APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 4483
Joined: Fri Dec 04, 2009 3:27 am

APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by APOD Robot » Tue Jan 26, 2021 5:05 am

Image Central NGC 1316: After Galaxies Collide

Explanation: How did this strange-looking galaxy form? Astronomers turn detectives when trying to figure out the cause of unusual jumbles of stars, gas, and dust like NGC 1316. Inspection indicates that NGC 1316 is an enormous elliptical galaxy that somehow includes dark dust lanes usually found in a spiral galaxy. Detailed images taken by the Hubble Space Telescope shows details, however, that help in reconstructing the history of this gigantic tangle. Deep and wide images show huge collisional shells, while deep central images reveal fewer globular clusters of stars toward NGC 1316's interior. Such effects are expected in galaxies that have undergone collisions or merging with other galaxies in the past few billion years. The dark knots and lanes of dust, prominent in the featured image, indicate that one or more of the devoured galaxies were spiral galaxies. NGC 1316 spans about 50,000 light years and lies about 60 million light years away toward the constellation of the Furnace (Fornax).

<< Previous APOD This Day in APOD Next APOD >>

User avatar
Ann
4725 Å
Posts: 11658
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by Ann » Tue Jan 26, 2021 7:25 am


























Well... first came Cen A, as the product of a collision between an elliptical galaxy and a spiral galaxy.

Then came NGC 1316, where the spiral galaxy has been absorbed into the elliptical galaxy, and all that remains is dust bunnies.

Ann
Color Commentator

User avatar
orin stepanek
Plutopian
Posts: 7011
Joined: Wed Jul 27, 2005 3:41 pm
Location: Nebraska

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by orin stepanek » Tue Jan 26, 2021 2:38 pm

APOD quote "indicate that one or more of the devoured galaxies were spiral galaxies." :shock: This elliptical must have an enormous black hole!😬 I dub thee; The galaxy eater!

gigantic tangle.?
fe3ed7e7796e5cac54b9f68447ec7d82.jpg
That's what APOD says! :lol2:
You do not have the required permissions to view the files attached to this post.
Orin

Smile today; tomorrow's another day!

User avatar
johnnydeep
Commander
Posts: 950
Joined: Sun Feb 20, 2011 8:57 pm

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by johnnydeep » Tue Jan 26, 2021 3:15 pm

Ann wrote:
Tue Jan 26, 2021 7:25 am

Well... first came Cen A, as the product of a collision between an elliptical galaxy and a spiral galaxy.

Then came NGC 1316, where the spiral galaxy has been absorbed into the elliptical galaxy, and all that remains is dust bunnies.

Ann
Aren't those two scenarios essentially the same thing? That is, a merger between an elliptical and a spiral? Or are you pointing out that a size difference between the merging pairs can be used to say that one merged into the other? Or just that in NGC 1316, the merger is further along than in Centaurus A?
Last edited by johnnydeep on Tue Jan 26, 2021 3:16 pm, edited 1 time in total.
--
"To B̬̻̋̚o̞̮̚̚l̘̲̀᷾d̫͓᷅ͩḷ̯᷁ͮȳ͙᷊͠ Go......Beyond The F͇̤i̙̖e̤̟l̡͓d͈̹s̙͚ We Know."

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18579
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

All the king's horses

Post by neufer » Tue Jan 26, 2021 3:16 pm

https://en.wikipedia.org/wiki/NGC_1316 wrote:
<<NGC 1316 (also known as Fornax A) is a lenticular galaxy about 60 million light-years away in the constellation Fornax. It is a radio galaxy and at 1400 MHz is the fourth-brightest radio source in the sky. NGC 1316 is located at the edge of the Fornax Cluster [which] is a part of larger Fornax Wall. The Fornax Wall is a superstructure known as a galaxy filament or galaxy wall. It is a long filament of galaxies with a major axis longer than its minor one. The filament contains not only Dorado Group but also the Fornax cluster of galaxies, which lies at the same distance.>>
APOD Robot wrote:
Tue Jan 26, 2021 5:05 am

Explanation: How did this strange-looking galaxy form? Astronomers turn detectives when trying to figure out the cause of unusual jumbles of stars, gas, and dust like NGC 1316. Inspection indicates that NGC 1316 is an enormous elliptical galaxy that somehow includes dark dust lanes usually found in a spiral galaxy. Detailed images taken by the Hubble Space Telescope shows details, however, that help in reconstructing the history of this gigantic tangle. Deep and wide images show huge collisional shells, while deep central images reveal fewer globular clusters of stars toward NGC 1316's interior. Such effects are expected in galaxies that have undergone collisions or merging with other galaxies in the past few billion years. The dark knots and lanes of dust, prominent in the featured image, indicate that one or more of the devoured galaxies were spiral galaxies. NGC 1316 spans about 50,000 light years and lies about 60 million light years away toward the constellation of the Furnace (Fornax).
Last edited by neufer on Tue Jan 26, 2021 6:38 pm, edited 1 time in total.
Art Neuendorffer

User avatar
Ann
4725 Å
Posts: 11658
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by Ann » Tue Jan 26, 2021 6:37 pm

johnnydeep wrote:
Tue Jan 26, 2021 3:15 pm
Ann wrote:
Tue Jan 26, 2021 7:25 am

Well... first came Cen A, as the product of a collision between an elliptical galaxy and a spiral galaxy.

Then came NGC 1316, where the spiral galaxy has been absorbed into the elliptical galaxy, and all that remains is dust bunnies.

Ann
Aren't those two scenarios essentially the same thing? That is, a merger between an elliptical and a spiral? Or are you pointing out that a size difference between the merging pairs can be used to say that one merged into the other? Or just that in NGC 1316, the merger is further along than in Centaurus A?
The latter. :wink:

Ann
Color Commentator

User avatar
Ann
4725 Å
Posts: 11658
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by Ann » Tue Jan 26, 2021 6:42 pm

orin stepanek wrote:
Tue Jan 26, 2021 2:38 pm
APOD quote "indicate that one or more of the devoured galaxies were spiral galaxies." :shock: This elliptical must have an enormous black hole!😬 I dub thee; The galaxy eater!

gigantic tangle.?


That's what APOD says! :lol2:
My goodness!!!!

The cuteness is killing me!!! 😻😻😻😻

Ann
Color Commentator

VictorBorun
Science Officer
Posts: 362
Joined: Fri Oct 16, 2020 10:25 pm

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by VictorBorun » Wed Jan 27, 2021 4:55 am

Ann wrote:
Tue Jan 26, 2021 7:25 am
Well... first came Cen A, as the product of a collision between an elliptical galaxy and a spiral galaxy.
Then came NGC 1316, where the spiral galaxy has been absorbed into the elliptical galaxy, and all that remains is dust bunnies.
Ann
Knowing that dust is visible in front of galaxy bulge backlight, what can we think about dust lanes here?
Is Cen A realy a dark olive tyre, shown almost edge-on at 15° to our line of sight, with radius of 4 times the width, centered around a shining ivory ball with dense core radius of 1/4 tyre's radius and the pale halo radius of 1 tyre's radius?
Is NGC 1316 really a latte-colored shining ball with long chestnut streacks all over the surface and volume, that are quite dark at the very surface and gradually get lost to our eyes before they sink any deeper than R/10 from the surface?

VictorBorun
Science Officer
Posts: 362
Joined: Fri Oct 16, 2020 10:25 pm

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by VictorBorun » Wed Jan 27, 2021 7:10 am

come to think of it the dust in Cen A can be a disk rather than a tyre and still look like a tyre because of the same visibily trick that make dust streaks in NGC 1316 look so superficial.
Then it is no coincedence that the radius of the tyre is the radius of the halo part of the bulge. Our side of the surface of the shining halo is the thin hemisphere layer of the visibility of the implied dust disk.

User avatar
Ann
4725 Å
Posts: 11658
Joined: Sat May 29, 2010 5:33 am

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by Ann » Wed Jan 27, 2021 7:26 am

VictorBorun wrote:
Wed Jan 27, 2021 4:55 am

Knowing that dust is visible in front of galaxy bulge backlight, what can we think about dust lanes here?
Is Cen A realy a dark olive tyre, shown almost edge-on at 15° to our line of sight, with radius of 4 times the width, centered around a shining ivory ball with dense core radius of 1/4 tyre's radius and the pale halo radius of 1 tyre's radius?
Is NGC 1316 really a latte-colored shining ball with long chestnut streacks all over the surface and volume, that are quite dark at the very surface and gradually get lost to our eyes before they sink any deeper than R/10 from the surface?
As for the dust disk of Cen A, ESO has revealed it to us. They describe it as the shape of a parallelogram. No doubt the twisted shape of the dust lane (or rather, dust disk) reflects the tidal forces tearing at the spiral as it is being absorbed into the larger elliptical galaxy.

The galaxy at right is the remarkable polar ring galaxy NGC 660.
Wikipedia wrote:

NGC 660 is a peculiar and unique polar-ring galaxy located approximately 45 million light-years from Earth in the Pisces constellation.[3] It is the only such galaxy having, as its host, a "late-type lenticular galaxy".[4] It was probably formed when two galaxies collided a billion years ago.[5] However, it may have first started as a disk galaxy that captured matter from a passing galaxy. This material could have, over time, become "strung out" to form a rotating ring.































As for NGC 1316, I think of it as a cross between elliptical shell galaxy NGC 474 and active galaxy NGC 1275.

NGC 474 has probably absorbed smaller galaxies in the past and developed shells - think of the small galaxies as "pebbles splashing into the larger galaxy" and causing "ripples in a pond" - and now NGC 474 is interacting with a close spiral companion, which is further messing up its outer structures.

NGC 1275 has collided with and is absorbing a spiral galaxy. The dusty remnants of the spiral are still forming stars.

As for NGC 1316, note that it has shells somewhat similar to the shells of NGC 474, and note that it has a small spiral companion very nearby, just like NGC 474.

Note that the dust structures in NGC 1316 are quite small, compared with the full extent of the galaxy. Note that the shape of the tattered dust structures are somewhat similar to the tattered dust structures in NGC 1275. But unlike the dust in NGC 1275, the dust in NGC 1316 is not forming stars.

And that is really all I can say about the dust in NGC 1316!

Ann
Color Commentator

VictorBorun
Science Officer
Posts: 362
Joined: Fri Oct 16, 2020 10:25 pm

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by VictorBorun » Wed Jan 27, 2021 11:31 am

inner globe in NGC 1316 is a carbon copy of APOD post of NGC 1316…
Wait! It is one and the same galaxy!

VictorBorun
Science Officer
Posts: 362
Joined: Fri Oct 16, 2020 10:25 pm

Re: APOD: Central NGC 1316: After Galaxies Collide (2021 Jan 26)

Post by VictorBorun » Thu Jan 28, 2021 1:41 pm

Ann wrote:
Wed Jan 27, 2021 7:26 am
As for NGC 1316, I think of it as a cross between elliptical shell galaxy NGC 474 and active galaxy NGC 1275.
NGC 1275 has collided with and is absorbing a spiral galaxy. The dusty remnants of the spiral are still forming stars.
Note that the dust structures in NGC 1316 are quite small, compared with the full extent of the galaxy. Note that the shape of the tattered dust structures are somewhat similar to the tattered dust structures in NGC 1275.
They say that NGC 1275 pic shows in fact a pair of things. If I get it right the dark-brown dust + blue giants' formation specs above the center and, partly, in 8 o'clock direction off the center, belongs to a cluster crasher, a galaxy in front of NGC 1275 ramming away from us and toward the NGC 1275 at high velocity of 3000 km/s proving it came from outside the cluster.
This high-speeder is partly stripped of its gas disk by intergalactic cluster gas and partly converted its gas disk into new stars' formation.
No longer a disk it is deformed by tidal forces though it has still 200 kly to go before smashing into NGC 1275.

Somewhat similar looks belong to reddish magnetic tentacles 20 kly long extending from the NGC 1275's 800 million Solar masses black hole+accretion disk.

So all of the dust is in front of the backlight and there is no dust visibility trick here.