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Questions tagged [event-horizon-telescope]

Questions about the Event Horizon Telescope, or EHT.

3 votes
0 answers
58 views

Mark 6 VLBI Recorder 32Gpbs, 2 bit sampling

I was reading the paper about the first M87 EHT Results, part 3 (link to article PDF), where the data processing pipeline is explained. The recording system used was a Mark 6 recorder with 32Gbps and ...
acoustica's user avatar
2 votes
2 answers
186 views

What is stopping Event Horizon Telescope the size of the Earth’s orbit?

There is a proposal to include a radio sensor in a telescope going to the Sun-Earth L2, getting 120x improvement in angular resolution to EHT. Knowing nothing about interferometry, it seems pretty ...
Ahmbak's user avatar
  • 123
6 votes
2 answers
106 views

In terms of results, how similar is a bunch of telescopes across the globe to an Earth-sized telescope?

The Event Horizon Telescope emulates an Earth-sized telescope by syncing a bunch of radio telescopes across the planet to do take pictures with a small enough angular resolution to take pictures of a ...
zucculent's user avatar
  • 1,758
7 votes
1 answer
714 views

Is this image of Sgr A* correctly labelled?

This BBC article contains this "schematic description" of the EHT Sgr A* image: The source is described only as "EHT Collaboration" and I haven't been able to find the original ...
Dave Gremlin's user avatar
  • 1,071
9 votes
2 answers
926 views

Why is the ring in this simulation of Sgr A* off center?

In the recent releases of images of Sgr A*, simulated versions of what they expected were included along side the actual images they were able to get. What confuses me about these simulated images (...
Justin T's user avatar
  • 3,404
3 votes
1 answer
141 views

Does the newly found orientation of Sgr A* match the theory that the Fermi bubbles might have been caused by jets?

The EHT just announced their great findings about Sgr A*, amongst other cool things they found that we look towards the black hole face on which means that if there is a jet it approximately looks ...
astronerd's user avatar
9 votes
1 answer
2k views

Doubt regarding size and shape of black hole images published by the Event Horizon Telescope (EHT)

The recent publications of the images of black hole shadow by the Event Horizon Telescope collaboration prompts us to study black hole images in more details. According to the no-hair theorem, the ...
Richard's user avatar
  • 323
2 votes
0 answers
93 views

Why hasn't the EHT taken an image of Sgr A*? [duplicate]

The Event Horizon Telescope or EHT took an image or the black hole at the center of M87 in 2019, and in 2021 it measured the polarization of the light from M87*. Right after the first image of M87* ...
usernumber's user avatar
  • 17.6k
6 votes
3 answers
827 views

Can the Event Horizon Telescope been used to find intergalactic distances?

Now that we have the Event Horizon Telescope (EHT), why can't we just guess and check intergalactic distances by changing the EHT's focal length? For instance why don't we take another picture of M87,...
Caston's user avatar
  • 329
3 votes
1 answer
200 views

How, precisely, do radio astronomers detect (and record) the phases of waves for interferometry?

Interferometry is always in the news, and at radio frequencies it has been for a long time... The popular press always talks about directly 'interfering' two waves as they come in, but can they tell ...
Kurt Hikes's user avatar
  • 5,177
3 votes
1 answer
280 views

How can light circle a black hole one or more times and then escape again? [duplicate]

The shadow that is cast by a black hole was beautifully captured by the event horizon telescope. A concentration of light in the photon sphere around the hole (adjacent to the event horizon) ...
Deschele Schilder's user avatar
3 votes
1 answer
349 views

How will they know when to start taking the picture of the black hole at the center of the Milky Way?

@csm's answer to Why not take a picture of a closer black hole? points out that it's necessary for the supermassive black hole at the center of a galaxy to be actively feeding for it to generate a ...
uhoh's user avatar
  • 30.7k
4 votes
1 answer
328 views

Will the first Event Horizon Telescope image of the Milky Way's black hole Sgr A* just be another lumpy orange donut?

@HDE226868's answer to Why doesn't the black hole in the center of the Milky Way glow similarly to the famous M87 image? explains that neither black hole is orange and any Event Horizon Telescope ...
uhoh's user avatar
  • 30.7k
7 votes
1 answer
143 views

Is there any work underway to push the long baseline capabilities of the Event Horizon Telescope to sub-millimeter wavelengths?

The Max Planck Institute for Radio Astronomy's press release Something is Lurking in the Heart of Quasar 3C 279; First Event Horizon Telescope Images of a Black-Hole Powered Jet shows a stunning ...
uhoh's user avatar
  • 30.7k
4 votes
1 answer
226 views

Why don't we build an interferometer between Earth and the Moon?

The Event Horizon Telescope (EHT) does interferometry from an array of telescopes spread all across Earth. The data is locally stored on a hard drive and shipped to a central location, so the ...
usernumber's user avatar
  • 17.6k

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