Imaging a black hole - the EHT

[Green Baron]

Here's food:

https://iopscience.iop.org/journal/2041-8205

Looks like being open access.

Have fun :-)

(retreats in a cave for reading)

Edited April 10, 2019 by Green Baron

[cubinator]

I bet that because of the temporal effects a timelapse of several days of images might be only a few minutes at the black hole - you could watch really fast activity in the accretion disk.

[MechBFP]

Very cool stuff. Image was even better than I was expecting. 

[ProtoJeb21]

22 minutes ago, cubinator said:

Sagittarius A* image will be ready very soon, they say. This one is of M87.

If they’ve managed to achieve this level of quality for the most difficult of the two black holes they targeted, then the image for Sag A* should be even better. 

[cubinator]

1 minute ago, ProtoJeb21 said:

If they’ve managed to achieve this level of quality for the most difficult of the two black holes they targeted, then the image for Sag A* should be even better. 

Sag A* is hard because it's moving much faster. M87* is seen almost head-on, apparently. I expect Sag A* to be more on the side for us, which will be exciting. 

[Just Jim]

Just.... Wow!!!

 

Edited April 10, 2019 by Just Jim

[Starstruck69]

Never doubted you Albert...

 

[Green Baron]

A sixth paper that is not in the "special edition" of ApJ letters above:

https://iopscience.iop.org/article/10.3847/2041-8213/ab1141

They are all openly licensed and surprisingly understandable.

Edited April 10, 2019 by Green Baron

[YNM]

Well, it's public since they've got what they want XD

 

But good work EHT team !

[Ultimate Steve]

Wait, so will we get the Sagittarius pictures today or later?

[cubinator]

2 minutes ago, Ultimate Steve said:

Wait, so will we get the Sagittarius pictures today or later?

Probably later.They're not quite done with it.

[Xd the great]

Looks like somone placed too much jam on one side of a donut.

[tater]

 

[YNM]

@tater What's brightness temperature ?

[tater]

2 minutes ago, YNM said:

@tater What's brightness temperature ?

It's the temperature of the emitting body.

It's the temp of a blackbody that would emit the same as was observed.

[klesh]

32 minutes ago, cubinator said:

Sag A* is hard because it's moving much faster. M87* is seen almost head-on, apparently. I expect Sag A* to be more on the side for us, which will be exciting. 

 

Funny, I had no idea they looked at 2, I was expecting todays announcement to be about A*.  

Can you explain what you mean by “it’s moving much faster?”

[cubinator]

Just now, klesh said:

 

Funny, I had no idea they looked at 2, I was expecting todays announcement to be about A*.  

Can you explain what you mean by “it’s moving much faster?”

I think it's because it's much closer and we're orbiting it.

[YNM]

4 minutes ago, tater said:

It's the temp of a blackbody that would emit the same as was observed.

Damn, that's hot...

Though some has been blueshifted by doppler effect... yet they're all redshifted from gravitation.

Still pretty hot.

[Green Baron]

27 minutes ago, Ultimate Steve said:

Wait, so will we get the Sagittarius pictures today or later?

They mention somewhere that an image of SgrA* drawn out of data from the 2017 campaign can be expected. If i understood it right, some adjustments must be made to the data crunching, so it may take some more time (interpretation mine).

Also, only a part of the petabytes of data has been used for the analyses presented today.

When the French NOEMA and the Greenland Telescope will join (this and the next year), there will be another leap in sensitivity, which may enable them to actually do "movies" of the swirling disc.

Within the limits of the uncertainties (that may be pushed further in upcoming campaigns and further refinement of the methods), the conformity with the predictions of GR (here: Kerr metric) is amazing, so it is said :-)

 

Edited April 10, 2019 by Green Baron

[tater]

24 minutes ago, YNM said:

Damn, that's hot...

Though some has been blueshifted by doppler effect... yet they're all redshifted from gravitation.

Still pretty hot.

It's the temp as if it was a block body. Doesn't mean that's the actual temp.

[Starstruck69]

 

 

 

43 minutes ago, Green Baron said:

They mention somewhere that an image of SgrA* drawn out of data from the 2017 campaign can be expected. If i understood it right, some adjustments must be made to the data crunching, so it may take some more time (interpretation mine).

Also, only a part of the petabytes of data has been used for the analyses presented today.

When the French NOEMA and the Greenland Telescope will join (this and the next year), there will be another leap in sensitivity, which may enable them to actually do "movies" of the swirling disc.

Within the limits of the uncertainties (that may be pushed further in upcoming campaigns and further refinement of the methods), the conformity with the predictions of GR (here: Kerr metric) is amazing, so it is said :-)

 

Yes just adding 2 improves it quite significantly. I think he mentioned between 30 to 50%

Edited April 10, 2019 by Starstruck69

[GluttonyReaper]

1 hour ago, ProtoJeb21 said:

If they’ve managed to achieve this level of quality for the most difficult of the two black holes they targeted, then the image for Sag A* should be even better. 

Not necessarily - although Sag A is way closer, it's also way smaller. M87's black hole is freakishly huge, like 1000 times bigger. Also Sag A lies in our galactic plane, which means you have to look through all the gas and dust in our galaxy to see it, while you have a much clearer shot for M87.

[sh1pman]

4 minutes ago, GluttonyReaper said:

M87's black hole is freakishly huge, like 1000 times bigger.

Must’ve eaten a few billion nearby stars to grow this big. 

[Green Baron]

Our central black hole has a slightly greater angular size than the M87 one, as observed from earth, but it is behind thick interstellar clouds.

The dark depression in the image presented is about double the size of the actual event horizon that would fit the mass 6.5 billion solar masses.

[Starstruck69]

10 minutes ago, Green Baron said:

Our central black hole has a slightly greater angular size than the M87 one, as observed from earth, but it is behind thick interstellar clouds.

The dark depression in the image presented is about double the size of the actual event horizon that would fit the mass 6.5 billion solar masses.

Its huge 1.5 light days accross. Wow!!