Questions tagged [supermassive-black-hole]

Questions regarding the most massive examples of black holes that typically reside at the centers of galaxies.

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Hypothetically, could a civilization in a solar system near a supermassive blackhole use the blackhole as a huge gravity lens telescope?

I have heard of various proposals that use the massive gravity of stars to sort of focus light at and observe with a suitable telescope placed at such a distance, and I am assuming here that bigger ...
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Is there a closest free-return trajectory to a black hole?

The scenario I am imagining is a test particle falling from infinity with an initial off-center velocity. In Newtonian mechanics the path would be a hyperbola. But I assume that, near a black hole, ...
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Do any particles in AGN jets escape the galaxy?

I have read, at http://www.thestargarden.co.uk/Black-holes.html for example, that whole stars can be ejected from certain galaxies. "These are thought to have been part of a binary star system ...
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What keeps galaxies together?

The super massive black hole at the centre of Milky Way has a mass of about 4 million times that of our sun. Is this enough to keep the entire galaxy together, is it this black hole which keeps the ...
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How spaghettification is possible at the Event Horizon of a supermassive black hole?

if gravity is too strong then it will break a object apart as gravity is strong enough to break the chemical composition of object why we consider "Spaghettification" relevant in this case ?
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Why don't black holes quickly eat up the galaxy/universe?

It's my understanding that the radius of the event horizon of a black hole is proportional to it's mass. Which means the surface area of a black hole is proportional to it's mass squared. Lets just ...
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What is the effect of extinction in the accretion disk for black hole mass determination?

I've created a basic model of the accretion disk (AD) by summing up blackbodies following the temperature profile of the AD according to Shakura & Sunyaev (1973) (extensively used in the ...
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How can a supermassive black hole be 13 billion years old?

A supermassive black hole was discovered recently that is 13 billion years old. This blackhole is 1.6 billion times the mass of the sun. How can this blackhole have formed so quickly after the big ...
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Correlation between supermassive black hole properties and galaxy rotation speed

Is there any correlation between the size or spin - or any other properties - of a galaxy's central supermassive black hole and the speed of galaxy rotation (which I think would also be proportional ...
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Why are galactic nuclei yellow?

So we've seen millions of galaxies, and all of them have a bright, yellow nucleus. What is the cause of the yellowness? Is it because of aging stars, redshift from the SMBH, or something else?
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What came first: Galaxies or Stars? [duplicate]

In Stephen Hawking's A Brief History Of Time, the book mentions that "in regions that were slightly denser than average...galaxies were born." (pg 123). However, according to many other ...
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Why is there no color shift on the photo of the M87 black hole?

Last year, the first photo of a black hole in Messier 87 was published: (Source: EHT) It is quite obvious that about the lower half of the accretion disk is brighter. This question (or rather, the ...
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Details of the M87 Active Galactic Nucleus — questions of scale

This video describes a scale model of the M87 SMBH (somewhat distorted to live in flat space and for other practical reasons) in which the Schwarzschild radius appears to be scaled to about 10cm, with ...
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Could blackholes warping space-time create dark energy?

I think the effects of blackholes on the surrounding space is localised to a small area around the blackhole but I wondered if the largest blackholes at the centre of massive clusters could be a ...
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Is the angular size of the black hole in the movie “interstellar” completely overblown?

I assume everybody is tired of reading questions derived from the movie Interstellar, I will try to keep this short and simple: In general in movies, in order to have stunning visuals, celestial ...
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Will the first Event Horizon Telescope image of the Milky Way's black hole be just another orange donut?

@HDE226868's answer to Why doesn't the black hole in the center of the Milky Way glow similarly to the famous M87 image? explains that neither black hole is orange and any Event Horizon Telescope ...
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Will the Sagittarius A* Black Hole eventually swallow the entire Galaxy?

In one of his interviews, Sir Roger Penrose mentioned that when the Milky Way and the Andromeda galaxies eventually "collide" and merge into one, their super-massive black holes will also ...
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Black Hole Collision & Gravitational Waves

The Gravitational waves detected by LIGO on 14th September 2015 are attributed to a collision of two black holes, which had been rotating near the speed of light around each other just before the ...
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Are there any predictions of what galaxies exist in the Norma cluster/ Abell 3267?

I am working on a map for a science fiction story and using what information is available I have a good idea of locations of nearby galaxy groups and clusters and where the known supermassive black ...
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Would DCBH form supermassive stars first before BH formation

In reading some literature it seems ambiguous (intentionally?) as to the path that Direct Collapse Black Holes (DCBH) take. Some papers do talk about pristine Halos collapsing to form supermassive ...
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How do we know that the discovered M87 black hole isn't just a star surrounded by a dust disk?

To an untrained eye like mine, pictures of stars surrounded by dust discs look very much similar to the picture of the M87 black hole. Here are some pictures of these dust discs: And here is a ...
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How does gas in accretion disks of supermassive black holes create orbital torques on smaller black holes within the disks causing them to migrate?

This answer to What enhances the capture and merge rates of pairs of small black holes orbiting around supermassive black holes? links to Migration Traps in Disks Around Supermassive Black Holes which ...
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Why would the merger of spinning black holes within the accretion disk of a supermassive black hole cause them to “shoot straight up” out of the disk?

I just tried to read the new New York Times article Two Black Holes Colliding Not Enough? Make It Three which links to the new 25-June-2020 Physical Review Letter Graham et al. Candidate ...
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What enhances the capture and merge rates of pairs of small black holes orbiting around supermassive black holes?

I just tried to read the new New York Times article Two Black Holes Colliding Not Enough? Make It Three which links to the new 25-June-2020 Physical Review Letter Graham et al. Candidate ...
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What happens when a huge star is being consumed by a black hole

What happens when a huge star in its later stage( iron core) is near a black hole that slowly consumes some of the matter from the star? Would this offset the imbalance caused by iron fusion ...
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What will be the eventual result of the Milky Ways future mergers?

I am wondering, after the Milky Way merges with Andromeda and other near by dwarf galaxies and globular clusters, will it then merge with galaxies in the Virgo cluster and even Laniakea? And if so ...
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What is the actual temperature of a quasar?

My daughter asked me last night: What is the hottest thing in the universe? The first thing that sprang to mind was the core of a fresh neutron star (this question agrees: What is the hottest thing ...
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Why don't they make an image of the black hole in the M33 galaxy?

Since we see the Triangulum galaxy M33 from a quite vertical position (contrary to our Milky Way and a bit the Andromeda galaxy) it should be easy to image the black hole in the center of it, shouldn'...
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Hills' mechanism for making Hypervelocity Stars

In Hill’s mechanism, the gravitational tidal force of a single MBH disrupts an approaching binary. One star is captured on an eccentric orbit around the MBH and, by conservation of energy, the ...
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A question related to black holes

Not a physicist just a simple guy, don't know much about physics as well. Just like to read things. I was reading about black holes and a question popped in my mind. If I understand it correctly ...
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Can dark energy or dark matter affect black holes

I was wondering if black holes are the greatest force of gravity how does other highly spoken about concepts such as dark energy or dark matter compare. Can a black hole absorb dark energy or dark ...
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How does a Super-Massive Black Hole 'flare'?

This week we have read of evidence of the Super Massive Black Hole in the centre of the Galaxy 'flaring'. My understanding is that light cannot escape from a black hole. My question is: How does a ...
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How did they estimate the mass of Sgr A*'s companion G2 without knowing what it was?

Gizmodo.com's Astronomers Spot Unprecedented Flashes From Our Galaxy's Black Hole mentions Sgr A*'s companion gas cloud G2. That Wikipedia article says: First noticed as something unusual in ...
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Are there galaxies with 2 or more super massive black holes orbiting each other?

We now know that most stellar systems have 2 or more stars orbiting each other. Do we know of any galaxies which have 2 or more super massive black holes orbiting each other? Is it possible?
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Two body orbit dynamics for orbital periods approaching light cone limit

How do you model a system of two large celestial bodies, where they achieve a rotation very close to the limit at which information can escape the system (heat, light, etc.), do they begin to appear ...
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How did they measure the distance to the center of our galaxy to 0.3% accuracy?

The abstract of A geometric distance measurement to the Galactic center black hole with 0.3% uncertainty (Open Access) says: We present a 0.16% precise and 0.27% accurate determination of R₀, the ...
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Size of a black hole

If there is no matter inside any of the black holes and all of them have a singularity in the center of them, which is infinitely small and infinitely dense, then how can they differ in size and ...
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How do two supermassive black holes reach “the last parsec” in merging galaxies?

This answer to Why can't supermassive black holes merge? (or can they?) describes the barrier to merging that two supermassive black holes face when two galaxies are in the process of merging or have "...
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Why can't supermassive black holes merge? (or can they?)

The CNet article Astronomers discover two supermassive black holes in a death spiral links to Discovery of a Close-separation Binary Quasar at the Heart of a z ~ 0.2 Merging Galaxy and Its ...
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How feasible is it that we could see the Central Black Hole Sgr A* occlude one of it's closely orbiting stars?

I'm thinking about the recent famous photo of a black hole, some months ago. It got me wondering if there isn't a way to more easily make a direct observation of these. We detect exoplanets in part ...
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Head on collision of two black holes [duplicate]

Inspired by If two black hole event horizons overlap (touch) can they ever separate again?, I was wondering what would happen if two black holes collided into each other in a head-on collision. In ...
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If two black hole event horizons overlap (touch) can they ever separate again?

Hypothetical question based on my understanding that two event horizons that overlap (touch) can't ever separate again: Imagine a 1 billion solar mass black hole (so the event horizon is massive and ...
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Why do things float in space, though the gravity of our star is always present? [closed]

In the solar system, things float around. We are so certain that the gravity of our sun exists. Still, why does that gravity not influence satellites and other objects there? Our solar system is also ...
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Could the largest SMBH swallow an entire galaxy?

It is unlikely that the largest supermassive black hole in the universe has already been discovered, there may be much larger ones. Are there, or could there be, supermassive black holes large ...
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Would Hubble Space Telescope improve black hole image observed by EHT if it joined array of telesopes?

My question is related to black hole image released in April. As far as I understand idea of EHT, it joins observations from multiple locations to work like one telescope with radius that is equal to ...
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How to convert the observed magnitude of a Quasar to it's bolometric luminosity?

How can I convert the observed magnitude to Bolometric Luminosity? I know the relation for the star but should it be same for a Quasar? Basically I want to convert the X-axis of this plot to ...
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Mass of Photon and Black holes [duplicate]

The gravity caused by a black hole is said to be so strong such that even light(photons) can not escape from it. since gravity exist only in between objects with mass, How does a black hole attract a ...
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Black hole density

How does more compression relate to a stronger gravitational pull. Like, when we say that a black hole is a tiny space that has 20-30 suns compressed in it, how does this increase its density and ...
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What is the actual resolution of Event Horizon Telescope?

I am quite impressed with the recently published image of M87* black hole. It appears that this image achieves spatial resolution well above and beyond what was available until today. But how high ...
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M87. What was the black hole before?

10 seconds before the M87 black hole was a black hole, what was it? A star 10 times the size of our solar system?