Black Holes Can Halt Star Formation in Massive Galaxies

This research published in Nature is the first direct confirmation that supermassive black holes are capable of shutting down galaxies

It’s difficult to actually visualise a universe that is changing. Things tend to happen at snails pace albeit with the odd exception. Take the formation of galaxies growing in the early universe. Their immense gravitational field would suck in dust and gas from the local vicinity creating vast collections of stars. In the very centre of these young galaxies, supermassive blackholes would reside turning the galaxy into powerful quasars. A recent survey by the James Webb Space Telescope (JWST) reveals that black holes can create a powerful solar wind that can remove gas from galaxies faster than they can form into stars, shutting off the creation of new stars.

Continue reading “Black Holes Can Halt Star Formation in Massive Galaxies”

Scientists Track How a Giant Wave Moved Through Our Galactic Backyard

Illustration: Radcliffe Wave model
This illustration shows how the Radcliffe Wave moves through the backyard of our sun (shown as a yellow dot). The white line represents the wave's current shape and motion. Magenta and green lines show how the wave is expected to move over time. (Credit: Ralf Konietzka, Alyssa Goodman and WorldWide Telescope via CfA)

Astronomers say there’s a wave rippling through our galactic neighborhood that’s playing a part in the birth and death of stars — and perhaps in Earth’s history as well.

The cosmic ripple, known as the Radcliffe Wave, was identified in astronomical data four years ago — but in a follow-up study published today by the journal Nature, a research team lays out fresh evidence that the wave is actually waving, like the wave that fans in a sports stadium create by taking turns standing up and sitting down.

“Similar to how fans in a stadium are being pulled back to their seats by the Earth’s gravity, the Radcliffe Wave oscillates due to the gravity of the Milky Way,” study lead author Ralf Konietzka, a researcher at Harvard and the Harvard-Smithsonian Center for Astrophysics, or CfA, said in a news release

Continue reading “Scientists Track How a Giant Wave Moved Through Our Galactic Backyard”

Even if We Can’t See the First Stars, We Could Detect Their Impact on the First Galaxies

Population III stars were the Universe's first stars. They were extremely massive, luminous stars, and many of them exploded as supernovae. How did they shape the early galaxies? Image Credit: DALL-E

For a long time, our understanding of the Universe’s first galaxies leaned heavily on theory. The light from that age only reached us after travelling for billions of years, and on the way, it was obscured and stretched into the infrared. Clues about the first galaxies are hidden in that messy light. Now that we have the James Webb Space Telescope and its powerful infrared capabilities, we’ve seen further into the past—and with more clarity—than ever before.

The JWST has imaged some of the very first galaxies, leading to a flood of new insights and challenging questions. But it can’t see individual stars.

How can astronomers detect their impact on the Universe’s first galaxies?

Continue reading “Even if We Can’t See the First Stars, We Could Detect Their Impact on the First Galaxies”

A Black Hole Has Cleared Out Its Neighbourhood

An artist's illustration of a supermassive black hole (SMBH.) The SMBH in a distant galaxy expelled all the material in its accretion disk, clearing out a vast area. Image Credit: ESA

We can’t see them directly, but we know they’re there. Supermassive black holes (SMBHs) likely dwell at the center of every large galaxy. Their overwhelming gravity draws material toward them, where it collects in an accretion disk, waiting its turn to cross the event horizon into oblivion.

But in one galaxy, the SMBH has choked on its meal and spit it out, sending material away at high speeds and clearing out the entire neighbourhood.

Continue reading “A Black Hole Has Cleared Out Its Neighbourhood”

Feast Your Eyes on 19 Face-On Spiral Galaxies Seen by Webb

These Webb images are part of a large, long-standing project, the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) program, which is supported by more than 150 astronomers worldwide. Before Webb took these images, PHANGS was already brimming with data from NASA’s Hubble Space Telescope, the Very Large Telescope’s Multi-Unit Spectroscopic Explorer, and the Atacama Large Millimeter/submillimeter Array, including observations in ultraviolet, visible, and radio light. Webb’s near- and mid-infrared contributions have provided several new puzzle pieces. Image Credit: NASA/ESA/CSA

If you’re fascinated by Nature, these images of spiral galaxies won’t help you escape your fascination.

These images show incredible detail in 19 spirals, imaged face-on by the JWST. The galactic arms with their multitudes of stars are lit up in infrared light, as are the dense galactic cores, where supermassive black holes reside.

Continue reading “Feast Your Eyes on 19 Face-On Spiral Galaxies Seen by Webb”

Young Stars in the Outskirts of Galaxies Finally Have an Explanation

Star formation is well understood when it happens in the populous centers of galaxies. From our vantage point on Earth, within the Milky Way, we see it happening all around us. But when newborn stars are birthed in the empty outskirts of galactic space, it requires a new kind of explanation. At the 243rd meeting of the American Astronomical Association yesterday, astronomers announced that they have observed, for the first time, the unique molecular clouds that give rise to star formation near the remote edges of galaxies.

Continue reading “Young Stars in the Outskirts of Galaxies Finally Have an Explanation”

The Oldest Known Spiral Galaxy Has Ripples Like the Surface of a Pond

This simulation illustrates a galaxy disk being disturbed, leading to the propagation of a seismic ripple throughout the disk. (Credit: Bland-Hawthorn and Tepper-Garcia, University of Sydney).

Astronomers have detected pond-like ripples across the gaseous disk of an ancient galaxy. What caused the ripples, and what do they tell us about the distant galaxy’s formation and evolution? And whatever happened, how has it affected the galaxy and its main job: forming stars?

Continue reading “The Oldest Known Spiral Galaxy Has Ripples Like the Surface of a Pond”

Astronomers Find the Birthplaces of Stars in the Whirlpool Galaxy

Understanding how star-forming works at a galactic scale is challenging in our Milky Way. While we have a general understanding of the layout of our galaxy, we can’t see all of the details head-on like we would want to if we were exploring a single galaxy for details of star formation. Luckily, we have a pretty good view of the entirety of one of the most famous galaxies in all of astronomy – M51, the Whirlpool Galaxy. Now, a team of researchers from the Max Planck Institute for Astronomy has completed a survey of molecules throughout the galaxy and developed a map of potential star-forming regions.

Continue reading “Astronomers Find the Birthplaces of Stars in the Whirlpool Galaxy”

JWST Reveals Protoplanetary Disks in a Nearby Star Cluster

This composite image contains X-ray data from NASA’s Chandra X-ray Observatory and the ROSAT telescope (purple), infrared data from NASA’s Spitzer Space Telescope (orange), and optical data from the SuperCosmos Sky Survey (blue) made by the United Kingdom Infrared Telescope. Located in our galaxy about 5,500 light years from Earth, NGC 6357 is actually a “cluster of clusters,” containing at least three clusters of young stars, including many hot, massive, luminous stars. The X-rays from Chandra and ROSAT reveal hundreds of point sources, which are the young stars in NGC 6357, as well as diffuse X-ray emission from hot gas
Composite images of NGC6357 (Credit : NASA)

The Orion Nebula is a favourite among stargazers, certainly one of mine. It’s a giant stellar nebula out of which, hot young stars are forming. Telescopically to the eye it appears as a grey/green haze of wonderment but cameras reveal the true glory of these star forming regions. The Sun was once part of such an object and astronomers have been probing their secrets for decades. Now, a new paper presents the results from a detailed study from the James Webb Space Telescope (JWST) that has been exploring planet forming disks around stars in the Lobster Nebula.

Continue reading “JWST Reveals Protoplanetary Disks in a Nearby Star Cluster”

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.

Continue reading “What Can Slime Mold Teach Us About the Universe?”