Astronomers have generally thought that massive black holes at the centers of galaxies expel gas in jets of material only during their formative years, when the central black hole is gobbling up gas and stars and producing lots of radiation. This makes them stand out as what astronomers call active galactic nuclei (AGN), or quasars.
If, as the new study suggests, the ionized hydrogen halo around galaxies is more diffuse, but also more extensive, than thought, this implies that the central black holes may actually become active at other times in their lives.
I love how we keep finding more and more about the role that black holes play in our universe.
If I understood this correctly, they analyzed incredibly blurry images and concluded that there are clouds of gas around galaxies, then they extrapolated the found gas up to all or almost all galaxies and concluded that it can fulfill the calculated expectations.
What I understood is kind of the opposite–they already knew there were hidrogene clouds around galaxies but analyzed some almost imperceptibly blurry images and found they were bigger than currently thought. They're blurry because they were taken in some wavelength not observable until now that is scattered by the ionized gas.
Gonna hijack this post to ask a somewhat related but possibly stupid question, would it be possible that instead of a singularity there happened to be a region of space with non-negligible size (ie, not a point sized region) that acted like a well instead? Things could “fall” into that well and not be able to escape, but it’s not like everything in the well is at a single point.
I may be misunderstanding your question, but black holes are regions of space that have non-negligible size; the boundary between what can escape and what can’t is called the event horizon. The singularity is what happens at the center.
I guess what I mean to say is, would a non-negligible sized “singularity” (I know I’m messing with that term quite a bit, I’ll stray from the mathematical definition) be consistent with our current theories?
Basically, what makes sense logically isn’t backed up by what data and math we have. Logically, we would assume as enough stuff is pulled together that the density hits a point where gravity is stronger than the bonds that hold matter together, that those bonds would break and the individual elements, initially atoms, but as gravity gets stronger and stronger the bonds between the components of atoms and so on and so forth also break down.
At some point, there is a limit to how much matter can break back down into further and further smaller components. What specifically happens when that limit is reached? That is a huge part of what could be throwing the math off. We don’t really know, but we have some guesses. Could be at the end, one of the components is weightless, and unaffected by the gravity, we do see some energy radiating out of some black holes in a straight line or “jet”. Hard to say for sure. Logic doesn’t always get us there when we don’t have enough data and need to make a leap. It might eventually, as we can slowly tie more and more stuff together with more data. Could be whatever energy starts that jet either immediately or already on the way out, mixes/mixed with other components and particles to become what we end up detecting it as. But if we could see it earlier, it maybe would be completely different before that.
Depends what you mean by “our current theories”. In classical General Relatively the answer is pretty conclusively no but many people think that a quantum theory of gravity should be able to remove the singularities. In fact, this article is about an attempt to do just that with a fairly natural extension to GR (albeit one that is only mathematically tractable in 5 or more dimensions) and seems to have succeeded for the static spherically symmetric case at least.
Nobody really thinks singularities exist. It’s only what comes out from our math. That’s also how we know our math is wrong, we’re just not sure yet how to do it better.
Ok so from what I can understand it blew off approximately a million years ago, and now it’s about 8.8k ly away. But where was it in relation to earth when it exploded?
Ok so from what I can understand it blew off approximately a million years ago, and now it’s about 8.8k ly away. But where was it in relation to earth when it exploded?
Putting on my sci-fi hat; a distant galaxy that is likely a billion years older than ours, very likely has had enough time to develop life somewhere in the trillions of stars that formed within it, by the time the photons of that galaxy finally reached us and hit that very specific telescope sensor at that very specific moment the JWT engineers were observing.
phys.org
Najnowsze