012
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5 / 5 (7) Feb 15, 2012
Modernmystic Actually, what they are saying in the quote is similar to what you are saying but not exactly the same. Unlike you, they are saying these are out there in great number but not many are visible since galaxy mergers have slowed and most intermediate BH's have either merged with central black holes or ran out of local gas and are thus not visible through the radiation spewed out as they gobble up gas.
4.6 / 5 (11) Feb 15, 2012
Just represents another case of astrophysicists not even understanding their own theories.

How about you get a PhD and publish your own paper on the topic?

I doubt you have enough brain cells to get past first year astronomy though.
Feb 15, 2012
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4.3 / 5 (12) Feb 15, 2012
I wouldn't want a PhD in much of anything in astronomy.

Ha You're making up excuses. You just don't have the motivation or intelligence to succeed.
not rated yet Feb 15, 2012
Modernmystic Actually, what they are saying in the quote is similar to what you are saying but not exactly the same. Unlike you, they are saying these are out there in great number but not many are visible since galaxy mergers have slowed and most intermediate BH's have either merged with central black holes or ran out of local gas and are thus not visible through the radiation spewed out as they gobble up gas.

Bazinga. Got it, makes sense now.
5 / 5 (2) Feb 15, 2012
if you dont like it here lurker you are free to leave. i think alot of us would appreciate that.
5 / 5 (3) Feb 15, 2012
It's about like the moderators and other forum mafia guys on here who immediately ridicule any mention of LENR as "pseudoscience," and ridicule anyone who attempts to explain it, or propose ways to use it, even though NASA has a patent on a device themselves...
Those who understand anything about science wouldn't say LENR is impossible, however it hasn't been shown to work yet which means unless you know how to make a device that successfully utilizes LENR and you're secretly holding out on the rest of us, you're just wishing for it to be real.

Regardless of what you think, NASA patents, or any patents for that matter, don't hold some kind of an indisputable truth by default.

Oh and what jsdarkdestruction said.
1 / 5 (3) Feb 15, 2012
I do believe, I can recognize a jet along the axis of galaxy at the above picture. It's very faint one.
1 / 5 (5) Feb 15, 2012
The object circled is blue. There are many other blue objects in this photo. Does that mean they are all intermediate black holes? If not then what makes this particular blue object a black hole whilst the others are not?
Finally might there be another explanation for the radiation you are observing other than it being a black hole?
Short bloke
1 / 5 (4) Feb 16, 2012
Lurker is correct concerning the practical impossibility of changing the scientific mindset concerning popular believed concepts that disregard the application of well recognised scientific laws. Laws such as the conservation of energy and well recognised physical realities appear to be disregarded when postulations are being made regarding astronomical anomalies. With regards to black holes or reoccurring gravity waves; try attempting to make contact with those who have made a career researching and promoting such believed phenomena in an attempt to present counter argument and reasons pertaining thereto. On this blog all such attempts are branded pseudoscience.
Short bloke
2.7 / 5 (7) Feb 16, 2012
The following is the concluding portion of the much reduced version of my above comment and may be of interest
Yes, matter warps the space surrounding it, and yes matter must due to its attributes influence the path of electromagnet photons, however, the knowledge of gravity is a very long way from being understood by the scientific community. The late and much revered Professor Albert Einstein provided a version of gravitation not gravity- that he derived from the application of geometrical based mathematics. Question. Can the scientific community provide an explanation of the fundamental dynamic nature of gravity that would lead to an explanation of gravitation? Also provide a logical reason for the fundamental dynamic physical attributes of matters property of inertia, and why the inertial property of matter is so closely related to that of gravity? I rest my case.
1 / 5 (4) Feb 21, 2012
This is likely an example of the birth of a daughter galaxy, rather than the death of a dwarf galaxy, stripped of it's stars. The core star is likely ejected from the parent galaxy, and over time grown into the intermediate class size, like many fast moving stars that have been discovered in our galaxy. In Subquantum Mechanics, the star grows from within, and with periodic outbursts, spawns stars around them. This could also be one mechanism that contributes to some of the long tails we see strung between some galaxies.
1 / 5 (2) Feb 29, 2012
A supermassive star has been observed ejecting at high speed from it's host galaxy.


And likely some other examples in Andromeda.


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