APOD: The Galactic Center in Radio from... (2019 Jul 08)

Comments and questions about the APOD on the main view screen.
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APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by APOD Robot » Mon Jul 08, 2019 4:12 am

Image The Galactic Center in Radio from MeerKAT

Explanation: What's happening at the center of our galaxy? It's hard to tell with optical telescopes since visible light is blocked by intervening interstellar dust. In other bands of light, though, such as radio, the galactic center can be imaged and shows itself to be quite an interesting and active place. The featured picture shows the inaugural image of the MeerKAT array of 64 radio dishes just completed in South Africa. Spanning four times the angular size of the Moon (2 degrees), the image is impressively vast, deep, and detailed. Many known sources are shown in clear detail, including many with a prefix of Sgr, since the Galactic Center is in the direction of the constellation Sagittarius. In our Galaxy's Center lies Sgr A, found here just to the right of the image center, which houses the Milky Way's central supermassive black hole. Other sources in the image are not as well understood, including the Arc, just to the left of Sgr A, and numerous filamentary threads. Goals for MeerKAT include searching for radio emission from neutral hydrogen emitted in a much younger universe and brief but distant radio flashes.

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heehaw

Re: APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by heehaw » Mon Jul 08, 2019 8:56 am

VERY nice! Thank you so much!

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Re: APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by orin stepanek » Mon Jul 08, 2019 11:10 am

Yes indeed; very interesting! Kind of reminds be of a vast explosion! :shock: Probably more of an implosion though; being dominated by a vast black hole!
Orin

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Re: APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by Boomer12k » Mon Jul 08, 2019 12:24 pm

Very interesting. I wonder what the arc and filaments are... they remind me of "Bow Shocks" from stars or something, but they look different, almost like lightning... and so many of them... a magnetic thing? they appear aligned....

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Re: APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by neufer » Mon Jul 08, 2019 12:57 pm

Click to play embedded YouTube video.







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Re: APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by Psnarf » Mon Jul 08, 2019 4:36 pm

That is an interesting thread to the right of Sgr C. I wonder, what is exciting those threads? :shock:

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Re: APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by Astronymus » Mon Jul 08, 2019 5:24 pm

Inferno
Boomer12k wrote:
Mon Jul 08, 2019 12:24 pm
Very interesting. I wonder what the arc and filaments are... they remind me of "Bow Shocks" from stars or something, but they look different, almost like lightning... and so many of them... a magnetic thing? they appear aligned....

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Re: APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by Chris Peterson » Mon Jul 08, 2019 5:55 pm

Astronymus wrote:
Mon Jul 08, 2019 5:24 pm
Inferno
Boomer12k wrote:
Mon Jul 08, 2019 12:24 pm
Very interesting. I wonder what the arc and filaments are... they remind me of "Bow Shocks" from stars or something, but they look different, almost like lightning... and so many of them... a magnetic thing? they appear aligned....

:---[===] *
Plasma trapped in terrifying magnetic fields.
Very likely plasma. But the magnetic fields are not strong in any absolute sense. Even within a parsec of the galactic center, field strengths are only around 2 mGauss... almost three orders of magnitude weaker than Earth's own magnetic field at its surface. These galactic magnetic fields produce interesting effects more by their scale than by their strength.
Chris

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Ann
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Re: APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by Ann » Mon Jul 08, 2019 7:10 pm


























At left is a more wide-angle view of the Galactic center in radio waves. Check out this page where you can read more about the center of our Galaxy.

One tiny thing that I find interesting is that there appear to be three smilar-sized supernova remnants to the left of Sagittarius A*, and two much larger and therefore older supernova remnants to the right of it. I assume that the sites of star formation near Sgr A* has shifted over time. Usually, and typically, barred galaxies often display a ring of star formation near their central black holes, but active star formation is not taking place everywhere along the ring at the same time.

That's why I'm wondering if the "clustering" of supernova remnants of different ages in different places in the Galactic core also means that the regions of most active star formation near Sgr A* also have shifted over time.

My guess is that the elongated structure that we see stretching from upper left to lower right in the picture I posted is the ring of enhanced star formation in the nuclear region in our Galaxy, seen edge on.

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Re: APOD: The Galactic Center in Radio from... (2019 Jul 08)

Post by AVAO » Tue Jul 09, 2019 5:48 am

Ann wrote:
Mon Jul 08, 2019 7:10 pm

One tiny thing that I find interesting is that there appear to be three smilar-sized supernova remnants to the left of Sagittarius A*, and two much larger and therefore older supernova remnants to the right of it. I assume that the sites of star formation near Sgr A* has shifted over time. Usually, and typically, barred galaxies often display a ring of star formation near their central black holes, but active star formation is not taking place everywhere along the ring at the same time.

That's why I'm wondering if the "clustering" of supernova remnants of different ages in different places in the Galactic core also means that the regions of most active star formation near Sgr A* also have shifted over time.

My guess is that the elongated structure that we see stretching from upper left to lower right in the picture I posted is the ring of enhanced star formation in the nuclear region in our Galaxy, seen edge on.

Ann
I think you are right!

We see the ring from the side as a bar just like NGC 6782. This can be seen very well in the graphic from page 6 at the following scientific presentation: https://slideplayer.com/slide/3396193/

Jac from the AVAO team