News Feeds

Scientists have developed a new AI algorithm that can separate brain patterns related to a particular behavior. This work promises to improve brain-computer interfaces and aid with the discovery of new brain patterns.

Ask most people what a galaxy is made up of, and they’ll say it’s made of stars. Our own galaxy, the Milky Way, hosts between about 100 to 300 billion stars, and we can see thousands of them with our unaided eyes. But most of a galaxy’s mass is actually gas, and the extent of the gas has been difficult to measure.

Researchers have found a way to see how far that gas extends into the cosmos.

One of the foundational questions about galaxies concerns their size. If we limit our observations to stars, then our galaxy, for example, is about 26.8 kiloparsecs, or about 87,000 light-years, across. Our neighbour, Andromeda, is about 46.56 kpcs or 152,000 light-years across. But do these measurements really define the sizes?

In new research published in Nature Astronomy, researchers measured the reach of the gas that extends beyond a galaxy’s stellar population. It’s titled “An emission map of the disk–circumgalactic medium transition in starburst IRAS 08339+6517.” The lead author is Nikole Nielsen, a researcher with Swinburne University and ASTRO 3D and an Assistant Professor at the University of Oklahoma.

Galaxies have gaseous haloes that serve as reservoirs of star-forming material called the circumgalactic medium (CGM). The CGM interfaces with the intergalactic medium (IGM), which is yet more gas that exists between galaxies. The CGM is notoriously difficult to observe because it’s so diffuse and extended. But it makes up about 70% of a typical galaxy (ignoring dark matter) and plays an important role. “This diffuse reservoir of gas, the circumgalactic medium, acts as the interface between a galaxy and the cosmic web that connects galaxies,” the authors explain in their paper.

Astronomers rely on bright background objects to try to observe the CGM. Things like distant quasars, pulsars, or other galaxies can light up the gas and allow astronomers to measure its spectra. But that only works when things line up right, and it only produces a beam-like image of the galaxy.

In this new research, a team of astronomers found a different way of observing the CGM. They used the Keck Cosmic Web Imager (KCWI) on the 10-meter Keck telescope in Hawaii to observe the gas around IRAS 08339+6517. Rather than a limited, beam-like look at the gas, they were able to detect the clouds of gas well outside the typical confines of a galaxy, out to 100,000 light-years beyond the limit of the starlight that typically defines a galaxy.

“We present kiloparsec-scale-resolution integral field spectroscopy of emission lines that trace cool ionized gas from the centre of a nearby galaxy to 30 kpcs into its circumgalactic medium,” the authors write. In their paper, they explain that “… we obtain the equivalent of thousands of quasar sightlines around a single galaxy.”

IRAS 08339+6517 is a starburst galaxy about 56 kpcs away. A starburst galaxy is one that is birthing stars at an extraordinarily high rate. Hubble images show that it’s a face-on spiral galaxy, and 90% of its starlight is contained within a radius of about 2.4 kpcs. “Unlike normal spirals, it has quite extreme properties, with a star formation rate (SFR) = 12.1 solar masses yr-1) that is ~ 10 times higher than typical for its mass and stellar populations that are dominated by very young (~ 4 – 6 Myr) stars,” the authors write.

The researchers found that as the CGM extends beyond the galaxy, the physical properties of the hydrogen and oxygen in the gas changed. The change was ubiquitous at a certain distance and indicates that the gas is interacting with different energy sources.

“We found it everywhere we looked, which was really exciting and kind of surprising,” said lead author Nielsen. “We’re now seeing where the galaxy’s influence stops, the transition where it becomes part of more of what’s surrounding the galaxy, and, eventually, where it joins the wider cosmic web and other galaxies. These are all usually fuzzy boundaries.”

“But in this case, we seem to have found a fairly clear boundary in this galaxy between its interstellar medium and its circumgalactic medium,” said Professor Nielsen.

“In the CGM, the gas is being heated by something other than typical conditions inside galaxies; this likely includes heating from the diffuse emissions from the collective galaxies in the Universe, and possibly some contribution is due to shocks,” said Dr Nielsen.

The boundary is where the gas is heated differently inside the galaxy compared to outside the galaxy. Inside the galaxy’s disk, gas is being photoionized by HII (ionized atomic hydrogen) star-forming regions. At further distances, the gas is being ionized by shocks or the extragalactic UV background.

“It’s this interesting change that is important and provides some answers to the question of where a galaxy ends,” she says.

This figure from the research shows the spatial distribution of ionized gas in the CGM at kiloparsec scales. Emission from [Oiii] ?5007 in the CGM of IRAS08 extends to at least 30 kpc from the galaxy center. The blue rectangle represents the field-of-view of the KCWI pointing covering the galaxy disk (emission map not shown). HI contours indicate levels of constant HI column density from the Very Large Array, where a filament extends from IRAS08 towards a smaller companion galaxy 60 kpc away. Image Credit: Nielsen et al. 2024.

These results make a contribution to one of the most interesting issues in astronomy: How do galaxies evolve?

Gas flows into galaxies and becomes fuel for more star formation. At the same time, gas flows out from a galaxy as part of stellar feedback. There are three broad types of galaxies: starburst galaxies with extreme amounts of star formation, quenched galaxies with very little star formation, and galaxies in between. The gas in the CGM and the IGM play roles in a galaxy’s gas budget.

IRAS08 has a remarkably strong outflow of gas, but its metallicity profile is flat and shallow. Astronomers typically assume that galaxies with these metallicities and high SFRs are acquiring significant amounts of gas. Other scientific observations of IRAS08 indicate “a rapid inflow of gas to the center of the disk that is fueling the very strong starburst and subsequently strong outflows,” the authors explain.

Gas flows into galaxies along spiralling filaments. This image of a galaxy shows a stream of inflowing gas, as rendered in a supercomputer. Image Credit: MPIA (G. Stinson / A.V. Maccio)

However, IRAS 08 is a complex object that’s also interacting with a nearby galaxy. “VLA observations of the HI gas around IRAS08 identified a filament extending out to ~ 40 kpcs from the galaxy and containing 70% of the neutral gas in the system,” the authors write. This filament interacts with a neighbouring galaxy about 60 kpcs away, which is only one-tenth the mass of IRAS-08.

The authors say that this interaction with its neighbour could enhance star formation, but there’s no evidence that it’s affecting IRAS-08’s morphology. This doesn’t appear to be the first stage of an eventual merger.

Finding the boundary between the CGM and the IGM could be a critical step in understanding how gas cycles in and out of galaxies and how gas may interact with neighbours without a merger.

“The circumgalactic medium plays a huge role in that cycling of that gas,” says Dr Nielsen. “So, being able to understand what the CGM looks like around galaxies of different types – ones that are star-forming, those that are no longer star-forming, and those that are transitioning between the two –we can observe differences in this gas, which might drive the differences within the galaxies themselves, and changes in this reservoir may actually be driving the changes in the galaxy itself.”

Nature has few discrete boundaries. Everything interacts with other things, including massive galaxies. The interactions hold the key to understanding.

These results could open up a whole new window into how galaxies, gas, and stars interact and how galaxies evolve.

The post The True Size of Galaxies is Much Larger Than We Thought appeared first on Universe Today.

Every living organism uses tiny quantities of metals to carry out biological functions, including breathing, transcribing DNA, turning food into energy, or any number of essential life processes.

The MXene class of materials has many talents. An international team has now demonstrated that MXenes, properly functionalized, are excellent catalysts for the oxygen evolution reaction in electrolytic water splitting. They are more stable and efficient than the best metal oxide catalysts currently available. The team is now extensively characterizing these MXene catalysts for water splitting at the Berlin X-ray source BESSY II and Soleil Synchrotron in France.

Physicists present a nanometer-sized light antenna with electrically modulated surface properties -- a breakthrough that could pave the way for faster computer chips.

Physicists present a nanometer-sized light antenna with electrically modulated surface properties -- a breakthrough that could pave the way for faster computer chips.

In a new study, astronomers report novel evidence regarding the limits of planet formation, finding that after a certain point, planets larger than Earth have difficulty forming near low-metallicity stars.

An assist from a Google Artificial Intelligence tool has helped scientists discover how the proteins of a heat-loving microbe respond to the crushing conditions of the planet's deepest ocean trenches, offering new insights into how these building blocks of life might have evolved under early Earth conditions.

Scientists captured clear images of biomolecules in single live cells in water for the first time using infrared (IR) transmission imaging. The IR technique enables researchers to measure the mass of biomolecules such as proteins in a cell. Using simple components, the method has the potential to speed up advances in biomanufacturing, cell therapy development and drug development.

Integrating artificial intelligence into today's environmental control systems could reduce energy consumption for indoor agriculture by 25% -- potentially helping to feed the world as its population rises, engineers have found.

Researchers have found a chemical 'chameleon' that could improve the process used to purify rare-earth metals used in clean energy, medical and national security applications.

Researchers have found a chemical 'chameleon' that could improve the process used to purify rare-earth metals used in clean energy, medical and national security applications.

A global survey of more than a thousand cities shows heat and air pollution in urban environments often have a measurable influence on rainfall, creating urban "wet islands"

Here at UT, we’ve had several stories that describe the concept of a space elevator. They are designed to make it easier to get objects off Earth and into space. That, so far, has proven technically or economically infeasible, as no material is strong enough to support the structure passively, and it’s too energy-intensive to support it actively. However, it could be more viable on other worlds, such as the Moon. But what about worlds farther afield? A student team from the University of Colorado at Colorado Springs looked at the use case of a space elevator on Ceres and found that it could be done with existing technology.

Before we discuss why anyone would want to put a space elevator on Ceres, let’s first examine the technologies that would make it possible. Every space elevator design has three different components: an anchor, a tether, and a counterweight. Each would require its own technologies.

The anchor is simple enough; it’s how the system interfaces with Ceres. The surface of Ceres is primarily made of clay, which is relatively good for anchoring technologies. Luckily, the force the anchor needs to withstand is only around 300N, which is much lower than the force on Earth, given Ceres’ small mass. There have already been asteroid anchoring technologies for other missions that can provide up to 500N of force resistance, so an anchor on Ceres should prove no real challenge.

Fraser describes the general idea of a space elevator.

The tether is where the technology falls short on Earth – no material known to science can withstand the forces exerted on the tether of a passively controlled space elevator when it is tied to Earth. However, the closest we can come, something space elevator enthusiasts mention as almost a holy grail, is carbon nanotubes. In the analysis for the space elevator on Ceres, they once again came out ahead. However, the limitation of actually physically creating a long tether will still plague any space elevator design on Ceres.

The counterweight is much simpler, as it can be just a big, dumb mass. However, its mass is proportional to the necessary length of cable—the heavier the mass, the shorter the cable. So, the tradeoff between having a heavier counterweight and a shorter cable is another design consideration when considering these systems.

Calculations from the team show that, with only a little more technological development, all three main systems could be ready for installation on Ceres itself. But what advantages does it have? It could be helpful as a launching point for accessing other asteroids in the asteroid belt. Ceres also has water relatively near the surface, which is helpful for all kinds of human exploration, either as rocket fuel or biological systems. It’s also well placed to quickly get things back to Earth using Jupiter as a gravity assist.

Isaac Arthur goes into a deeper description of space elevators and their advantages.

But before it can provide any of those advantages, someone is going to have to pay for it. Estimates of the overall cost of the system total about $5.2 billion — not too far out of the range of larger-scale space exploration projects. But more than most countries are likely willing to pony up for a grand infrastructure project that hasn’t yet proven its benefit.

So, for now, any space elevator will remain in the realm of science fiction. But research like this and other ongoing technological improvements is how we will eventually push forward to that future. Whether it’s a space elevator on Ceres, on the Moon, or some other novel launch technology, someday humans will need a better way to get off Earth rather than burning dead living organisms. Hopefully, that day will come sooner rather than later.

Learn More:
Bate et al. – Analyzing the Potential of Space Elevator Technology for Sustainable Asteroid Mining
UT – What is a Space Elevator?
UT – A New Method for Making Graphene has an Awesome Application: A Space Elevator!
UT – A Japanese Company is About to Test a Tiny Space Elevator… in Space

Lead Image:
Artistic view of a possible space elevator.
Credit: NASA

The post Using A Space Elevator To Get Resources Off the Queen of the Asteroid Belt appeared first on Universe Today.

Are humanoid robots the future of space exploration? New Scientist reporter James Woodford took NASA's Valkyrie for a spin to find out

The Arrhenius equation, which has accurately described rates of chemical reactions for more than a century, may have to be tweaked for the quantum realm

Levels of certain cells, fatty molecules and proteins in the blood are different in people with chronic fatigue syndrome than in those without it, which could help doctors spot the condition sooner

X-ray videos of Japanese eels swallowed whole by dark sleeper fish have revealed how the eels can make a daring escape from being digested

Forget atomic clocks. Nuclear clocks, which only drop a second every 300 billion years, can test whether nature's fundamental constants are constant after all

Exoplanets have been discovered with a wide range of environmental conditions. WASP-76b is one of the most extreme with a dayside temperature of over 2,000 degrees. A team of researchers have found that it’s even more bizarre than first thought! It’s tidally locked to its host star so intense winds encircle the planet. They contain high quantities of iron atoms that stream from the lower to upper layers around the atmosphere.

Exoplanets exist outside of our Solar System and orbit other stars. The first confirmed discovery was back in the 1990’s and since then, over 5,200 have been discovered. Many of them are gas giants like Jupiter or Saturn and others are small rocky Earth like planets, minus perhaps their habitability status. As more advanced telescopes and detection techniques are developed not only will our detection levels increase further but so will our ability to explore these alien worlds. 

Artist impression of glory on exoplanet WASP-76b. Credit: ESA

One such exoplanet, WASP-76b has received quite a lot of attention of late. It is an ultra-hot gas giant that is 640 light years from us in the direction of the constellation Pisces. It was discovered back in 2013 and has an orbit that is very close to its host star, completing one orbit in just 1.8 Earth days! It’s the proximity to the star that has led to the extreme daytime temperatures of over 2,000 degrees. The intense heat is thought to vaporise iron which then condenses into liquid on the cooler night-time side and fall as iron rain! 

A team of astronomers, with some from the University of Geneva, announced their findings in the journal Astronomy & Astrophysics of evidence for intense iron winds in the atmosphere of WASP-76b. Astronomers have been focussing on this planet since its discovery to try and understand the mechanisms in the atmosphere of this ultra-hot Jupiter world. It really is a fascinating world and even a rainbow was detected there last April! 

The team kept their attention on the day-time side where the temperatures are far higher. They used the ESPRESSO spectrograph that was installed on the European Southern Observatory’s Very Large Telescope (yes that’s its name!) It is known for its stability and high spectral resolution so it can discern wonderfully fine levels of detail in a stellar spectrum. 

The four 8.2-metre Unit Telescopes of the Very Large Telescope at the Paranal Observatory complex. ESO/VLT

Using a technique known as high resolution emission spectroscopy, the team studied the visible light spectrum. The approach relies upon the detection of emission lines in a spectrum and enables the chemical composition to be decoded. Here they detected the chemical signature of iron and found that they were moving from lower levels to the higher layers of the atmosphere.

The study of exoplanet atmospheres help us to further develop our understanding of the range of environments on these alien worlds. As a gas giant, the discoveries on WASP-76b help us learn a little more about the climates of worlds that are barraged by extreme levels of radiation from their host star.

Source : Iron winds on an ultra-hot exoplanet

The post Iron Winds are Blowing on WASP-76 b appeared first on Universe Today.