Posted on by Evan Gough

No Merger Needed: A Rotating Ring of Gas Creates A Hyperluminous Galaxy

This is a distant Hyper Luminous Infrared Galaxy named PJ0116-24. These galaxies experience rapid star formation that astronomers think is triggered by mergers. But this one suggests otherwise. Warm gas is shown in red and cold gas is shown in blue. Image Credit: PJ0116-24

Some galaxies experience rapid star formation hundreds or even thousands of times greater than the Milky Way. Astronomers think that mergers are behind these special galaxies, which were more abundant in the earlier Universe. But new results suggest no mergers are needed.

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Posted on by Matt Williams

Astronomers See the Same Supernova Four Times Thanks to a Gravitational Lens

A gravitational lens caused by a galaxy in the foreground leading to an "Einstein Cross." Credit: NASA/ESA/STScI
A gravitational lens caused by a galaxy in the foreground leading to an "Einstein Cross." Credit: NASA/ESA/STScI

Measuring cosmic distances is challenging, and astronomers rely on multiple methods and tools to do it – collectively referred to as the Cosmic Distance Ladder. One particularly crucial tool is Type Ia supernovae, which occur in binary systems where one star (a white dwarf) consumes matter from a companion (often a red giant) until it reaches the Chandrasekhar Limit and collapses under its own mass. As these stars blow off their outer layers in a massive explosion, they temporarily outshine everything in the background.

In a recent study, an international team of researchers led by Ariel Goobar of the Oskar Klein Centre at Stockholm University discovered an unusual Type Ia supernova, SN Zwicky (SN 2022qmx). In an unusual twist, the team observed an “Einstein Cross,” an unusual phenomenon predicted by Einstein’s Theory of General Relativity where the presence of a gravitational lens in the foreground amplifies light from a distant object. This was a major accomplishment for the team since it involved observing two very rare astronomical events that happened to coincide.

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Posted on by Brian Koberlein

What is Gravitational Lensing?

Hubble Frontier Fields observing programme, which is using the magnifying power of enormous galaxy clusters to peer deep into the distant Universe. Credit: NASA.

Gravity’s a funny thing. Not only does it tug away at you, me, planets, moons and stars, but it can even bend light itself. And once you’re bending light, well, you’ve got yourself a telescope.

Everyone here is familiar with the practical applications of gravity. If not just from exposure to Loony Tunes, with an abundance of scenes with an anthropomorphized coyote being hurled at the ground from gravitational acceleration, giant rocks plummeting to a spot inevitably marked with an X, previously occupied by a member of the “accelerati incredibilus” family and soon to be a big squish mark containing the bodily remains of the previously mentioned Wile E. Coyote.

Despite having a very limited understanding of it, Gravity is a pretty amazing force, not just for decimating a infinitely resurrecting coyote, but for keeping our feet on the ground and our planet in just the right spot around our Sun. The force due to gravity has got a whole bag of tricks, and reaches across Universal distances. But one of its best tricks is how it acts like a lens, magnifying distant objects for astronomy.

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