a thought for the day

www.sciencealert.com/hubble-has-imaged-a-spooky-face-staring-at-us-from-deep-space?fbclid=IwAR3dcE9F4yjBB4LsciuUq3wBd2DjGaCF6Y0iqa23IdBmJIGEoI4Aid2yEXs

Arp-Madore 2026-424; located around 704 million light-years away, it sports an unusual head-shaped appearance because of the turbulent effects of two galaxies colliding.
The blue 'ring' around the merging galaxies is a product of the collision. As the two galaxies merge, their interaction is thought to produce a gravitational shock wave that pushes material outwards. When this material collides and compresses, it triggers a wave of star formation. The ring is made of millions of bright, young stars.

Mind boggling.

I know what you mean, but it's slow motion at hundreds of km/second - galaxies are so damn big the motion seems imperceptible.

It's incomprehensible, really.

Real Science Fiction

Was it Hitch Hikers that said.....
Yes
“Space is big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.”

― Douglas Adams, The Hitchhiker's Guide to the Galaxy

Incomprehensible

The later stages of a 3 way galaxy collision - and the super massive black holes that were at the centre of each galaxy have been detected within a mere 3,000 light years of each other, each one is >90 million solar masses. They will likely merge within a few million years to become the central focus of the giant galaxy that will form and settle down to 'normality' over the next billion years or so.



NGC 6240 is an ongoing collision between three galaxies about 300 million light years away. Hard X-rays from two sources near the center of the merging galaxies indicated the presence of two supermassive black holes. Astronomers have now found a third.

astronomynow.com/2019/11/23/a-galactic-train-wreck-with-three-supermassive-black-holes/

What an amazing image.
This galaxy is a real mystery.



"[Hoags Object: A Nearly Perfect Ring Galaxy ]
Is this one galaxy or two? This question came to light in 1950 when astronomer Arthur Hoag chanced upon this unusual extragalactic object.

On the outside is a ring dominated by bright blue, younger stars, while near the center lies a ball of much redder stars that are likely much older. Between the two is a gap that appears almost completely dark.

How Hoag's Object formed, including its nearly perfectly round ring of stars and gas, remains unknown. Genesis hypotheses include a galaxy collision billions of years ago and the gravitational effect of a central bar that has since vanished.

The photo was taken by the Hubble Space Telescope and recently reprocessed using an artificially intelligent de-noising algorithm. Observations in radio waves indicate that Hoag's Object has not accreted a smaller galaxy in the past billion years.

Hoag's Object spans about 100,000 light years and lies about 600 million light years away toward the constellation of the Snake (Serpens). Many galaxies far in the distance are visible toward the right, while coincidentally, visible in the gap at about seven o'clock, is another but more distant ring galaxy."

The two galaxies in this image taken by Hubble, named NGC 6285 (left) and NGC 6286 (right), have strayed a little too close. Together, the duo is named Arp 293 and they are interacting, their mutual gravitational attraction pulling wisps of gas and streams of dust from them, distorting their shapes, and gently smudging and blurring their appearances on the sky

The peculiarities of this galaxy are (probably) not the result of a collision with another galaxy, but it's a fascinating and very pretty one!

[Starburst Galaxy M94 from Hubble ]
Why does this galaxy have a ring of bright blue stars? Beautiful island universe Messier 94 lies a mere 15 million light-years distant in the northern constellation of the Hunting Dogs (Canes Venatici). A popular target for Earth-based astronomers, the face-on spiral galaxy is about 30,000 light-years across, with spiral arms sweeping through the outskirts of its broad disk.

But this Hubble Space Telescope field of view spans about 7,000 light-years across M94's central region. The featured close-up highlights the galaxy's compact, bright nucleus, prominent inner dust lanes, and the remarkable bluish ring of young massive stars.

Within the bright ring new stars are forming at a high rate and many young, bright stars are present within it – thanks to this, this feature is called a starburst ring.  
The ring stars are all likely less than 10 million years old, indicating that M94 is a starburst galaxy that is experiencing an epoch of rapid star formation. 
The cause of this peculiarly shaped star-forming region is likely a pressure wave going outwards from the galactic centre, compressing the gas and dust in the outer region. The compression of material means the gas starts to collapse into denser clouds. Inside these dense clouds, gravity pulls the gas and dust together until temperature and pressure are high enough for stars to be born.

Credit:
ESA/Hubble & NASA





And the whole of the M94 galaxy is shown in the photo below.
It looks to me that the outer regions are in a very disturbed state, so I do wonder if some form of galaxy-galaxy encounter has disrupted it.