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 Post subject: Re: Cosmology Thread
PostPosted: Thu Nov 17, 2016 3:54 pm 
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Newest fast radio burst hints at makeup of the cosmic web

http://www.astronomy.com/news/2016/11/n ... cosmic-web

Quote:
The newest FRB actually had little evidence of Faraday rotation, leading the team to believe that the area that the radio wave traveled through wasn’t very magnetic, and that the “space” was thinner in that region. The intergalactic medium or what we think about as “space” is made up of plasma, an ionized gas, but it’s not a uniform consistency. Shannon explains, “this burst was scintillating, so the brightness varies if you look at different wavelengths of light. Not unlike when a star twinkles in the sky, that light is traveling through diffuse gas in the intergalactic medium. What this tells us is that there’s a bit of turbulence churning around, but not that much.”

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 Post subject: Re: Cosmology Thread
PostPosted: Thu Nov 17, 2016 8:42 pm 
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Astronomers have confirmed that a force of nature in a distant galaxy is the same as on Earth

http://www.sciencealert.com/a-cosmic-ba ... -of-nature

Quote:
In the end, they found that the electromagnetic force in the distant galaxy is the same as here on Earth, suggesting that researchers have been correct in their suspicions that electromagnetism is a constant of nature.

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 Post subject: Re: Cosmology Thread
PostPosted: Fri Nov 25, 2016 10:04 am 
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Has dogma derailed the scientific search for dark matter?

https://aeon.co/ideas/has-dogma-deraile ... ark-matter

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Are rigid scientific assumptions clouding our understanding of the universe?

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 Post subject: Re: Cosmology Thread
PostPosted: Mon Nov 28, 2016 2:14 pm 
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Theory challenging Einstein's view on speed of light could soon be tested

https://www.theguardian.com/science/201 ... -be-tested

Quote:
Magueijo and Afshordi’s theory does away with inflation and replaces it with a variable speed of light. According to their calculations, the heat of universe in its first moments was so intense that light and other particles moved at infinite speed. Under these conditions, light reached the most distant pockets of the universe and made it look as uniform as we see it today. “In our theory, if you go back to the early universe, there’s a temperature when everything becomes faster. The speed of light goes to infinity and propagates much faster than gravity,” Afshordi said. “It’s a phase transition in the same way that water turns into steam.”

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 Post subject: Re: Cosmology Thread
PostPosted: Wed Nov 30, 2016 3:35 pm 
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Sent to me by Rich Brady!

First signs of weird quantum property of empty space?

https://www.sciencedaily.com/releases/2 ... 082804.htm

Quote:
These fields are so strong that they even affect the properties of the empty space around the star. Normally a vacuum is thought of as completely empty, and light can travel through it without being changed. But in quantum electrodynamics (QED), the quantum theory describing the interaction between photons and charged particles such as electrons, space is full of virtual particles that appear and vanish all the time. Very strong magnetic fields can modify this space so that it affects the polarisation of light passing through it.

Mignani explains: "According to QED, a highly magnetised vacuum behaves as a prism for the propagation of light, an effect known as vacuum birefringence."

Among the many predictions of QED, however, vacuum birefringence so far lacked a direct experimental demonstration. Attempts to detect it in the laboratory have not yet succeeded in the 80 years since it was predicted in a paper by Werner Heisenberg (of uncertainty principle fame) and Hans Heinrich Euler.

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 Post subject: Re: Cosmology Thread
PostPosted: Wed Nov 30, 2016 5:37 pm 
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This link's a little more accessible. Emphasis on "little".

Quantum 'Ghosts' Seen in Neutron Star's Extreme Magnetism

http://www.seeker.com/astronomy-quantum ... 33521.html

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 Post subject: Re: Cosmology Thread
PostPosted: Thu Dec 01, 2016 2:17 pm 
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Celestial Cartography Is in the Midst of a Dramatic Upgrade

https://www.scientificamerican.com/arti ... c-upgrade/

Quote:
The updated map has been highly anticipated; on the first day of the initial data release in September at least 10,000 people accessed the archive, says Gaia project scientist Timo Prusti. The dataset includes the preliminary positions of one billion stars (future data releases will improve these numbers) and the distances and sideways motions of the two million brightest stars in the sky. With each subsequent release, the distances and motions of stars at greater and greater distances within the galaxy will be revealed, creating successive maps that radiate outward from the sun like ripples on a pond.

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 Post subject: Re: Cosmology Thread
PostPosted: Fri Dec 02, 2016 4:09 pm 
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VIDEO: The astrophysicist searching for the Universe’s ‘dark stars’

http://www.bbc.com/future/story/2016120 ... e-universe

Quote:
It is the ultimate detective story.

The suspect is the basic matter that makes up as much as 25% of the Universe. It is part of the very web of all that we live in. And yet because it is not made of even the most basic building blocks of the atoms that create stars and life itself, it remains invisible. It doesn’t even interact with light.

The search for the dark matter particle has been a quest for scientists since the 1930s. Today, there are more than 100 teams around the world grappling with how we can prove it exists.

Astrophysicist Katherine Freese is one of those who have dedicated their lives to trying to find the answer. Thirty years ago, her theories on the existence of dark stars which exert an invisible influence on the Universe led to the building of particle accelerators underground. In the video above, she explains how we might find these stars – and how their discovery might change everything we know about the Universe we live in.

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 Post subject: Re: Cosmology Thread
PostPosted: Thu Dec 08, 2016 10:06 am 
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The Universe Is Flat... Now What?

http://www.livescience.com/57131-the-un ... -flat.html

Very accessible article and the author, shock horror, has [spoiler]fun[/spoiler] with the topic.

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 Post subject: Re: Cosmology Thread
PostPosted: Mon Dec 19, 2016 3:55 pm 
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3-D Printing the Young Universe as a Lumpy Softball

http://www.nytimes.com/2016/12/19/scien ... verse.html

If you're in Toms River, KT's Office Services provides 3D printing services.

http://www.ktoss.com/3d-printers-and-3dhub/

There are many other 3D printing services available online. Just google it.

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 Post subject: Re: Cosmology Thread
PostPosted: Tue Dec 20, 2016 10:18 am 
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Hunting Dark Matter between the Ticks of an Atomic Clock

https://www.scientificamerican.com/arti ... mic-clock/

Quote:
But in Monday’s Nature Astronomy report, physicist Piotr Wcisło at Nicolaus Copernicus University in Poland and his colleagues suggest a single atomic clock might be sensitive enough to shed light on the nature of dark matter. The researchers analyzed how topological defects might influence an individual optical atomic clock, which uses visible laser beams to measure the dances of atoms when they are slowed down by cooling them to temperatures near absolute zero. The researchers’ model demonstrates that passing through a defect in the proposed dark matter field could increase or decrease the overall strength of the electromagnetic force, which in turn would alter how atoms would respond to illumination.

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 Post subject: Re: Cosmology Thread
PostPosted: Wed Dec 21, 2016 6:48 am 
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There’s no trace of dark matter inside the gamma ray background, researchers find

http://www.sciencealert.com/there-s-no- ... chers-find

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 Post subject: Re: Cosmology Thread
PostPosted: Mon Jan 02, 2017 4:15 pm 
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January 1, 1925: The Day We Discovered the Universe

http://blogs.discovermagazine.com/outth ... -universe/

On the origins of cosmology as a science, rather than a philosophy.

Not that there's anything necessarily wrong with philosophy.

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 Post subject: Re: Cosmology Thread
PostPosted: Thu Jan 12, 2017 5:16 pm 
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Photons Struggle to Escape Distant Galaxies

http://www.astrowatch.net/2017/01/photo ... stant.html

Quote:
"Galaxies forming stars in the distant Universe seem to be surrounded by an impressively large, faint halo of Lyman-alpha photons that had to travel for hundreds of thousands of light years in an almost endless series of absorption and re-emission events, until they were finally free. We now need to understand exactly how and why that happens", adds Sobral.

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 Post subject: Re: Cosmology Thread
PostPosted: Mon Jan 16, 2017 11:07 am 
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Absolutely Every Bit of Our Galaxy

https://www.nytimes.com/2017/01/16/scie ... -mass.html

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Astronomers have arrived at what they believe to be the most accurate measure yet of the mass of the Milky Way

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 Post subject: Re: Cosmology Thread
PostPosted: Tue Jan 17, 2017 1:58 pm 
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Is It Time to Give Up on Dark Matter?

https://www.scientificamerican.com/vide ... rk-matter/

It's a video. meh.

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 Post subject: Re: Cosmology Thread
PostPosted: Tue Jan 17, 2017 2:08 pm 
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Galaxy Noir: The Case of the Stellar Strangulation

https://esoterx.com/2017/01/17/galaxy-n ... ngulation/

Quote:
And the question on every gumshoe’s mind was this: Who was murdering all the galaxies across the universe? Those big brains over at the International Centre for Radio Astronomy Research (ICRAR) took a look at 11000 galaxies, and found the some unsavory character has been on a spree, sweeping away their gas like a giant cosmic broom. Galaxies are all about the gas, since it fuels star formation. Take away the gas and all you’ve got is the lifeless corpse of a galaxy, strangled to death.


Cold gas stripping in satellite galaxies: from pairs to clusters

https://arxiv.org/abs/1611.00896

Quote:
In this paper we investigate environment driven gas depletion in satellite galaxies, taking full advantage of the atomic hydrogen (HI) spectral stacking technique to quantify the gas content for the entire gas-poor to -rich regime. We do so using a multi-wavelength sample of 10,600 satellite galaxies, selected according to stellar mass (log M⋆/M⊙ ≥ 9) and redshift (0.02 ≤ z ≤ 0.05) from the Sloan Digital Sky Survey, with HI data from the Arecibo Legacy Fast ALFA (ALFALFA) survey. Using key HI-to-stellar mass scaling relations, we present evidence that the gas content of satellite galaxies is, to a significant extent, dependent on the environment in which a galaxy resides. For the first time, we demonstrate that systematic environmental suppression of gas content at both fixed stellar mass and fixed specific star formation rate (sSFR) in satellite galaxies begins in halo masses typical of the group regime (log Mh/M⊙ < 13.5), well before galaxies reach the cluster environment. We also show that environment driven gas depletion is more closely associated to halo mass than local density. Our results are then compared with state-of-the-art semi-analytic models and hydrodynamical simulations and discussed within this framework, showing that more work is needed if models are to reproduce the observations. We conclude that the observed decrease of gas content in the group and cluster environments cannot be reproduced by starvation of the gas supply alone and invoke fast acting processes such as ram-pressure stripping of cold gas to explain this.

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 Post subject: Re: Cosmology Thread
PostPosted: Sat Jan 28, 2017 8:51 am 
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Cosmic Lenses Support Finding on Faster than Expected Expansion of the Universe
http://www.astrowatch.net/2017/01/cosmi ... aster.html

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 Post subject: Re: Cosmology Thread
PostPosted: Mon Jan 30, 2017 11:47 am 
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Milky Way being pushed through space by cosmic dead zone

https://www.theguardian.com/science/201 ... scientists

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The movement of the Milky Way is dominated by the gravitational attraction of the galaxies around it. If galaxies were scattered randomly through space, the pull would be the same in every direction. But galaxies are not evenly spread out in the universe. As a result, patches of space that are dense in galaxies draw others towards them, while regions that are emptier than normal literally fail to pull their weight: they effectively push objects away from them.

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 Post subject: Re: Cosmology Thread
PostPosted: Thu Feb 02, 2017 5:54 pm 
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'Ghost Particles' Could Improve Understanding the Universe

http://www.astrowatch.net/2017/02/ghost ... prove.html

Quote:
“Neutrinos have a habit of changing, or oscillating, between three types, we call them ‘flavors,’” said Joshua Hignight, the MSU research associate who presented the new results at the meeting. “So, if one neutrino is a precisely equal mix of two flavors, it could be a surprising coincidence or there might be a deeper reason for it coming from the physics beyond the Standard Model.”

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 Post subject: Re: Cosmology Thread
PostPosted: Thu Feb 09, 2017 7:09 pm 
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A Bridge of Stars Connects Two Dwarf Galaxies

http://www.astrowatch.net/2017/02/a-bri ... dwarf.html

Quote:
“Stellar streams around the Clouds were predicted but never observed,” explains Dr Belokurov. “Having marked the locations of the Gaia RR Lyrae on the sky, we were surprised to see a narrow bridge-like structure connecting the two clouds. We believe that at least in part this ‘bridge’ is composed of stars stripped from the Small Cloud by the Large. The rest may actually be the LMC stars pulled from it by the Milky Way.”

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 Post subject: Re: Cosmology Thread
PostPosted: Sun Feb 12, 2017 12:58 pm 
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Ancient Signals From the Early Universe

http://www.astrowatch.net/2017/02/ancie ... verse.html

Quote:
Using numerical simulations, the theoretical physicist and his team were able to calculate the shape of the oscillon’s signal, which was emitted just fractions of a second after the Big Bang. It appears as a pronounced peak in the otherwise rather broad spectrum of gravitational waves. “We would not have thought before our calculations that oscillons could produce such a strong signal at a specific frequency,” Antusch explains. Now, in a second step, experimental physicists must actually prove the signal’s existence using detectors.

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 Post subject: Re: Cosmology Thread
PostPosted: Mon Feb 20, 2017 5:50 pm 
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Cosmos Controversy: The Universe Is Expanding, But How Fast?

https://www.nytimes.com/2017/02/20/scie ... speed.html

Quote:
There is a crisis brewing in the cosmos, or perhaps in the community of cosmologists. The universe seems to be expanding too fast, some astronomers say. Recent measurements of the distances and velocities of faraway galaxies don’t agree with a hard-won “standard model” of the cosmos that has prevailed for the past two decades. The latest result shows a 9 percent discrepancy in the value of a long-sought number called the Hubble constant, which describes how fast the universe is expanding. But in a measure of how precise cosmologists think their science has become, this small mismatch has fostered a debate about just how well we know the cosmos. “If it is real, we will learn new physics,” said Wendy Freedman of the University of Chicago, who has spent most of her career charting the size and growth of the universe.

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 Post subject: Re: Cosmology Thread
PostPosted: Thu Feb 23, 2017 10:50 am 
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A Giant Galaxy Orbiting Our Own Just Appeared Out Of Nowhere

http://www.physics-astronomy.com/2016/0 ... -just.html

Quote:
That being said, the question arises, how did we still not know (Crater 2) was there? A new research paper published in Monthly Notices of the Royal Astronomical Society from astronomers at the University of Cambridge has an answer for us. It turns out that, regardless of being huge and close, Crater 2 is also a pretty dark galaxy. Actually, it’s one of the faintest galaxies ever detected in the cosmos. That, along with some much perkier neighbors, let the galaxy that astronomers have nicknamed “the feeble giant” remain hidden from our eyes until now.


The feeble giant. Discovery of a large and diffuse Milky Way dwarf galaxy in the constellation of Crater

https://academic.oup.com/mnras/article- ... nd-diffuse

Quote:
We announce the discovery of the Crater 2 dwarf galaxy, identified in imaging data of the VLT Survey Telescope ATLAS survey. Given its half-light radius of ∼1100 pc, Crater 2 is the fourth largest satellite of the Milky Way, surpassed only by the Large Magellanic Cloud, Small Magellanic Cloud and the Sgr dwarf. With a total luminosity of MV ≈ −8, this galaxy is also one of the lowest surface brightness dwarfs. Falling under the nominal detection boundary of 30 mag arcsec−2, it compares in nebulosity to the recently discovered Tuc 2 and Tuc IV and UMa II. Crater 2 is located ∼120 kpc from the Sun and appears to be aligned in 3D with the enigmatic globular cluster Crater, the pair of ultrafaint dwarfs Leo IV and Leo V and the classical dwarf Leo II. We argue that such arrangement is probably not accidental and, in fact, can be viewed as the evidence for the accretion of the Crater-Leo group.

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 Post subject: Re: Cosmology Thread
PostPosted: Thu Mar 02, 2017 11:00 am 
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There's a Massive, Glowing Blob in the Universe, and a Mystery Source Is Lighting It Up

http://www.sciencealert.com/there-s-a-m ... ting-it-up

The Slug Nebula

Quote:
What we do know is the light has the same wavelength that's absorbed and emitted by hydrogen atoms as they cool down - a discharge known as Lyman-alpha radiation - but it's not clear what's been heating them up.

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