APOD: The Galactic Center Radio Arc (2023 Apr 03)

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APOD Robot
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APOD: The Galactic Center Radio Arc (2023 Apr 03)

Post by APOD Robot » Mon Apr 03, 2023 4:05 am

Image The Galactic Center Radio Arc

Explanation: What causes this unusual curving structure near the center of our Galaxy? The long parallel rays slanting across the top of the featured radio image are known collectively as the Galactic Center Radio Arc and point out from the Galactic plane. The Radio Arc is connected to the Galactic Center by strange curving filaments known as the Arches. The bright radio structure at the bottom right surrounds a black hole at the Galactic Center and is known as Sagittarius A*. One origin hypothesis holds that the Radio Arc and the Arches have their geometry because they contain hot plasma flowing along lines of a constant magnetic field. Images from NASA's Chandra X-ray Observatory appear to show this plasma colliding with a nearby cloud of cold gas.

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AVAO
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Re: APOD: The Galactic Center Radio Arc (2023 Apr 03)

Post by AVAO » Mon Apr 03, 2023 5:44 am

APOD Robot wrote: Mon Apr 03, 2023 4:05 am Image The Galactic Center Radio Arc

Explanation: What causes this unusual curving structure near the center of our Galaxy? The long parallel rays slanting across the top of the featured radio image are known collectively as the Galactic Center Radio Arc and point out from the Galactic plane. The Radio Arc is connected to the Galactic Center by strange curving filaments known as the Arches. The bright radio structure at the bottom right surrounds a black hole at the Galactic Center and is known as Sagittarius A*. One origin hypothesis holds that the Radio Arc and the Arches have their geometry because they contain hot plasma flowing along lines of a constant magnetic field. Images from NASA's Chandra X-ray Observatory appear to show this plasma colliding with a nearby cloud of cold gas.

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Well researched article. Also look at the previous discussions:
viewtopic.php?t=42190

Ideally, however, an attempt should be made with reference documents to refer to open sources at arxiv or researchgate.

E.g. at: ...One origin hypothesis holds... https://www.researchgate.net/publicatio ... center_arc

E.g. at: ...to show this plasma colliding... https://www.researchgate.net/publicatio ... _Radio_Arc

Image

Sgr A* - 100 LY
Image

Sgr A* - 10 LY
Image

Sgr A* - 1 LY
Image

Sgr A* - 18 LightDays
Image

black hole
Image

jac berne (flickr)

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Re: APOD: The Galactic Center Radio Arc (2023 Apr 03)

Post by johnnydeep » Mon Apr 03, 2023 8:52 pm

Very nice zoom-in sequence AVAO! [ PS - why are most of your images in your posts non-clickable (no underlying "hot" URL), and how is that done? ]
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Re: APOD: The Galactic Center Radio Arc (2023 Apr 03)

Post by VictorBorun » Tue Apr 04, 2023 11:32 am

AVAO wrote: Mon Apr 03, 2023 5:44 am Sgr A* - 1 LY
Image

Sgr A* - 18 LightDays
Image

black hole
Image

jac berne (flickr)
do we see trails in a long exposure?

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AVAO
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Re: APOD: The Galactic Center Radio Arc (2023 Apr 03)

Post by AVAO » Tue Apr 04, 2023 7:25 pm

VictorBorun wrote: Tue Apr 04, 2023 11:32 am
AVAO wrote: Mon Apr 03, 2023 5:44 am Sgr A* - 1 LY
Image

Sgr A* - 18 LightDays
Image

black hole
Image

jac berne (flickr)
do we see trails in a long exposure?

In a sense yes...

The images come from "time-lapse film sequences", which are superimposed. So what you see is the movement of the closest stars around the black hole over about 10 years. Very fast moving stars show a darkly spaced pattern. It is interesting that the image of the black hole has only the size of the white pixel in the image above it, i.e. it is really extremely extremely small.

The image of the black hole with tentacle arms is also a superimposed version of all the variants that were submitted to the selection panel, from which one was then chosen. (The prettiest, the statistically most average, the one that fits best with the idea of a black hole, whatever)

...and by the way, I believe these tentacles are real .-) too

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Re: APOD: The Galactic Center Radio Arc (2023 Apr 03)

Post by VictorBorun » Tue Apr 04, 2023 8:45 pm

AVAO wrote: Tue Apr 04, 2023 7:25 pm
VictorBorun wrote: Tue Apr 04, 2023 11:32 am
AVAO wrote: Mon Apr 03, 2023 5:44 am Sgr A* - 1 LY
Image
do we see trails in a long exposure?
In a sense yes...

The images come from "time-lapse film sequences", which are superimposed. So what you see is the movement of the closest stars around the black hole over about 10 years. Very fast moving stars show a darkly spaced pattern. It is interesting that the image of the black hole has only the size of the white pixel in the image above it, i.e. it is really extremely extremely small.

The image of the black hole with tentacle arms is also a superimposed version of all the variants that were submitted to the selection panel, from which one was then chosen. (The prettiest, the statistically most average, the one that fits best with the idea of a black hole, whatever)

...and by the way, I believe these tentacles are real .-) too
Then straight lines must be back/fore ground stars too distant from Sgr A* to feel the attraction?

offtopic on tentacles
Given a small mass for Milky Way size galaxy and the story of mergers, is it probable that Sgr A* is a new impostor in the place of the original billion suns BH, that got kicked out after firing a gravitation waves packet in a merger with a dwarf galaxy BH with co-directional spin?
And that the impostor is a growing central BH currently multiple in a tight orbit?

offtopic 2
Asimov in a Foundation's sequel re-wrote Trantor's location off the galactic center. Must has been clear even then what a volcano it would be to settle around
Last edited by VictorBorun on Tue Apr 04, 2023 8:58 pm, edited 2 times in total.

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Chris Peterson
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Re: APOD: The Galactic Center Radio Arc (2023 Apr 03)

Post by Chris Peterson » Tue Apr 04, 2023 8:48 pm

VictorBorun wrote: Tue Apr 04, 2023 8:45 pm
AVAO wrote: Tue Apr 04, 2023 7:25 pm
VictorBorun wrote: Tue Apr 04, 2023 11:32 am
do we see trails in a long exposure?
In a sense yes...

The images come from "time-lapse film sequences", which are superimposed. So what you see is the movement of the closest stars around the black hole over about 10 years. Very fast moving stars show a darkly spaced pattern. It is interesting that the image of the black hole has only the size of the white pixel in the image above it, i.e. it is really extremely extremely small.

The image of the black hole with tentacle arms is also a superimposed version of all the variants that were submitted to the selection panel, from which one was then chosen. (The prettiest, the statistically most average, the one that fits best with the idea of a black hole, whatever)

...and by the way, I believe these tentacles are real .-) too
Then straight lines must be back/fore ground stars too distant from Sgr A* to feel the attraction?
I would think they are stars orbiting Sgr A* far enough away that their short arcs appear nearly straight.
Chris

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