One spiral galaxy eating another
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of an on-going survey of known pecular-looking galaxies. This pair is believed to be 570 million light years away. From the caption:
Galaxies are composed of stars and their solar systems, dust and gas. In galactic collisions, therefore, these constituent components may experience enormous changes in the gravitational forces acting on them. In time, this completely changes the structure of the two (or more) colliding galaxies, and sometimes ultimately results in a single, merged galaxy. That may well be what results from the collision pictured in this image. Galaxies that result from mergers are thought to have a regular or elliptical structure, as the merging process disrupts more complex structures (such as those observed in spiral galaxies). It would be fascinating to know what Arp 122 will look like once this collision is complete . . . but that will not happen for a long, long time.
From our viewpoint, the spiral galaxy at the top appears warped by the gravitational pull of the face-on spiral at the bottom, as if it is being sucked into the bottom galaxy. In truth, both galaxies are pulling on each other. If we could circle around and see them in three dimensions we would almost certainly see distortions in the bottom spiral as well.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Click for original image.
Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken by the Hubble Space Telescope as part of an on-going survey of known pecular-looking galaxies. This pair is believed to be 570 million light years away. From the caption:
Galaxies are composed of stars and their solar systems, dust and gas. In galactic collisions, therefore, these constituent components may experience enormous changes in the gravitational forces acting on them. In time, this completely changes the structure of the two (or more) colliding galaxies, and sometimes ultimately results in a single, merged galaxy. That may well be what results from the collision pictured in this image. Galaxies that result from mergers are thought to have a regular or elliptical structure, as the merging process disrupts more complex structures (such as those observed in spiral galaxies). It would be fascinating to know what Arp 122 will look like once this collision is complete . . . but that will not happen for a long, long time.
From our viewpoint, the spiral galaxy at the top appears warped by the gravitational pull of the face-on spiral at the bottom, as if it is being sucked into the bottom galaxy. In truth, both galaxies are pulling on each other. If we could circle around and see them in three dimensions we would almost certainly see distortions in the bottom spiral as well.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
They’re not colliding, they’re hugging! https://thompsonblog.co.uk/2024/01/the-thrill-of-word-policing.html
Shouldn’t the universal expansion have kept them from running into each other?
If they were formed close to each other they would not have had time to form spirals. They would have merged long before then.
All formed galaxies should be moving away from each other right?
pzatchok-
pretty much all formed (or not) galaxies are moving away from each other, except for those that are gravitationally bound to each other.
“… except for those that are gravitationally bound to each other.”
That’s the rub. Large, extensive galaxy clusters aren’t gravitationally bound together, but smaller clusters – such as, e.g., our Local Group of galaxies, which includes our Milky Way as well as Andromeda (M31) and more than 80 other galaxies (mostly dwarf) – can be and are bound together gravitationally.
Robert – My humble typo help: “One spiral galaxy ***eatng*** another” – eatng = eating?
Thanks for all your great work.
Doubting Thomas: I had to look three times before I saw the problem. Now fixed. Thank you.
Pink Floyd – Dark Side Of The Moon
“Speak To Me / Breath”
https://youtu.be/DLOth-BuCNY
(7:26)
[The whole thing is good but jump to 4:40 for some cool galaxy-collision animation.]
Wayne, perfect audio choice. The 60’s and 70’s certainly were the decades of American reflection and realization. What will 2024 be? The year of subjugation and authoritarian control?
Or political realization and revolution within the mass of the people of America?
Stand by.
“Truth is not the job of government; control of power and governance is the job of the entity “Government” (SEE: S.O.M.). Your, my, our juvenile paternal need to see government as the teller of truth and having our best interests in mind is a false reality Pedestrian Realm perspective. And fear related to that perspective is a tool of manipulation in pursuit of power and control.”
https://www.sigma3ioc.com/post/about-climate-change
Why the small clusters and not the large clusters?
Gravity should be just as strong between the large as the small.
The small combine into large.
Technically, the galaxies aren’t so much ‘moving away from each other’ as much as ‘space is being created between them.’ How much space is created is more-or-less constant, as near as we can tell, so the distance created over a given time span is a linear relation to the distance between the objects. Meanwhile, the gravity effect decreases by the square of the distance.
Anyway, point is universal expansion is a bigger deal the further away two objects are, while gravity becomes lesser, so once you get far enough away the space between gets bigger faster than gravity can pull them together. Eventually, they end up so far away that space in between expands faster than light can travel and you can’t see it any longer.
Unless, of course, they’re close enough that gravity wins the tug-of-war and they eventually ‘hug.’
It’s also worth pointing out that small and large galactic clusters aren’t bigger and smaller versions at more-or-less the same scale; a large cluster is a collection of small clusters, magnitudes bigger in scale.