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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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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Ideas about the origin of the “black hole - galaxy mass” relation?

It has been extensively shown that the mass of black-holes located at the center of galaxies scales with several galaxy properties, most notably the stellar velocity dispersion of the stellar bulge, ...
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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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1answer
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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?
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Can a star fall in a super massive black hole without getting destroyed?

This is the first of many similar questions I have to build up to a specific question or scenario that I want to explore and find an answer to.
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Event Horizon Telescope Data Cleanup

I was wondering how the researchers were able to minimize or neutralize confirmation bias regarding the data collected? As I understand it, the algorithm pruned much of the data, which would make ...
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Does the “photo of a black hole” taken by EHT actually depict a visible light-based scenario?

I'm still at my bachelor of electronic and communications engineering, so I'm not an expert of radiotelescopes; however, I surely know that, typically, radio communications are characterized by a RX ...
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Why not take a picture of a closer black hole?

There are closer galaxies than Messier 87 for sure, even ours! It sparked my curiosity that they went with one 53 million light years away. Is there a reason for this?
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What is the orientation of the M87 black hole image relative to the jet?

On the image of the M87 black hole released today by the Event Horizon Telescope team, which direction points towards the jet? Is it on the brighter side of the ring? To resolve ambiguity, I'm ...
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Why didn't the Event Horizon Telescope team mention Sagittarius A*?

At the press conference this morning, the Event Horizon Telescope team didn't say much about Sagittarius A*, which was the target many of us have been waiting for. Is there any explanation anywhere ...
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Are gravitational waves part of dark energy?

Do the current models of the universe consider the energy release of gravitational waves? E.g. iirc, the last black hole merger detected had a gravitational wave energy equal to ~3 solar masses (hope ...
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Quantum tunneling in black holes

My hypothesis is: "quantum tunneling in black hole". The matter which is consumed by a black holes is shifting to another part of the universe by quantum tunneling. Can it be possible?
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What happens if a black hole is produced inside another black hole?

Similar question here. The question I linked got me thinking. It is known that a black hole doesn't let anything escape its event horizon, not even light. Thus, naturally, anything that passes the ...
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What would happen if a star went supernova inside a supermassive black hole? [closed]

A black hole swallows a star. The star remains intact. Then goes supernova. What would happen to the star? Could we detect this event?
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How did they make a video of the center of the galaxy, and what is it exactly that's flashing there?

The ESA video ESOcast 173: First Successful Test of Einstein’s General Relativity Near Supermassive Black Hole includes a clip of images of stars at the center of our galaxy orbiting around SgrA*, a ...
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Black hole, escape velocity, going up?

I do know nothing can escape a black hole, and I understand popsci explanation of geodesics of space-time around and inside the event horizon. I however have some trouble with following thought ...
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1answer
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How to convert factors of time dilation into something relatable? [duplicate]

On this post, Time according to the gravity of Sagittarius A? They found the factor of time on the varying distances from the SMBH, I am curious on how to turn those factors into relatable terms ...
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What is it exactly about these flares of infrared light from Sgr A* that “confirms” it is a supermassive black hole?

CNET.com's SCI-TECH Scientists confirm a 'supermassive black hole' at the heart of our galaxy It's "mind-boggling", they say. This links to Astronomy.com's Scientists finally confirm the Milky Way ...
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What defines the plane of an accretion disk around a black hole?

The question Do we know at which angle the Event Horizon Telescope will look at the accretion disk of Sagittarius A*? about just how close to edge-on we would be viewing any accretion disk around the ...
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Do we know at which angle the Event Horizon Telescope will look at the accretion disk of Sagittarius A*?

Do we know at which angle the Event Horizon Telescope will look at the accretion disk of Sagittarius A*? Additionally, would it matter if we are exactly in the plane with the accretion disk, i.e. ...
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Can a black hole be torn apart by SMBHs?

Suppose two SMBHs (supermassive black holes) are brought close (e.g. during a galactic merger). Suppose that a "normal" black hole drifts into the space between the SMBHs. Could the gravitational pull ...
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Why smaller black holes are considered to be more dangerous than bigger black holes?

More massive the body is more is the gravity.Still often smaller black holes are considered to be very dangerous than the bigger ones,why?
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What will happen to the shape of a galaxy when a super massive black hole lying in its center dies(evaporates out)?

What's at the Center of the Milky Way? In this article it is said that a supermassive black hole lies in the center of milky way galaxy. At its center, surrounded by 200-400 billion stars and ...
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Why black holes are extremely cold?

"The most massive black holes in the Universe, the supermassive black holes with millions of times the math [sic] of the Sun will have a temperature of 1.4 x $10^{-14}$ Kelvin. That's low. Almost ...
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If a black hole has a mass of a universe what will be the volume of it?

Will it suck the entire universe in? What will the black hole look like to us, assuming we do not immediately get sucked in?
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Why is frequency different for gravitational waves coming from SMBHs vs small compact binaries?

Why do gravitational waves emitted by supermassive black holes binaries have low-frequency range (~10$^{-9}$ - 10$^{-2}$ Hz) than those emitted by stellar mass compact binaries (~10$^{-4}$ - 10$^2$ ...
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Singularity at the time of origins

According to the big Bang Theory, the universe have started from a point and it describes how the universe expanded from a very high-density and high-temperature state.The initial singularity was a ...
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Gravitational eddies across the galaxy?

I read about natural gravitational eddies that travel in a wave that black holes have. They also have a strong magnetic field. Does those eddies follow magnetic field lines of the rotating black hole? ...
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Is it possible that quasars are not powered by black holes but some other kind of compact, massive object?

AFAIK, objects in the universe thought to be black holes show evidence of radiatively inefficient accretion flow. But is this the case with Quasars? If not, is there a possibility that the core of a ...
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Black holes and super massive black holes [duplicate]

What is the difference between a black hole and a super massive black hole?
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Why is Sagittarius A* called so?

At the center of the Milky Way, we have a supermassive black hole. It's name is "Sagittarius A*". I was wondering that why is it called so? I mean, why "A*" why not just "A". Is there a naming system ...