Messy Eaters

[Astro Noodles]

Which is the more messy eater?

One of these?

Or this?

I think they are about the same. 😁

[lenscap]

7 minutes ago, Astro Noodles said:

Which is the more messy eater?

Well the black hole could be ( in a ) Messier. 😀

[Viktiste]

Tons of videos online about that Black hole image of course. I found this one from Veritasium good to explain what we are actually seeing in that picture.

https://www.youtube.com/watch?v=zUyH3XhpLTo

Edited August 17, 2021 by Viktiste

[robin_astro]

Not as close in as the famous image of course but you can observe  the light from the material orbiting the black hole with a relatively simple spectrograph as here on my BAA page

https://britastro.org/observations/observation.php?id=20190411_213200_531d1ec6d134b3dc

Cheers

Robin

 

[Astro Noodles]

I was reading about the disagreement in cosmology over what came first, the galaxy or the supermassive black hole at the centre of it. It would seem logical to believe that it was the black hole which drew all the matter to it because of the gravity. but this is not certain. My understanding is that there is a limit to the amount of stuff which can go into a black hole in a given timescale. And further to this, that there is not enough time for a stellar mass black hole to accumulate mass. So supermassive black holes at the centres of galaxies must have started as supermassive black holes and not grown from stellar mass black holes.

That got me thinking about how black holes consume stuff. They are very messy eaters as far as I can see. Rather than swallow stuff across the event horizon, they reduce their food to an energetic 'soup' through gravity, friction, pressure etc which then spins around the black hole. A good deal of that 'soup' then escapes the black hole in the form of light and other energy. Besides that, we have observed jets of matter and energy hundreds or thousands of light years long shooting out of the poles of feeding supermassive black holes. Not content with stuff in their immediate vicinity, black holes often gravitationally catapult stars off into interstellar space or ricocheting along the plane of the galaxy. The chances of falling into a black hole seem fairly slim. It seems more likely that a body would be torn into it's most basic particular state and most of that would be flung or squirted off back into the universe.

They seem to throw their food around like characters from 'Animal House'.😄

Edited August 18, 2021 by Astro Noodles

[robin_astro]

It has managed to garner an impressive amount of rotational energy though which (may) power the relativistic jet.  As the authors of this paper 

https://arxiv.org/abs/1904.07923

put it

"This enormous amount of energy trapped in the black hole rotation implies a rotational energy of about 10^64 erg, comparable to the energy emitted by the brightest quasars over billion year timescales"

 

Edited August 18, 2021 by robin_astro

[Lariliss]

1. Black holes may have been  common in the early universe. There are founding that at least 20% of the infrared cosmic background, light emitted 400 million to 800 million years after the Big Bang 13.8 billion years ago

2. Black holes don't have any property beyond their mass, spin, and charge.
Since, for what is already gone behind event horizon the information is get lost

AGN one of the most explored matter around black holes. Exploration is still hard and uncertain, it is dependent on the black hole to be fed. Are showing to be stable.

High luminosities of AGN imply high masses such that gravity can combat radiation pressure, which would otherwise blow the object apart. AGN therefore are of very high mass density, and it has long been assumed that they consist of a massive black hole, accreting the gas and dust at the center of a galaxy.

3. Black holes have a key role in Galaxy forming, as the document explains:https://arxiv.org/pdf/0907.1608.pdf