Early Massive Galaxies ran out of gas, Shutting Down Their Star Formation

Galaxies that formed within the first few billion years after the Big Bang should have lived long, healthy lives. After all, they were born with rich supplies of cold hydrogen gas, exactly the fuel needed to continue star formation. But new observations have revealed “quenched” galaxies that have shut off star formation. And astronomers have no idea why.

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The Galactic Beauty of Star Formation

I’d never seen galaxy images like this before. Nobody had! These images highlight star forming regions in nearby(ish) galaxies. There are still a number of unanswered questions surrounding how star formation actually occurs. To answer those questions, we are observing galaxies that are actively forming stars within giant clouds of gas. Until recently, we didn’t have the resolution needed to clearly image the individual gas clouds themselves. But images released by a project called PHANGS (Physics at High Angular resolution in Nearby GalaxieS) in a collaboration between the European Southern Observatory Very Large Telescope and the Atacama Large millimeter/submillmeter Array (ALMA) have provided never before seen detail of star forming clouds in other galaxies.

This image combines observations of the nearby galaxies NGC 1300, NGC 1087, NGC 3627 (top, from left to right), NGC 4254 and NGC 4303 (bottom, from left to right) taken with the Multi-Unit Spectroscopic Explorer (MUSE) on ESO’s Very Large Telescope (VLT). Each individual image is a combination of observations conducted at different wavelengths of light to map stellar populations and warm gas.. Image and Image Description PHANGS/ESO. Original Image
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Supermassive Black Hole Winds Were Already Blowing Less Than a Billion Years After the Big Bang

At the heart of most galaxies is a supermassive black hole. These beasts of gravity can play a crucial role in the formation and evolution of their galaxy. But astronomers still don’t fully understand when the influence of black holes becomes significant. Did large black holes form early in the universe, causing galaxies to form around them? Or did black holes grow after its primordial galaxy had begun to form? You might call this the chicken or egg problem. But a recent study suggests that galaxies and their supermassive black holes can have a mutual interaction that allows them to co-evolve.

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Rare Triple Galaxy Merger With at Least Two Supermassive Black Holes

One of the best things about that universe is that there is so much to it.  If you look hard enough, you can most likely find any combination of astronomical events happening.  Not long ago we reported on research that found 7 separate instances of three galaxies colliding with one another.  Now, a team led by Jonathan Williams of the University of Maryland has found another triple galaxy merging cluster, but this one might potentially have two active supermassive black holes, allowing astronomers to peer into the system dynamics of two of the universe’s most extreme objects running into one another.

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Protogalaxy Cluster Found When the Cosmic Fog Was Starting to Clear, When the Universe Was Just 750 Million Years Old

Origin stories are a focus of many astronomical studies.  Planetary formation, solar system formation, and even galaxy formation have long been studied in order to understand how the universe came to be where it is today.  Now, a team of scientists from the Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) consortium have found an extremely early “protogalaxy” that was formed approximately 750 million years after the big bang.  Studying it can provide insights into that early type of galaxy formation and everything that comes after.

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Astronomers Can Predict When a Galaxy’s Star Formation Ends Based on the Shape and Size of its Disk

A galaxy’s main business is star formation. And when they’re young, like youth everywhere, they keep themselves busy with it. But galaxies age, evolve, and experience a slow-down in their rate of star formation. Eventually, galaxies cease forming new stars altogether, and astronomers call that quenching. They’ve been studying quenching for decades, yet much about it remains a mystery.

A new study based on the IllustrisTNG simulations has found a link between a galaxy’s quenching and its stellar size.

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When Galaxies Collide, Black Holes Don’t Always Get the Feast They Were Hoping for

What happens when galaxies collide? Well, if any humans are around in about a billion years, they might find out. That’s when our Milky Way galaxy is scheduled to collide with our neighbour the Andromeda galaxy. That event will be an epic, titanic, collision. The supermassive black holes at the center of both galaxies will feast on new material and flare brightly as the collision brings more gas and dust within reach of their overwhelming gravitational pull. Where massive giant stars collide with each other, lighting up the skies and spraying deadly radiation everywhere. Right?

Maybe not. In fact, there might be no feasting at all, and hardly anything titanic about it.

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