Big Announcement coming soon from the Event Horizon Telescope about our galaxy.

[walterpthefirst]

https://www.sciencealert.com/astronomers-are-about-to-make-a-massive-announcement-about-the-milky-way

 

For the sake of context, the Event Horizon Telescope is a linked system of radio telescopes from all corners of the world.

 

https://eventhorizontelescope.org/

 

In 2019 they unveiled an image of the super massive black hole in the centre of M87, a nearby galaxy.

 

Please keep May 12 free to tune in to live broadcasts.

 

https://www.eso.org/public/announcements/ann22006/

 

Thank you.

 

Walter.

[pantheory]

Sounds cool.  With a name like the Event Horizon telescope, they have distinguished the event horizon of Andromeda galaxies large central galactic black hole and are working on observing the huge central black hole of our own galaxy called Sagittarius A.   This radio-scope consists of a large array of radio-scopes around the world working in synchronicity via computers and image collecting devices.  These radio scopes collectively could picture of our galactic black hole as a circular glowing disk with a doughnut hole center like the picture they took of Andromeda galaxy's central black hole in 2019. Astronomical objects that have a changing magnetic field can produce radio waves such as  galactic black holes and polar jets coming from them.

 

For the Event Horizon scopes, such a big planned announcement event about the Milky Way would need to be something that has never been seen before. It is unexpectedly a "picture" of our own galaxy's central black hole Sagittarius A, which would be a visual image made from radio waves. But I guess their announcement could be of another large radio wave emitter in our galaxy, which could be even more surprising.

[walterpthefirst]

https://www.eso.org/public/images/eso2208-eht-mwa/

 

The diameter of the Sagittarius A*  (Sag A-Star) black hole at the centre of the Milky Way galaxy was quoted as being equivalent to the diameter of the orbit of the planet Mercury.  Which would be approximately 58,000 kilometres.  This is in excellent agreement with the diameter inferred from the movement of the S-Stars around Sag A*.

 

 https://en.wikipedia.org/wiki/Sagittarius_A*_cluster

 

Thank you.

 

Walter.

[pantheory]

From the amalgamated image, the surrounding groupings of stars and gas appear to form a triad grouping that also appear to orbit their mutual centers of gravity as well as the central black hole. Or course this is side view of it and a 2D image of a 3D entity. Our view and perspective of it is formed from within the Milky Way disc Whereas it should appear to be more symmetrical from a perspective above or below the galaxy,  90⁰ from our observation perspective along the plane of our galactic disc, which probably would produce an image more like our view of the central black hole of Andromeda.

[walterpthefirst]

Pantheory,

 

I'm by no means an expert here, but if memory serves what we are seeing is what's called the photon ring (or photon sphere in 3D) of Sag A*.

 

https://en.wikipedia.org/wiki/Photon_sphere

 

Therefore, those three bright regions cannot be the locations of stars, but are more likely knots of gas forming standing waves in the accretion disk, just before they disappear over the event horizon.  Because they are quantum-scale objects photons do not 'feel' the gravitational shearing forces that gravitationally-bound collections of molecules (i.e., stars) would.  Gases can deform, be compressed or be stretched by Sag A*'s gravity because they have no internal structure to lose.

 

But stars are spheres of differentiated, increasingly dense plasmas held together by mutual gravitational attraction.  They would have been tidally disrupted by the black hole's immense gravity far outside the limits of the image we are seeing.

 

https://en.wikipedia.org/wiki/Tidal_disruption_event

 

Finally, the theory of Luminet and Carter was confirmed by the observation of spectacular eruptions resulting from the accretion of stellar debris by a massive object located in the heart of the AGN (e.g. NGC 5128 or NGC 4438) but also in the heart of the Milky Way (Sgr A *).

 

Thank you.

 

Walter.

 

 

 

 

[pantheory]

42 minutes ago, walterpthefirst said:

Pantheory,

 

I'm by no means an expert here, but if memory serves what we are seeing is what's called the photon ring (or photon sphere in 3D) of Sag A*.

 

https://en.wikipedia.org/wiki/Photon_sphere

 

Therefore, those three bright regions cannot be the locations of stars, but are more likely knots of gas forming standing waves in the accretion disk, just before they disappear over the event horizon.  Because they are quantum-scale objects photons do not 'feel' the gravitational shearing forces that gravitationally-bound collections of molecules (i.e., stars) would.  Gases can deform, be compressed or be stretched by Sag A*'s gravity because they have no internal structure to lose.

 

But stars are spheres of differentiated, increasingly dense plasmas held together by mutual gravitational attraction.  They would have been tidally disrupted by the black hole's immense gravity far outside the limits of the image we are seeing.

 

https://en.wikipedia.org/wiki/Tidal_disruption_event

 

Finally, the theory of Luminet and Carter was confirmed by the observation of spectacular eruptions resulting from the accretion of stellar debris by a massive object located in the heart of the AGN (e.g. NGC 5128 or NGC 4438) but also in the heart of the Milky Way (Sgr A *).

 

Thank you.

 

Walter.

 

 

 

Yes, what we are seeing is part of the photon sphere but not like the one we observed in Andromeda because we are looking at a side view of a doughnut shaped object. The surrounding light that we see is probably on the top and bottom of the doughnut. For Andromeda we are able to look from a much better perspective angle. Like I said above, if we could look at our central black hole from above or below our galaxy, which we cannot do, it would likely look more like Andromeda's central black hole.

[walterpthefirst]

Pantheory,

 

Could you please post a link to where your information about the Andromeda supermassive black hole originates.

 

I'm not calling what you say into question, btw.

 

It's just that the Andromeda data has passed me by.

 

Thank you.

 

Walter.

[pantheory]

30 minutes ago, walterpthefirst said:

Pantheory,

 

Could you please post a link to where your information about the Andromeda supermassive black hole originates.

 

I'm not calling what you say into question, btw.

 

It's just that the Andromeda data has passed me by.

 

Thank you.

 

Walter.

 

Our radio telescopic preliminary "images" of Andromeda's galactic Black Hole, and related information. First ever complete image of central Black Hole M87

[walterpthefirst]

2 hours ago, pantheory said:

 

Our radio telescopic preliminary "images" of Andromeda's galactic Black Hole, and related information. First ever complete image of central Black Hole M87

 

Sorry to be awkward Pantheory, but your link seems to give results that fall into two categories.

 

Stellar mass black holes in M31, the Andromeda galaxy and the Event Horizon Telescope image of the supermassive black hole in M87, that was discovered in 2019.

 

The photon rings of stellar mass black holes in Andromeda would not be visible, even to the EHT.

 

This link says that a supermassive black hole has been detected in Andromeda, but gives no information about images of its photon ring.

 

https://en.wikipedia.org/wiki/Andromeda_Galaxy

 

So I'm a bit of a loss to understand why you mentioned a donut-shaped photon ring in Andromeda.

 

 

Walter.

 

 

 

 

[LogicalFallacy]

Scientists unveil first image of 'gentle giant' black hole at Milky Way's centre | Newshub

 

I think this is what the two of you are referencing? 

[pantheory]

17 hours ago, walterpthefirst said:

 

Sorry to be awkward Pantheory, but your link seems to give results that fall into two categories.

 

Stellar mass black holes in M31, the Andromeda galaxy and the Event Horizon Telescope image of the supermassive black hole in M87, that was discovered in 2019.

 

The photon rings of stellar mass black holes in Andromeda would not be visible, even to the EHT.

 

This link says that a supermassive black hole has been detected in Andromeda, but gives no information about images of its photon ring.

 

https://en.wikipedia.org/wiki/Andromeda_Galaxy

 

So I'm a bit of a loss to understand why you mentioned a donut-shaped photon ring in Andromeda.

 

 

Walter.

 

 

Most of my explanations above refer to the M87 central black hole, not Andromeda's which I mistakenly referred to. We are looking at M87 almost face on, which I referred to as a 90⁰ angle. We are looking at Andromeda at maybe a 35⁰ to 40 ⁰ angle, which makes it more difficult to observe its details and its central black hole than M87, but not as difficult as our own galactic black hole which we are trying to look at edge on, while looking through the galactic disc -- sounds even harder to me.

 

Some ground grouping of radio scopes have looked at Andromeda and have made tentative observations of its central black hole but that was not what I was mistakenly referring to. The link I posted was a google search of the Andromeda central black hole, What I originally saw, not too long ago, was probably observations and simulations combined, involving the word "preliminary."

 

This is a similar link regarding the news, but without the same "simulated" picture.

 

https://chandra.harvard.edu/press/00_releases/press_011400m31.html

[walterpthefirst]

9 hours ago, LogicalFallacy said:

Scientists unveil first image of 'gentle giant' black hole at Milky Way's centre | Newshub

 

I think this is what the two of you are referencing? 

 

Umm... I can't speak for anyone else LF, but when I click on your link I get this message...

 

Sorry!  This content is not available in your region.

 

 

 

[walterpthefirst]

7 hours ago, pantheory said:

 

Most of my explanations above refer to the M87 central black hole, not Andromeda's which I mistakenly referred to. We are looking at M87 almost face on, which I referred to as a 90⁰ angle. We are looking at Andromeda at a 45⁰ to 50⁰ angle, which makes it more difficult to observe than M87, but not as difficult as our galactic black hole which we are trying to look at edge on, while looking through the galactic disc -- sounds even harder to me.

 

Some ground grouping of radio scopes have looked at Andromeda and have made tentative observations of its central black hole but that was not what I was mistakenly referring to. The link I posted was a google search of the Andromeda central black hole, What I originally saw, not too long ago, was probably observations and simulations combined, involving the word "preliminary."

 

This is a similar link regarding the news, but without the same "simulated" picture.

 

https://chandra.harvard.edu/press/00_releases/press_011400m31.html

 

Ok, thanks Pantheory.

 

I understand now.

 

Walter.

[pantheory]

16 hours ago, LogicalFallacy said:

Scientists unveil first image of 'gentle giant' black hole at Milky Way's centre | Newshub

 

I think this is what the two of you are referencing? 

 

Howdy LF,  Haven't seen your postings for awhile now, already missing you   How are things South and East of down-under? Yeah, the Milky Way's central black hole and its imaging was the subject of this thread. I was wrongly referring to another galaxy's central black hole which was not really pertinent to this discussion.

[walterpthefirst]

https://webbtelescope.org/contents/news-releases/2021/news-2021-053.html

 

NASA’s Webb Will Join Forces with the Event Horizon Telescope to Reveal the Milky Way’s Supermassive Black Hole

This article is from last year, so the EHT had imaged the supermassive black hole in the centre of M87, but hadn't yet imaged Sag A*, in our galaxy.

 

Thank you.

 

Walter.