APOD: Hyperion: Largest Known Galaxy... (2018 Oct 23)

[APOD Robot]

Hyperion: Largest Known Galaxy Proto-Supercluster

Explanation: How did galaxies form in the early universe? To help find out, astronomers surveyed a patch of dark night sky with the Very Large Telescope array in Chile to find and count galaxies that formed when our universe was very young. Analysis of the distribution of some distant galaxies (redshifts near 2.5) found an enormous conglomeration of galaxies that spanned 300 million light years and contained about 5,000 times the mass of our Milky Way Galaxy. Dubbed Hyperion, it is currently the largest and most massive proto-supercluster yet discovered in the early universe. A proto-supercluster is a group of young galaxies that is gravitationally collapsing to create a supercluster, which itself a group of several galaxy clusters, which itself is a group of hundreds of galaxies, which itself is a group of billions of stars. In the featured visualization, massive galaxies are depicted in white, while regions containing a large amount of smaller galaxies are shaded blue. Identifying and understanding such large groups of early galaxies contributes to humanity's understanding of the composition and evolution of the universe as a whole.

<< Previous APOD

This Day in APOD

Next APOD >>

[bystander]

viewtopic.php?t=38798

[Boomer12k]

It would be interesting to see US...from that perspective...


:---[===] *

[BDanielMayfield]

For comparison to superclusters our galaxy is associated with:

The Virgo Supercluster (Virgo SC) or the Local Supercluster (LSC or LS) is a mass concentration of galaxies containing the Virgo Cluster and Local Group, which in turn contains the Milky Way and Andromeda galaxies. At least 100 galaxy groups and clusters are located within its diameter of 33 megaparsecs (110 million light-years). The Virgo SC is one of about 10 million superclusters in the observable universe and is in the Pisces–Cetus Supercluster Complex, a galaxy filament.

A 2014 study indicates that the Virgo Supercluster is only a lobe of an even greater supercluster, Laniakea, a larger, competing referent of Local Supercluster centered on the Great Attractor.

The Laniakea Supercluster (Laniakea; also called Local Supercluster or Local SCl or sometimes Lenakaeia)[2] is the galaxy supercluster that is home to the Milky Way and approximately 100,000 other nearby galaxies.[3] It was defined in September 2014, when a group of astronomers including R. Brent Tully of the University of Hawaii, Hélène Courtois of the University of Lyon, Yehuda Hoffman of the Hebrew University of Jerusalem, and Daniel Pomarède of CEA Université Paris-Saclay published a new way of defining superclusters according to the relative velocities of galaxies. The new definition of the local supercluster subsumes the prior defined local supercluster, the Virgo Supercluster, as an appendage.[4][5][6][7]

Follow-up studies suggest that Laniakea is not gravitationally bound; it will disperse rather than continue to maintain itself as an overdensity relative to surrounding areas.[8]

[JohnD]

It would be interesting to see US...from that perspective...
:---[===] *

If "US" is the Solar System, just under 2 light years wide if you include the Oort Cloud, then 'we' would be a spot 0.0000133millimetres wide on that screen image [ (200mm x 2)/300 x 10^6 ] That's 0.00000013metres or 0.1 micrometres. Invisible on your screen as a pixel is about 0.3mm wide

If it means United States, then the numbers just get silly. The US is one 9.461 x 10^12 th of a light year wide. Divide 0.1micrometres by that and you're down to the region of 1 x 10^19 th of a meter, when the Plank Length is 1.616x10^-35 meters.

John

[Paul Becker]

Jacques Cartier, right this way
I'll put your coat up on the bed
Hey, man, you've got the real bum's eye for clothes
And come on in, sit right down
No, you're not the first to show
We've all been here since, God, who knows?

[Ele6]

Is the arc to the right of centre a gravitational lens?

[4321lynx]

an enormous conglomeration of galaxies that spanned 300 million light years and contained about 5,000 times the mass of our Milky Way Galaxy. Dubbed Hyperion, it is currently the largest and most massive proto-supercluster yet discovered

ONLY 5,000 TIMES THE MASS OF OUR GALAXY ??? Are there some zeros missing here ???

[4321lynx]

Dis regarding the fact that it may not be a proto-super cluster just look at the mass of Laneakia and compare with the mass given to Hyperion.

[4321lynx]

Sorry for appearing again but cannot edit posts here

The Laniakea Supercluster encompasses approximately 100,000 galaxies stretched out over 160 megaparsecs (520 million light-years). It has the approximate mass of 1017 solar masses, or a hundred thousand times that of our galaxy,

[Chris Peterson]

Is the arc to the right of centre a gravitational lens?

Do you mean the arc of bright points? No, they're just galaxies that happen to line up in a pattern that attracts our attention.

[BDanielMayfield]

an enormous conglomeration of galaxies that spanned 300 million light years and contained about 5,000 times the mass of our Milky Way Galaxy. Dubbed Hyperion, it is currently the largest and most massive proto-supercluster yet discovered

ONLY 5,000 TIMES THE MASS OF OUR GALAXY ??? Are there some zeros missing here ???

That seemed low to me also. But consider, the Milky Way today is a larger than the average galaxy even in the current epoc. These galaxies in Hyperion appear as they were when they were very young and therefor much less massive than the current typical galaxy.


Bruce