){kind=spacer}
COSMIC DRIFTER: The black hole in the massive galaxy M87 is off-center [lower left]. In the more panoramic image [right], M87's jet is clearly visible. (The bright spot marked HST-1 in the lower left image is a knot in the jet.)
Image: NASA, ESA, D. Batcheldor and E. Perlman (Florida Institute of Technology), the Hubble Heritage Team (STScI/AURA), and J. Biretta, W. Sparks, and F.D. Macchetto (STScI)
-
The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
Read More »
MIAMI—Observations from NASA space telescopes have revealed new quirks about the supermassive black holes at the heart of two galaxies. In the supersize elliptical galaxy M87 some 55 million light-years away, for one, the black hole is not in the galaxy's center of mass, apparently having been pushed askew by some violent process. And in the Andromeda Galaxy, a neighbor to our own Milky Way just 2.5 million light-years away, the black hole appears to have recently—and very suddenly—awoken from a slumber. Two groups presented the black-hole findings Tuesday at the semiannual meeting of the American Astronomical Society being held here this week.
Daniel Batcheldor of the Florida Institute of Technology and his colleagues used high-resolution imagery from the Hubble Space Telescope's Advanced Camera for Surveys to determine the location of M87's galactic center, finding that the galaxy's black hole is off-center by about 22 light-years. (The black hole, though itself invisible, is relatively easy to detect, as the material falling into it gives off copious amounts of radiation.) "The black hole is not where it's expected to be," said Batcheldor, whose group says its finding has been accepted for publication in the Astrophysical Journal Letters.
A number of processes could explain the displacement, including a push from the bright jet that is seen to emanate from the black hole region. But the jet does not appear to be powerful enough, and may not be one-sided in any event—that is, there may be a counterjet pointed in the opposite direction. A more likely mechanism, Batcheldor said, is a past merger between two black holes that generated a gravitational recoil, knocking the resulting black hole, which packs the mass of about six billion suns, out of whack.
Batcheldor added that a similar test could be carried out on other galaxies to see how common the phenomenon is. "To be honest, it's a very straightforward technique," he said. The problem is that the high-resolution channel of the Hubble instrument that his group used to look at M87 is no longer functional, so archival data will have to be mined to check whether other black holes are similarly offset.
The nearby Andromeda Galaxy, a spiral like our own Milky Way, is home to its own black hole intrigue. And like the black hole at the center of the Milky Way, the Andromeda black hole has been quiescent, said Zhiyuan Li of the Harvard–Smithsonian Center for Astrophysics. In fact, Li said, the x-ray luminosity of the Andromeda black hole, which is as massive as 140 million suns, is about one ten-billionth of its theoretical maximum. That indicates that it is accreting rather slowly, as rapid growth is usually accompanied by bountiful x-rays from the soon-to-be-devoured material swirling around the black hole.
At least, that was the case when Li and his colleagues started observing Andromeda's black hole with the Chandra X-Ray Observatory in 1999. In January 2006, though, things changed—the black hole suddenly perked up in x-ray luminosity, flaring up to roughly 100 times its typical levels. And that flare appears not to have been a fluke in the data—since that time, the activity of the black hole has hovered around an average x-ray luminosity roughly seven times its pre-2006 value. "The black hole appears to enter a relatively active phase," Li said, adding that he and his colleagues have a tentative explanation for the phenomenon. Episodic ejections of plasma blobs at nearly the speed of light, somewhat analogous to solar outbursts called coronal mass ejections, could be the culprit.
The Milky Way's own supermassive black hole, a relative lightweight compared with those of M87 and Andromeda at a mere four million solar masses, occasionally flares up as well. But Li said that its luminosity generally returns to the quiet preflare level, making the lasting change in M87 rather unique. "This is really, to our knowledge, the first example of a supermassive black hole showing such temporal behavior," he said.
See what we're tweeting about
15 Comments
Add CommentI find it difficult to believe but, reviewing the paper to be published, its all about the disappointed expectation that a spiral galaxy's supermassive black hole is not exactly located, not at its collective center of mass even, but its photometric spatial center-point!
Reply | Report Abuse | Link to thisThe authors of "A DISPLACED SUPERMASSIVE BLACK HOLE IN M87" used luminosity to determine the spatial dimensions of the nebulous galactic 'bulge' within the central region of the galaxy, and found that the expulsion jets of the active supermassive black hole (or binary pair) were offset from its geometric center!
It might be expected that supermassive black holes would be found at the collective center of galactic mass (if that could be precisely determined), but it was not. It was expected that the supermassive black hole would be located at the geometric center of the luminous nebula in the middle of the galaxy. Why this might be expected is not explained.
I can only guess that the expectations producing this surprising result themselves result from our own conception of orbital systems derived from our familiarity with the exceedingly centralized mass solar system. Nearly 98% of all Solar system mass resides within the Sun. Supermassive black holes are estimated to 'contain' 0.5% of their galaxy's 'visible' mass.
For further reading about how the central mass bias of our gravitational perspective influences our interpretations of orbital systems, leading to the apparent requirements for compensatory Dark Matter, please review the essay, "Mass Distribution Characteristics Invalidate the Galaxy Rotation Problem" posted at:
http://www.sciencewithoutfiction.com/uploads/Mass_Distribution-_Galaxy_Rotation_Problem.pdf
Why , what's wrong?...fix it!!!?
Reply | Report Abuse | Link to thisThe problem is that the high-resolution channel of the Hubble instrument that his group used to look at M87 is no longer functional, so archival data will have to be mined to check whether other black holes are similarly offset.
Bops - Offset from what? Is there some theoretical basis for expecting that the supermassive black hole should be located at any specific location, other than perhaps the axis of rotation, if that could be precisely determined? I'd appreciate your insight.
Reply | Report Abuse | Link to thisSpeaking as one of the authors of the Batcheldor et al. M87 paper ...
Reply | Report Abuse | Link to thisWhile it is true that supermassive black holes constitute a tiny fraction of the mass of the galaxies they reside in, there are two good reasons why we would have expected that they should be located at the centers of galaxies' potential wells.
(1) Quasars and galaxies are both observed out to redshifts of at least 7. This means that they formed at nearly the same time (i.e., we have no evidence for a delay between when galaxies formed and when their black holes formed), and so the location of the black hole should be the dynamical center of the perturbation that coalesced to form the galaxy.
(2) Numerical simulations find that, over time, the heaviest objects should sink to the center of a cluster of stars. Now, the context for the simulations is globular clusters, not galaxy centers; however, the physics are the same. In fact, n-body simulations of this sort are now beginning to be done -- the only difference is that general relativity has to be included to model the formation of the black hole itself. There is a good -- albeit a few years out of date -- list of references on this subject at http://jila.colorado.edu/~pja/astr6000/index07.html which was from a grad-school seminar (at the University of Colorado) on this subject exactly.
Our result really does not relate to whether or not galaxies' rotation curves require dark matter or not. That is an entirely separate argument, and something for which there is very good evidence, contrary to the statements made in Mr. Dwyer's essay, which has problems galore.
Finally, I wish we could fix the High Resolution Channel of the Advanced Camera for Surveys. The problem is, it's shorted out, and was pronounced beyond repair during the last Hubble Servicing Mission. Some of the slack could be taken up by the UVIS channel of the new Wide Field Camera-3, but if the displacement of the black hole is less than about half what we see in M87, we're out of luck, because the pixels are a full 60% bigger than those in the HRC.
esperlman - Thanks for responding, even to generally dismiss my efforts without even suggesting issues that might be responded to. I'm not trying to pretend to be a physicist: if I were I could provide mathematical proofs and data analysis to support my arguments.
Reply | Report Abuse | Link to thisUnfortunately, you did not explain why the dynamical center of a spiral galaxy should be found at the geometric center of a nebulous 'bulge' of luminous gasses. This is the essence of my argument, which is not overwhelmed by simulations or credentials.
I'm sure any scholar or student can find (unspecified) problems with my informal essay, but that not really the point, is it? Can you explain why highly distributed masses should be expected to exhibit the rotational characteristics of the highly centralized sparse orbital systems? If you or others can do so, I would be happy to apologize and desist.
esperlman - One small point:
Reply | Report Abuse | Link to this"(2) Numerical simulations find that, over time, the heaviest objects should sink to the center of a cluster of stars..."
That assertion would infer that stellar black holes, having migrated from throughout the galaxy, rather than old, massive stars should be found in large numbers rapidly orbiting nearest the supermassive black hole of spiral galaxies.
In contrast, I would predict that stellar black holes, locally bound with other masses within the arms of spiral galaxies, would not likely migrate anywhere.
Shouldn't these conflicting predictions be confirmed through observation rather than relying on some presumptive simulation models?
esperlman - Back to the ‘central’ issue I have with your paper: your analysis is based on the presumption that a spiral galaxy’s supermassive black hole can be expected to be precisely located at the photo-center of the galaxy, which can be used to identify the location of the galaxy center of mass. These are invalid assumptions, with no theoretical or observational basis.
Reply | Report Abuse | Link to thisStrange physic’s contradiction
Reply | Report Abuse | Link to this1
On the one hand
The particles in the Universe are more than antiparticles
/ Baryon asymmetry /
2
On the other hand
Dark matter in the Universe is more than visual matter
Question
Does one physic’s hand know that the other hand do ?
Israel Sadovnik Socratus
==========.
Best wishes.
Israel Sadovnik. Socratus.
James, I'll try to respond to all your queries in one message.
Reply | Report Abuse | Link to this(1) Of course any assumption or prediction from numerical simulations needs to be verified by observational data! This is exactly why we did this work.
(2) I don't agree that there was no theoretical reason to believe that the supermassive black hole (SMBH hereafter) would be at the center. The papers I referred to are very strong on the theoretical side, and in globular clusters that contain smaller (10^4-10^5) solar mass black holes -- of which three are known in our own galaxy, including that of Omega Cen -- they are dead center. As mentioned previously, the physics is the same in galactic centers. So that's why we looked at other causes for the displacement, such as recoil from a merger event or the jet.
(3) I don't agree that stellar mass black holes would migrate from throughout the galaxy and congregate near the SMBH. Remember that the SMBH's mass is less than 0.1% of that of the mass of the galaxy, and if you look at its sphere of influence -- that is, where orbital velocities around the SMBH exceed random velocities in the bulge -- it's actually not that large a region of space ... less than a hundred light-years. There *will* be some in-migration of high-mass stellar objects within the nucleus, but not the entire galaxy. And in fact, this is seen in our own galaxy's center, where the star clusters have a much larger fraction of high-mass (>10 solar mass) objects than clusters elsewhere in the galaxy.
(4) You ask, "why highly distributed masses should be expected to exhibit the rotational characteristics of the highly centralized sparse orbital systems?" It's not at all clear to me what you're asking here. Now, one assumption we make is that the stellar distribution tracks the mass distribution. That's not always true, but it is in M87, which is an elliptical galaxy that has little dust and no evidence of molecular gas. This is why M87 was an ideal test case.
(5) As far as your paper goes, you confuse spirals and ellipticals in multiple places. You expect large-scale rotation in galaxies, from conservation of angular momentum in the material that formed them. That's what you see in spirals, although it should be noted that their rotation is differential, not solid-body, with their spiral arms representing density waves, not trails of stars as you say in your paper. Ellipticals are a different beast, often not dominated by rotation -- which is why simulations say you a major merger to produce them.
esperlman – Thanks for your considered response – it is very helpful. I had reconsidered my original comment and realized that I had expressed excessive, unwarranted frustration. I apologize for being so unprofessional (I am a retired Technical Fellow, IT Systems Planning). I also realize that I had reviewed your paper sometimes from a spiral galaxy perspective. More on that later…
Reply | Report Abuse | Link to this(1,2) Given the observational evidence of similar galaxies’ SMBH being photo-centric, I agree that this was a reasonable expectation for E0 galaxies, and apologize for my unwarranted aspersions.
While M87 appears to be essentially spherical from our observational perspective, so does a rocket if viewed from certain perspectives. Has it been definitively determined that M87 is a truly spherically symmetrical distribution of masses?
(3) I was overly aggressive in specifying a test condition for the assertion that” the heaviest objects should sink to the center of a cluster of stars”. That assertion seems to rely on the traditional centralized conception of the effects of gravitation, ignoring local effects. I’d expect that is the basis for any numerical simulations in use… Without extensively qualifying that statement it must be considered to apply to all clusters of stars. I certainly agree that is true of many examples of ‘star clusters’ it is not of many others. It is these types of statements that are often generalized and applied to inappropriate conditions, such as spiral galaxies should comply with Keplerian rotational curves.
(4) That spiral galaxies should comply with Keplerian rotational curves is perhaps less clearly restated as: "why highly distributed masses should be expected to exhibit the rotational characteristics of the highly centralized sparse orbital systems?" The question applies to spiral galaxies. Since I did not specify you naturally presumed I was referring to elliptical galaxies…
(5) I have searched my paper for ‘elliptical’ and found it used to describe the shape of the Andromeda galaxy’s disc in the sky (since it is viewed from an angle), and used again in listing the various categories of galaxies. That’s it. I can only guess that, just as I had viewed you paper while thinking of spiral galaxies, you had read my essay while thinking of elliptical galaxies. Otherwise I have no idea how you could conclude: “you confuse spirals and ellipticals in multiple places.”
I do appreciate very much your pointing out that I had completely neglected the Density Wave theory of spiral galaxies. Actually, the local binding explanation I subscribe to was the original explanation for spiral structures. However, presuming that spiral galaxies comply with Keplerian rotational curves, the spiral arms would quickly become too tightly bound. In order to solve that problem while still presuming compliance with Keplerian rotation, the Lin-Shu density wave theory was proposed in 1964. It has become an established assumption, but never proved. In fact, it obviously does not solve the Keplerian rotation problem as intended. As you indicated, density waves are now commonly presumed to be proven fact.
I still need to identify a potential solution to the ‘Winding Problem’, but I expect this will not require a new form of undetected matter to resolve.
Frankly, I’m getting exhausted and must take an extended break. I apologize for my transgressions and very much appreciate your help.
While inertial mass may be equivalent to gravitational mass, inertial velocity is completely distinct from gravitational mass. The gyro compass works on this principle which General Relativity cannot account for. Plancks constant clearly indicates that the universe is discontinuous. Light comes to us in a series of pulses. This is strong evidence that atomic matter itself is discontinuous, being synchronously projected in a series of still frames from an alternate formless quantum energy mode that is timeless and orthogonal to the integrated fabric of space and time. The wave particle nature of matter derives from this oscillation between a timeless/formless mode and a series of still space frames defined by atomic particles linked up by light in each frame. Space and time do not constitute an a priori continuum. They are quantized and derive a posteriori from creation.
Reply | Report Abuse | Link to thisThe point here is that the galactic center of inertial angular velocity need not be consistent with the distribution of gravitational mass. A discontinuous universe requires a complete review of astrophysics and cosmology. See the article on Cosmology at www cosmic-mindreach.com.
Black holes ejecting blobs of matter, increased radiation from black holes, off center centers of mass.... do we really want to continue to call the entity a black hole? Physics (from quantum physics to astrophysics) appears to have the need to re-evaluate what is a 'black hole'. Everything that we observe must occur outside of the event horizon. Nothing that happens inside the event horizon will ever be communicated to us (the observers) outside of the discontinuity. The fact that stellar black holes and supermassive black holes are functionally different, have a different origin, and there is not a continuous spectra of masses from stellar class to super massive class black holes should tell the observant individual that these are identical physical boundaries developed by different astronomical mechanics.
Reply | Report Abuse | Link to thisSomeone observe the sky in the night?
Reply | Report Abuse | Link to thisWhen i see the stars, i see one thing.
The universe branch out and for example today one star are in the place and tomorrow are in another place.
And the blacks holes are in move in this universe. I belive in this.
I just have to say "You Guys are SMART"
Reply | Report Abuse | Link to thisThanks!And Your God and bible?
Reply | Report Abuse | Link to this