APOD: The Hercules Cluster of Galaxies (2014 Jun 25)

[APOD Robot]

The Hercules Cluster of Galaxies

Explanation: These are galaxies of the Hercules Cluster, an archipelago of island universes a mere 500 million light-years away. Also known as Abell 2151, this cluster is loaded with gas and dust rich, star-forming spiral galaxies but has relatively few elliptical galaxies, which lack gas and dust and the associated newborn stars. The colors in this remarkably deep composite image clearly show the star forming galaxies with a blue tint and galaxies with older stellar populations with a yellowish cast. The sharp picture spans about 3/4 degree across the cluster center, corresponding to over 6 million light-years at the cluster's estimated distance. Diffraction spikes around brighter foreground stars in our own Milky Way galaxy are produced by the imaging telescope's mirror support vanes. In the cosmic vista many galaxies seem to be colliding or merging while others seem distorted - clear evidence that cluster galaxies commonly interact. In fact, the Hercules Cluster itself may be seen as the result of ongoing mergers of smaller galaxy clusters and is thought to be similar to young galaxy clusters in the much more distant, early Universe.

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[Ann]

The Hercules cluster is certainly an exciting and unusual galaxy cluster! The reason for its varied appearance was stated by today's caption:

APOD Robot wrote:
In fact, the Hercules Cluster itself may be seen as the result of ongoing mergers of smaller galaxy clusters and is thought to be similar to young galaxy clusters in the much more distant, early Universe.

So the Hercules cluster may be very young as galaxy clusters go, and many spiral galaxies remain inside it. Of course, the Hercules cluster is best known for its wonderful interacting galaxies. Most famous of them all is the interacting duo (if not triplet?), known as NGC 6050. Note the little barred galaxy at top that appears to be caught in the spiral arms of the two larger galaxies! (And there is possibly a fourth galaxy, yellow and blue-green in color, peeking through a "loop" made of blue spiral arms belonging to one of the two major galaxies!)

Another amazing interacting pair is IC 1178 and IC 1181. This is the only picture I could find of them. In today's APOD, you find them at about 3 o'clock. These two galaxies are undergoing a so-called "dry merger", which means that they contain no gas, so that their merger produces no star formation. But look at those spectacular tidal tails of old red stars!

There are at least two more amazing galaxies in the Hercules cluster. One is IC 1182. This picture is strangely pink in color, but it does show the two spectacular blue jets - one long, straight, bright and full of clumps, one fainter and curved - emerging from this otherwise yellow galaxy.

The fourth galaxy I want to call attention to is located close to NGC 6050 and close to a blue star. It is a barred galaxy, surrounded by a blue ring. James D Wray, author of The Color Atlas of Galaxies, wrote about this galaxy that it has an

...extraordinary blue bar. There are practically no galaxies with bars similar to this...

So the Hercules Cluster is a wonderful cluster, with all sorts of galactic activity going on!

Ann

[metamorphmuses]

Although 500 million years distant is relatively close in astronomical terms, when the light we are now seeing from the Hercules cluster left it, here on Earth the Cambrian period was at its height. That was when some of the most basal forms of our vertebrate ancestors were flourishing. Humbling and wonderful at the same time.

[CURRAHEE CHRIS]

For some reason, today's picture reminds me of the beginning of the Doctor Who intro music from the 70's and 80's..........

[neufer]

Although 500 million years distant is relatively close in astronomical terms, when the light we are now seeing from the Hercules cluster left it, here on Earth the Cambrian period was at its height. That was when some of the most basal forms of our vertebrate ancestors were flourishing. Humbling and wonderful at the same time.

With a redshift z ~ 0.036, the Hercules Cluster of Galaxies is most certainly relatively close
as compared against the (redshift z ~ 1) Hubble Extreme Deep Field set of galaxies.

One must note, however, that whenever Ben Bob & Jerry use the term "mere"
they are almost always being facetious
(; something I, personally, would never ever do).

[img3="Ben & Jerry's Vermonster includes "a mere" 20 scoops of ice cream, 4 bananas, 4 ladles of hot fudge, 3 chocolate chip cookies, 1 chocolate fudge brownie, 10 scoops of walnuts, 2 scoops each of 4 toppings of your choice, and whipped cream. It contains 14,000 calories, and 500 grams of fat."]http://poshposh.com/Ben%20%26%20Jerry%2 ... onster.jpg[/img3]

<<The Hercules–Corona Borealis Great Wall (Her–CrB GW) is an immense superstructure of galaxies that measures more than 10 billion light-years across. It is the largest and the most massive structure known in the observable universe. This huge structure was discovered in November 2013 by a mapping of gamma-ray bursts that occur in the distant universe. The astronomers used data from the Swift Gamma-Ray Burst Mission and the Fermi Gamma-ray Space Telescope. The Hercules–Corona Borealis Great Wall was also the first structure other than large quasar groups that held the title as largest known structure in the universe, since 1991.

The structure is a galaxy filament, or a huge group of galaxies assembled by gravity. It is about 10 billion light-years at its longest dimension, which is approximately 1/9 of the diameter of the observable universe, 7.2 billion light-years wide, but only 900 million light-years thick, and is the largest known structure in the universe. It is at redshift 1.6–2.1, corresponding to a distance of approximately 10 billion light-years away, and is located in the sky in the direction of the constellations Hercules and Corona Borealis.

Prior to the discovery of the Hercules–Corona Borealis Great Wall, the largest scale at which the universe showed evidence of hierarchical structure was on the scale of superclusters and filaments. At larger scales, around 250–300 million light-years, no more fractal structuring is apparent; this was called the "End of Greatness". The homogeneity exhibited at this scale and the apparent normal density of the universe (as determined by the cosmic microwave background) implied an upper homogeneity scale about 4 times as large (1 to 1.2 billion light years).

Such large structures like the Hercules–Corona Borealis Great Wall may form part of the vast intergalactic cosmic web, an endless continuous sheet of galaxies and dark matter. Although this web was never directly observed, the relatively large sizes of structures in the nearby universe provides the possibility of the existence of this web. Such gigaparsec-scale structures, including the Hercules–Corona Borealis Great Wall, may be the intersections of smaller subfilaments within this vast structure, where there are overdensities of galaxies connecting other filaments within this vast web. If verified, the Hercules–Corona Borealis Great Wall will be one of the first evidences of the existence of this web.>>

[LocalColor]

Although 500 million years distant is relatively close in astronomical terms, when the light we are now seeing from the Hercules cluster left it, here on Earth the Cambrian period was at its height. That was when some of the most basal forms of our vertebrate ancestors were flourishing. Humbling and wonderful at the same time.

Early Cambrian on Earth:
http://cpgeosystems.com/500marect.jpg

[Ron-Astro Pharmacist]

Although 500 million years distant is relatively close in astronomical terms, when the light we are now seeing from the Hercules cluster left it, here on Earth the Cambrian period was at its height. That was when some of the most basal forms of our vertebrate ancestors were flourishing. Humbling and wonderful at the same time.

With a redshift z ~ 0.036, the Hercules Cluster of Galaxies is most certainly relatively close
as compared against the (redshift z ~ 1) Hubble Extreme Deep Field set of galaxies.

One must note, however, that whenever Ben Bob & Jerry use the term "mere"
they are almost always being facetious
(; something I, personally, would never ever do).

[img3="Ben & Jerry's Vermonster includes "a mere" 20 scoops of ice cream, 4 bananas, 4 ladles of hot fudge, 3 chocolate chip cookies, 1 chocolate fudge brownie, 10 scoops of walnuts, 2 scoops each of 4 toppings of your choice, and whipped cream. It contains 14,000 calories, and 500 grams of fat."]http://poshposh.com/Ben%20%26%20Jerry%2 ... onster.jpg[/img3]

<<The Hercules–Corona Borealis Great Wall (Her–CrB GW) is an immense superstructure of galaxies that measures more than 10 billion light-years across. It is the largest and the most massive structure known in the observable universe. This huge structure was discovered in November 2013 by a mapping of gamma-ray bursts that occur in the distant universe. The astronomers used data from the Swift Gamma-Ray Burst Mission and the Fermi Gamma-ray Space Telescope. The Hercules–Corona Borealis Great Wall was also the first structure other than large quasar groups that held the title as largest known structure in the universe, since 1991.

The structure is a galaxy filament, or a huge group of galaxies assembled by gravity. It is about 10 billion light-years at its longest dimension, which is approximately 1/9 of the diameter of the observable universe, 7.2 billion light-years wide, but only 900 million light-years thick, and is the largest known structure in the universe. It is at redshift 1.6–2.1, corresponding to a distance of approximately 10 billion light-years away, and is located in the sky in the direction of the constellations Hercules and Corona Borealis.

Prior to the discovery of the Hercules–Corona Borealis Great Wall, the largest scale at which the universe showed evidence of hierarchical structure was on the scale of superclusters and filaments. At larger scales, around 250–300 million light-years, no more fractal structuring is apparent; this was called the "End of Greatness". The homogeneity exhibited at this scale and the apparent normal density of the universe (as determined by the cosmic microwave background) implied an upper homogeneity scale about 4 times as large (1 to 1.2 billion light years).

Such large structures like the Hercules–Corona Borealis Great Wall may form part of the vast intergalactic cosmic web, an endless continuous sheet of galaxies and dark matter. Although this web was never directly observed, the relatively large sizes of structures in the nearby universe provides the possibility of the existence of this web. Such gigaparsec-scale structures, including the Hercules–Corona Borealis Great Wall, may be the intersections of smaller subfilaments within this vast structure, where there are overdensities of galaxies connecting other filaments within this vast web. If verified, the Hercules–Corona Borealis Great Wall will be one of the first evidences of the existence of this web.>>

I think Ben and Jerry have described an essential force in nature!

A Ben and Jerry Particle Collision

Atlas Experiment.jpg (4.2 KiB) Viewed 9156 times

[starsurfer]

I knew this image was going to make APOD! Ken Crawford is awesome at processing galaxies and revealing faint tidal features, there is a very good reason after all that he is part of David Martinez-Delgado's tidal stream survey team. Can't wait to see the future unpublished results! I would be incredibly happy if he released an image of a planetary nebula later this year!

The Hercules Galaxy Cluster is my favourite galaxy cluster due to its sheer number of peculiar, interacting and merging galaxies! It is also the galaxy cluster that contains the most number of Arp peculiar galaxies. They are:
1. Arp 71: NGC 6045, the elongated galaxy at the centre.
2. Arp 122, NGC 6040A and NGC 6040B, the weird and wonderful interacting pair of spirals near the top left corner.
3. Arp 172, IC 1178 and IC 1181, the two dancing galaxies near the top right corner.
4. Arp 272: NGC 6050 and IC 1179, the interacting pair to the right of NGC 6045.

There are at least two more amazing galaxies in the Hercules cluster. One is IC 1182. This picture is strangely pink in color, but it does show the two spectacular blue jets - one long, straight, bright and full of clumps, one fainter and curved - emerging from this otherwise yellow galaxy.

Actually the so-called "jet" of IC 1182 is a complex tidal tail, read more here. The other thing about IC 1182 that interests me greatly are the hints of tidal shells around the core.


Also the APOD description should have included a link to the labeled image.

[Ron-Astro Pharmacist]

As noted central in the picture you can see NGC 6050 / IC 1179 in collision.

http://hubblesite.org/newscenter/archiv ... /image/al/

What appeared as brightened star in NGC 6050 spiral arm looks more like a swirl with its own rotation.

The galaxy interactions in this cluster do indeed seem worthy of much investigation. Thanks to APOD for showing this view of a small piece of our sky.

An APOD of yesterday mornings Venus / crescent moon conjunction (if that's the right word) will hopefully be in our future. Hint, hint - not that suggestions are requested. It's just that surely someone got a better photo than I managed.

[hlwelborn]

My boat is so small.

[Boomer12k]

Hmmmmm......Making BIG ONES out of LITTLE ONES.......maybe one day, the whole Universe is ONE GINORMOUS GALAXY????

Probably not....

:---[===] *

[neufer]

Hmmmmm......Making BIG ONES out of LITTLE ONES.......maybe one day, the whole Universe is ONE GINORMOUS GALAXY????

Probably not....

:---[===] *

Not if Dark Energy has anything to say about it.

However, maybe one day, the whole Hercules Cluster is ONE HUMONGOUS GALAXY.

[markjaffemd]

I am a newbie, but how does one image galaxies 500 million light years distant when there are so many galaxies in front of it. For example, wouldn't the numerous stars and dust lying in front of the Hercules Cluster block our view of this cluster?

[Chris Peterson]

I am a newbie, but how does one image galaxies 500 million light years distant when there are so many galaxies in front of it. For example, wouldn't the numerous stars and dust lying in front of the Hercules Cluster block our view of this cluster?

There's not much in front. Just a handful of nearby stars. That's pretty much the case whenever you look at a small patch of sky.