A sky survey by the Chandra X-ray Observatory has revealed in detail, for the first time, the shock wave placed on the galaxy Centaurus A by powerful plasma jets emanating from the supermassive black hole at the galaxy's core
A sky survey by the Chandra X-ray Observatory has revealed in detail, for the first time, the shock wave imposed on a galaxy by powerful plasma jets emanating from the supermassive black hole at the galaxy's core. The observations of Centaurus A, the closest galaxy to us that has such jets, caused astronomers to dramatically change their way of thinking about the effect of the jets on the galaxies in which they are located.
The results are presented in the journals European Week of Astronomy and Space Science in Hatfield by Dr. Judith Croston from the University of Hertfordshire.
The team led by Dr. Croston and Dr. Ralph Kraft, from Harvard University in the US, used X-ray observations from Chandra's deep space to obtain a new view of the jets of Centaurus A. The jets accelerate the expansion of a large bubble field made of energetic particles, which causes a shock wave in the stars of the galaxy and in a neighboring galaxy. By analyzing the details of the X-ray emission and how the rapidly expanding bubble collides with the neighboring galaxy, the team was able to show for the first time that the particles are accelerated to very high energy levels at the wavefront, which causes them to emit powerful X-rays and gamma rays. Another team of scientists using the High Energy Stereoscopic Telescope in Namibia (HESS) first detected very high intensity gamma rays emitted by Centaurus A.
"While we predict that galaxies with tidal waves are common in the universe, Centaurus A is the closest system that can be studied in detail," says Dr Croston. "By understanding the effects of the jets on the galaxy, on its gas and stars, we hope to understand how the shock waves fit into the life cycle of other distant galaxies."
The powerful jets occur in only a small percentage of galaxies, but are common in the largest galaxies, where the largest black holes are likely to be found. The scientists believe that the jets are produced close to the supermassive black hole at the center of the galaxy. They fly at the speed of light and travel a huge distance of thousands upon thousands of light years. Recent advances in understanding galaxy evolution suggest that these bubble-producing jets play an important role in the life cycles of the largest galaxies in the universe.
Energetic particles from radio galaxies may reach us as cosmic rays reach and hit the Earth's atmosphere. Many of the most energetic cosmic rays probably reach our atmosphere from Centaurus A. The team believes that the results of the study are extremely important for understanding the formation of energetic particles in galaxies and the formation of galaxies.
44 תגובות
I think the black hole serves the universe as a simple filter
It takes junk that sails by and turns it into a form of radiation
soup:
Regarding what an observer from Earth sees - there is a general agreement that he sees the astronaut "stuck" forever on the event horizon (if you can call it "seeing" because, as mentioned, the wavelength of the electromagnetic radiation emitted from him becomes infinite.
As for what the astronaut himself will feel - there is a disagreement among the scientists when some claim that he will cross the event horizon and reach the singularity and some claim that he will not be able to cross the event horizon.
Regarding black holes, I still haven't understood one thing.
As far as I know relative to an outside observer, the time of a body falling into a black hole slows down as it approaches the event horizon, so the time required for that body to cross the event horizon is infinite.
From this I understand that a simple body cannot cross the event horizon. Hence, relative to an observer on Earth, no body has ever crossed any event horizon. Is it really so?
And what about an observer being sucked into a black hole? If an astronaut who falls into a black hole, assuming he manages to survive to the event horizon, will see everything around him accelerated, until in his second particle outside, billions of years pass, in which the black hole has already evaporated?
A. Ben-Ner:
For section A - the reference is to the infinite collapse of the hole itself. I emphasize that I am not saying here what necessarily happens but what Kraus claims and what I think Hawking also claims. According to this claim, it is something that is more far-reaching than an infinite collapse into a singularity, but in that at each stage there is still matter outside the event horizon (!).
If I'm not mistaken, it should be - not only with regard to the material added to the hole but also with regard to the material that creates it in the first place.
For section b - I didn't exactly understand the question. In any case, as far as I understand - all the laws of nature have to be preserved both in the formation and in the decay of a black hole and this also includes the conservation of angular momentum.
For section c - the lengthening of time and the lengthening of the wavelength are actually different aspects of the same phenomenon. If time moves slower relative to an outside observer, then the frequency of the emitted light also decreases relative to that observer, and since the frequency is inversely proportional to the length of the wave, the wave lengthens.
For section d - it doesn't matter, both because escape velocity is the same regardless of the direction of movement (since it is derived from potential energy and it has no direction) and because of the fact that the speed of light cannot be exceeded anyway.
To Michael R.
I asked
A. Regarding "Black Hole Neverending Creation",
Does this mean that the black hole continues to absorb matter in an infinite process or, that the infinite process also takes place within the internal volume of the black hole (meaning of course within the volume defined by the event horizon) in a kind of infinite collapse into the singularity?
B. Regarding the rotational energy of the black hole itself.
Does the black hole also emit gravitational energy that reduces its moment of inertia?
third. As far as I understood your words, according to you our inability to see matter adsorbed into a black hole is due
from the lengthening of the emitted wavelengths due to the speed
of the matter falling to the event horizon (the speed of light), however, the claim I know is that the reason is the lengthening of time, according to the equations of special relativity. The reason you mentioned is of a "technical" nature, while the second reason imposes a fundamental limitation that "blocks" the existence of the possibility of crossing the event horizon.
D. Is it necessarily the speed of the fall (of the material to the event horizon) that is indeed the speed of light. After all, it is only about the central component of the speed and not about the radial component.
Wow, Michael, you are too serious.
I spoke on my own behalf, 😉
I ran things in my head on my own,
And for all intents and purposes Michael has nothing to do with what I said at all.
Gil Dotan:
Speak for yourself.
Allow me to disagree with your claim that when you say something related to cosmology (without knowing its laws and without knowing how to manipulate its formulas) it is equivalent to Hawking or Krauss or even me saying it.
I guess if you say you don't understand it must be true but who are you to say that others don't understand?
Of course - there is always doubt in science, but that's not what we're talking about here, right? (because how many times can one make the useless claim that we actually know nothing for sure)
Yael:
Pretty.
I wonder what you will think of your words when you read how much poison is in them after you calm down.
FYI - the universe I described is not simplistic - it is the universe described by contemporary cosmology.
The correctness of my statement does not depend on the existence of black holes in the center of the galaxy.
In the simplistic universe (!!!) that I (and others who understand nothing) are talking about there are gravitational waves even without black holes and these waves cause a loss of rotational energy.
That's why all galaxies will behave simply and collapse.
At a certain point (because a galaxy is not a small thing) enough matter will accumulate in the center of the galaxy to create a black hole and therefore all galaxies will turn into black holes.
You are wrong and mislead the public when you say that I speak emphatically about the theories when it is clear that no one asked anyone to predict and all people wanted to know was what the theories accepted in science today say about the situation and that is what I tried to include in my responses.
Of course I am aware of the existence of stray bodies that are not related to every galaxy, but these are null in sixty (million) and in my opinion the question was not aimed at them.
In my opinion, your entire response was written out of anger and not out of a desire to contribute to the discussion.
Michael,
The simplistic universe you described does not correspond to reality.
Although many galaxies, especially spiral galaxies, are thought to have a black hole at their center, not all galaxies have black holes. In addition to this, there are also other creatures (clusters, dust, errant stars) that roam the universe without being connected to a galaxy and without coming into contact with a black hole. So it's not clear why you think the entire universe will consist of only black holes at the end of time.
You mislead the public when you speak strongly about the theories you believe. Most cosmological theories have not been proven, there is evidence here and there. So please do not exaggerate the value of these unconfirmed models, but reveal the whole truth which consists of arguments for all sides.
Yes, huh?
To the extent that ? That everything revolves around a single project?
CERN will free us from the explosions of physics and cosmology very soon
Pretty,
But the sentence is a drop in the air... either Hawking radiation is the information and it doesn't seem to me that it is equivalent to all the information that came in or there is an emission of information that we don't know about,
Everything is up in the air.
It's like I will make a claim (which maybe made) that the black hole just disappeared one day in a quantum vibration..if you find remnants of gravity where there is nothing then maybe it is the remnant.
Maybe dark matter is the "information" converted by a black hole?
Either way we got to today and now we are stuck.
Gravitational vision is still beyond him.
age:
In Kraus's article that I pointed to, there is a proposal to solve the problem.
A moment ago I saw an article here on the website in which it was claimed that Hawking's opinion was similar.
The article is this:
https://www.hayadan.org.il/hawking-0704/
And in it Hawking is quoted as saying:
"The black hole just seems to form, but later it opens up and releases information about what fell into it, so we can be sure of the past and predict the future."
This exactly matches what I wrote in response 10
Gil, there is the interesting idea that a black hole gives birth to a new universe "inside the black hole". This is one of the possible mechanisms for cosmic evolution.
Everything ends in the information paradox, doesn't it?
The universe has disappeared into black holes and there is no idea where..
No?
fresh:
I also agree that black black exists.
The only question is whether its collapse is ever resolved and the answer is no.
The truth is that Wikipedia also has errors regarding various aspects of black hole behavior but that is not relevant to us at the moment.
According to the Wikipedia entry of a black hole:
"A minority of physicists do not agree that black holes exist" meaning that most physicists today think black black is something that exists.
fresh:
If you had read the discussion in depth you would have seen that Kraus also says this
fresh:
I explained why this is so
fresh:
Each question may have a more precise answer in the future but that doesn't mean there isn't an answer now.
Michael
You claim "you can't get out of a black hole and it follows that you can't get into it either"?
Where did you hear these things? Which scientist claims this?
to the point
Maybe when science fully understands what time is, you can have an answer to this question.
point::
The fact that the black holes do not complete their formation can also be seen as follows:
There is no irreversible process in nature (with the exception of considerations of entropy, but assuming that we manage to conserve energy - any process that occurs can be reversed by reinvesting the energy that was wasted during it).
This is true in all physics and in particular in falling into a black hole.
We know that it is not possible to get out of a black hole and it follows that it is also not possible to enter it (because if it were possible to enter - it would also be possible to exit).
Another way to see it is as follows.
The speed needed to escape a black hole exceeds the speed of light (it is equal to the speed of light right at the event horizon).
This means that if any body were to fall into the hole it would exceed the speed of light.
Yael:
There was no mess and what the current theories predict was faithfully described in my words. I don't know why you claim that what I said about the galaxies falling into the black holes in their center is not true (because you didn't say why it's not true, you just stated it) but in my opinion it is absolutely true and I even explained why (because of the loss of the rotational energy in favor of the gravitational waves created in the rotation). You are welcome to explain why you think this is not true. You are welcome - on the other hand - to admit that it is true.
Today it is common to think that the universe is open (due to the acceleration of expansion which is attributed to dark energy).
My answer 12 really covered everything and even left an opening for the possibility that it would turn out that the universe is still closed because it conditioned the prediction on it continuing to expand (which, as mentioned, is now widely believed to happen).
It seems to me that only Michael understood the intent of my question.
I will present my question from a different perspective: When an astronaut falls towards the black hole, will he reach the event horizon and pass it before the universe outside the black hole has passed an infinite amount of time?
What this means is blacks exist but only in the future. They do not exist in the present because they take infinite time (from our point of view) to form due to time slowing down.
Or maybe all of this is not true and there is an offset of the slowing down of time with relative effects of the falling speed of the material (which can also be considered infinite) or the astronaut.
The question is whether there is an entropy that is common to all the multiverse (or multiverse) or does each universe in the multiverse have its own entropy?
Today it is already known and accepted that the dark energy will cause the universe to expand forever and ever in a cold and dark death, but it will only happen in about 50 billion years I think, so there is nothing to worry about.
Michael,
You wrote that all stars will fall into black holes at some point and that is not true.
Let's sort out the mess, the first question was whether the universe would eventually consist only of black holes. So I said that it is impossible to know what will happen at the end of the universe and it depends on whether the universe is open or closed because in an open universe for example this question has no validity. And I also said that there is a theory, Rabbi Yakom, that does not place our universe in a closed box but opens a door to an infinite number of other universes, therefore if it is not a closed box it affects the entropy in it.
Yael:
I didn't force you to enter this theory, but I suggest you read my response again and see that everything you wrote appears in it.
By the way, Rabbi Yakum is currently only a theory and there is still no evidence of his existence.
Listen Michael, you are forcing me to enter the end of the universe theory now and it is hard to resist the temptation.
There are several cosmological models, the two main ones are closed or open.
The closed means that the big bang the universe expanded and it will continue to expand until a certain point from which it will start collapsing back into itself in the "big squeeze".
Open means that the universe will continue to expand forever and eventually the energy will run out and the temperatures will drop to almost absolute zero. This is where Ron's question comes in, because at this point black holes will be the only source of energy in the universe, although there will still be particles unrelated to black holes that will continue to float and perish in space. After the black holes evaporate all that will be left in the universe will be a number of protons and positrons orbiting each other.
But none of this really means anything until you find out what dark energy is, the mysterious force that causes the universe to accelerate, and the thing that makes up most of the universe.
By the way, another very interesting model on the subject of the universe is the multi-universe theory, for which supporting evidence is accumulating today, and it says that there are many universes when from each universe another universe bubble sprouts and the process continues ad infinitum.
Yael:
Ron didn't ask if all stars turned into black holes but if eventually there would only be black holes in the universe.
I explained why - at a certain point - this was the case - not because all the stars would turn into black holes but because all the stars would fall into the black holes in the center of the galaxy.
Black holes are real creatures. At the center of every spiral galaxy, a black hole is believed to be found and although they cannot be seen with telescopes, it is seen that a lot of matter is being pumped to a certain point at an enormous speed. It is also possible to infer the size of a black hole due to the amount and speed of the stars around it as well as according to the gravitational mixing of the light that takes place in its environment.
In the past it was thought that since blacks do not emit any light, then they are non-volatile, and should exist forever. But then Hawking and Einstein discovered Hawking radiation (and still haven't proven it as far as I remember), which means that theoretically the black hole is indeed volatile, although it will take longer than the age of the universe to completely evaporate.
And black holes can grow.
I didn't really understand the question about our point of view. If you can't see something, it doesn't mean it doesn't exist.
Inside the black hole the density is infinite, time and space are warped and things unknown to science happen. This is the meaning of "singular point" - when scientists put things in formulas and suddenly they get a deviation in the denominator or some term that gives a result of infinity. Science does not know how to deal with it and mathematics does not know how to deal with it.
And to Ron's question,
Not all stars become black holes at the end of their lives, only very massive stars 20 solar masses or more can explode as a supernova and possibly become a black hole. The rest of the stars can also become white dwarfs or neutron stars at the end of their lives.
There are several possible scenarios for the end of the universe. Scientists disagree and it also depends on what they find about dark energy (if I have time later today, I'll write about the end of the universe theories here).
Ron:
It is true that nothing you say is clear from what has been said here so far, but:
One of the possible scenarios is that given enough time each galaxy will turn into a black hole in formation (due to the loss of energy to gravitational waves).
However - turning the galaxies into black holes will not increase their gravitational pull, so if the universe continues to expand as it is happening now - they will not collapse but will continue to move away.
In the many trillions it is also expected that the background radiation will introduce into each black hole less energy than it loses in Hawking radiation and all the black holes will "evaporate"
It seems to me that Danny Rupp would be dead to give a forecast for such a range.
So in the end, if the universe doesn't collapse on its own, will it just be a field of black holes?
(And maybe this is what will cause the collapse?)
For number 6:
As far as I know - no.
Be that as it may - a "black hole in infinite formation" will also end its revival in the same way (and precisely after a finite time - that is, before the completion of its own formation, the black hole will cease to form as a result)
A. Ben-Ner:
I answered I also answered.
When I said that for all practical purposes the hole that is in infinite formation functions as a black hole I meant that too.
During the fall towards the hole in the formation, the wavelength of the light emitted from the falling body goes and lengthens (in terms of our visual acuity) to a level where we simply do not see it.
The way the material does before, of course, it passes through the adsorption disk and radiates as it was supposed to do, and in short - everything is normal.
Material can be seen being sucked in in the case of a hole close to the star.
And there is the famous coil that comes out of the star into the hole.
As for B, it's not closed, but I don't think they know what's going on there.
That's why I asked about the end of the life of a black hole and if it was documented?
To Yael, to Michael and all the other commenters.
As far as I understand, none of you answered the interesting question of "from a point". I will repeat the question
In my wording:
1]. From our point of view, is it not possible to "see" matter adsorbed into the black hole?
2]. Does it follow that from our point of view all black holes do not grow, because we cannot see material attached to them, but they are small, due to Hawking radiation?
Didn't they see Black ending his life?
Congratulations!
Michael,
Which process "wins" in the end: the formation process or Hawking radiation?
Yael and Point:
There are more and more people coming to the conclusion that the black hole never ends its formation.
The formulas of relativity do say so.
See, for example, an article by Kraus on the subject:
http://arxiv.org/abs/gr-qc/0609024
However, for all practical purposes, a black hole in an infinite process of formation functions as a black hole.
Black holes exist. When a big old star ends its life and uses up all its energy, it no longer undergoes nuclear fusion and then the enormous gravitational forces pull it in and cause it to collapse in on itself. After the collapse it can become a black hole which is a singular point where the laws of physics as we know them no longer apply.
Black holes swallow everything in their path, and nothing can escape their event horizon except Hawking radiation.
Do black holes exist?
After all, time stops at the event horizon, so the star will never collapse into a black hole at a finite time. or i'm wrong