from the billions-and-billions-of-stars dept.
New Scientist is reporting Giant Flashlight Illuminates Cosmic Network:
The cobwebby filaments that stretched between galaxies in the early universe have shown themselves for the first time. Light from the activity of a distant supermassive black hole is serving as a giant cosmic flashlight, illuminating an enormous strand of gas held together by invisible dark matter.
[...] The geometry of large-scale cosmic structures helps us piece together the processes that formed the universe. Though this first glimpse mostly fits with existing models, there is one surprise that suggests some processes are currently missing in our understanding.
[...] They searched for some of the brightest sources of radiation in the universe: discs of hot gas surrounding supermassive black holes at the centres of distant galaxies, called quasars. When the light from these beacons shines on the gas in a cosmic filament, the gas can absorb and re-emit the light in another wavelength.
Detecting such light is still a challenge. The team had to build a custom filter tuned specifically to the wavelength of the light from each quasar, and put it on the camera of the 10-metre Keck telescope in Hawaii, one of the largest telescopes on Earth.
So it was a surprise when the first quasar [Sebastiano] Cantalupo [University of California, Santa Cruz] observed at Keck, called UM 287, shone on a filament right away. "It was a very lucky night," he says. "I thought these things might be extremely rare, and so was very surprised when my first night at Keck we detected this filament." It turned out he was right about their rarity: none of the 10 other quasars they observed revealed anything.
[...] However, the filament does contain one surprise: it is much more massive than simulations predicted, containing gas that weighs the equivalent of a thousand billion suns. "This is probably telling us that we are missing some physical processes in our models of intergalactic gas at large scales."
Archive.org has an abstract and full report (pdf) available.
(Score: 2) by ticho on Tuesday January 20 2015, @08:04AM
Was it perhaps an intelligent galaxy taking a selfie? I wonder if it pursed whatever passes for its lips. :-)
Seriously, though, good for the scientists. Even if we may never be able to visit those parts, every little bit of understanding of things around us helps.
(Score: 3, Funny) by morgauxo on Tuesday January 20 2015, @02:11PM
I think Earth proves pretty well that this is NOT an intelligent galaxy.
(Score: 0) by Anonymous Coward on Tuesday January 20 2015, @08:33AM
So how does this extra gas affect the calculations of the amount of dark matter in the universe? Maybe all the dark matter actually is such gas?
(Score: 1, Informative) by Anonymous Coward on Tuesday January 20 2015, @03:22PM
By definition, yes, this is dark matter. Dark matter is matter not undergoing fusion or other processes to generate light, and thus it is "dark" to us. Non-fusing gas strung out in filaments is exactly what dark matter should be.
(Score: 2, Informative) by gnuman on Tuesday January 20 2015, @06:05PM
No, that is not "dark matter". If you notice, there are a few things about "Dark Matter"
http://en.wikipedia.org/wiki/Dark_matter [wikipedia.org]
The total mass–energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy.[3][4] Thus, dark matter is estimated to constitute 84.5% of the total matter in the Universe, while dark energy plus dark matter constitute 95.1% of the total content of the Universe.
where ordinary matter is defined as what is around you,
Nearly all matter that may be encountered or experienced in everyday life is baryonic matter, which includes atoms of any sort, and provides those with the quality of mass. Non-baryonic matter, as implied by the name, is any sort of matter that is not composed primarily of baryons. Those might include neutrinos or free electrons dark matter, such as supersymmetric particles, axions, or black holes.
The very existence of baryons is also a significant issue in cosmology because it is assumed that the Big Bang produced a state with equal amounts of baryons and antibaryons. The process by which baryons came to outnumber their antiparticles is called baryogenesis.
Anyway, baryogenesis, dark energy, dark matter, axions, supersymmetric anything are all guesses and hand-waving arguments (hypothesis). Gas that is non-luminous is ordinary matter and does not fit the criteria for dark matter. Things like filaments have been seen before, but with non-visible light. For example, see this,
http://spacefellowship.com/news/art21600/picture-of-the-day-dust-around-the-black-eye-galaxy.html [spacefellowship.com]
that gas looks very much different in infrared or radio. Examples I could find is M31, Andromeda galaxy, visible then infrared
http://tvdavisastropics.com/astroimages-1_00000d.htm [tvdavisastropics.com]
http://wordlesstech.com/2011/01/21/beautiful-andromeda-galaxy/ [wordlesstech.com]
Here's even better comparison,
http://orbitingfrog.com/2008/06/25/earth-and-friends-in-multiple-wavelengths/ [orbitingfrog.com]
And none of these are dark matter.
As for current filaments, well, they are much larger than what was imaged close to the qasar,
http://en.wikipedia.org/wiki/Galaxy_filament [wikipedia.org]
This news seems to be about imaging of non-luminous gas outside quasars (or active galaxies) in the early universe.
(Score: 2) by marcello_dl on Tuesday January 20 2015, @10:59PM
I am not implying that it will always be this way but, dark matter is currently the factor fixing up current models, except that they still don't work because the gas filaments are too massive.
It's like, say, the "dog that ate your homework" starting to regurgitate pages from a porn magazine.
(Score: 2) by FatPhil on Tuesday January 20 2015, @12:06PM
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves