galaxies Archives

December 29, 2022December 29, 2022 by Brian Koberlein

New Measurements of Galaxy Rotation Lean Towards Modified Gravity as an Explanation for Dark Matter

Although dark matter is a central part of the standard cosmological model, it’s not without its issues. There continue to be nagging mysteries about the stuff, not the least of which is the fact that scientists have found no direct particle evidence of it. Despite numerous searches, we have yet to detect dark matter particles. So some astronomers favor an alternative, such as Modified Newtonian Dynamics (MoND) or modified gravity model. And a new study of galactic rotation seems to support them.

December 23, 2022December 23, 2022 by Scott Alan Johnston

Is the Milky Way… Normal?

Studying the large-scale structure of our galaxy isn’t easy. We don’t have a clear view of the Milky Way’s shape and features like we do of other galaxies, largely because we live within it. But we do have some advantages. From within, we’re able to carry out close-up surveys of the Milky Way’s stellar population and its chemical compositions. That gives researchers the tools they need to compare our own galaxy to the many millions of others in the Universe.

This week, an international team of researchers from the USA, UK, and Chile released a paper that does just that. They dug through a catalogue of ten thousand galaxies produced by the Sloan Digital Sky Survey, searching for galaxies with similar attributes to our own.

They discovered that the Milky Way has twins – many of them – but just as many that are only superficially similar, with fundamental differences buried in the data. What they discovered has implications for the future evolution of our own galaxy.

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December 7, 2022December 7, 2022 by Evan Gough

A Star was Blocking a Galaxy, but Now it’s Moved Enough That Astronomers can Finally Examine What it Was Hiding

NASA's Hubble Space Telescope captured a detailed image of the tiny galaxy HIPASS J1131–31, nicknamed the "Peekaboo Galaxy." It's more like an ancient galaxy from the Universe's early days than a modern galaxy. Image Credit: NASA, ESA, and Igor Karachentsev (SAO RAS); Image Processing: Alyssa Pagan (STScI)

One of the biggest puzzles in astronomy, and one of the hardest ones to solve, concerns the formation and evolution of galaxies. What did the first ones look like? How have they grown so massive?

A tiny galaxy only 20 million light-years away might be a piece of the puzzle.

November 28, 2022November 28, 2022 by Nancy Atkinson

Gaze Slack-jawed at the Haunting Beauty of Galaxy NGC 1566, Captured by JWST, Processed by Judy Schmidt

NGC 1566, as seen by the James Webb Space Telescope's Mid-Infrared Instrument. Credit: NASA/ESA/CSA/Judy Schmidt.

Here’s an absolutely stunning new view from the James Webb Space Telescope of a dusty spiral galaxy, NGC 1566. Amateur (but expert!) image editor Judy Schmidt took the raw data from JWST’s Mid-Infrared Instrument (MIRI) and teased out this eerie, spider-web-like view of this distant galaxy. The swirling and symmetrical arms are so full of dust that not many stars are visible.

November 7, 2022November 7, 2022 by Evan Gough

The Perfect Tidal Tail Connects These two Galaxies Seen by Hubble

This image from the NASA/ESA Hubble Space Telescope shows two of the galaxies in the galactic triplet Arp 248. Image Credit: ESA/Hubble & NASA, Dark Energy Survey/Department of Energy/Fermilab Cosmic Physics Center/Dark Energy Camera/Cerro Tololo Inter-American Observatory/NOIRLab/National Science Foundation/AURA Astronomy; J. Dalcanton

Sometimes it’s tempting to imagine a supernatural hand behind the arrangement of celestial bodies. But the Universe is big, huge even, and nature’s flow presents many fascinations.

So it is with the galactic triplet Arp 248, an arrangement of interacting galaxies that’s both visually and scientifically fascinating.

October 25, 2022October 25, 2022 by Nancy Atkinson

Webb and Hubble Peer Into the Wreckage of a Galactic Collision

This image from the NASA/ESA/CSA James Webb Space Telescope depicts IC 1623, an entwined pair of interacting galaxies which lies around 270 million light-years from Earth in the constellation Cetus. Credit: ESA/Webb, NASA & CSA, L. Armus & A. Evans; CC BY 4.0 Acknowledgement: R. Colombari.

Earlier this month we asked, what could be better than a pair of galaxies observed by a pair of iconic space telescopes? Now, there is an exciting new answer. Even better than a pair of galaxies is a pair of galaxies that are colliding!

The Hubble Space Telescope and the James Webb Space Telescope have each taken a look at a pair of intertwined galaxies that are 270 million light-year away from Earth, together called IC 1623. Scientists say this galactic collision has ignited frenzied star formation called a starburst, creating new stars at a rate more than 20 times that of our Milky Way.

October 7, 2022October 7, 2022 by Nancy Atkinson

Webb and Hubble Work Together to Reveal This Spectacular Galaxy Pair — and Several Bonuses!

By combining data from the James Webb Space Telescope and the Hubble Space Telescope, this image of galaxy pair VV 191 includes near-infrared light from Webb, and ultraviolet and visible light from Hubble. Credit: NASA, ESA, CSA, Rogier Windhorst (ASU), William Keel (University of Alabama), Stuart Wyithe (University of Melbourne), JWST PEARLS Team, Alyssa Pagan (STScI).

What’s better than a pair of galaxies observed by a pair of iconic space telescopes? The answer to that, according to researchers using the Hubble and James Webb Space Telescopes, is finding even more galaxies and other remarkable details no one expected in the duo’s observations.

“Galaxies in the foreground, background, deep background, and into the depths,” said astronomer William Keel from Galaxy Zoo, on Twitter.

September 13, 2022September 13, 2022 by Nancy Atkinson

Galactic Photobombing

These two spiral galaxies appear to be colliding, but are only overlapping from our vantage point at Earth. Credit: ESA/Hubble & NASA, W. Keel/Galaxy Zoo.

This image, taken by the Hubble Space Telescope, appears to show two spiral galaxies colliding. In fact, they are just overlapping from our vantage point and are likely quite distant from each other. The galaxies are named SDSS J115331 and LEDA 2073461, and they lie more than a billion light-years from Earth. This ‘photobombing’ of one galaxy getting in the same picture as another was originally found by volunteers from the Galaxy Zoo project, which uses the power of crowdsourcing to find unusual galaxies in our Universe.

August 17, 2022August 18, 2022 by Nancy Atkinson

Here’s the Largest Image JWST Has Taken So Far

Image of CEERS scientists looking at the Epoch 1 NIRCam color mosaic in TACC's visualization lab at UT Austin. Credit: R. Larson

A team of scientists using the James Webb Space Telescope have just released the largest image taken by the telescope so far. The image is a mosaic of 690 individual frames taken with the telescope’s Near Infrared Camera (NIRCam) and it covers an area of sky about eight times as large as JWST’s First Deep Field Image released on July 12. And it is absolutely FULL of stunning early galaxies, many never seen before. Additionally, the team may have photographed one of the most distant galaxies yet observed.

July 15, 2022July 15, 2022 by Paul M. Sutter

The Earliest Galaxies Rotated Slowly, Revving up Over Billions of Years

This image features the spiral galaxy NGC 691, imaged in fantastic detail by Hubble’s Wide Field Camera 3 (WFC3). This galaxy is the eponymous member of the NGC 691 galaxy group, a group of gravitationally bound galaxies that lie about 120 million light-years from Earth. Objects such as NGC 691 are observed by Hubble using a range of filters. Each filter only allows certain wavelengths of light to reach Hubble’s WFC3. The images collected using different filters are then coloured by specialised visual artists who can make informed choices about which colour best corresponds to which filter. By combining the coloured images from individual filters, a full-colour image of the astronomical object can be recreated. In this way, we can get remarkably good insight into the nature and appearance of these objects. Links Video of the Eponymous NGC 691

A team of astronomers have used the ALMA telescope to find a slowly-rotating galaxy in the early universe. That galaxy is the youngest ever found with a measured rotation, and it’s much slower than present-day galaxies.