APOD: Spiral Galaxy NGC 1512: The Nuclear Ring (2017 Jul 10)

[APOD Robot]

Spiral Galaxy NGC 1512: The Nuclear Ring

Explanation: What's happening around the center of this spiral galaxy? Seen in total, NGC 1512 appears to be a barred spiral galaxy -- a type of spiral that has a straight bar of stars across its center. This bar crosses an outer ring, though, a ring not seen as it surrounds the pictured region. Featured in this Hubble Space Telescope image is an inner ring -- one that itself surrounds the nucleus of the spiral. The two rings are connected not only by a bar of bright stars but by dark lanes of dust. Inside of this inner ring, dust continues to spiral right into the very center -- possibly the location of a large black hole. The rings are bright with newly formed stars which may have been triggered by the collision of NGC 1512 with its galactic neighbor, NGC 1510.

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[/b]

[Ann]

Click to view full size image

Starburst ring of unbarred spiral M94.
Source: https://www.spacetelescope.org/images/potw1542a/

Click to view full size image

Barred NGC 6782 with an inner and an outer ring.

Click to view full size image

The inner and the outer ring of NGC 1512.
Photo: NASA, ESA, and D. Maoz

Those inner stellar rings are not entirely uncommon. Of course, they are mostly seen in barred galaxies, and M94, in the picture at top left, is not barred. But NGC 1512 is. And barred spirals sometimes have both an inner and an outer ring.

And NGC 1512 is one of those galaxies that have an inner and an outer ring, just like NGC 6782.

Ann

[MikeA]

What strikes me in this picture is the seeming disconnect between the dust lanes and the star-forming regions - as if to imply that star nurseries are not reliant on an abundance of inter-stellar dust.

[Boomer12k]

In the Ultraviolet image on Wikipedia, I think it is clear, it had disrupted, and STOLEN some of the other galaxy's gas dust and stars... it appears, "Mid-Merger"... the other appears totally disrupted... poor thing is in Shock...

https://en.wikipedia.org/wiki/NGC_1512

My thought.
:---[===] *

[Guest]

Terrible apod. The explanation didn't make sense until I found the picture of the entire galaxy which this is part of. They should have posted that picture instead or posted a split screen with both.

[heehaw]

Great APOD! Made me use my brain! Whee!
This galaxy made me think of Hamlet: "There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy."

[JohnD]

I share Guest's confusion!

The blurb just doesn't match the image shown as today's APOD, or the galaxies that the blurb links to!
It just doesn't look like a barred galaxy - no bar! - and nothing like the example NGC 1672.
The Wiki entry for NGC 1512, given to show it "Seen in total", looks exactly like the APOD - no outer rings at all.
And a Google for other images of 1512 find it as an oval, angulated as seen from Earth, with a distinct bar, no dust lanes and wide spiral arms, not an outer ring. See: http://www.billionsandbillions.com/ngc_1512.html

Shurley shome osher Galashie?
John

[JohnD]

PS Is the Galaxy shown, whichever it is, a precursor to the type represented by Hoag's Object?
Featured four times in previous APODs! Last: https://apod.nasa.gov/apod/ap130728.html

[Case]

I share Guest's confusion! […] And a Google for other images of 1512 find it as an oval, angulated as seen from Earth, with a distinct bar, no dust lanes and wide spiral arms, not an outer ring. See: http://www.billionsandbillions.com/ngc_1512.html

Steve Mazlin, also from SSRO-South (Chile), like your link, imaged it too, and processed it a bit differently: http://www.starshadows.com/gallery/disp ... ?imgID=534 (mirrored for some reason).

The ring you see there *is* the outer ring. The bright center harbours the inner ring. (I’ll use a DSS II image, so I don’t need anyone’s permission. A bit blue for this part of the sky, but those are the breaks.) The red box in the center represents today’s APOD field of view. Total field of view is 15 arcmin. Note that it doesn’t show the outer arms as clearly as the links above.

[JohnD]

OK, thank you, Case, for that clarification! All is now clear(er).
But it certainly wasn't clear from the blurb!

The Wiki entry for 1510 shows how the spiral arms of 1512 have been splayed out most clearly - that entry is in the German Wiki
https://de.wikipedia.org/wiki/NGC_1510 and shows the outer ring clearly, while the inner that the APOD focussed down on is shown as just a galactic hub glow. That and yours reveals the APOD as a remarkable image!

John

[starsurfer]

This circumnuclear ring is awesome! The CHART32 image shows the whole galaxy. NGC 1433 in the same constellation also has one!

Also I think tomorrow's APOD will be Omega Centauri.

[Guest]

I deeply appreciate that I am the duffer in this flight, but the assertion that "dust continues to spiral right into the very center" of this galaxy defies basic observational logic. I know what I am about to suggest completely defies current thinking, but it looks to me that the brilliant area in the center of this galaxy is the SOURCE of the material in the arms of the galaxy. It looks like a lawn sprinkler shooting out water. I know the universe is stranger than we can imagine, but isn't the physics we experience down here the same as what we observe out there?

[Chris Peterson]

I deeply appreciate that I am the duffer in this flight, but the assertion that "dust continues to spiral right into the very center" of this galaxy defies basic observational logic. I know what I am about to suggest completely defies current thinking, but it looks to me that the brilliant area in the center of this galaxy is the SOURCE of the material in the arms of the galaxy. It looks like a lawn sprinkler shooting out water. I know the universe is stranger than we can imagine, but isn't the physics we experience down here the same as what we observe out there?

The dust is neither moving inwards nor outwards. Any given region of dust is orbiting the center of the galaxy in an elliptical orbit (just like the physics we observe everywhere).

Morphologically, the spiral structure continues to the very center. That isn't the same as saying that dust is being transported radially.

[neufer]

Those inner stellar rings are not entirely uncommon. Of course, they are mostly seen in barred galaxies, and M94 is not barred. But NGC 1512 is. And barred spirals sometimes have both an inner and an outer ring.

---

<<Messier 94 (also known as NGC 4736) contains both an inner ring with a diameter of 70 arcseconds and an outer ring with a diameter of 600 arcseconds. The inner ring is the site of strong star formation activity and is sometimes referred to as a starburst ring. This star formation is fueled by gas that is dynamically driven into the ring by the inner oval-shaped bar-like structure. There are several possible external events that could have led to the origin of M94's outer disk including the accretion of a satellite galaxy or the gravitational interaction with a nearby star system. However, further research found problems with each of these scenarios. Therefore, the report concludes that the inner disk of M94 is an oval distortion which led to the creation of this galaxy's peripheral disk.

A study was published in 2008 showing that M94 had very little or no dark matter present. The study analyzed the rotation curves of the galaxy's stars and the density of hydrogen gas and found that ordinary luminous matter appeared to account for all of the galaxy's mass. This result has yet to be confirmed or accepted by other research groups, however, and has not actually been tested against the predictions of standard galaxy formation models.>>

When two comparably sized galaxies (e.g., Andromeda & the Milky Way) collide
what prevents their dark matter from elastically escaping into space
and leave their disturbed in-elastically colliding gases behind

[bystander]

[img3="NGC 1512 - Credit: NASA / ESA / LEGUS / Judy Schmidt"]https://c1.staticflickr.com/1/645/30969 ... 7524_z.jpg[/img3][hr][/hr]

Terrible apod. The explanation didn't make sense until I found the picture of the entire galaxy which this is part of. They should have posted that picture instead or posted a split screen with both.

I share Guest's confusion! The blurb just doesn't match the image shown as today's APOD, or the galaxies that the blurb links to! It just doesn't look like a barred galaxy - no bar! - and nothing like the example NGC 1672. ...

I think maybe you just aren't parsing the blurb correctly. I think it clearly states that this is just the central region of NGC 1512.

...
This bar crosses an outer ring, though, a ring not seen as it surrounds the pictured region. Featured in this Hubble Space Telescope image is an inner ring -- one that itself surrounds the nucleus of the spiral. ...

If you follow the link "an outer ring," it becomes very clear.

[neufer]

I think maybe you just aren't parsing the blurb correctly.
I think it clearly states that this is just the central region of NGC 1512.

• [list]"Parsing the Blurb"

Sunset and evening star,
And one clear call for me!
And may there be no moaning of the blurb,
When I put out to sea,

But such a tide as moving seems asleep,
Too full for sound and foam,
When that which drew from out the boundless deep
Turns again home.

Twilight and evening bell,
And after that the dark!
And may there be no sadness of farewell,
When I embark;

For tho' from out our bourne of Time and Place
The flood may bear me far,
I hope to see my Pilot face to face
When I have parst the blurb.[/list]

[geoffrey.landis]

The explanation didn't make sense until I found the picture of the entire galaxy which this is part of. They should have posted that picture instead or posted a split screen with both.

Absolutely agree-- without the context (https://www.flickr.com/photos/geckzilla ... otostream/), the APoD image zoomed in to just the nucleus is pretty much uncomprehensible.
(I think it would also be useful if the APoD had pointed out that this is from a UV survey, and hence the colors shown are most likely UV-- older stars are not going to show up very brightly in the image.)

[MarkBour]

... warped Tennyson ...

Nice. Not a poem I'd read before, but it seems it could be fit to a galactic encounter.

[neufer]

... warped Tennyson ...

Nice. Not a poem I'd read before, but it seems it could be fit to a galactic encounter.

<<Vogon poetry is described as "the third worst poetry in the Universe" (behind that of the Azgoths of Kria; four members of an audience died of internal haemorrhaging during a recitation by their poet master Grunthos the Flatulent of his poem "Ode to a Small Lump of Green Putty I Found in My Armpit One Midsummer Morning" while the President of the Mid-Galactic Arts Nobbling Council survived by gnawing one of his own legs off. Grunthos himself was later killed by his own major intestine, which leaped up through his neck and throttled his brain when he attempted to read his twelve-book epic "My Favourite Bathtime Gurgles". Their poetry was also behind that of Paula Nancy Millstone Jennings of Sussex, which was destroyed when the Earth was.)>>

[geckzilla]

The explanation didn't make sense until I found the picture of the entire galaxy which this is part of. They should have posted that picture instead or posted a split screen with both.

Absolutely agree-- without the context (https://www.flickr.com/photos/geckzilla ... otostream/), the APoD image zoomed in to just the nucleus is pretty much uncomprehensible.
(I think it would also be useful if the APoD had pointed out that this is from a UV survey, and hence the colors shown are most likely UV-- older stars are not going to show up very brightly in the image.)

One of the great things about the LEGUS survey is that they are also collecting broadband blue, green, and near-infrared data on top of the three (usually) UV bands. In my descriptions below the images at Flickr you can see things like F814W which indicate the center wavelength and the width of the band pass. In this case, 814 is the wavelength in nanometers (just beyond human vision) and W for wide.

Regarding the confusion of the APOD, I must also note that I found it difficult to post about both of the images in a way that was not momentarily confusing. The fact that the galaxy has two rings and that Hubble is looking at it so closely does make it disorienting. I just wish figuring it out made people happy instead of annoyed.

[Chris Peterson]

Regarding the confusion of the APOD, I must also note that I found it difficult to post about both of the images in a way that was not momentarily confusing. The fact that the galaxy has two rings and that Hubble is looking at it so closely does make it disorienting. I just wish figuring it out made people happy instead of annoyed.

Some people are never happy.

[neufer]

-- without the context (https://www.flickr.com/photos/geckzilla ... otostream/), the APoD image zoomed in to just the nucleus is pretty much uncomprehensible.

Regarding the confusion of the APOD, I must also note that I found it difficult to post about both of the images in a way that was not momentarily confusing. The fact that the galaxy has two rings and that Hubble is looking at it so closely does make it disorienting. I just wish figuring it out made people happy instead of annoyed.

It certainly would have helped if the first reference to NGC 1512 went to https://www.flickr.com/photos/geckzilla/30969093023/ (or some other full picture) and not to a Wikipedia site that also talks first about it being a barred galaxy without showing it.

(Most APOD users are visually biased.)

Glossologics: Can’t see the Wood for the Trees
September 6, 2013 by alexpolistigers

<<This expression, still popular today, has been in use in largely the same form for centuries. Many dictionaries trace it back as far as 1546, where it was recorded in John Heywood’s “Prouerbes in the English Tongue”. He wrote “Plentie is no deinte, ye see not your owne ease. I see, ye can not see the wood for trees.” However, in order for Heywood to include it in his work, it must have already been widely known and recognised, which of course gives us the first clue that there might be a longer history than at first thought.

An intriguing reference appears in a work by Thomas More, who was famously executed by King Henry VIII. This was the enormously titled “The second parte of the confutacion of Tyndals answere in whyche is also confuted the chyrche that Tyndale deuyseth. And the chyrche also that frere Barns deuyseth”, generally known simply as “The Confutation of Tyndale’s Answer”, which is dated 1533, thus putting it 13 years before Heywood’s work.

Here’s the section, with the expression at the end: “Uery well declared, as though he wold tell vs that there were a woman that went inuysyble, and that he ment not that her handes, or her fete, or her hed, or any parte of her were inuysyble / but all her partes beynge vysyble, her self were yet inuysyble. And as he myght tell vs, that of Poules chyrch we may well se the stones, but we can not se the chyrce. And then we may well tell hym agayne, that he can not se the wood for the trees.” (p. ccccxxxvii, in Book VIII.)>>

[JohnD]

Is that you Art, making Tennyson turn in his grave?
Nice one!
John

[neufer]

Is that you Art, making Tennyson turn in his grave? Nice one!

Yours is not to make reply,
Yours is not to reason why,
Yours is but to do & die,

(And may there be no moaning of the blurb,)

[Fred the Cat]

I just wish figuring it out made people happy instead of annoyed.

Fiat Lux. Not that one. This one.

And it was good! Thanks Geck and Isaac.

And we still so humbled in not knowing the answer.