Study Finds Sgr A* Black Hole's Actual Age and How It Was Formed

Summary

This video explores the recent findings about Sagittarius A*, the Milky Way's central black hole. The study by Wang and Jang suggests that the black hole's unusual spin is due to a massive collision with another black hole approximately 9 billion years ago, likely from the Gaia Enceladus Galaxy. This discovery supports the hierarchical black hole growth theory, providing evidence for how supermassive black holes can reach enormous sizes and potentially allowing us to predict future mergers.

Takeaways

• 🌌 The video discusses recent discoveries about the central black hole of the Milky Way, Sagittarius A*.
• 📸 The iconic Event Horizon Telescope captured an image of this black hole, which led to a Nobel Prize.
• 🔍 A study by Wang and Jang focuses on how Sagittarius A* was most likely formed and when it was formed.
• 🌟 The researchers potentially discovered the origin story of Sagittarius A*, answering questions about massive black hole formations.
• 🌌 The black hole in the Milky Way is relatively close to Earth, allowing detailed observations not possible with more distant black holes.
• 🌠 Observations have revealed that Sagittarius A* has unusual emissions and occasional major eruptions.
• 🌪️ The energy from the black hole sometimes forms 'chimneys' and exhaust vents, but these do not significantly contribute to its mass.
• 🌌 Sagittarius A* is not growing significantly from the destruction of stars, suggesting it must have grown to its current size through other means.
• 💥 The study suggests that Sagittarius A* grew through a massive black hole collision, a process previously lacking evidence.
• 🌀 The black hole's unusual spin is evidence of a past collision, likely with the Gaia Enceladus Galaxy around 9 billion years ago.
• 📈 This discovery supports the hierarchical black hole growth theory and suggests that we might witness similar collisions in the future.

Q & A

What is the name of the black hole at the center of the Milky Way galaxy?

The black hole at the center of the Milky Way galaxy is called Sagittarius A*.

What recent discovery about Sagittarius A* is discussed in the video?

The recent discovery discussed in the video is how Sagittarius A* was most likely formed and when it was formed, based on a study by Wang and Jang.

What is the mass of Sagittarius A* compared to other black holes?

Sagittarius A* has a mass of just over 4 million solar masses, which is relatively small compared to other black holes like the one in the middle of the M87 galaxy, which is closer to 6 billion solar masses.

How far away from Earth is Sagittarius A*?

Sagittarius A* is approximately 26,000 light years away from Earth.

What types of emissions can be observed from Sagittarius A*?

Sagittarius A* produces emissions that can be observed in X-rays, infrared, and radio wavelengths.

How often does Sagittarius A* have major eruptions?

It is believed that Sagittarius A* has at least one major eruption every few hundred years.

What is the role of the 'chimneys' discovered in the vicinity of Sagittarius A*?

The 'chimneys' are structures through which a lot of energy from the black hole is guided and eventually released all at once.

What evidence suggests that Sagittarius A* grew through collisions?

The evidence comes from the spin of Sagittarius A*, which is unusual and misaligned with the rest of the Galaxy, suggesting it resulted from a massive collision.

What was the mass ratio of the black holes in the collision that formed Sagittarius A*?

The mass ratio of the black holes in the collision that formed Sagittarius A* was about 4 to 1.

How long ago is the Gaia Enceladus Galaxy believed to have merged with the Milky Way?

The Gaia Enceladus Galaxy is believed to have merged with the Milky Way approximately 9 billion years ago.

What is the hierarchical black hole growth theory mentioned in the video?

The hierarchical black hole growth theory suggests that massive black holes grow by colliding and merging with other black holes.

Outlines

00:00

🌌 Discovery of the Milky Way's Central Black Hole Origin

This paragraph discusses recent findings about the central black hole of the Milky Way, known as Sagittarius A*. The iconic Event Horizon Telescope captured an image of this black hole, which was a significant achievement that led to a Nobel Prize. The focus is on a study by Wang and Jang that explores the formation and origin of Sagittarius A*. The researchers examined details that were previously overlooked, potentially uncovering the black hole's origin story. The video also touches on the broader question of how massive black holes formed in the universe billions of years ago. Observations from the Event Horizon Telescope have allowed scientists to draw conclusions about Sagittarius A*, despite it being relatively small compared to other black holes in the universe. The black hole's mass is over 4 million solar masses, and it is located just 26,000 light-years away from Earth, providing an opportunity to observe details that would be invisible in more distant black holes. The paragraph also mentions the various emissions from the black hole across different wavelengths, such as X-rays, infrared, and radio waves, and how these emissions provide insights into the black hole's activity and its impact on the surrounding environment.

05:00

🌀 Unraveling the Spin Mystery of Sagittarius A*

The second paragraph delves into the unusual spin characteristics of Sagittarius A*, which spins rapidly and is misaligned with the rest of the Milky Way galaxy. This misalignment suggests that the black hole's spin axis does not align with the galactic disc, hinting at a possible massive collision in its past. Scientists used this evidence to create models based on the assumption that the misalignment was due to such a collision. Their models suggest a merger between two black holes with a mass ratio of about 4 to 1, occurring at an inclination of approximately 145 to 180°. This collision is believed to have resulted from the Gaia Enceladus Galaxy merging with the Milky Way around 9 billion years ago. This merger not only added significant mass to the Milky Way but also played a crucial role in finalizing the mass of Sagittarius A*. The event likely triggered a period of star formation and altered the shape of the Milky Way's disc, making it thicker and contributing to the formation of global clusters like NGC 20808. The study provides evidence for the hierarchical black hole growth theory, suggesting that massive black holes grow through collisions. This discovery is significant as it offers a potential explanation for the unusual spin of Sagittarius A* and supports the idea that such collisions are not only possible but also relatively frequent, with predictions that another such event could be observed within the next decade.

Keywords

💡Event Horizon Telescope

The Event Horizon Telescope (EHT) is a virtual Earth-sized telescope that combines data from multiple radio telescopes around the world to observe black holes. In the video, it is mentioned as the instrument that captured the image of the black hole at the center of the Milky Way, Sagittarius A*, providing crucial evidence for the study of black holes.

💡Sagittarius A*

Sagittarius A* is the supermassive black hole at the center of the Milky Way galaxy. The video discusses recent discoveries about its formation and characteristics. It is a key subject of the video, with the script mentioning how its image was captured and its role in understanding black hole formation.

💡Black Hole Formation

Black hole formation refers to the process by which a black hole comes into existence. The script discusses the discovery of how Sagittarius A* was most likely formed, which is a major focus of the video. It ties into the broader theme of understanding the origins of massive black holes in the universe.

💡Massive Black Holes

Massive black holes are black holes with a mass greater than a certain threshold, often millions or billions of times the mass of the Sun. The video explores how these black holes form and grow, with Sagittarius A* being a comparatively smaller example in comparison to others like the one in the M87 galaxy.

💡Cosmology

Cosmology is the study of the origin and evolution of the universe. The script mentions it in the context of scientists trying to understand how massive black holes formed billions of years ago, which is a significant question in modern cosmology.

💡X-ray Detections

X-ray detections refer to the observation of X-ray emissions from celestial bodies. In the video, it is mentioned that recent X-ray detections have shown a sudden brightening near Sagittarius A*, indicating activity that could be related to the black hole's behavior.

💡Emissions

Emissions in the context of the video refer to the release of energy from the black hole in the form of radiation, such as X-rays, infrared, and radio waves. The script discusses how emissions from Sagittarius A* have been observed and studied to understand the black hole's activity.

💡Chimneys

Chimneys, as used in the script, are unusual formations discovered in studies of black holes, which guide energy and result in exhaust vents releasing energy. The video suggests that these structures provide insights into the processes occurring near the black hole.

💡Accretion

Accretion is the process by which matter accumulates and collects around a massive object, like a black hole. The video discusses accretion as one of the potential means by which black holes grow, although it is suggested that it might not be sufficient to account for the size of some black holes.

💡Black Hole Collision

A black hole collision refers to the event where two black holes merge due to their gravitational attraction. The video presents evidence that Sagittarius A* may have formed as a result of such a collision, which is a significant discovery for understanding black hole growth.

💡Gaia-Enceladus Galaxy

The Gaia-Enceladus Galaxy is a hypothetical galaxy that is believed to have merged with the Milky Way about 9 billion years ago. The video suggests that this merger could have contributed to the formation and growth of Sagittarius A*, providing a timeline and context for the black hole's origins.

Highlights

Recent discoveries about the central black hole of the Milky Way galaxy.

Discussion on the black hole image captured by the Event Horizon telescope.

The black hole's discovery led to the Nobel Prize a few years ago.

Study by Wang and Jang reveals how the black hole was most likely formed.

Researchers potentially discovered the origin story of Sagittarius A*.

Exploration of how massive black holes formed billions of years ago.

Observations from the Event Horizon telescope provide insights into the black hole.

Sagittarius A* has a mass of over 4 million solar masses.

Comparison of Sagittarius A* to the black hole in the M87 galaxy.

Visualization of the size difference between black holes.

Sagittarius A* allows observation of additional details due to its proximity.

Detection of various emissions from the black hole in different wavelengths.

Discovery of signs of previous emissions by observing echoes from gas around the black hole.

Observation of a star approaching the black hole and being disrupted.

Discovery of unusual formations called 'chimneys' guiding energy release.

Calculation of the amount of mass the black hole consumes annually.

Theories on how black holes grow: accretion of matter or massive black hole collision.

The final parac problem: lack of evidence on how supermassive black holes collide.

First piece of evidence suggesting black holes grow through collisions.

Observations from the Event Horizon telescope show the spin of Sagittarius A*.

The black hole's unusual spin suggests a massive collision in its past.

Modeling suggests a merger between two black holes with a 4 to 1 mass ratio.

The Gaia Enceladus Galaxy merged with the Milky Way approximately 9 billion years ago.

The merger likely resulted in a star-forming period and changed the shape of the Milky Way.

The hierarchical black hole growth theory gains evidence from Sagittarius A*'s formation.

The study suggests we may witness a black hole merger event within the next 10 years.

The discovery provides insights into the evolution of the Milky Way and the formation of its black hole.

Transcripts

hello INF full person this is Anton and

in this video we're going to discuss

some of the recent discoveries in

regards to the central black hole of the

Milky Way galaxy the black hole whose

image was captured by the iconic Event

Horizon telescope and the black hole

whose Discovery led to the Nobel Prize

just a few years ago and in the last few

months there's actually been a few

discoveries about the black hole but

today we're going to focus on one of the

major discoveries the discovery coming

from this study by Wang and Jang that in

essence discovers how our black hole was

most likely formed and when it was

formed by focusing on certain details

that were previously ignored and so in

other words the researchers behind the

study potentially discovered the origin

story of the Sagittarius AAR that's of

course the name for this black hole

while also to some extent answering a

few questions about the formations of

massive black holes which is actually

one of the major questions in modern

cosmology because scientists today are

trying to understand how these Giants

formed billions of years ago and what

exactly caused some of them to grow to

enormous sizes sometimes billions of

solar masses in Mass but in order to try

to start answering these questions we

obviously have to understand the central

black hole of our own Galaxy just a

little bit better and well thanks to the

observations from the Evan Horizon

telescope we can finally start making

certain conclusions although I guess the

the thing is even though this is the

closest super massive black hole to

planet Earth it's not particularly big

compared to a lot of other black holes

in other galaxies here the mass is just

over 4 million solar masses whereas the

black hole in the middle of m87 galaxy

is actually closer to 6 billion solar

masses and so there's definitely a

tremendous difference here's actually a

really intriguing visualization showing

us this size comparison but because

Sagittarius AAR is only 26,000 light

years away from us which is relatively

close when it comes to black holes it

actually allows us to see a lot of

additional details that would be

invisible for any other black hole out

there for example we can observe various

emissions in the x-rays infrared and

radio wheel lengths which we know this

black hole produces once in a while for

example here's one of the recent x-ray

detections showing us a sudden

brightening in the x-rays and a lot of

previous studies that focused on the

environment around this black hole

actually discovered signs of previous

emissions by observing various Echo

coming from the gas around the black

hole there was hundreds and thousands of

light years away and as a result today

we know that every few hundred years

there seems to be at least one major

eruption possibly the result of some

kind of a star approaching the black

hole Too Close being disrupted in the

process but this process of shredding

and destruction of stars despite being

relatively powerful does not actually

contribute enough Mass to the black hole

itself and that's because the majority

of mass ends up being ejected from the

black hole or turned into energy and

interestingly in one of the recent

studies researchers even discovered how

a lot of this energy seems to be guided

by something resulting in these unusual

formations scientists now refer to as

chimneys that eventually result in

various exhaust vents where a lot of

this energy is suddenly released all at

once but by observing the amount of

energy released here we can obviously

calculate the amount of mass of black

hole consumes every single year and well

it's actually quite minuscule as a

matter of fact if the black hole was

consuming this much mass it would not

grow to these sizes even after a 100

billion years and so even though we

found structures like the firy bubbles

you see right here that suggest very

powerful emissions even if these

emissions were happening every single

year the black hole would still not

really be big enough so it must have

grown to its current size through some

other means and right now we only think

there are possibly two means for black

holes to grow either accretion of matter

over time which as I just mentioned

potentially doesn't actually add enough

of mass or a massive black hole

collision and this is of course where we

don't really have any evidence as a

matter of fact this even results in

what's known as the final parac problem

it's basically an astrophysical Paradox

where the scientists don't actually know

how two super massive black holes could

possibly Collide you can learn more

about this in one of the videos any

description but as of today there's

almost a complete lack of evidence that

super massive black ho can Collide and

can thus grow larger yet we know super

massive black hos get really big so how

exactly do they do this and looks like

we finally have our first piece of

evidence from right here in the Milky

Way and the answer seems to be

collisions after all but how exactly do

we know this and what exactly is this

evidence and turns out that all of this

evidence was in these observations from

The Event Horizon telescope and it's the

evidence that shows us the spin of the

black hole turns out Sagittarius AAR is

just a little bit unusual it seems to

spin really fast but also in a little

bit of a misalign way compared to the

rest of the Galaxy in other words it

doesn't actually spin on the same axis

as the galactic disc itself and this was

enough evidence for the scientist behind

his paper to start crunching numbers and

to start producing models with basically

just one assumption the Assumption being

that this misalignment was the result of

a massive collision and so following a

bunch of models they finally discovered

one that seemed to fit the observations

here this was a merger between two

relatively massive black holes with a

mass ratio of about 4 to one so

essentially one of these black holes was

about four times as massive and the

Collision itself very likely happened

with the inclination of about 145 to

180° formed by the line of sight from

planet Earth and turns out that this

Collision basically replicates exactly

what we observe here and by having this

inclination and basically by knowing how

this small Galaxy possibly orbited

around the Milky Way they now think they

know exactly what happened and when this

is now believed to be the result of the

Gaia Enceladus Galaxy the signs of which

were discovered around the Milky Way

several years ago that merged with the

Milky Way approximately 9 billion years

ago and this seems to have been the last

major merger in the Milky Way adding a

huge amount of mass to the Galaxy but

also finalizing the mass of our black

hole and intriguingly this Collision

very likely resulted in a star forming

period that lasted for a few hundred

million years but also changing the

shape of the disc of the Milky Way

making it much thicker and also adding a

few Global clusters such as NGC 20808

you see right here and so it was very

likely the result of this merger that

basically fin Iz the Milky Wass black

hole suggesting that the black hole

itself kind of formed 9 billion years

ago and right now this is the best

explanation we have for the unusual spin

of Sagittarius A star and naturally if

the study here is correct it also

provides us with very important evidence

for how massive black holes most likely

grow and how they reach these massive

sizes this is actually known as the

hierarchical black hole murder Theory

and you can learn a little bit more

about it in one of the papers in the

description and and though technically

this is probably the most accepted

Theory up to this point there was just a

complete lack of evidence but now we

have some evidence from our own black

hole which provides us with some really

important answers and it technically

even tells us how frequent these

collisions are around the entire

universe in other words by learning that

9 billion years ago Sagittarius A star

was formed as a result of a merger we

can now infer a merger rate allowing us

to potentially detect one of these

events sometimes in the future and so

the conclusion from this paper is that

we should be seeing at least one of

these events sometimes in the near

future possibly within the next 10 years

but at least for now this is still a

pretty important discovery that helps us

understand the evolution of our own

Galaxy and naturally provides us with

more details for when the massive black

hole in the Milky Way actually formed

with the date being approximately 9

billion years ago but I'm sure in the

next few months we're going to discover

even more details and learn so much more

about Sagittarius AAR and what's

happening in its vicinity and so if

you'd like to learn more make sure to

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