Skip to comments.Astronomers Spot Two Massive Galaxies Surrounded by a Halo of Dark Matter at the Dawn of Time
Posted on 12/06/2017 11:31:18 AM PST by Red Badger
Less than a billion years after the Big Bang, two titans speed toward each other.
NRAO/AUI/NSF; D. Berry
Just 780 million years after the universe formed in the Big Bang, two galaxies speed to confront each other in a head-on collision that will lead to a merger between the twoand one of them is towing along a clump of dark matter larger than any spotted before.
The research paper, published today in Nature, highlights a little-understood era of the universe known as the Epoch of Reionization. This is when the first galaxies came together and lit up the universe by converting hydrogen from a neutral atom to an ionized state, making the universe more transparent.
Most galaxies of the era were believed to be small, low-mass dwarf galaxies. But the results of this studyand an unrelated paper also published in Nature today that highlights a supermassive black hole from this period, the oldest ever discoveredpaint a different picture of the early universe. One of the galaxies in the pair known as SPT0311-58 is only slightly less massive than the Milky Way, though the other is much smaller.
The Milky Way's mass is equal to some 480 billion suns, while SPT0311-58 has about 440 billion solar masses. The smaller galaxy in the ancient pair is about 35 billion solar masses. A halo of dark matter surrounding the two is about 100 billion solar masses.
The galaxies, created via a composite image of several telescopes. ALMA (ESO/NAOJ/NRAO), Marrone, et al.; B. Saxton (NRAO/AUI/NSF); NASA/ESA Hubble ==========================================================================================
Though the dark matter halo cant be seen, its presence is inferred through gravitational interactions with the galaxies, which suggest it is enveloping both as they merge. The galaxies are messy in appearance as they havent had time to settle into a spiral (or other) shape due to their relative youth.
According to a NRAO press release, there are more galaxies waiting to be discovered in the same field. The pair was discovered by the South Pole Telescope, which is specifically attuned to the early universe, and follow-up observations were made with the Atacama Large Millimeter/submillimeter Array (ALMA).
Our hope is to find more objects like this, possibly even more distant ones, to better understand this population of extreme dusty galaxies and especially their relation to the bulk population of galaxies at this epoch, said Joaquin Vieira of the University of Illinois at Urbana-Champaign in a press release.
How the first galaxies formed in the ether of the early universe is one of the biggest questions in astronomy. Studying galaxies like SPT0311-58 could help scientists understand the strange dynamics of this ancient time in the cosmos.
Good Lord...it’s Bill and Hillary.
If only their telescopes could look to the end of time, I’m sure they would still see them.
Cool article. We need an Epoch of Reionization in DC.
One again dark matter is not observed. It’s inferred because without it mainstream theory becomes bogus.
What’s Dark Matter made of?....................
The first picture is Jesus giving the Father (whose hand and sleeve are visible) a high five.
Or is that a hight 10?
A spiral (to me) always suggest something being sucked into a vortex.
Very few galaxies look like they are exploding outward
They ARE being sucked into a black hole! In the center of the galaxy...................
I could see that!..................
Dark Matter matters....................
Dark matter is a placeholder. It’s sort of a shorthand way of saying that there is more mass in the universe than what can presently be observed.
Like ‘gravity’, it’s just a word for something we don’t understand...............
I think gravity is relatively well-defined at this point. ;) Dark matter could be one thing or a combination of things. Or maybe our math is just wrong. :)
So...how was this "spotting" done?
Gravity can be measured.
Gravity can be predicted and characterized.
Gravity can be identified.
But it can’t be explained.
Same with magnetism...................
Good Grief! Big Bang, little bang, gang bang.
Just Give it a Rest!
No one can say. But as it’s gravitationally interactive, one would expect to see huge globules of the stuff crashing into visible bodies throughout the cosmos. Yet no such interactions are seen. Thus it seems but a device to explain something not yet explainable.
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