Black Hole in Search of a Home

jose parinas writes "Interesting news from the ESO observatory on Paranal about black holes that travel. From the article: 'For 19 of [the low redshift quasars], they found, as expected, that these super massive black holes are surrounded by a host galaxy. But when they studied the bright quasar HE0450-2958, located some 5 billion light-years away, they couldn't find evidence for an encircling galaxy. This, the astronomers suggest, may indicate a rare case of collision between a seemingly normal spiral galaxy and a much more exotic object harbouring a very massive black hole.'" More from the article: "Has the host galaxy been completely disrupted as a result of the collision? It is hard to imagine how that could happen. Has an isolated black hole captured gas while crossing the disc of a spiral galaxy? This would require very special conditions and would probably not have caused such a tremendous perturbation as is observed in the neighbouring galaxy. Another intriguing hypothesis is that the galaxy harbouring the black hole was almost exclusively made of dark matter." Update: 09/17 00:15 GMT by Z : Edited for clarity.

Comments

Stephens theories,....

[crkpot]

I would be interested in how this data applies to the Stephen Hawkings theory of radiation expelled at the end of a Black hole - his come-back theory that everyone is still waiting to hear about. Dark Matter though compelling leaves us with more questions than answers.

Why couldn't it have

[geekoid]

just 'consumed' the galaxy it started with? sure it would take a long time, but it's probably been there a long time.

Dark matter?

[bradbury]

An alternative explanation which is seldom discussed is that there could be a completely developed (mature) galaxy composed entirely of Kardashev Type II civilizations, also known as Matrioshka Brains. As was pointed out by Marvin Minsky at the Byurakan CETI conference in 1971 *advanced* civilizations, for thermodynamic efficiency reasons, will radiate their waste heat at slightly above the cosmic microwave background temperature. The VLT and HST which were used in these studies are incapable of detecting radiation at these wavelengths so any galaxies being managed by advanced civilizations would effectively be invisible.

A reasonable person might well consider an explanation that included the natural evolution of advanced technological civilizations before they resorted to the invention of new particles and laws of physics (as is typically a requirement as soon as you mention 'dark matter').

It is useful to keep in mind that several papers by Charley Lineweaver's group document that ~70% of the "Earth's" in our galaxy are significantly older than ours (perhaps billions of years older). It would not be that unexpected that from time to time we might encounter a galaxy where advanced civilizations had placed *all* of the reasonably available matter and energy "under management". (For the purposes of discussion we will assume that black holes do not constitute a "reasonably available" useful resource despite proposals from time to time that require rather creative physics to make them "useful".)

Re:Dark matter?

[Anonymous Coward]

> It is useful to keep in mind that several papers by Charley Lineweaver's [anu.edu.au] group document that ~70% of the "Earth's" in our galaxy are significantly older than ours (perhaps billions of years older). It would not be that unexpected that from time to time we might encounter a galaxy where advanced civilizations had placed *all* of the reasonably available matter and energy "under management".

Bullshi*hey, hang on a sec*

At ~1% of c, we're talking 500 years to Alpha Centauri. (400 years of travel time, plus 100 years to build two identical colony ships.)

At ~1% of c, a civilization could colonize a 100,000 light-year wide galaxy in 10 million (1* 10^7) years. If each colony produces only one colony ships per century, humans could do it, and the galaxy would end up colonized even if half these spawned colony worlds had full-blown ecosphere-destroying wars within 100 years of colonization.

s/Bull/Holy /g

As in, "Holy shit!"

It not only isn't much of a stretch to believe that at least one out of several hundred billion galaxies is completely colonized, it's probably a certainty.

Going from there to a galaxy entirely populated by Type II civilizations isn't much of a stretch. If humanity (yeah, you, me, and the rest of us genocidal maniacs) could pull off galactic colonization starting next Tuesday using technology we invented in the 60s, it's not much of a stretch that at least one (of tens/hundreds of millions) of the resulting colonized worlds would be able to defend itself without destroying itself. (And all they'd have to do is outlast the rest of us, and recolonize the galaxy after everyone else blowed themselves up :)

A galaxy of Type II civilizations within a billion years may be a practical inevitability within a few generations of the first interstellar colonies.

Thanks, dude. First reason for optimism I've had about intelligence in the universe in about 12 years. It really does only have to get off its homeworld once. The laws of exponential growth take care of the rest.

Re:Dark matter?

[bradbury]

No, I'm not Ray, though I am very distantly related. So you don't feel I'm appealing to "inaccessible literature", I post the following from the source proceedings (edited by Sagan).

Dyson had made a set of points, one of which was:
"Point 3. If a society is very highly developed technologically, it must emit intense infrared radiation, not necessarily a planetary spectrum, but necessarily a large intensity of infrared radiation, whether or not this society wishes to communicate. Consequently, we should use infrared radiation, as a signpost indicating priority areas toward which we should direct searches by radio and other techniques."

There was some discussion which eventually led to the following exchange:

OLIVER: Why do you suggest civilizations must of necessity produce large amounts of infrared radiation? It seems to me that the infrared radiation that would be produced by even a very much farther advanced civilization than ours would be negligible compared to their primary star. For example, in California, which has a very high usage of electricity, the power generation at the present time is only 0.1 percent of the sunlight falling on the state.

DYSON: What I am saying is that the civilizations which are observable to us will have this character.

OLIVER: But you are suggesting, are you not, that the infrared emission will be an observable characteristic? I am suggesting it is far down in the stellar noise.

DYSON: No, I am saying that the generation of large amounts of infrared radiation is not necessarily an accompaniment of a high civilization at all. Only if it occurs is it something we can see.

MINSKY: Since radiation at any temperature above 3K is wasteful and a squandering of natural resources, the higher the civilization, the lower the infrared radiation. We should look for extended sources of 4K radiation. There should be very few natural such sources.

DYSON: I don't quite go along with this but to some extent you are right.

The reason that Dyson didn't go along with this is because he still tended to view "advanced" civilizations as those operating on the basis of "biological" systems (remember this is 1971!) rather than engineered computational systems which can function at a much wider temperature range (in fact Likharev's "Rapid Single Flux Quantum Logic" (based on Josephson junctions) *have* to operate at temperatures much closer to those Minsky suggests). Thus AIs constructed of such devices would emit IR at a temperatures much lower than "primitive" civilizations (i.e. "wet" brain based) which function at the liquid water temperatures that Dyson tended to prefer.

The theories behind Matrioshka Brains are in large part based on Minsky's observation, which are in turn related to Dyson's perspective reagarding Dyson "spheres" (really shells). They are however updated to recognize the fact that computational architectures which can support intelligence (and therefore advanced civilizations) can operate over a much wider temperature range (both higher and lower) than liquid water can provide.

The complete proceedings from the conference can be purchased from Amazon for $3-7.

It's that simple.

[Hurricane78]

The host galaxy is *inside* the black hole. It got "eaten" completely. To me this sounds pretty realistic if it's a huge black hole...

"Complete disruption of a galaxy?"

[Anonymous Coward]

What if the supermassive black hole was rotating such that it's poles were pointing into the disk of the parent galaxy?

The artilce mentions that there is eveidence that a companion galaxy has collided witht the quarsar withing the last 100 million years or so (relative to the observation).

If so, when the collision occured and provided material to feed the quasar, the polar jets would have plowed right into the parent galaxy, and perhaps blowing away the gas in the disk over that 100 million year period.

Any thoughts on this?

-- Trent