APOD: Journey to the Center of the Galaxy (2024 Nov 24)

[APOD Robot]

Journey to the Center of the Galaxy

Explanation: What lies at the center of our galaxy? In Jules Verne's science fiction classic, A Journey to the Center of the Earth, Professor Liedenbrock and his fellow explorers encounter many strange and exciting wonders. Astronomers already know of some of the bizarre objects that exist at our Galactic Center, including vast cosmic dust clouds, bright star clusters, swirling rings of gas, and even a supermassive black hole. Much of the Galactic Center is shielded from our view in visible light by the intervening dust and gas, but it can be explored using other forms of electromagnetic radiation. The featured video is actually a digital zoom into the Milky Way's center which starts by utilizing visible light images from the Digitized Sky Survey. As the movie proceeds, the light shown shifts to dust-penetrating infrared and highlights gas clouds that were recently discovered in 2013 to be falling toward the central black hole.

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[AVAO]

Journey to the Center of the Galaxy

Explanation: What lies at the center of our galaxy? In Jules Verne's science fiction classic, A Journey to the Center of the Earth, Professor Liedenbrock and his fellow explorers encounter many strange and exciting wonders. Astronomers already know of some of the bizarre objects that exist at our Galactic Center, including vast cosmic dust clouds, bright star clusters, swirling rings of gas, and even a supermassive black hole. Much of the Galactic Center is shielded from our view in visible light by the intervening dust and gas, but it can be explored using other forms of electromagnetic radiation. The featured video is actually a digital zoom into the Milky Way's center which starts by utilizing visible light images from the Digitized Sky Survey. As the movie proceeds, the light shown shifts to dust-penetrating infrared and highlights gas clouds that were recently discovered in 2013 to be falling toward the central black hole.

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The white pixel in the middle has a size of 260 light minutes.
This means that the SMB is again 26 times smaller.
That is really extremely small.

[Ann]

Wow, Jac, that's a fantastic set of images as usual!

Yes indeed, the central black hole of the Milky Way is small and mostly quiet, and I think we are very lucky that that is the case. Consider the large galaxy grups that are completely dominated by barren ellipticals that are continually bathed the plasma and "explosive" winds from the humongous jets from the enormous black holes of the dominant ellipticals in such galaxy groups (think M87).

Radio image of M87. Note the jet. Credit: National Radio Astronomy Observatory/National Science Foundation

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The dominant galaxy in the system 3C 321 is actually striking its neighbor or satellite galaxy with its jet:

This is an illustration of what is actually going in in 3C 321. Credit: NASA, CXC, M. Weiss, Fine Art America

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The dominant galaxy in the system 3C 321 is zapping its neighbor with its jet. Credit: NASA, ESA, D. Evans (Harvard-Smithsonian Center for Astrophysics), X-ray: NASA/CXC/CfA/D.Evans et al.; Optical/UV: NASA/STScI; Radio: NSF/VLA/CfA/D.Evans et al., STFC/JBO/MERLIN

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These "death jets" are a part of the explanation of why mature galaxy clusters are completely dominated by "red and dead" elliptical galaxies. Of course, another explanation is the continuous "jostling", "fraying" and galactic "harassment" going on inside dense clusters where galaxies interact in such a way that they drive gas out of one another. The dominant galaxies in such clusters may have started their lives as ultraluminous infrared galaxies caught in a torrent of star formation which, however, soon consumed much of the gas reservoir of the galaxy and drove out much of the rest by exploding supernovas and a growing black hole.

I was not able to find a really impressive picture of an ultraluminous infrared galaxy, so you will have to settle for this infrared Spitzer Space Telescope image of M82, which is losing its gas because hundreds of supernovas are exploding after a torrent of star formation. Credit:

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Red and dead galaxy cluster Abell 1689. Credit: NASA/JPL/CaltechNASA; ESA; L. Bradley (Johns Hopkins University); R. Bouwens (University of California, Santa Cruz); H. Ford (Johns Hopkins University); and G. Illingworth (University of California, Santa Cruz)

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Yes! But we have a nice fairly small rather well-behaved black hole in Sagittarius A*. And so far, we are mostly undisturbed by either Andromeda or the Large Magellanic Cloud, although both of them will eventually come and get us!

Pastoral Landscape with Stream Fisherman and Strollers - Henri Rousseau

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But that will not happen in a long, long time, and humanity will not be here to witness it.

Time. Image credit: Shutterstock

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Ann

[johnnydeep]

That smudge of presumably gas at the end of the video looks like it is orbiting the SMB, not just falling in to it. But I suppose that all things do orbit a while first before being eaten. The orbital period here looks to be about a mere 10 years or so.

[Chris Peterson]

That smudge of presumably gas at the end of the video looks like it is orbiting the SMB, not just falling in to it. But I suppose that all things do orbit a while first before being eaten. The orbital period here looks to be about a mere 10 years or so.

The only way an orbiting body can fall into a black hole is for its orbit to decay, which requires removing energy. In the case of rigid bodies like planets or stars, that might be by radiating gravitational waves, but that takes a long, long time until the very end. In the case of gas, it's internal friction and turbulence, which is faster and explains accretion disk behavior. In most cases, black hole systems are very stable.

[johnnydeep]

That smudge of presumably gas at the end of the video looks like it is orbiting the SMB, not just falling in to it. But I suppose that all things do orbit a while first before being eaten. The orbital period here looks to be about a mere 10 years or so.

The only way an orbiting body can fall into a black hole is for its orbit to decay, which requires removing energy. In the case of rigid bodies like planets or stars, that might be by radiating gravitational waves, but that takes a long, long time until the very end. In the case of gas, it's internal friction and turbulence, which is faster and explains accretion disk behavior. In most cases, black hole systems are very stable.

So is the blob of gas really orbiting and destined to fall in? How long could that take?

[Chris Peterson]

That smudge of presumably gas at the end of the video looks like it is orbiting the SMB, not just falling in to it. But I suppose that all things do orbit a while first before being eaten. The orbital period here looks to be about a mere 10 years or so.

The only way an orbiting body can fall into a black hole is for its orbit to decay, which requires removing energy. In the case of rigid bodies like planets or stars, that might be by radiating gravitational waves, but that takes a long, long time until the very end. In the case of gas, it's internal friction and turbulence, which is faster and explains accretion disk behavior. In most cases, black hole systems are very stable.

So is the blob of gas really orbiting and destined to fall in? How long could that take?

A "blob" of gas in an otherwise reasonably gas-free orbit might go around for a long time, since it's probably behaving similarly to a rigid body... although I'm sure there is still energy lost to internal turbulence from tidal forces if nothing else, so it's going to be a lot less stable than a star. Also, a blob of gas would normally dissipate/evaporate, not condense, which is a further complication in predicting its future.

[johnnydeep]

The only way an orbiting body can fall into a black hole is for its orbit to decay, which requires removing energy. In the case of rigid bodies like planets or stars, that might be by radiating gravitational waves, but that takes a long, long time until the very end. In the case of gas, it's internal friction and turbulence, which is faster and explains accretion disk behavior. In most cases, black hole systems are very stable.

So is the blob of gas really orbiting and destined to fall in? How long could that take?

A "blob" of gas in an otherwise reasonably gas-free orbit might go around for a long time, since it's probably behaving similarly to a rigid body... although I'm sure there is still energy lost to internal turbulence from tidal forces if nothing else, so it's going to be a lot less stable than a star. Also, a blob of gas would normally dissipate/evaporate, not condense, which is a further complication in predicting its future.

Ok.

[Christian G.]

Journey to the Center of the Galaxy

Explanation: What lies at the center of our galaxy? In Jules Verne's science fiction classic, A Journey to the Center of the Earth, Professor Liedenbrock and his fellow explorers encounter many strange and exciting wonders. Astronomers already know of some of the bizarre objects that exist at our Galactic Center, including vast cosmic dust clouds, bright star clusters, swirling rings of gas, and even a supermassive black hole. Much of the Galactic Center is shielded from our view in visible light by the intervening dust and gas, but it can be explored using other forms of electromagnetic radiation. The featured video is actually a digital zoom into the Milky Way's center which starts by utilizing visible light images from the Digitized Sky Survey. As the movie proceeds, the light shown shifts to dust-penetrating infrared and highlights gas clouds that were recently discovered in 2013 to be falling toward the central black hole.

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10 ly

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1 ly

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18 LightDays

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The white pixel in the middle has a size of 260 light minutes.
This means that the SMB is again 26 times smaller.
That is really extremely small.

Indeed a fascinating sequence of images, AVAO!

If I journeyed to the center of the Galaxy I would definitely make a quick stop by the Quintuplet cluster to admire the Pistol star! Unless I’m mistaken it's in the area circled in white in the third image.

gc.jpg

[Ann]

If I journeyed to the center of the Galaxy I would definitely make a quick stop by the Quintuplet cluster to admire the Pistol star! Unless I’m mistaken it's in the area circled in white in the third image.

Click to view full size image

This is my favorite portrait of the galactic center. It's a Hubble/Spitzer collaboration:

STScI-01EVT5Y35KFV7KFJ7ERSGDNV40[1].jpg

Hubble-Spitzer Color Mosaic of the Galactic Center.
Credits: Hubble image: NASA, ESA, and Q.D. Wang;
Spitzer image: NASA, Jet Propulsion Laboratory, and S. Stolovy

Pistol Star Quintuplet Cluster Arches Cluster Hubble Spitzer.png

Ann

[AVAO]

[...]

Indeed a fascinating sequence of images, AVAO!

If I journeyed to the center of the Galaxy I would definitely make a quick stop by the Quintuplet cluster to admire the Pistol star! Unless I’m mistaken it's in the area circled in white in the third image.

Cool idea. I just don't know where you could get a sunscreen with protective factor 1.7E6

[Ann]

[...]

Indeed a fascinating sequence of images, AVAO!

If I journeyed to the center of the Galaxy I would definitely make a quick stop by the Quintuplet cluster to admire the Pistol star! Unless I’m mistaken it's in the area circled in white in the third image.

Cool idea. I just don't know where you could get a sunscreen with protective factor 1.7E6

Click to view full size image

Please tell me, Jac, how did you find - or create? - this image?

Ann

[AVAO]

[...]

Indeed a fascinating sequence of images, AVAO!

If I journeyed to the center of the Galaxy I would definitely make a quick stop by the Quintuplet cluster to admire the Pistol star! Unless I’m mistaken it's in the area circled in white in the third image.

Cool idea. I just don't know where you could get a sunscreen with protective factor 1.7E6

Click to view full size image

Please tell me, Jac, how did you find - or create? - this image?

Ann

There are no really good IR images of this object that also show the Pistol Star's surroundings well.
My image collage is a composite of various sources and a subjective choice of color just4fun.
That's why this is only an attachment and not in my actual Flickr gallery.
But okay, let's wait for JWST. I don't think it will be long now.
The JWST images in the near infrared (212N/322W) are unfortunately not yet released.

On ARXIV there are only old images like this:

Click to view full size image

Source: https://arxiv.org/abs/1407.1854

[Christian G.]

If I journeyed to the center of the Galaxy I would definitely make a quick stop by the Quintuplet cluster to admire the Pistol star! Unless I’m mistaken it's in the area circled in white in the third image.

Click to view full size image

This is my favorite portrait of the galactic center. It's a Hubble/Spitzer collaboration:

STScI-01EVT5Y35KFV7KFJ7ERSGDNV40[1].jpg

Hubble-Spitzer Color Mosaic of the Galactic Center.
Credits: Hubble image: NASA, ESA, and Q.D. Wang;
Spitzer image: NASA, Jet Propulsion Laboratory, and S. Stolovy

Pistol Star Quintuplet Cluster Arches Cluster Hubble Spitzer.png

Ann

I think it has become my favorite one also, thanks! It has an inferno feel to it.

opo0902a.jpg

And if you crop the full size original, the result is not that bad!

Pistol star.jpeg