Astronomers Uncover Dozens of Previously Unknown Ancient and Massive Galaxies

For decades, astronomers have been trying to see as far as they can into the deep Universe. By observing the cosmos as it was shortly after the Big Bang, astrophysicists and cosmologists hope to learn all they can about the early formation of the Universe and its subsequent evolution. Thanks to instruments like the Hubble Space Telescope, astronomers have been able to see parts of the Universe that were previously inaccessible.

But even the venerable Hubble is incapable of seeing all that was taking place during the early Universe. However, using the combined power of some of the newest astronomical observatories from around the world, a team of international astronomers led by Tokyo University’s Institute of Astronomy observed 39 previously-undiscovered ancient galaxies, a find that could have major implications for astronomy and cosmology.

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Maybe Dark Matter is Warm, Not Cold

Since the “Golden Age of General Relativity” in the 1960s, scientists have held that much of the Universe consists of a mysterious invisible mass known as “Dark Matter“. Since then, scientists have attempted to resolve this mystery with a double-pronged approach. On the one hand, astrophysicists have attempted to find a candidate particle that could account for this mass.

On the other, astrophysicists have tried to find a theoretical basis that could explain Dark Matter’s behavior. So far, the debate has centered on the question of whether it is “hot” or “cold”, with cold enjoying an edge because of its relative simplicity. However, a new study conducted led by the Harvard-Smithsonian Center for Astrophysics (CfA) revits the idea that Dark Matter might actually be “warm”.

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Meet Our Neighbour, The Local Void. Gaze Into It, Puny Humans.

Our planet is part of the larger structure of the Solar System, shaped and made stable by the force of gravity. Our Solar System is gravitationally bound to the Milky Way galaxy, along with hundreds of millions of other solar systems. And our galaxy is also part of a larger structure, where not only gravity, but the expansion of the Universe, shapes and molds that structure. For regular Universe Today readers, none of that is news.

Now a new study sheds some light on a curious part of our cosmic neighbourhood, where there is basically nothing: The Local Void.

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New observations from the Planck mission don’t resolve anomalies like the CMB “cold spot”

Back in 2013, the European Space Agency released its first analysis of the data gathered by the Planck observatory. Between 2009 and 2013, this spacecraft observed the remnants of the radiation that filled the Universe immediately after the Big Bang – the Cosmic Microwave Background (CMB) – with the highest sensitivity of any mission to date and in multiple wavelengths.

In addition to largely confirming current theories on how the Universe evolved, Planck’s first map also revealed a number of temperature anomalies – like the CMB “Cold Spot” – that are difficult to explai. Unfortunately, with the latest analysis of the mission data, the Planck Collaboration team has found no new evidence for these anomalies, which means that astrophysicists are still short of an explanation.

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Is Dark Matter Made of Axions? Black Holes May Reveal the Answer

What is dark matter made of? It’s one of the most perplexing questions of modern astronomy. We know that dark matter is out there, since we can see its obvious gravitational influence on everything from galaxies to the evolution of the entire universe, but we don’t know what it is. Our best guess is that it’s some sort of weird new particle that doesn’t like to talk to normal matter very often (otherwise we would have seen it by now). One possibility is that it’s an exotic hypothetical kind of particle known as an axion, and a team of astronomers are using none other than black holes to try to get a glimpse into this strange new cosmic critter.

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Meet WFIRST, The Space Telescope with the Power of 100 Hubbles

WFIRST ain’t your grandma’s space telescope. Despite having the same size mirror as the surprisingly reliable Hubble Space Telescope, clocking in at 2.4 meters across, this puppy will pack a punch with a gigantic 300 megapixel camera, enabling it to snap a single image with an area a hundred times greater than the Hubble.

With that fantastic camera and the addition of one of the most sensitive coronagraphs ever made – letting it block out distant starlight on a star-by-star basis – this next-generation telescope will uncover some of the deepest mysteries of the cosmos.

Oh, and also find about a million exoplanets.

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This Star Has Been Going Nova Every Year, for Millions of Years

A nova star is like a vampire that siphons gas from its binary partner. As it does so, the gas is compressed and heated, and eventually it explodes. The remnant gas shell from that explosion expands outward and is lit up by the stars at the center of it all. Most of these novae explode about once every 10 years.

But now astrophysicists have discovered one remnant so large that the star that created it must have been erupting yearly for millions of years.

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Uh oh, a Recent Study Suggests that Dark Energy’s Strength is Increasing

Staring into the Darkness

The expansion of our universe is accelerating. Every single day, the distances between galaxies grows ever greater. And what’s more, that expansion rate is getting faster and faster – that’s what it means to live in a universe with accelerated expansion. This strange phenomenon is called dark energy, and was first spotted in surveys of distant supernova explosions about twenty years ago. Since then, multiple independent lines of evidence have all come to the same morose conclusion: the universe is getting fatter and fatter faster and faster.

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Quasars with a Double-Image Gravitational Lens Could Help Finally Figure out how Fast the Universe is Expanding

A Hubble Space Telescope image of a doubly-imaged quasar. Image Credit: NASA Hubble Space Telescope, Tommaso Treu/UCLA, and Birrer et al

How fast is the Universe expanding? That’s a question that astronomers haven’t been able to answer accurately. They have a name for the expansion rate of the Universe: The Hubble Constant, or Hubble’s Law. But measurements keep coming up with different values, and astronomers have been debating back and forth on this issue for decades.

The basic idea behind measuring the Hubble Constant is to look at distant light sources, usually a type of supernovae or variable stars referred to as ‘standard candles,’ and to measure the red-shift of their light. But no matter how astronomers do it, they can’t come up with an agreed upon value, only a range of values. A new study involving quasars and gravitational lensing might help settle the issue.

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Astronomers Count all the Photons in the Universe. Spoiler Alert: 4,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 Photons

Imagine yourself in a boat on a great ocean, the water stretching to the distant horizon, with the faintest hints of land just beyond that. It’s morning, just before dawn, and a dense fog has settled along the coast. As the chill grips you on your early watch, you catch out of the corner of your eye a lighthouse, feebly flickering through the fog.

And – yes – there! Another lighthouse, closer, its light a little stronger. As you scan the horizon more lighthouses signal the dangers of the distant coast.
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