APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

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APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by APOD Robot » Mon Jul 16, 2018 4:05 am

Image Neutrino Associated with Distant Blazar Jet

Explanation: With equipment frozen deep into ice beneath Earth's South Pole, humanity appears to have discovered a neutrino from far across the universe. If confirmed, this would mark the first clear detection of cosmologically-distant neutrinos and the dawn of an observed association between energetic neutrinos and cosmic rays created by powerful jets emanating from blazing quasars (blazars). Once the Antarctican IceCube detector measured an energetic neutrino in 2017 September, many of humanity's premier observatories sprang into action to try to identify a counterpart in light. And they did. An erupting counterpart was pinpointed by high energy observatories including AGILE, Fermi, HAWC, H.E.S.S., INTEGRAL, NuSTAR, Swift, and VERITAS, which found that gamma-ray blazar TXS 0506+056 was in the right direction and with gamma-rays from a flare arriving nearly coincidental in time with the neutrino. Even though this and other position and time coincidences are statistically strong, astronomers will await other similar neutrino - blazar light associations to be absolutely sure. Pictured here is an artist's drawing of a particle jet emanating from a black hole at the center of a blazar.

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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by heehaw » Mon Jul 16, 2018 8:48 am

"Artist's drawings" of "things astronomical" always bother me. I fear that the public because of these too often thinks that REAL images are artist's conceptions, and so miss true wonders. (But then "real images" only capture a small fraction of what is going on anyway...)

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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by Boomer12k » Mon Jul 16, 2018 9:07 am

I don't know...in my mind it would a total white out....

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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by neufer » Mon Jul 16, 2018 11:31 am

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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by neufer » Mon Jul 16, 2018 12:56 pm

Click to play embedded YouTube video.
heehaw wrote:
Mon Jul 16, 2018 8:48 am

"Artist's drawings" of "things astronomical" always bother me. I fear that the public because of these too often thinks that REAL images are artist's conceptions, and so miss true wonders. (But then "real images" only capture a small fraction of what is going on anyway...)
Art Neuendorffer

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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by Ann » Mon Jul 16, 2018 1:16 pm

heehaw wrote:
Mon Jul 16, 2018 8:48 am
"Artist's drawings" of "things astronomical" always bother me. I fear that the public because of these too often thinks that REAL images are artist's conceptions, and so miss true wonders. (But then "real images" only capture a small fraction of what is going on anyway...)
Today's APOD screams "artist's impression" to me. I think it is because of the perfect circularity of the accretion disk of the black hole, which makes the accretion disk look like a good ol' vinyl long-playing record.

For me as a color commentator, I also question the fact that the entire system seems to be the same eerie whitish cyan color. Surely there must be temperature variations in a blazar system, too?

For all of that, the picture looks kind of cool to me. Or hot. I rather like it, even though I have reservations.

Ann

EDIT: Okay, I can see not that some of the outer parts of the blazar system are grayish-green rather than whitish cyan. And lo and behold, I spotted a reddish star!
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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by neufer » Mon Jul 16, 2018 1:39 pm

Ann wrote:
Mon Jul 16, 2018 1:16 pm
heehaw wrote:
Mon Jul 16, 2018 8:48 am

"Artist's drawings" of "things astronomical" always bother me. I fear that the public because of these too often thinks that REAL images are artist's conceptions, and so miss true wonders. (But then "real images" only capture a small fraction of what is going on anyway...)
Today's APOD screams "artist's impression" to me. I think it is because of the perfect circularity of the accretion disk of the black hole, which makes the accretion disk look like a good ol' vinyl long-playing record. For me as a color commentator, I also question the fact that the entire system seems to be the same eerie whitish cyan color. Surely there must be temperature variations in a blazar system, too?
Ergo...

1) it immediately sticks in your head along with associations (e.g., good ol' vinyl long-playing records)
2) and it makes you think about what is possibly wrong (or possibly right) with the image.
  • Who could ask for anything more :?:
https://en.wikipedia.org/wiki/Vera_Rubin wrote:
<<Vera Florence Cooper Rubin (July 23, 1928 – December 25, 2016) was an American astronomer who pioneered work on galaxy rotation rates. Her legacy was described by The New York Times as "ushering in a Copernican-scale change" in cosmological theory. As a young woman, Rubin decided to attend Vassar College because of Maria Mitchell, one of the first female astronomers, worked there. At the time, few women went to college, and almost no women studied math or science. When she was first applying for school, Rubin’s advisors told her to just become an astronomical artist instead of focusing on actual astronomy.>>
Last edited by neufer on Mon Jul 16, 2018 5:04 pm, edited 1 time in total.
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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by bystander » Mon Jul 16, 2018 2:24 pm

Ann wrote:
Mon Jul 16, 2018 1:16 pm
Today's APOD screams "artist's impression" to me. I think it is because of the perfect circularity of the accretion disk of the black hole, which makes the accretion disk look like a good ol' vinyl long-playing record.
APOD Robot wrote:
Mon Jul 16, 2018 4:05 am
Pictured here is an artist's drawing of a particle jet emanating from a black hole at the center of a blazar.

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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by Ann » Mon Jul 16, 2018 5:11 pm

neufer wrote:
Mon Jul 16, 2018 1:39 pm
Ann wrote:
Mon Jul 16, 2018 1:16 pm
heehaw wrote:
Mon Jul 16, 2018 8:48 am

"Artist's drawings" of "things astronomical" always bother me. I fear that the public because of these too often thinks that REAL images are artist's conceptions, and so miss true wonders. (But then "real images" only capture a small fraction of what is going on anyway...)
Today's APOD screams "artist's impression" to me. I think it is because of the perfect circularity of the accretion disk of the black hole, which makes the accretion disk look like a good ol' vinyl long-playing record. For me as a color commentator, I also question the fact that the entire system seems to be the same eerie whitish cyan color. Surely there must be temperature variations in a blazar system, too?
Ergo...

1) it immediately sticks in your head along with associations (e.g., good ol' vinyl long-playing records)
2) and it makes you think about what is possibly wrong (or possibly right) with the image.
  • Who could ask for anything more :?:
Well, it had to be an "artist's impression", because to my knowledge no actual detailed photo has ever been made of the inner workings of a blazar.

I also found the the accretion disk almost "impossibly" symmetrical. But I may be wrong there.

I also considered it a given thing that the inner parts of the accretion disk had to be hotter than the outer parts. Again I might be wrong. It could probably also be argued that the APOD really suggests that the inner parts of the accretions disk are hotter than the outer ones.

But once again, the picture had to be a painting, since no photo exists of the motif depicted.

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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by neufer » Mon Jul 16, 2018 6:40 pm

Ann wrote:
Mon Jul 16, 2018 5:11 pm

I also considered it a given thing that the inner parts of the accretion disk had to be hotter than the outer parts. Again I might be wrong. It could probably also be argued that the APOD really suggests that the inner parts of the accretions disk are hotter than the outer ones.
You do realize that all extremely hot objects have the same (Rayleigh–Jeans Law) blue color
with an intensity only linearly proportional to temperature:


Ann wrote:
Mon Jul 16, 2018 5:11 pm

But once again, the picture had to be a painting, since no photo exists of the motif depicted.
The issue at hand, IMO, is whether artistic renderings are inherently "bad" because:
  • 1) they are not recognized as such,
    2) they are inaccurate and/or
    3) they spoil many us from appreciating true (often blurry) representations.
For you to state that you personally recognize it as an inaccurate "fake" begs the question, IMO.
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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by Chris Peterson » Mon Jul 16, 2018 6:41 pm

Ann wrote:
Mon Jul 16, 2018 5:11 pm

I also found the the accretion disk almost "impossibly" symmetrical. But I may be wrong there.
I'm not sure what we'd see in terms of visible structure within an accretion disk. But I think they have to be extremely circular.
Chris

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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by Ann » Tue Jul 17, 2018 5:07 am

neufer wrote:
Mon Jul 16, 2018 6:40 pm
Ann wrote:
Mon Jul 16, 2018 5:11 pm

But once again, the picture had to be a painting, since no photo exists of the motif depicted.
The issue at hand, IMO, is whether artistic renderings are inherently "bad" because:
  • 1) they are not recognized as such,
    2) they are inaccurate and/or
    3) they spoil many us from appreciating true (often blurry) representations.
For you to state that you personally recognize it as an inaccurate "fake" begs the question, IMO.
I didn't, although I jumped to an inaccurate conclusion regarding the circularity of the disk.

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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by neufer » Tue Jul 17, 2018 3:58 pm

Ann wrote:
Tue Jul 17, 2018 5:07 am

I jumped to an inaccurate conclusion regarding the circularity of the disk.
https://en.wikipedia.org/wiki/Accretion_disk wrote:
<<When the accretion rate is sub-Eddington and the opacity very high, the standard thin accretion disk is formed. It is geometrically thin in the vertical direction (has a disk-like shape), and is made of a relatively cold gas, with a negligible radiation pressure. The gas goes down on very tight spirals, resembling almost circular, almost free (Keplerian) orbits. Thin disks are relatively luminous and they have thermal electromagnetic spectra, i.e. not much different from that of a sum of black bodies. Radiative cooling is very efficient in thin disks. Pringle contributed in the past thirty years many key results to accretion disk theory, and wrote the classic 1981 review that for many years was the main source of information about accretion disks, and is still very useful today.

A fully general relativistic treatment, as needed for the inner part of the disk when the central object is a black hole, has been provided by Page and Thorne, and used for producing simulated optical images by Luminet and Marck, in which it is to be noted that, although such a system is intrinsically symmetric its image is not, because the relativistic rotation speed needed for centrifugal equilibrium in the very strong gravitational field near the black hole produces a strong Doppler redshift on the receding side (taken here to be on the right) whereas there will be a strong blueshift on the approaching side. It is also to be noted that due to light bending, the disk appears distorted but is nowhere hidden by the black hole (in contrast with what is shown in the misinformed artist's impressions).
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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by MarkBour » Tue Jul 17, 2018 4:29 pm

Thanks for posting those added materials, Art. I loved Nino the Neutrino.
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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by neufer » Tue Jul 17, 2018 5:18 pm

MarkBour wrote:
Tue Jul 17, 2018 4:29 pm

Thanks for posting those added materials, Art. I loved Nino the Neutrino.
  • Well, it had to be an "artist's impression",
    because to my knowledge no actual detailed photo has ever been made of a neutrino.
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Re: APOD: Neutrino Associated with Distant Jet... (2018 Jul 16)

Post by MarkBour » Wed Jul 18, 2018 5:48 pm

neufer wrote:
Tue Jul 17, 2018 5:18 pm
MarkBour wrote:
Tue Jul 17, 2018 4:29 pm

Thanks for posting those added materials, Art. I loved Nino the Neutrino.
  • Well, it had to be an "artist's impression",
    because to my knowledge no actual detailed photo has ever been made of a neutrino.
Darn. But it is true, these fundamental particles speak Italian, right?
Mark Goldfain