galaxies Archives

November 8, 2023November 8, 2023 by Evan Gough

What Can Slime Mold Teach Us About the Universe?

A simulation of the cosmic web, diffuse tendrils of gas that connect galaxies across the universe. Credit: Illustris Collaboration

What can slime molds tell us about the large-scale structure of the Universe and the evolution of galaxies? These things might seem incongruous, yet both are part of nature, and Earthly slime molds seem to have something to tell us about the Universe itself. Vast filaments of gas threading their way through the Universe have a lot in common with slime molds and their tubular networks.

October 26, 2023October 26, 2023 by Nancy Atkinson

What a Mess. When the Milky Way and Andromeda Merge, it'll Look Like This

This mess is the billion-year-old aftermath of a double spiral galaxy collision. At the heart of this chaotic interaction, entwined and caught amid the chaos, is a pair of supermassive black holes — the closest such pair ever recorded from Earth. The image was taken by Gemini South, one half of the International Gemini Observatory. Credit: International Gemini Observatory/NOIRLab/NSF/AURA

No need to panic, but the Andromeda Galaxy is barreling towards us. It is due to begin merging with the our Milky Way Galaxy in a few billion years. From an outside observer, that process will very likely look like this new picture captured by the Gemini South Observatory. This is NGC 7727, a peculiar galaxy in the constellation Aquarius, about 90 million light-years away. Two giant spiral galaxies are merging, their gravitational interactions are hurling giant tidal tails of stars into the cosmos.

October 20, 2023October 20, 2023 by Nancy Atkinson

Astronomers Release a Cosmic Atlas of 380,000 Galaxies in our Neighborhood

Optical mosaics of 42 galaxies from the SGA-2020 sorted by increasing angular diameter from the top-left to the bottom-right. This figure illustrates the tremendous range of types, sizes, colors and surface brightness profiles, internal structure, and environments of the galaxies in the SGA. Credit: CTIO/NOIRLab/DOE/NSF/AURA/J. Moustakas.

The Milky Way is just one galaxy in a vast cosmic web that makes up the Universe’s large-scale structure. While ESA’s Gaia spacecraft is building a map of our stellar neighborhood, a team of astronomers with the Dark Energy Spectroscopic Instrument (DESI) Legacy Survey have released a comprehensive galactic map that includes all the data from three wide-ranging surveys completed between 2014 and 2017. Called the Siena Galaxy Atlas (SGA), it contains the distance, location, and chemical profile of 380,000 galaxies across half of the night sky.

“Previous galaxy compilations have been plagued by incorrect positions, sizes and shapes of galaxies, and also contained entries which were not galaxies but stars or artifacts,” explained Arjun Dey, an astronomer with NOIRLab, who was involved in the project. “The SGA cleans all this up for a large part of the sky. It also provides the best brightness measurements for galaxies, something we have not reliably had before for a sample of this size.”

October 11, 2023October 11, 2023 by Evan Gough

Compare Images of a Galaxy Seen by Both Hubble and JWST

NGC 5068 is a barred spiral galaxy about 20 million light-years away. The Hubble captured this image of NGC 5068 in ultraviolet, visible, and near-infrared light. Image Credits: NASA, ESA, R. Chandar (University of Toledo), and J. Lee (Space Telescope Science Institute); Processing: Gladys Kober (NASA/Catholic University of America)

The James Webb Space Telescope is widely considered to be better than the Hubble Space Telescope. But the JWST doesn’t replace its elder sibling; it’s the Hubble’s successor. The Hubble is nowhere near ready to retire. It’s still a powerful science instrument with lots to contribute. Comparing images of the same object, NGC 5068, from both telescopes illustrates each one’s value and how they can work together.

October 4, 2023October 4, 2023 by Evan Gough

Seeing the Web Connecting Galaxies Across the Universe

New research has imaged the Cosmic Web of cold dark gas that interconnects the Universe's galaxies. Image Credit: Martin et al. 2023.

One hundred years ago, we didn’t know there was anything outside of our own galaxy, the Milky Way. Now we know that our puny planet Earth, and everything else, is part of a vast structure called the Cosmic Web. Its scale is difficult to comprehend in any concrete way, and the system’s complexity and magnitude brings our most powerful supercomputers to their knees.

Astronomers have known about the Cosmic Web for some time, as they’ve caught glimpses of it. But a new instrument has given us our most complete view of it yet.

September 29, 2023September 29, 2023 by Evan Gough

Lose Yourself in the JWST’s Exquisite Image of Barnard’s Galaxy

The JWST's NIRCam captured this image of the irregular galaxy NGC 6822. NIRCam probes the near-infrared, which in this case makes it suitable for observing the densely packed star field. Image Credit: ESA/Webb, NASA & CSA, M. Meixner

There may come a day when we grow weary of JWST images. But it’s not today. Today, we can lose ourselves in the space telescope’s engrossing image of NGC 6822, also called Barnard’s Galaxy.

September 25, 2023September 25, 2023 by Nancy Atkinson

Finally! Astronomers are Starting to See the First Galaxies Coming Together With JWST

The big galaxy in the foreground is named LEDA 2046648, and is seen just over a billion years back in time, while most of the others lie even farther away, and hence are seen even further back in time. CREDIT: ESA/Webb, NASA & CSA, A. Martel.

One of the James Webb Space Telescope’s principal science goals is to observe the epoch where we think that the first galaxies were created, to understand the details of their formation, evolution, and composition. With each deep look back in time, the telescope seems to break its own record for the most distant galaxy ever seen. Science papers are now are starting to trickle in, as astronomers are finally starting to collect enough data from JWST to build a deeper understanding of the early Universe.

In a new study published in Nature Astronomy, a team of researchers in Denmark believe they have observed some of the very first, earliest galaxies with JWST. These galaxies are so old, they are likely still in the process of being formed.

September 22, 2023September 22, 2023 by Evan Gough

The JWST is Forcing Astronomers to Rethink Early Galaxies

The graceful winding arms of the grand-design spiral galaxy M51 stretch across this image from the NASA/ESA/CSA James Webb Space Telescope. New JWST observations of the early Universe are upending our understanding of galaxy evolution. Credit: ESA/Webb, NASA & CSA, A. Adamo (Stockholm University) and the FEAST JWST team

The JWST has surprised astronomers again. Contrary to our existing understanding, the JWST showed us that the early Universe was full of fully-formed galaxies similar to the ones we see today. The widely-held belief is that the early Universe was too chaotic in its early years, and frequent mergers would’ve disrupted galaxies’ graceful shapes.

September 19, 2023September 19, 2023 by Carolyn Collins Petersen

The Race to Find the Farthest Galaxy Continues

Scientists with the CEERS Collaboration have identified an object (Maisie’s galaxy) that may be one of the earliest and farthest galaxies ever observed. Credit: NASA/STScI/CEERS/TACC/S. Finkelstein/M. Bagley/Z. Levay.

The very early Universe was a busy place, particularly when stars and galaxies began to form. Astronomers eagerly search for the farthest galaxy—that elusive “first” one to form. JWST is part of that hunt through its Cosmic Evolution Early Release Survey (CEERS).

September 19, 2023September 19, 2023 by Evan Gough

Galaxies Breathe Gas, and When They Stop, No More Stars Form

Artist concept of how a galaxy might accrete mass from rapid, narrow streams of cold gas. These filaments provide the galaxy with continuous flows of raw material to feed its star-forming at a rather leisurely pace. Credit: ESA–AOES Medialab

For most of the history of astronomy, all we could see were stars. We could see them individually, in clusters, in nebulae, and in fuzzy blobs that we thought were clumps of stars but were actually galaxies. The thing is, most of what’s out there is much harder to see than stars and galaxies. It’s gas.

Now that astronomers can see gas better than ever, we can see how galaxies breathe it in and out. When they stop breathing it, stars stop forming.