APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

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APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by APOD Robot » Tue Nov 26, 2024 5:06 am

Image The Sombrero Galaxy from Webb and Hubble

Explanation: This floating ring is the size of a galaxy. In fact, it is a galaxy -- or at least part of one: the photogenic Sombrero Galaxy is one of the largest galaxies in the nearby Virgo Cluster of Galaxies. The dark band of dust that obscures the mid-section of the Sombrero Galaxy in visible light (bottom panel) actually glows brightly in infrared light (top panel). The featured image shows the infrared glow in false blue, recorded recently by the space-based James Webb Space Telescope (JWST) and released yesterday, pictured above an archival image taken by NASA's Hubble Space Telescope in visible light. The Sombrero Galaxy, also known as M104, spans about 50,000 light years and lies 28 million light years away. M104 can be seen with a small telescope in the direction of the constellation Virgo.

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Ann » Tue Nov 26, 2024 6:50 am

It is interesting to compare the new Webb image of M104 with an old Spitzer infrared image of the same galaxy:


Even though the JWST image is so much more detailed than the picture by Spitzer, both images reveal much the same inner structure of the Sombrero galaxy. There is a bright disk, and inside it there is a "gap" of some sort and inside that, close to the core, is another disk.

The text accompanying the Spitzer image contained this fascinating piece of into (or guesswork?):

Universe Today wrote:

“The Sombrero is more complex than previously thought,” said Dimitri Gadotti of the European Southern Observatory in Chile and lead author of the report. “The only way to understand all we know about this galaxy is to think of it as two galaxies, one inside the other.”

Although it might seem that the Sombrero is the result of a collision between two separate galaxies, that’s actually not thought to be the case. Such an event would have destroyed the disk structure that’s seen today; instead, it’s thought that the Sombrero accumulated a lot of extra gas billions of years ago when the Universe was populated with large clouds of gas and dust. The extra gas fell into orbit around the galaxy, eventually spinning into a flattened disk and forming new stars.

This is one of the first galaxies to be seen with such a dual structure — even though M104 has been known about since the mid-1700s.

I find this so fascinating. Perhaps the inner disk that we can see in both the JWST and the Spitzer images is the original disk, and the dust ring surrounding it is the extra gas that fell into orbit around the galaxy, eventually forming new stars?

Speaking about forming new stars, M104 appears to be almost devoid of new stars, the way I understand it. Let me show you two (small) ultraviolet images from GALEX, one showing M104, one showing NGC 1512. Note that M104 looks "all yellow", whereas NGC 1512 contains a lot of blue stuff:

M104 GALEX.png
M104 in ultraviolet light.
Credit: NASA/JPL-Caltech.

This is my point. NGC 1512 is not a very blue galaxy. Its B-V index is 0.810, which is kind of red, and its U-B index is 0.170, which is "okay ultraviolet". The U-B index shows that there is indeed star formation going on in NGC 1512, and hot ultraviolet stars are present. These hot stars are detected by GALEX, and they are shown as blue in the GALEX image.

So what about M104? Well, its B-V index is 0.980, which definitely makes the Sombrero Galaxy redder than NGC 1512. More interesting, however, is the U-B index of M104. It is 0.530. This means that so few hot stars are present in M104 that star formation in this galaxy is negligible. And because there are so extremely few hot stars in M104, GALEX makes M104 look all yellow.


And finally, I can't help myself. Don't you think that M104 looks quite a bit like Saturn?


I guess that the ice particles of Saturn's rings have fallen into orbit around Saturn in much the same way that those extra gas clouds fell into orbit around what was the original version of M104. Well, that's my amateur guess, anyway! :D

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Christian G. » Tue Nov 26, 2024 2:33 pm

Striking contrast for a stunning object! Webb images sure bring an edge to edge-on galaxies…
Sombrero_WebbHubble_960.jpg

Then again, M104 is stunningly beautiful no matter the image quality!
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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Cousin Ricky » Tue Nov 26, 2024 2:45 pm

APOD Robot wrote: Tue Nov 26, 2024 5:06 am Explanation: This floating ring is the size of a galaxy. In fact, it is a galaxy -- or at least part of one: the photogenic Sombrero Galaxy is one of the largest galaxies in the nearby Virgo Cluster of Galaxies. [...] The Sombrero Galaxy, also known as M104, spans about 50,000 light years and lies 28 million light years away. M104 can be seen with a small telescope in the direction of the constellation Virgo.
If it’s only 28 million light years away, how can it be a member of the Virgo Cluster? Isn’t it just in the cluster’s line of sight?

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Chris Peterson » Tue Nov 26, 2024 2:52 pm

Cousin Ricky wrote: Tue Nov 26, 2024 2:45 pm
APOD Robot wrote: Tue Nov 26, 2024 5:06 am Explanation: This floating ring is the size of a galaxy. In fact, it is a galaxy -- or at least part of one: the photogenic Sombrero Galaxy is one of the largest galaxies in the nearby Virgo Cluster of Galaxies. [...] The Sombrero Galaxy, also known as M104, spans about 50,000 light years and lies 28 million light years away. M104 can be seen with a small telescope in the direction of the constellation Virgo.
If it’s only 28 million light years away, how can it be a member of the Virgo Cluster? Isn’t it just in the cluster’s line of sight?
Indeed, it is not a member of the Virgo Cluster. It is part of a smaller cluster that (like the Local Group and the Virgo Cluster) are components of the Virgo Supercluster.
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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by gvann » Tue Nov 26, 2024 3:09 pm

In the Hubble picture, in the distant background, you can see a galaxy far, far away that looks like a miniature M104. It is in the upper right quadrant of the picture, about one fifth of the way down from the top and one sixth of the way left from the right edge. Like M104, it is seen edge-on and has a dark band that obscures part of the central bulge.

It's interesting to note that, in the JWST picture, the central bulge of that galaxy disappears, and the dark band shines brightly in blue, just like M104.

DanSzumski

Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by DanSzumski » Tue Nov 26, 2024 3:38 pm

When I see APOD photographs taken by telescopes confined to different portions of the electromagnetic spectrum, I always think that there could be on planet earth, organisms that see in alternative spectral ranges, for instance, infrared.

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Chris Peterson » Tue Nov 26, 2024 3:57 pm

DanSzumski wrote: Tue Nov 26, 2024 3:38 pm When I see APOD photographs taken by telescopes confined to different portions of the electromagnetic spectrum, I always think that there could be on planet earth, organisms that see in alternative spectral ranges, for instance, infrared.
There are organisms on Earth that see into the near-IR, and can sense (if not exactly "see") into middle-IR (thermal). And organisms that can see into near-UV, as well. Outside of that range biological detection starts running up against physical limits.
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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Ann » Tue Nov 26, 2024 4:51 pm

gvann wrote: Tue Nov 26, 2024 3:09 pm In the Hubble picture, in the distant background, you can see a galaxy far, far away that looks like a miniature M104. It is in the upper right quadrant of the picture, about one fifth of the way down from the top and one sixth of the way left from the right edge. Like M104, it is seen edge-on and has a dark band that obscures part of the central bulge.
APOD 26 November 2024 detail annotated.png

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by VictorBorun » Tue Nov 26, 2024 7:54 pm

Ann wrote: Tue Nov 26, 2024 4:51 pm
gvann wrote: Tue Nov 26, 2024 3:09 pm In the Hubble picture, in the distant background, you can see a galaxy far, far away that looks like a miniature M104. It is in the upper right quadrant of the picture, about one fifth of the way down from the top and one sixth of the way left from the right edge. Like M104, it is seen edge-on and has a dark band that obscures part of the central bulge.

APOD 26 November 2024 detail annotated.png


Ann
the Webb picture shows Mini-Sombrero too
The Sombrero Galaxy from Webb and Hubble (2024 Nov 26) -1.jpg
is this in fact a background galaxy? where is then this phenomenal object:
Besides that, M104 is also accompanied by an ultra-compact dwarf galaxy, discovered in 2009, with an absolute magnitude of −12.3, an effective radius of just 47.9 ly (3.03 million astronomical units), and a mass of 3.3×10^7 M_☉[37]
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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by VictorBorun » Tue Nov 26, 2024 8:47 pm

I wonder if there is a third concentric galaxy here, an elliptic galaxy half the size of the large disk galaxy.
It's hard to see in the w/h pictures
The Sombrero Galaxy from Webb and Hubble (2024 Nov 26) h.jpg
The Sombrero Galaxy from Webb and Hubble (2024 Nov 26) w.jpg
...
Click to view full size image 1 or image 2
but is prominent in ultra-violet
Image
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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by VictorBorun » Tue Nov 26, 2024 8:49 pm

GALEX.jpg
GALEX + h.jpg
GALEX + w.jpg
...
Click to view full size image 1 or image 2
Click to view full size image 1 or image 2
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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Ann » Tue Nov 26, 2024 8:58 pm

VictorBorun wrote: Tue Nov 26, 2024 8:47 pm I wonder if there is a third concentric galaxy here, an elliptic galaxy half the size of the large disk galaxy.
It's hard to see in the w/h pictures
The Sombrero Galaxy from Webb and Hubble (2024 Nov 26) h.jpgThe Sombrero Galaxy from Webb and Hubble (2024 Nov 26) w.jpg
...
Click to view full size image 1 or image 2
but is prominent in ultra-violet
Image
The bright yellow spot to the lower right of M104 in the GALEX image is a star, HD 110086.

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by johnnydeep » Tue Nov 26, 2024 10:30 pm

Ann wrote: Tue Nov 26, 2024 8:58 pm
VictorBorun wrote: Tue Nov 26, 2024 8:47 pm I wonder if there is a third concentric galaxy here, an elliptic galaxy half the size of the large disk galaxy.
It's hard to see in the w/h pictures
The Sombrero Galaxy from Webb and Hubble (2024 Nov 26) h.jpgThe Sombrero Galaxy from Webb and Hubble (2024 Nov 26) w.jpg
...
Click to view full size image 1 or image 2
but is prominent in ultra-violet
Image
The bright yellow spot to the lower right of M104 in the GALEX image is a star, HD 110086.

Ann
I believe Victor is referring not to that star on the lower right, but to the elliptical-ish bulge of stars at the center of the Sombrero. I myself however doubt it's another galaxy. But if it was, it might have been the seed around which the two rings formed by galactic cannibalism later on.
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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by johnnydeep » Tue Nov 26, 2024 10:34 pm

Speaking of yellow blobs, what's this one - just another foreground star, or is it background almost spherical elliptical galaxy?

whats this in the sombrero galaxy.jpg
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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by AVAO » Tue Nov 26, 2024 10:41 pm

APOD Robot wrote: Tue Nov 26, 2024 5:06 am Image The Sombrero Galaxy from Webb and Hubble
[...]
The Sombrero Galaxy, also known as M104, spans about 50,000 light years and lies 28 million light years away.
[...]

Hmmm. When I look at the cloud of X-ray sources around the Sombrero Galaxy, I don't know if it was originally that small.
Or to put it another way, what if we only see a small circle of dust around the center of the whole galaxy.

Click to view full size image 1 or image 2
original data: NASA/ESA/CSA (HST/JWST) (CHANDRA)
original data: WEBBLE with NASA/ESA/CSA (HST/JWST)

bigggger: https://live.staticflickr.com/65535/541 ... 0f30_o.jpg
Last edited by AVAO on Wed Nov 27, 2024 7:00 am, edited 1 time in total.

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by VictorBorun » Tue Nov 26, 2024 11:57 pm

johnnydeep wrote: Tue Nov 26, 2024 10:34 pm Speaking of yellow blobs, what's this one - just another foreground star, or is it background almost spherical elliptical galaxy?


whats this in the sombrero galaxy.jpg
it's large, it's visible in IR only. How can it be a star?

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by johnnydeep » Wed Nov 27, 2024 12:40 am

VictorBorun wrote: Tue Nov 26, 2024 11:57 pm
johnnydeep wrote: Tue Nov 26, 2024 10:34 pm Speaking of yellow blobs, what's this one - just another foreground star, or is it background almost spherical elliptical galaxy?


whats this in the sombrero galaxy.jpg
it's large, it's visible in IR only. How can it be a star?
And for that matter, it doesn't have diffraction spikes either!
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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by VictorBorun » Wed Nov 27, 2024 12:43 am

johnnydeep wrote: Wed Nov 27, 2024 12:40 am
VictorBorun wrote: Tue Nov 26, 2024 11:57 pm
johnnydeep wrote: Tue Nov 26, 2024 10:34 pm Speaking of yellow blobs, what's this one - just another foreground star, or is it background almost spherical elliptical galaxy?


whats this in the sombrero galaxy.jpg
it's large, it's visible in IR only. How can it be a star?
And for that matter, it doesn't have diffraction spikes either!
no stellar or quasar spikes in Hubble/Webb/GALEX of M104. Somehow

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Ann » Wed Nov 27, 2024 5:30 am

AVAO wrote: Tue Nov 26, 2024 10:41 pm
APOD Robot wrote: Tue Nov 26, 2024 5:06 am Image The Sombrero Galaxy from Webb and Hubble
[...]
The Sombrero Galaxy, also known as M104, spans about 50,000 light years and lies 28 million light years away.
[...]

Hmmm. When I look at the cloud of X-ray sources around the Sombrero Galaxy, I don't know if it was originally that small.
Or to put it another way, what if we only see a small circle of dust around the center of the whole galaxy.

Click to view full size image 1 or image 2
original data: NASA/ESA/CSA (HST/JWST) (CHANDRA)
original data: WEBBLE with NASA/ESA/CSA (HST/JWST)

bigg: https://live.staticflickr.com/65535/541 ... 0f30_o.jpg

Wikipedia does not agree with the APOD caption about the size of M104:

Wikipedia wrote about M104:

It has an isophotal diameter of approximately 29.09 to 32.32 kiloparsecs (94,900 to 105,000 light-years), making it slightly bigger in size than the Milky Way.
Wikipedia wrote:

The isophotal diameter is typically defined as the region enclosing all the light down to 25 mag/arcsec2 in the blue B-band, which is then referred to as the D25 standard.

I think that the swarm of X-ray sources around M104 belongs to the halo, and they don't necessarily say anything about the size of the original galaxy.

Then again, perhaps they really do. M104 may originally have been a purely elliptical galaxy with a small disk near its core. This inner disk may "always" have been smaller than the elliptical component of M104. Quite a few elliptical galaxies have got these small inner disks:


Even galaxies with very small central cores and no obvious signs of black holes may have small-ish inner disks surrounded by a smooth halo of old stars. Consider NGC 2976. And let's not even talk about disk galaxy M64 with its black eye!


The inner disk of M104 looks completely calm and undisturbed, and there are no signs of any even moderately recent outbursts of the galaxy's central black hole.

The formation history and inner workings of M104 are mysterious.

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by AVAO » Wed Nov 27, 2024 6:56 am

Ann wrote: Wed Nov 27, 2024 5:30 am

Wikipedia does not agree with the APOD caption about the size of M104:

Wikipedia wrote about M104:

It has an isophotal diameter of approximately 29.09 to 32.32 kiloparsecs (94,900 to 105,000 light-years), making it slightly bigger in size than the Milky Way.
Wikipedia wrote:

The isophotal diameter is typically defined as the region enclosing all the light down to 25 mag/arcsec2 in the blue B-band, which is then referred to as the D25 standard.

I think that the swarm of X-ray sources around M104 belongs to the halo, and they don't necessarily say anything about the size of the original galaxy.

Then again, perhaps they really do. M104 may originally have been a purely elliptical galaxy with a small disk near its core. This inner disk may "always" have been smaller than the elliptical component of M104. Quite a few elliptical galaxies have got these small inner disks:


Even galaxies with very small central cores and no obvious signs of black holes may have small-ish inner disks surrounded by a smooth halo of old stars. Consider NGC 2976. And let's not even talk about disk galaxy M64 with its black eye!


The inner disk of M104 looks completely calm and undisturbed, and there are no signs of any even moderately recent outbursts of the galaxy's central black hole.

The formation history and inner workings of M104 are mysterious.

Ann

ThanX Ann for your exciting report. Here is the comparison with the Andromeda galaxy. Jac

original data: NASA/ESA/CSA (JWST/CHANDRA)

original data: NASA/ESA (HERSCHEL/SST/CHANDRA)

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Ann » Wed Nov 27, 2024 10:17 am

AVAO wrote: Wed Nov 27, 2024 6:56 am

ThanX Ann for your exciting report. Here is the comparison with the Andromeda galaxy. Jac

original data: NASA/ESA/CSA (JWST/CHANDRA)

original data: NASA/ESA (HERSCHEL/SST/CHANDRA)

The contrast between the distribution of X-ray sources in M104 and Andromeda is striking indeed! But then again, Andromeda does not have an elliptical component or any sort of large diffuse halo.

Okay, well, correction... this is the size of Andromeda's halo:


All right! But Andromeda's halo is very, very different from the halo of M104. Read about Andromeda's halo here.

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by AVAO » Wed Nov 27, 2024 11:20 am

Ann wrote: Wed Nov 27, 2024 10:17 am
AVAO wrote: Wed Nov 27, 2024 6:56 am

ThanX Ann for your exciting report. Here is the comparison with the Andromeda galaxy. Jac
The contrast between the distribution of X-ray sources in M104 and Andromeda is striking indeed! But then again, Andromeda does not have an elliptical component or any sort of large diffuse halo.

Ann
Hmmm. What is the difference between the central bulge region of the Andromeda galaxy and an elliptical galaxy? Both are relatively gas-poor and full of old stars?

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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by Ann » Wed Nov 27, 2024 2:51 pm

AVAO wrote: Wed Nov 27, 2024 11:20 am
Ann wrote: Wed Nov 27, 2024 10:17 am
AVAO wrote: Wed Nov 27, 2024 6:56 am

ThanX Ann for your exciting report. Here is the comparison with the Andromeda galaxy. Jac
The contrast between the distribution of X-ray sources in M104 and Andromeda is striking indeed! But then again, Andromeda does not have an elliptical component or any sort of large diffuse halo.

Ann
Hmmm. What is the difference between the central bulge region of the Andromeda galaxy and an elliptical galaxy? Both are relatively gas-poor and full of old stars?

The difference is that Andromeda has a large flat (possibly warped) disk and a small bulge, whereas M104 has a huge spherical halo. Size matters!

Consider the difference between elliptical galaxies and spiral galaxies:


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Re: APOD: The Sombrero Galaxy from Webb and Hubble (2024 Nov 26)

Post by VictorBorun » Wed Nov 27, 2024 2:55 pm

Ann wrote: Wed Nov 27, 2024 10:17 am
AVAO wrote: Wed Nov 27, 2024 6:56 am

ThanX Ann for your exciting report. Here is the comparison with the Andromeda galaxy. Jac

original data: NASA/ESA/CSA (JWST/CHANDRA)

original data: NASA/ESA (HERSCHEL/SST/CHANDRA)

The contrast between the distribution of X-ray sources in M104 and Andromeda is striking indeed! But then again, Andromeda does not have an elliptical component or any sort of large diffuse halo.

Okay, well, correction... this is the size of Andromeda's halo:


All right! But Andromeda's halo is very, very different from the halo of M104. Read about Andromeda's halo here.

Ann
Can we say a large regular galaxy has 2 components, a planar viscous gas/dust disk and a spherical purely stellar bulge.
If the bulge is tiny then it is called a core and the host galaxy is called a disk galaxy;
if the disk is tiny then the host galaxy is called an elliptic galaxy,
and if the two are comparable in size then the host galaxy is called a bulge Sombreroid?
Last edited by VictorBorun on Wed Nov 27, 2024 4:14 pm, edited 1 time in total.