Elendirs

First real Black Hole image - 10 April 2019

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"On April 10th 2019, the Event Horizon Telescope (EHT) Collaboration will present its first results in multiple simultaneous press conferences around the world, and many satellite events organized by its stakeholder and affiliated institutions. Press conferences will be held simultaneously in Brussels (in English), Lyngby (in Danish), Santiago (in Spanish), Shanghai (in Mandarin), Tokyo (in Japanese), Taipei (in Mandarin), and Washington D.C. (in English), starting at 13:00 Universal Time [...] Major press conferences will be streamed live online via the following channels:



Simulations and expected results can be found here https://eventhorizontelescope.org/simulations-gallery 

More informations : https://eventhorizontelescope.org/science

What do you think/expect, are you excited ? I surely am!

eventhorizon-shadows_0.jpg

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Posted (edited)

Here it is, the first real immage of a Black Hole in the center of the galaxy M87.

black hole.png

 

black hole 3.png

Edited by Elendirs

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16 minutes ago, Elendirs said:

Here it is, the first real immage of Sag A.

I originally assumed that as well. Actually it is in another galaxy, M87. Which just makes it even more impressive!

https://eventhorizontelescope.org

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11 minutes ago, Strange said:

I originally assumed that as well. Actually it is in another galaxy, M87. Which just makes it even more impressive!

https://eventhorizontelescope.org

Thanks for the correction, it is an honor for me to be alive in this time!

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Just now, Elendirs said:

Thanks for the correction, it is an honor for me to be alive in this time!

:-)    Yea - it's awesome!  :-) 

I am shamelessly pinching that photo as my avatar for a bit if no-one minds. 

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Congrats to EHT! The black hole  photo looks amazing. Looks like it could be enhanced even more with deblurring and the proper deblur point spread function.

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1 hour ago, DrP said:

I am shamelessly pinching that photo as my avatar for a bit if no-one minds. 

Yes I noticed that.  Very quick on the draw...:-)

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2 hours ago, DrP said:

I am shamelessly pinching that photo as my avatar for a bit if no-one minds. 

Dang, you were first with it. Lets take monthly turns! :P 

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4 minutes ago, QuantumT said:

Is the image constructed from x-ray data?

Microwave.

It has to be something that can be detected on Earth (ie through the atmosphere) and also a low-enough frequency that signals from multiple source can be combined coherently. (I have tabs open with papers describing some of the processing involved but haven't had chance to read them yet)

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5 hours ago, StringJunky said:

So, GR is correct again?

So far that appears to be the case. At least in early morning [here in Australia's east coast] news reports. Obviously awaiting full confirmation from the professionals.

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24 minutes ago, Strange said:

Microwave.

It has to be something that can be detected on Earth (ie through the atmosphere) and also a low-enough frequency that signals from multiple source can be combined coherently. (I have tabs open with papers describing some of the processing involved but haven't had chance to read them yet)

Also, a wavelength short enough to give reasonable resolution.

Good discussion of this and all the other issues here: https://www.forbes.com/sites/startswithabang/2019/04/10/black-holes-are-real-and-spectacular-and-so-are-their-event-horizons/ (including why M87 before Sagitarius A*)

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5 hours ago, Elendirs said:

Thanks for the correction, it is an honor for me to be alive in this time!

We are living in incredible scientific times! And thanks for the photos and links...nice work!

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This article, reviewing the work done on simulated imaging of black holes done since 1972, has some great images: https://arxiv.org/pdf/1902.11196.pdf

Figure 8 is a simpler version of the image later generated by ray-tracing for Inception. But in this, the dots are all drawn by hand!

Figure 12 shows what the black hole would look like from different angles relative to the accretion disk.

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What is the size of the black thing? I couldn't find this data in the link provided by Strange.

What is the source of the background microwave radiation? Seems huge.

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5 minutes ago, Danijel Gorupec said:

What is the size of the black thing? I couldn't find this data in the link provided by Strange.

I was just about to post this, which partly answers it:

m87_black_hole_size_comparison.png

From: https://xkcd.com/2135/

5 minutes ago, Danijel Gorupec said:

What is the source of the background microwave radiation? Seems huge.

It is from the accretion disk. M87 is a fairly active black hole - see the massive polar jets in the second image in that Forbes article.

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3 minutes ago, Strange said:

It is from the accretion disk. M87 is a fairly active black hole - see the massive polar jets in the second image in that Forbes article.

Great photo - thanks.

Accretion disk! I thought it is some sort of occultation that was imaged (I assumed this because of all the talk regarding the shape of its shadow)... If it is accretion disk, then I guess it is lucky that it is angled the way to show us the black middle.

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2 minutes ago, Danijel Gorupec said:

Accretion disk! I thought it is some sort of occultation that was imaged (I assumed this because of all the talk regarding the shape of its shadow)... If it is accretion disk, then I guess it is lucky that it is angled the way to show us the black middle.

Actually, whatever the angle, you can always see the whole accretion disk (including the part behind the black hole!) and you can always observe most of the "shadow" of the event horizon because it absorbs all the light that would stop you seeing it. I think I saw another thread that might explain the "shadow" concept; it is basically the photon sphere, so the black area is much larger than the event horizon.

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Posted (edited)
25 minutes ago, Strange said:

Actually, whatever the angle, you can always see the whole accretion disk (including the part behind the black hole!) and you can always observe most of the "shadow" of the event horizon because it absorbs all the light that would stop you seeing it. I think I saw another thread that might explain the "shadow" concept; it is basically the photon sphere, so the black area is much larger than the event horizon.

Is the bright bit/ring actually a sphere and not a disc?

Edited by StringJunky

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Posted (edited)
31 minutes ago, Strange said:

Actually, whatever the angle, you can always see the whole accretion disk (including the part behind the black hole!) and you can always observe most of the "shadow" of the event horizon because it absorbs all the light that would stop you seeing it. I think I saw another thread that might explain the "shadow" concept; it is basically the photon sphere, so the black area is much larger than the event horizon.

this one?

http://digg.com/video/understanding-black-hole-image

More data.....

 https://iopscience.iop.org/article/10.3847/2041-8213/ab0ec7/meta

 

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

extract:

"The sequence of Letters in this issue provides the full scope of the project and the conclusions drawn to date. Paper II opens with a description of the EHT array, the technical developments that enabled precursor detections, and the full range of observations reported here. Through the deployment of novel instrumentation at existing facilities, the collaboration created a new telescope with unique capabilities for black hole imaging. Paper III details the observations, data processing, calibration algorithms, and rigorous validation protocols for the final data products used for analysis. Paper IV gives the full process and approach to image reconstruction. The final images emerged after a rigorous evaluation of traditional imaging algorithms and new techniques tailored to the EHT instrument--alongside many months of testing the imaging algorithms through the analysis of synthetic data sets. Paper V uses newly assembled libraries of general relativistic magnetohydrodynamic (GRMHD) simulations and advanced ray-tracing to analyze the images and data in the context of black hole accretion and jet-launching. Paper VI employs model fits, comparison of simulations to data, and feature extraction from images to derive formal estimates of the lensed emission ring size and shape, black hole mass, and constraints on the nature of the black hole and the space-time surrounding it. Paper I is a concise summary.

Our image of the shadow confines the mass of M87 to within its photon orbit, providing the strongest case for the existence of supermassive black holes. These observations are consistent with Doppler brightening of relativistically moving plasma close to the black hole lensed around the photon orbit. They strengthen the fundamental connection between active galactic nuclei and central engines powered by accreting black holes through an entirely new approach. In the coming years, the EHT Collaboration will extend efforts to include full polarimetry, mapping of magnetic fields on horizon scales, investigations of time variability, and increased resolution through shorter wavelength observations.

In short, this work signals the development of a new field of research in astronomy and physics as we zero in on precision images of black holes on horizon scales. The prospects for sharpening our focus even further are excellent."

Edited by beecee

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12 minutes ago, StringJunky said:

Is the bright bit/ring actually a sphere and not a disc?

This video explains it pretty well:

 

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58 minutes ago, Strange said:

m87_black_hole_size_comparison.png

What is the estimated size of the M87* singularity?

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Just now, QuantumT said:

What is the estimated size of the M87* singularity?

The black hole is approximately 6.5 billion masses of our sun. 

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