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AI Created a Detailed 3D Map of Stars, Galaxies, and Quasars

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Pan-STARRS telescope in Hawai’i

Pan-STARRS telescope in Hawai’i
Image: University of Hawai’i

A team of astronomers from the University of Hawaiʻi at Mānoa’s Institute for Astronomy (IfA) has produced the most comprehensive astronomical imaging catalog of stars, galaxies, and quasars ever created with help from an artificially intelligent neural network.

The group of astronomers from the University of Hawaiʻi at Mānoa’s Institute for Astronomy (IfA) released a catalog containing 3 billion celestial objects in 2016, including stars, galaxies, and quasars (the active cores of supermassive black holes). Needless to say, the parsing of this extensive database—packed with 2 petabytes of data—was a task unfit for puny humans, and even grad students. A major goal coming out of the 2016 catalog release was to better characterize these distant specks of light, and to also map the arrangement of galaxies in all three dimensions. The Pan-STARRS team can now check these items off their to-do list, owing to the powers of machine learning. The results of their work have been published to the Monthly Notices of the Royal Astronomical Society.

Their PS1 telescope, located on the summit of Haleakalā on Hawaii’s Big Island, is capable of scanning 75% of the sky, and it currently hosts the world’s largest deep multicolor optical survey, according to a press release put out by the University of Hawaiʻi. By contrast, the Sloan Digital Sky Survey (SDSS) covers just 25% of the sky.

Density map of the universe, for galaxies between 1.5 and 3 billion light years away.

Density map of the universe, for galaxies between 1.5 and 3 billion light years away.
Image: University of Hawai’i

To provide the computer with a frame of reference, and to teach it how to discern celestial classes of objects from one another, the team turned to publicly available spectroscopic measurements. These measures of colors and sizes of objects numbered in the millions, as Robert

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‘Echo mapping’ in faraway galaxies could measure vast cosmic distances

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'Echo mapping' in faraway galaxies could measure vast cosmic distances
A disk of hot material around a supermassive black hole emits a burst of visible light, which travels out to a ring of dust that subsequently emits infrared light. The blue arrows show the light from the disk moving toward the dust and the light from both events traveling toward an observer. Credit: NASA/JPL-Caltech

When you look up at the night sky, how do you know whether the specks of light that you see are bright and far away, or relatively faint and close by? One way to find out is to compare how much light the object actually emits with how bright it appears. The difference between its true luminosity and its apparent brightness reveals an object’s distance from the observer.


Measuring the luminosity of a celestial object is challenging, especially with black holes, which don’t emit light. But the supermassive black holes that lie at the center of most galaxies provide a loophole: They often pull lots of matter around them, forming hot disks that can radiate brightly. Measuring the luminosity of a bright disk would allow astronomers to gauge the distance to the black hole and the galaxy it lives in. Distance measurements not only help scientists create a better, three-dimensional map of the universe, they can also provide information about how and when objects formed.

In a new study, astronomers used a technique that some have nicknamed “echo mapping” to measure the luminosity of black hole disks in over 500 galaxies. Published last month in the Astrophysical Journal, the study adds support to the idea that this approach could be used to measure the distances between Earth and these faraway galaxies.

The process of echo mapping, also known as reverberation mapping, starts when the disk of hot plasma (atoms that have lost their electrons) close

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Black Hole From the Beginning of Time Has Galaxies Caught in Its ‘Spider Web’

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Artist’s impression of the ancient web-like structure, featuring a central supermassive black hole, copious amounts of gas, and at least six primordial galaxies.

Artist’s impression of the ancient web-like structure, featuring a central supermassive black hole, copious amounts of gas, and at least six primordial galaxies.
Image: ESO

A remote structure consisting of a supermassive black hole, several primordial galaxies, and copious amounts of gas finally explains how some of the earliest black holes were able to grow so quickly.

The deeper we look into space, the further we look back into time. In this case, astronomers have caught a glimpse of the universe when it was just a toddler—a mere 900 million years after the Big Bang. Using a batch of powerful telescopes, and after a decade’s worth of astronomical observations, an international team of scientists has confirmed the presence of multiple primordial galaxies caught under the influence of an unusually large and bright supermassive black hole, the light from which took 12.9 billion years to reach Earth.

“This is the first spectroscopic identification of a galaxy overdensity around a supermassive black hole in the first billion years of the Universe,” wrote the researchers in their study, published today in Astronomy & Astrophysics. The “absence of earlier detections of such systems is likely due to observational limitations,” they added.

Indeed, astronomers have never seen this sort of thing before, but it’s not entirely unexpected, as the astral arrangement is helping to explain the early appearance of supermassive black holes. As the new research suggests, these web-like structures provided a gas-filled environment in which the first black holes were able to feed and grow.

“The galaxies stand and grow where the filaments cross, and streams of gas—available to fuel both the galaxies and the central supermassive black hole—can flow along the filaments,” explained Marco Mignoli, the lead author of the study and an astronomer at the National Institute for Astrophysics (INAF)

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Very Large Telescope spots galaxies trapped in the web of a supermassive black hole

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ESO telescope spots galaxies trapped in the web of a supermassive black hole
With the help of ESO’s Very Large Telescope (VLT), astronomers have found six galaxies lying around a supermassive black hole, the first time such a close grouping has been seen within the first billion years of the Universe. This artist’s impression shows the central black hole and the galaxies trapped in its gas web. The black hole, which together with the disc around it is known as quasar SDSS J103027.09+052455.0, shines brightly as it engulfs matter around it. Credit: ESO/L. Calçada

With the help of ESO’s Very Large Telescope (VLT), astronomers have found six galaxies lying around a supermassive black hole when the Universe was less than a billion years old. This is the first time such a close grouping has been seen so soon after the Big Bang and the finding helps us better understand how supermassive black holes, one of which exists at the centre of our Milky Way, formed and grew to their enormous sizes so quickly. It supports the theory that black holes can grow rapidly within large, web-like structures which contain plenty of gas to fuel them.


“This research was mainly driven by the desire to understand some of the most challenging astronomical objects—supermassive black holes in the early Universe. These are extreme systems and to date we have had no good explanation for their existence,” said Marco Mignoli, an astronomer at the National Institute for Astrophysics (INAF) in Bologna, Italy, and lead author of the new research published today in Astronomy & Astrophysics.

The new observations with ESO’s VLT revealed several galaxies surrounding a supermassive black hole, all lying in a cosmic “spider’s web” of gas extending to over 300 times the size of the Milky Way. “The cosmic web filaments are like spider’s web threads,” explains Mignoli. “The galaxies stand and grow