Tag: galaxies
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Seeing the unseeable: humanity’s first image of a black hole
Yesterday, the Event Horizon Telescope collaboration released the first image of a black hole humanity has ever seen. That simple-looking image represents a century of scientific work: from the first theoretical calculations describing black holes; to the earliest hints that every large galaxy contains a supermassive black hole at its heart; to the technological advances […]
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Om nom nom: a black hole ate a star and left crumbs for us to see
[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ] And if I can be shameless: Forbes pays according to traffic, so the more of you who click on the link below and read my stuff, the better they […]
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A multitude of faint and fluffy galaxies
[ This blog is dedicated to tracking my most recent publications. Subscribe to the feed to keep up with all the science stories I write! ] Scientists Discover Hundreds of Hidden Galaxies The new type of faint, fluffy galaxy might help resolve a cosmological conundrum For The Daily Beast: When we think of galaxies, we […]
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How did the biggest black holes form?
The most massive known object in the cosmos is the black hole at the center of M87, a huge galaxy in the Virgo Cluster. While most large galaxies (including the Milky Way) harbor supermassive black holes, the very largest are interesting. That’s because galaxies and their black holes seem to share a history, based on […]
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A glowing filament shows us where the dark matter hides
Astronomers have identified a filament in the cosmic web, which is the pattern formed by dark matter. That web in turn dictates the distribution of galaxies, since the dark matter attracts ordinary matter — atoms — through its gravity. However, it’s hard to spot the filaments connecting the different halos of dark matter, because […]
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Early galaxies: live large, die big, burn bright
How did the biggest galaxies form? Based on the ages of stars inhabiting them, the largest elliptical galaxies — those kind of boring egg-shaped clouds of stars with no pretty spiral arms — formed fairly early in the history of the Universe. While smaller elliptical galaxies likely are the modern version of submillimeter bright galaxies […]
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Green Peas were all my joy, galaxies were my delight
Most galaxies are somewhat red or blue in appearance, depending on the populations of stars that comprise them. However, citizen scientists working with the GalaxyZoo project identified a previously unknown type of galaxy: Green Peas, so named because they are small and green. The color comes from ionized oxygen, a particular form of emission that […]
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Why do half of Andromeda’s satellite galaxies orbit in a plane?
Our local group of galaxies—known imaginatively as the Local Group—has two huge galaxies: the Milky Way and M31, also known as the Andromeda Galaxy. Both of these galaxies are large enough to have a number of satellites, including the substantial Magellanic Clouds and M33 (Triangulum Galaxy). However, most satellites are dwarf galaxies, very faint and […]
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The galaxy from the dawn of time
The first galaxies in the Universe probably played a major part in reionization—the event in which primordial gas was turned into a plasma. However, observations of this era are very hard: we’re looking back in time to when the first stars formed, over 95% of the total age of the Universe. As a result, the […]