Universe's Oldest Known Quasar Discovered 13 Billion Light-Years Away 38
Astronomers have found the farthest known source of radio emissions in the universe: a quasar 13 billion light-years from Earth spewing jets of particles at nearly the speed of light. Live Science reports: Quasars are some of the oldest, most distant, most massive and brightest objects in the universe. They make up the cores of galaxies where a rapidly spinning supermassive black hole gorges on all the matter that's unable to escape its gravitational grasp. While the black hole is devouring this matter, it's also blasting out an enormous amount of radiation that collectively can be more than a trillion times more luminous than the brightest stars, making quasars the brightest objects in the observable universe.
This quasar in particular, named P172+18, is a relic from around 780 million years after the Big Bang and reveals clues about one of the earliest ages of the universe -- the epoch of reionization. At the start of this period, the universe was darkly veiled by a mostly uniform cloud of hydrogen gas. Scientists refer to this time as the universe's dark ages, because most light emitted was quickly absorbed by the neutrally charged gas. Eventually, gravity collapsed the primordial gas into the first stars and quasars, which began to heat and ionize the surrounding gases, allowing light to pass through. [...] Further observations from telescopes [...] showed that P172+18 is nearly 300 million times more massive than the sun and is among the fastest-growing quasars ever discovered. The problem is, scientists don't know how a black hole became so massive this early on in the universe. The radio jets could be an explanation. The researchers' findings will be published in The Astrophysical Journal.
This quasar in particular, named P172+18, is a relic from around 780 million years after the Big Bang and reveals clues about one of the earliest ages of the universe -- the epoch of reionization. At the start of this period, the universe was darkly veiled by a mostly uniform cloud of hydrogen gas. Scientists refer to this time as the universe's dark ages, because most light emitted was quickly absorbed by the neutrally charged gas. Eventually, gravity collapsed the primordial gas into the first stars and quasars, which began to heat and ionize the surrounding gases, allowing light to pass through. [...] Further observations from telescopes [...] showed that P172+18 is nearly 300 million times more massive than the sun and is among the fastest-growing quasars ever discovered. The problem is, scientists don't know how a black hole became so massive this early on in the universe. The radio jets could be an explanation. The researchers' findings will be published in The Astrophysical Journal.
Hard to get a perspective.... (Score:2)
The photons were emitted 13 billion years ago, when the solar system wasn't even here!
Re: Hard to get a perspective.... (Score:2)
Yeah... in this "time," all quasars disappeared long ago... right? They're something that happened long, long ago. Or am I just too befuddled at 4am to think this through properly?
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Re: Hard to get a perspective.... (Score:5, Informative)
Yeah... in this "time," all quasars disappeared long ago... right?
No, the peak was long ago, but they still exist. There is/was one just 581 million light-years away.
And you don't want to be too close.
https://hubblesite.org/content... [hubblesite.org]
Seyfert galaxies, 3C273 and AGNs (Score:2)
I think proper quasars have pretty much disappeared, making them for the most part relics of the early Universe.
There are quasar-like things called Seyfert galaxies and Active Galactic Nuclei nearby and hence "recent." Quasars and AGNs are hypothesized to all be powered by massive black holes, but the nearby AGNs are wimpy, they don't make them like they used to versions of quasars.
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Yeah... in this "time," all quasars disappeared long ago... right? They're something that happened long, long ago. Or am I just too befuddled at 4am to think this through properly?
Quasars are just rapidly feeding black holes. From observation, and partly from common sense too, early on there is lots more gas and material for them to feed on. But as the material is consumed, they clear out the region around them and eventually go silent when there is little left to eat by comparison. The reason it keeps making the news is scientist want to understand the process better because generally the largest black holes initially grew faster than we expect.
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The photons were emitted 13 billion years ago,
Newsflash: the steady-state theory has been discredited. The universe is expanding!
So assuming TFA has not made the same rookie error, the photons are substantially younger.
The CMB, from 13.8 billion years ago comes from a region of space now 46 billion light years away.
This quasar in particular, named P172+18, is a relic from around 780 million years after the Big Bang
Oh fuck :-(
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Complicated isn't it :)
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The photons were emitted 13 billion years ago,
Newsflash: the steady-state theory has been discredited. The universe is expanding!
So assuming TFA has not made the same rookie error, the photons are substantially younger.
No. When we look at the quasar today it appears to be 13Bly away, therefore the light we see has travelled 13Bly and is 13 billion years old (at least), regardless of where the quasar is today.
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Maybe from your perspective, but from the perspective of the photons, they just left.
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Maybe from your perspective, but from the perspective of the photons, they just left.
Time is a null value for photons; it makes no more sense to talk about them being young or old from their perspective. That's why they were able to find you (or the machine making the observation). But for things which exist inside of time it does make sense and since they're the ones writing the article, that's fair enough.
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When we look at the quasar today it appears to be 13Bly away
Which is pretty confusing, given the age of the quasar. Ftom TFS:
a relic from around 780 million years after the Big Bang
So using a classic model of expansion, these quasars should be no more than 1560 million light years from the farthest point in the observable universe. Assuming that both the quasar and observer receded from each other at near the velocity c. And thanks to relativity, the observer can't "outrun" light. A photon emitted by an object traveling near c in one direction and observed from a point traveling near c in the other direction still passe
Distance Seen Not Distance Now (Score:3)
So assuming TFA has not made the same rookie error, the photons are substantially younger. The CMB, from 13.8 billion years ago comes from a region of space now 46 billion light years away.
When you take a picture you state the distance seen in the picture not your current distance to the object. If you went whale watching in Alaska and took a photo of a whale and sometime later at home a friend sees it and asks: "how close is that whale?" they are not expecting to get an answer of a few thousand kilometres.
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I'm no astronomy expert (Score:2)
Re: I'm no astronomy expert (Score:3)
To think of space as having any region which is nothing is a grave mistake. It's like realizing the abstract nature of the number 0.
The theory of an accelerating universe essentially states there is no nothing in a concrete fashion. The vacuum of space has a none zero energy state which accounts for the nature of expansion. Virtual particles also play into this reality that nothing in fact is always something or rather always has a subtle something going on within it.
The idea of nothing will likely alway
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So while it’s true that the distance is somewhat complicated, it’s trad
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As we all know, light without dark has no meaning, one without another is nothing. And as the great gurus of the world have taught us, everything is one. Therefore, everything is nothing. QED
Re: I'm no astronomy expert (Score:2)
I think your mistake is between observable universe and the totality of the universe. likewise with the nature of infinity. The universe is infinite and I believe we fairly say unbounded but the latter term is confusing in this context, as sizes of infinity are often confusing to non mathematicians. The observable universe is finite and unbounded. This is easier to grasp. It's like saying a set of numbers grows by adding more numbers.
Re: I'm no astronomy expert (Score:2)
Sorry. My example was poor. Adding new numbers changes the size of the set. A better example might be to say scaling the values of a set. But my analogy here and my mathematical language is rusty.
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The universe is infinite and I believe we fairly say unbounded but the latter term is confusing in this context, as sizes of infinity are often confusing to non mathematicians.
It's confusing why our lack of ability to observe an edge supposedly proves that there isn't one
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It's confusing why our lack of ability to observe an edge supposedly proves that there isn't one
Not really, every fraction of a second we are seeing light from further and further away, there is no receding edge at all and I doubt a single actual physicist believes that there is an actual edge at the limit of the visible. Pretty much every last physicist realizes that either the universe either has curvature or is flat and in all cases there is a distinctive lack of an edge.
Practically, this is close enough to a proof as to be understood as true despite not being a rigorous proof. No one really b
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I think it best comes down to the cosmological principle which states no matter where we observe the universe, that it should look roughly the same in a sense of energy and matter. This is accepted as an axiom and is like saying our perspective of the universe is not "special" in any way. If we do not suppose this, then it gets really hard to consider many aspects of cosmology because we have no real reason to suppose that anything we see relates to what's going on in the rest of the universe.
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I think it best comes down to the cosmological principle which states no matter where we observe the universe, that it should look roughly the same in a sense of energy and matter.
That idea is based on our current sensory ability and nothing else.
If we do not suppose this, then it gets really hard to consider many aspects of cosmology
Yeah, life is hard when you try to make linear extrapolations from incomplete data.
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In general this is called the flatness [wikipedia.org] of space, and it’s been measured to be within 1% of perfectly flat. However, to measure it being infinitely flat is not possib
Meaning of 'see' (Score:2)
If you see something from '13 billion light years' that doesn't mean its literally '13 billion light years away' because there is this thing called the expansion of the universe.
You did literally see it from 13 billion light-years away though because that is how far the photons travelled.
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Both perspectives are valid. The photon both took time and didn't take time. Weird things happen when space itself expands. We're seeing the obje
Summary wrong about transparent / opaque (Score:3)
The summary is wrong (inside the article quote) when it says
Scientists refer to this time as the universe's dark ages, because most light emitted was quickly absorbed by the neutrally charged gas. Eventually, gravity collapsed the primordial gas into the first stars and quasars, which began to heat and ionize the surrounding gases, allowing light to pass through
It is free electrons (ionized gas) that make a region opaque. At ~400,000 years, roughly the age of this quasar, the "soup" had recombined into neutral hydrogen and helium that was nice and transparent.
Subsequent reionization as stars formed was not enough to make the universe opaque again, because by then gas densities were extremely low.
Physics Error (Score:3)
Eventually, gravity collapsed the primordial gas into the first stars and quasars, which began to heat and ionize the surrounding gases, allowing light to pass through.
That is completely backwards. Neutral hydrogen gas will only absorb light at particular frequencies of visible light while the plasma you get from heating it to the point of ionization will interact with any frequency due to the free electrons and so be opaque. This is why the sun is not transparent it is also why we can see the cosmic microwave background radiation which are the photons released from the plasma that filled the universe when it transitioned to a neutral gas which was transparent.
The universe's dark age was simply a time when there was no source of light. The universe was transparent and not absorbing photons otherwise the cosmic microwave background would have been absorbed! The heating and re-ionization of the gas to form stars provided light sources that ended the dark ages by providing light.
3C273 (Score:2)
I've seen 3C273 in a telescope, a mere 2.5 billion light years away. A dim bluish star-like object in Virgo. When the photons that hit my retina started their journey multicellular life hadn't evolved on Earth.
As a challenge the next night I observed the nearest star, Proxima Centauri. Yes, I was in the tropics. A nondescript faint star in a busy Milky Way Field.
...laura
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I was at a science fair where someone had knitted a view of the sky, with LEDs for stars. Betelgeuse was in red. The presenter said it was red because it was likely to super-nova soon. My 10 year old daughter said "it might have super-noved already, but the light not reached us yet". That made my day.
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I was traveling in the Andes in 1987 and the bus I was on had a flat tire in the middle of nowhere just after midnight. A bunch of us got off, and most people took the unscheduled bathroom break and then got back on the warm bus, I walked over a hillock until I was shielded from even the bus lights and looked up. It was incredible. I got to see the first naked-eye visible supernova in four centuries, and stayed there until I was shivering so bad I could hardly hold my binoculars (it's freaking cold at 14