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publiusr
2012-Dec-01, 06:27 PM
http://arxiv.org/abs/1211.6429 An Over-Massive Black Hole in the Compact Lenticular Galaxy NGC1277
Remco C. E. van den Bosch (1), Karl Gebhardt (2), Kayhan Gültekin (3), Glenn van de Ven (1), Arjen van der Wel (1), Jonelle L. Walsh

Observations show that a typical galaxy has a central black hole mass of ~.01% of the central bulge mass. NGC 4486B has the largest current published black hole mass at 11%. This paper looks at NGC1277, who’s black hole mass is 59% of the central bulge. Four other galaxies with similar properties may also contain black holes with a larger than normal mass relation. It also references three galaxies with smaller than normal black hole mass. Whether these over and below typical mass black holes represent the ends of the distributions or separate classes of objects is currently unknown.

That one throws me. I would think a giant black hole like that would only be seen in the future when Milkomeda and other members of the Local group merge into supergalaxies...

Now an earlier paper linked to here seemed to take a dim view on the possibilities of the existence of Textures, but could one of those take the place of a galactic core black hole?

antoniseb
2012-Dec-01, 07:00 PM
I imagine that this black hole might be the result of a merger of two counter-rotating galaxies hitting at just the right angle to end up with a near-zero net angular momentum, so that materials would fall into the center. This case is very strange in that the central bulge has about 70% of its mass in this black hole, whereas most galaxies only have 0.1%.

Still, the whole idea of discussing this as a Texture seems a little out of place... and if you'd like to discuss it, you should say more about how a Texture could take the place of a central black hole, and how you think it got there.

publiusr
2012-Dec-01, 08:23 PM
There was some talk about a cold spot being a texture--I guess that isn't the case now. If so, that would have been pretty large. The collision idea seems right.

Now, let's say that a texture was a little more stable than thought, and lasted long enough to pick up something from tidal tails of other galactic collisions, and left room for a broader rotation with a lot less initial material? I'm clutching at straws at this point--but the counter rotating scenario does seem more likely.

I'm trying to imagine what a texture would look like surrounded by very little material...

TooMany
2012-Dec-02, 12:10 AM
I imagine that this black hole might be the result of a merger of two counter-rotating galaxies hitting at just the right angle to end up with a near-zero net angular momentum, so that materials would fall into the center. This case is very strange in that the central bulge has about 70% of its mass in this black hole, whereas most galaxies only have 0.1%.


That's a huge deviation from the usual case.

In the proposed collision, gas and dust would collide resulting in low angular momentum (with dissipation of KE) and therefore enter the well. But the existing stars are unlikely to collide. Wouldn't their motions just randomize? As they don't collide, they have no mechanism for loosing KE so they cannot stop in their tracks and fall.

Perhaps a lot of star formation would occur before the gas and dust was able to fall. Those new stars would have low angular momentum and would fall into highly elliptical orbits, but I would not expect too many to end up in the hole, unless it is already very large?

antoniseb
2012-Dec-02, 12:31 AM
... But the existing stars are unlikely to collide. Wouldn't their motions just randomize? As they don't collide, they have no mechanism for loosing KE so they cannot stop in their tracks and fall. ...
Suppose that the collision happened before the creation of most stars, and that a huge star forming process happened with clusters all falling in toward the center, and enough ferocity to blow much of the remaining gas out of the galaxy.
Just to be clear about my position on this, I have NOT done any kind of simulation or numerical analysis, so somebody showing that I'm wrong won't crush me... just inform me.

TooMany
2012-Dec-02, 05:59 PM
Suppose that the collision happened before the creation of most stars, and that a huge star forming process happened with clusters all falling in toward the center, and enough ferocity to blow much of the remaining gas out of the galaxy.
Just to be clear about my position on this, I have NOT done any kind of simulation or numerical analysis, so somebody showing that I'm wrong won't crush me... just inform me.

OK it's a clever speculation. After thinking about it a bit, I wonder even more how these super-massive black holes can form. I'll have to do some searching to see if simulations or calculations have been done that can account for the formation of these black holes.

Tensor
2012-Dec-03, 12:04 AM
OK it's a clever speculation. After thinking about it a bit, I wonder even more how these super-massive black holes can form. I'll have to do some searching to see if simulations or calculations have been done that can account for the formation of these black holes.

Go to the original link in the OP and look at references 2, 3, 4, 5, and 6. Each has a link to ADS, which then has a link to the paper in arXiv. In addition, you might want to look at this paper (http://arxiv.org/pdf/1003.4404v1.pdf) as it details three methods of how SMBH can form (including references to calculations where the gas would lose 90% of it's angular momentum). That paper also references other papers with specific calculations, I just didn't provide the specific links. You may have to dig a bit for those by doing a google search with the title of the paper. And getting this out of the way early, after all of these, it still simply isn't known for sure. The simulations and observations are consistent, with several different possibilities, but hardly definitive. I present them only because you stated you wanted to do some searching and I thought I'd help you along.

Over the last couple of days, I've found that there is a huge perception problem with the paper in the OP. Most people who hear about this wants to focus on the large SMBH mass to bulge mass relationship of NGC1277. While that is interesting, don't forget, the paper lists several other possibilities for large SMBH/bulge relationship and it mentions possibilities on very small SMBH/bulge relationship and whether these are the ends of the distribution of the relationship. There are more than a few people in the astrophysical community who are really excited about the high quality of the data in the paper. I wasn't fully aware of this when I wrote the blurb or I would have made that point more prominent.

Don Alexander
2012-Dec-03, 02:03 AM
Also, don't forget, everyone, whatever happened, it happened at least 8 billion years ago. The galaxy has been quiescent since then.

I'm looking forward to what they find for the other galaxies in their sample that are given in the table.

I also wonder if the event horizon is large enough to image somehow, maybe with VLBI.

antoniseb
2012-Dec-03, 12:27 PM
... I also wonder if the event horizon is large enough to image somehow, maybe with VLBI.
That would be pretty cool. The EH for this one is about 4000 times the diameter of Sgr A*'s EH. The distance is about 8,000 times... so once the Event Horizon Telescope is able to resolve our local one, it should only be a few years before we can resolve the one in NGC1277.

ngc3314
2012-Dec-03, 02:14 PM
The bad news for seeing the event horizon signature is that NGC 1277 has an extraordinarily quiet nucleus - NED doesn't even show a detection from any of the VLA surveys, although certainly it will be coming in for close scrutiny along with its compatriots in the van den Bosch et al. list. Without background emission, there's nothing to lens.

Someone (van den Bosch, maybe) lately remarked that there's no evidence that the most massive SMBHs have been AGN over about the last half of cosmic time. One relevant point is that the tidal-disruption radius becomes so large that stars could be accreted whole rather than being disrupted; another is that the volume out to the last stable orbit becomes so large that it takes progressively more mass to establish an active accretion disk.

I agree that the data look solid, and the galaxy modeling has all the standard features. Handwaving has been accompanied by mentions of early direct collapse or evolution of a relativistic cluster of SMBHs, but unless NGC 1277 is the tiny remnant of a galaxy stripped long ago of most of its stars and dark matter in the Perseus cluster environment, these don't say much about how you get the high-mass object in such a modest galaxy.

chornedsnorkack
2012-Dec-03, 06:09 PM
The bad news for seeing the event horizon signature is that NGC 1277 has an extraordinarily quiet nucleus - NED doesn't even show a detection from any of the VLA surveys, although certainly it will be coming in for close scrutiny along with its compatriots in the van den Bosch et al. list. Without background emission, there's nothing to lens.

Someone (van den Bosch, maybe) lately remarked that there's no evidence that the most massive SMBHs have been AGN over about the last half of cosmic time. One relevant point is that the tidal-disruption radius becomes so large that stars could be accreted whole rather than being disrupted; another is that the volume out to the last stable orbit becomes so large that it takes progressively more mass to establish an active accretion disk.


If a star approaching a massive and quiet black hole remains undisrupted all the way to event horizon, and does not form any accretion disc, does it mean that stars could often be seen in periapse passages outside the event horizon at relativistic speeds?

The red and blue shifts of a star would change during a periapse passage. How would it look through the gravitational lens? Would the light arriving at any one time have same shift?

TooMany
2012-Dec-05, 12:40 AM
Go to the original link in the OP and look at references 2, 3, 4, 5, and 6. Each has a link to ADS, which then has a link to the paper in arXiv. In addition, you might want to look at this paper (http://arxiv.org/pdf/1003.4404v1.pdf) as it details three methods of how SMBH can form (including references to calculations where the gas would lose 90% of it's angular momentum). That paper also references other papers with specific calculations, I just didn't provide the specific links. You may have to dig a bit for those by doing a google search with the title of the paper. And getting this out of the way early, after all of these, it still simply isn't known for sure. The simulations and observations are consistent, with several different possibilities, but hardly definitive. I present them only because you stated you wanted to do some searching and I thought I'd help you along.

Over the last couple of days, I've found that there is a huge perception problem with the paper in the OP. Most people who hear about this wants to focus on the large SMBH mass to bulge mass relationship of NGC1277. While that is interesting, don't forget, the paper lists several other possibilities for large SMBH/bulge relationship and it mentions possibilities on very small SMBH/bulge relationship and whether these are the ends of the distribution of the relationship. There are more than a few people in the astrophysical community who are really excited about the high quality of the data in the paper. I wasn't fully aware of this when I wrote the blurb or I would have made that point more prominent.

Thanks Tensor, I'll put those on my reading list.