Cool, nebulous ring around Milky Way's supermassive black hole

Cool, nebulous ring around Milky Way's supermassive black hole
ALMA image of the disk of cool hydrogen gas flowing around the supermassive black hole at the center of our galaxy. The colors represent the motion of the gas relative to Earth: the red portion is moving away, so the radio waves detected by ALMA are slightly stretched, or shifted, to the "redder" portion of the spectrum; the blue color represents gas moving toward Earth, so the radio waves are slightly scrunched, or shifted, to the "bluer" portion of the spectrum. The crosshair represents the location of the black hole. Credit: ALMA (ESO/NAOJ/NRAO), E.M. Murchikova; NRAO/AUI/NSF, S. Dagnello

New ALMA observations reveal a never-before-seen disk of cool, interstellar gas wrapped around the supermassive black hole at the center of the Milky Way. This nebulous disk gives astronomers new insights into the workings of accretion: the siphoning of material onto the surface of a black hole. The results are published in the journal Nature.

Through decades of study, astronomers have developed a clearer picture of the chaotic and crowded neighborhood surrounding the at the center of the Milky Way. Our galactic center is approximately 26,000 light-years from Earth and the supermassive black hole there, known as Sagittarius A* (A "star"), is 4 million times the mass of our Sun.

We now know that this region is brimming with roving stars, interstellar dust clouds, and a large reservoir of both phenomenally hot and comparatively colder gases. These gases are expected to orbit the black hole in a vast accretion disk that extends a few tenths of a light-year from the black hole's event horizon.

Until now, however, astronomers have been able to image only the tenuous, hot portion of this flow of accreting gas, which forms a roughly spherical flow and showed no obvious rotation. Its temperature is estimated to be a blistering 10 million degrees Celsius (18 million degrees Fahrenheit), or about two-thirds the temperature found at the core of our Sun. At this temperature, the gas glows fiercely in X-ray light, allowing it to be studied by space-based X-ray telescopes, down to scale of about a tenth of a light-year from the black hole.

Cool, nebulous ring around Milky Way's supermassive black hole
Artist impression of ring of cool, interstellar gas surrounding the supermassive black hole at the center of the Milky Way. New ALMA observations reveal this structure for the first time. Credit: NRAO/AUI/NSF; S. Dagnello

In addition to this hot, glowing gas, previous observations with millimeter-wavelength telescopes have detected a vast store of comparatively cooler hydrogen gas (about 10 thousand degrees Celsius, or 18,000 degrees Fahrenheit) within a few light-years of the black hole. The contribution of this cooler gas to the accretion flow onto the black hole was previously unknown.

Although our black hole is relatively quiet, the radiation around it is strong enough to cause hydrogen atoms to continually lose and recombine with their electrons. This recombination produces a distinctive millimeter-wavelength signal, which is capable of reaching Earth with very little losses along the way.

With its remarkable sensitivity and powerful ability to see fine details, the Atacama Large Millimeter/submillimeter Array (ALMA) was able to detect this faint radio signal and produce the first-ever image of the cooler gas disk at only about a hundredth of a light-year away (or about 1000 times the distance from the Earth to the Sun) from the supermassive black hole. These observations enabled the astronomers both to map the location and trace the motion of this gas. The researchers estimate that the amount of hydrogen in this cool disk is about one tenth the mass of Jupiter, or one ten-thousandth of the mass of the Sun.

By mapping the shifts in wavelengths of this radio light due to the Doppler effect (light from objects moving toward the Earth is slightly shifted to the "bluer" portion of the spectrum while light from objects moving away is slightly shifted to the "redder" portion), the astronomers could clearly see that the gas is rotating around the black hole. This information will provide new insights into the ways that devour matter and the complex interplay between a black hole and its galactic neighborhood.

"We were the first to image this elusive disk and study its rotation," said Elena Murchikova, a member in astrophysics at the Institute for Advanced Study in Princeton, New Jersey, and lead author on the paper. "We are also probing accretion onto the black hole. This is important because this is our closest supermassive black hole. Even so, we still have no good understanding of how its accretion works. We hope these new ALMA observations will help the black hole give up some of its secrets."


Explore further

Hiding black hole found

More information: A cool accretion disk around the Galactic Centre black hole, Nature (2019). DOI: 10.1038/s41586-019-1242-z , https://www.nature.com/articles/s41586-019-1242-z
Journal information: Nature

Citation: Cool, nebulous ring around Milky Way's supermassive black hole (2019, June 5) retrieved 17 June 2019 from https://phys.org/news/2019-06-cool-nebulous-milky-supermassive-black.html
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Jun 05, 2019
Cool.

Jun 05, 2019
In search of black holes and dark matter astrophysicists are relying on indirect observations. It would seem that the measurement of the event horizon of a black hole directly would be a direct evidence. However, by the nature of a horizon, any real measurement of the event horizon will be indirect. The Event Horizon Telescope will get picture of the silhouette of the Sgr A* which is due to optical effects of spacetime outside of the event horizon. The result will be determined by the simple quality of the resulting image that does not depend on the properties of the spacetime within the image. So, it will be also indirect and an existence of BH is a hypothesis.
https://www.acade...ilky_Way
https://www.acade...and_Jets

Jun 05, 2019
existence of BH is a hypothesis.


no.

Jun 05, 2019
Last I heard the Event Horizon Telescope did not find a BH there.

Jun 05, 2019
That's like saying that, since I can only see light waves producing the image of a table, and not the table directly, tables area hypothesis.

Jun 05, 2019
thank you bert.
gor your cogent explanation pf how to observe & describe reality.

a waste of good pearls of wisdom before the denialist swine
but a good effort anyway to try to educate the dullards to the standards of scientific analysis.

the looneyticks will whinge about your moniker
BH is sin to their cult of ignorance.

Jun 05, 2019
Worth mentioning that the EHT merely failed to *image* the black hole; that's no proof it doesn't exist. Absence of evidence isn't evidence of absence, particularly when it's absence of only one kind of evidence and there are many others.

Jun 05, 2019
""We are also probing accretion onto the black hole. This is important because this is our closest supermassive black hole. Even so, we still have no good understanding of how its accretion works."

IIRC, the last time they mentioned Sgr*A, the images they took of it were too jittery, so they concentrated on M87 instead which looked more like a donut/bagel.
So not only does Sgr*A have a cool accretion disc, but they still had to hire an artist impressionist to show what they think it looks like?
But wait - this cool ring of Hydrogen gas is outside of the hot Event Horizon. Did I get that right? If so, is there any heat transfer going on between the 2 rings?

Jun 05, 2019
Looks like rrwillsj is still inadequate when it comes to discussing science, only preferring and being able to spout accusations and name-calling in her quest to remain somehow relevant to the discussions that the commentators are engaging in. Perhaps someday soon rrwillsj will get on her broomstick and fly to the far side of the moon to live with Chinese rovers.
We can only hope.

Jun 05, 2019
That's like saying that, since I can only see light waves producing the image of a table, and not the table directly, tables area hypothesis.
says Bert_Halls

Ahhh The tale of the table that wasn't there. How did that go again, Bert? How many times did you trip over the table before you recognised that it was real?

Jun 05, 2019
I encourage @rrwillsj to continue opposing the evidence-free assertions of anti-science trolls with assertions of his own. Tit for tat. If it bothers you perhaps you'll fuck off to somewhere else and we can talk about science without nutjobs who psychotically claim to be mind-reading aliens.

Jun 05, 2019
LOL rrwillsj is unable to talk about the science due to her preference for name-calling and abusive, inappropriate language. IF rrwillsj had any knowledge of science, she might not be so willing to imitate SpookyOtto1923 and CaptainDumpy's attack dog, Schneibo.
So THIS phorum is now ruined by the presence of the two.

Jun 06, 2019
Worth mentioning that the EHT merely failed to *image* the black hole; that's no proof it doesn't exist.
......there's no better way to prove it.

Jun 06, 2019
The similarity between black hole accretion discs and hurricanes on earth is uncanny, the presence of accretion discs can easily be explained by fluid dynamics caused by pressure differential in the galactic centre. Centrifugal force from galactic rotation leaves negative pressure in the core, the effect being material getting sucked into rotation abound the centre of the galaxy as a result of galactic rotation. So in effect we have an equilibrium between centripetal and centrifugal forces creating a rotating ring of matter in the galactic centre.

The question really becomes: What is a black hole? Is it a physical entity or is it a vacuumous region of space arising from pressure differential?

Jun 06, 2019
And no worse way to claim it's disproved.

Jun 06, 2019
the Atacama Large Millimeter/submillimeter Array (ALMA) was able to detect this faint radio signal and produce the first-ever image of the cooler gas disk at only about a hundredth of a light-year away (or about 1000 times the distance from the Earth to the Sun) .
........"faint radio signal" from a supposedly supermassive object they can't locate? It must not be quite the supermassive thing they have been trying to make us believe if the radio signal is so pathetically weak.

I see in the first so-called picture they had to colorize the radio signal in blue just like they did to create the MS87 radio wavelength Einstein Ring their hideous EHT algorithms produced.

Jun 06, 2019
not to feed the troll ...

but the "faint radio signal" was in reference to the cool hydrogen gas that is orbiting the supermassive black hole. It's hard to detect that faint signal because the gas is relatively cool given all the surrounding material and intermediate objects producing the same em wavelengths between us and it has to travel through all the dust and material at the center of the galaxy out to us - things that generally absorb the frequency of em waves emitted from cooler gasses.

If you're going to spout trollish dribble where everyone needs a burden of proof far greater if not impossible to achieve compared to your own personal one to be true/valid at least read the text.

Jun 06, 2019
well ds, i gotta say, thank you?

you've been the only one to recognize the 3-card monte game i've been inflicting on the looneyticks & woomongers.

grabbing the verminous likes of sillyegghead & benni & the rest

shoving their snouts into the pools of ignorant shit, they leave all over this site.

aillyegghead blubbers that i do not respond to it's anti-science cant with facts & evidence,

Seems rather a pointless exercise expecting any of the cretin posse to understand empirical evidence.

they are a bad lot of poorly coded circuitry emanating from the russian & saudi Dark Web sites.
with criminally treasonous intent when you include the antivaxxers, the nazis, the klanners, copperheads & quislings.

with the fakirs of pseudo-science such as silly & benni blatantly trying to extort Real Scientists through agitprop campaigns to shatter the Public belief in Science.

in addition to trying to subvert their way into corrupting the accredited peer-reviewed publications.

Jun 06, 2019
well ds, i gotta say, thank you?

you've been the only one to recognize the 3-card monte game i've been inflicting on the looneyticks & woomongers.

grabbing the verminous likes of sillyegghead & benni & the rest

shoving their snouts into the pools of ignorant shit, they leave all over this site.

aillyegghead blubbers that i do not respond to it's anti-science cant with facts & evidence,

Seems rather a pointless exercise expecting any of the cretin posse to understand empirical evidence.

they are a bad lot of poorly coded circuitry emanating from the russian & saudi Dark Web sites.
with criminally treasonous intent when you include the antivaxxers, the nazis, the klanners, copperheads & quislings.

with the fakirs of pseudo-science such as silly & benni blatantly trying to extort Real Scientists through agitprop campaigns..
sez rrwillsj

Providing us with yet another commentary filled with scientific knowledge of Astrophysics in clear layman's terminology.

Jun 06, 2019
the "faint radio signal" was in reference to the cool hydrogen gas that is orbiting the supermassive black hole. It's hard to detect that faint signal because the gas is relatively cool given all the surrounding material and intermediate objects producing the same em wavelengths
........sure, and the only place in the Universe this cool H gas can be found is only when a SMBH is nearby, right? And this to you proves a BH exists at SgrA* ?

I hate being the bearer of bad tidings to you, but cool H gas is the most common interstellar medium found everywhere in the Universe, and it moves around a lot forming new stars. And when it's moving around in recombination with electrons it gives up ENERGY, radio waves are ENERGY.

The center of the Milky Way is a nursery bursting with star birth, but you think these radio weak waves are the signature of a nearby BH? That H is in orbit around a crowded field of newly forming stars.

If you're going to spout trollish dribble......

Jun 07, 2019

Ahhh The tale of the table that wasn't there. How did that go again, Bert? How many times did you trip over the table before you recognised that it was real?


Ah, yes, I see it now.
So for the Milky Way SMBH, basically you are saying that we already have the proof we need through the orbital motions of a number of stars and S2 orbiting Sagittarius A*.

Nice :)


Jun 07, 2019
It's always amusing to see people claim to be skeptics then reject data. Skeptics don't reject data. Trolls and liar deniers reject data. Suck it up and admit what you are.

Jun 07, 2019

Ahhh The tale of the table that wasn't there. How did that go again, Bert? How many times did you trip over the table before you recognised that it was real?


Ah, yes, I see it now.
So for the Milky Way SMBH, basically you are saying that we already have the proof we need through the orbital motions of a number of stars and S2 orbiting Sagittarius A*.

Nice :)

........jonesy

Jun 07, 2019

Ahhh The tale of the table that wasn't there. How did that go again, Bert? How many times did you trip over the table before you recognised that it was real?


Ah, yes, I see it now.
So for the Milky Way SMBH, basically you are saying that we already have the proof we need through the orbital motions of a number of stars and S2 orbiting Sagittarius A*.

Nice :)

says the self-admitted homosexual, kl31415

I said no such thing. I was referring to the 'table' which Bert mentioned. You shouldn't read things into comments that haven't been explicitly said. Your imagination is working overtime, similar to your buttbuddy, Schneibo

Jun 07, 2019
Last I heard the Event Horizon Telescope did not find a BH there.
says Benni

They found a hot looking bagel or donut with a bit of a cream cheese-looking substance leaking out of the bagel. Or is it a SM muffin?
So they're done with M87 and are working to prove that SgrA* is another hot bagel or donut. Waiting is so hard to do.

Jun 07, 2019
Last I heard the Event Horizon Telescope did not find a BH there.

They found a hot looking bagel or donut with a bit of a cream cheese-looking substance leaking out of the bagel. Or is it a SM muffin?
So they're done with M87 and are working to prove that SgrA* is another hot bagel or donut. Waiting is so hard to do.
If you notice, they're not talking much about either.

What I think is happening is that because the M87 ring looked so exactly like an Einstein Ring that the EHT Team is having a really hard time pushing the BH concept. Couple this with the fact that SgrA* being immensely closer & they came up with ZERO data for that, all the while a majority of real scientists are very skeptically accepting the MS87 algorithm that was essentially an artist's illustration of what the EHT Team interprets as a BH casting further doubt on a BH at MS87.

Face it, if they can't even get data for something 26k ly away, what is the confidence level for one at 550 million?

Jun 07, 2019
When the Tate had the bricks, the sardine cans, the blank canvas and now Selfie...

Mathematics and Art are destined never to mix
Benni> What I think is happening is that because the M87 ring looked so exactly like an Einstein Ring that the EHT Team is having a really hard time pushing the BH concept

As long as these Artists Illustrations
Keep up with these plethora of outflows of hot air
Without a dreaded Selfie insight
We will all sleep soundly in our beds

Jun 07, 2019
As long as these Artists Illustrations
Keep up with these plethora of outflows of hot air
Without a dreaded Selfie insight
We will all sleep soundly in our beds
.....but not if that hooty owl shows up again at the tree line 100 feet from my bedroom window like it did at 3 AM last night, I'll shoot the damn thing. I even stuck my head out the window & yelled at the damn bird & it wouldn't shut the hell up.

Jun 08, 2019
Katie Bouman's Algorithmic redoubt

Assistant Professor
At Caltech
In computational imaging
Integrating algorithm
Sensor design
Making possible observing phenomena previously impossible to measure
Benni> What I think is happening is that because the M87 ring looked so exactly like an Einstein Ring Couple this with the fact that SgrA* being immensely closer & they came up with ZERO data
casting further doubt on a BH at MS87

For if Katie Bouman
Had seen through these advancing light years
An advancing army of light solders
Katie crouched in the safety of her redoubt
From these advancing light sabres
Was not in distance from these light sabres
Her safety was in close contact with these advancing light sabres
For if Katie reassessed her predicament in her redoubt
As Assistant Professor
Would have noticed
The closer Katie gets
To her BHs
The less they appear as BHs
As at 26 thousand Lys
We have the perfect example
SgrA*, Katie Bouman's Algorithmic redoubt

Jun 08, 2019
The closer Katie gets
To her BHs
The less they appear as BHs
As at 26 thousand Lys
We have the perfect example
SgrA*, Katie Bouman's Algorithmic redoubt
.......granDy, this is really good. Face it, if they can't even get data for something 26k ly away, what is the confidence level for one at 550 million?

Jun 08, 2019
Face it, if they can't even get data for something 26k ly away, what is the confidence level for one at 550 million?


Face it - who gives a toss about the musings of a scientifically illiterate cretin like you?

RNP
Jun 08, 2019
@Benni
Face it, if they can't even get data for something 26k ly away,
what is the confidence level for one at 550 million?


If you were actually interested in the answer to this question you would read, and try to understand, what the actual scientists said. Here is an explanation;

"Event Horizon Telescope director Shep Doeleman explains that Messier 87 is a better option, precisely because it is so far away. Thus, the supermassive black hole is more fixed in position and does not move from its spot in the sky compared to the much nearer Sagittarius A*.

Furthermore, BGR notes that with Sagittarius A* in the same galaxy as Earth, the scientists don't have an ideal vantage point of this black hole. There are too many cosmic objects in between the two with billions of stars, planets, and dust floating in the same flat disk of the Milky Way."


Jun 08, 2019
SgrA*, Katie Bouman's Algorithmic redoubt
The closer Katie gets
To her BHs
The less they appear as BHs
As at 26 thousand Lys
We have the perfect example
SgrA*, Katie Bouman's Algorithmic redoubt
.......granDy, this is really good Face it if they can't even get data for something 26kly away what is the confidence level for one at 550million

For on APRIL the 10th Astronomers deliver first photo of black hole
The overriding enthusiasm of the Caltech team
Their obvious enthusiasm to get off the set
For all the photographers
This limelight to begone
Is where these searching question in algorithmics began
This candle in this darkness
Katie Bouman's Algorithmic creation
For Katie diligently enlightened
As we have never seen a BH
We have only seen artist's interpretations of BHs
As all algorithms make all photographs the same
Katie explained
We manipulated this algorithm
Till it matches
This artist's impression
We have become accustomed to seeing
BHs as we imagine them

Jun 08, 2019
For every BH in its Galactic Galaxies Centre

RNP
This sage in the life and styles of BHs
Furthermore
BGR notes that with Sagittarius A*
In the same galaxy as Earth
The scientists don't have an ideal vantage point of this black hole
There are too many cosmic objects
In between the two
With billions of stars
Planets
And dust floating in the same flat disk of the Milky Way

A well thought out and correct conclusion, RNP
As you have correctly concluded these are the conditions all Galactic BHs reside
That in case you have failed to notice
Sagittarius A* and M87 also are equally shrouded in your conclusions

Sagittarius A* and M87 are equally shrouded in this veil of dusty secrecy
And RNP, if truth be told
As M87 is further from planet earth than Sagittarius A*
M87 is harder to see
Because
M87 being further, is shrouded in billions of more stars
That are occupying this vacuous vacuum, RNP

Jun 08, 2019
@Benni
Face it, if they can't even get data for something 26k ly away,
what is the confidence level for one at 550 million?


If you were actually interested in the answer to this question you would read, and try to understand, what the actual scientists said. Here is an explanation;

"Event Horizon Telescope director Shep Doeleman explains that Messier 87 is a better option, precisely because it is so far away. Thus, the supermassive black hole is more fixed in position and does not move from its spot in the sky compared to the much nearer Sagittarius A*.

Furthermore, BGR notes that with Sagittarius A* in the same galaxy as Earth, the scientists don't have an ideal vantage point of this black hole. There are too many cosmic objects in between the two with billions of stars, planets, and dust floating in the same flat disk of the Milky Way."

says RNP

All the more reason to consider that it may not BE a Black Hole at all then. Just not enough evidence.

Jun 13, 2019
says the self-admitted homosexual, kl31415

I said no such thing. I was referring to the 'table' which Bert mentioned. You shouldn't read things into comments that haven't been explicitly said. Your imagination is working overtime, similar to your buttbuddy, Schneibo


Definitely better than the self admitted incubator of alien astral projections...
Indeed, if you would state this to a doctor, you would definitely be admitted in an institution ;)

Homophobia is very often :
- a sign of the individual trying to deny his own homosexuality
- a sign of an intellectually challenged religious nutcase
- or both

Although not sure how it works with self hating schizophrenic individuals such as @StupidEgg.

If only you could understand the stupidity you supply to this forum @StupidEgg, you might actually have more than an imaginary friend in this life...

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