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An atlas doesn’t seem to be an essential item in cars these days but think about them and most people will think about distances. An atlas of the stars not only covers distances but must also take into account time too. The Andromeda galaxy for example is so far away that its light takes 2.5 million years to reach us. A team of researchers have now built a catalogue that contains information on millions of galaxies including their distance and looks back in time up to 10 billion years!

Like anything that has – hmmmm lots of stuff, there are always catalogues to capture information about them. Astronomy is no different and there are plenty of catalogues; Messier, New General, Second Cambridge Catalogue of Radio Sources and the Two Micron All Sky Survey, the list goes on. Now a new catalogue has been created to provide information on millions of distant galaxies. It’s been created by a collaboration of organisations led by the Institute of Space Sciences as a result of the Physics of the Accelerating Universe Survey (PAUS.)

This new NASA/ESA Hubble Space Telescope shows Messier 96, a spiral galaxy just over 35 million light-years away in the constellation of Leo (The Lion). It is of about the same mass and size as the Milky Way. It was first discovered by astronomer Pierre Méchain in 1781, and added to Charles Messier’s famous catalogue of astronomical objects just four days later. The galaxy resembles a giant maelstrom of glowing gas, rippled with dark dust that swirls inwards towards the nucleus. Messier 96 is a very asymmetric galaxy; its dust and gas is unevenly spread throughout its weak spiral arms, and its core is not exactly at the galactic centre. Its arms are also asymmetrical, thought to have been influenced by the gravitational pull of other galaxies within the same group as Messier 96. This group, named the M96 Group, also includes the bright galaxies Messier 105 and Messier 95, as well as a number of smaller and fainter galaxies. It is the nearest group containing both bright spirals and a bright elliptical galaxy (Messier 105).

Over a period of 200 nights between 2015 and 2019, the teams embarked on their survey using the PAUCAM mounted upon the William Herschel Telescope (WHT) in La Palma. The camera is mounted at the prime focus of the WHT giving it a whopping 1 degree field of view. There are filter trays in front of the CCDs with 42 narrowband filters ranging from 4400 to 8600 angstroms. The team used the different filters to image the same field numerous times. The light from more distant objects will be shifted toward the red end of the spectrum and the multiple images of the same field will enable distance calculations to be made.

The William Herschel Telescope, part of the Isaac Newton group of telescopes, located on Canary Island. Credit: ing.iac.es

Overall, the survey covers 50 square degrees on the sky. To put that into context, the full moon measures half a degree across so the full survey maps out an area of sky equivalent to about 250 full moons. Having analysed the full set of images, the catalogue that has been developed includes data for 1.8 million objects which will be the foundations for astronomers to better understand the structure of the Universe. 

Understanding the structure of the universe is to understand the distribution of dark matter and dark energy. Dark energy is thought to make up 70 percent of the Universe but we still don’t know what it is. We can see its effect in the accelerated expansion of the Universe but its nature remains a mystery to us. The new survey will help to shine a light on dark energy with its comprehensive data set of galaxies that span more than 10 billion light years. 

This multiwavelength image of the Cloverleaf ORC (odd radio circle) combines visible light observations from the DESI (Dark Energy Spectroscopic Instrument) Legacy Survey in white and yellow, X-rays from XMM-Newton in blue, and radio from ASKAP (the Australian Square Kilometer Array Pathfinder) in red. X. Zhang and M. Kluge (MPE), B. Koribalski (CSIRO)

The results are a significant step forward in research into the cosmic distance scale and offers an extensive catalogue of photometric redshift measurements as they appeared billions of years ago. Over the months that follow, the team are planning on exploring galaxy clustering and galaxy shapes to help understand the evolution of the universe. 

Source : New cosmic distance catalogue to unlock the mysteries of Universe formation

The post A New Catalog Charts the Evolution of the Universe Over Time appeared first on Universe Today.

The largest Einstein Cross dwells among a rare arrangement of seven gravitationally lensed galaxies called the Carousel Lens located between 7 billion and 12 billion light-years from Earth.

Three crewmates have landed Earth after a record-long stay on the International Space Station (ISS) for two of them. For one, the 374 days has amounted to only a third of his total time in space.

Field trials indicate that pumping seawater onto the snow on top of Arctic sea ice can make the ice thicker, offering a possible way to preserve sea ice throughout the summer

Field trials indicate that pumping seawater onto the snow on top of Arctic sea ice can make the ice thicker, offering a possible way to preserve sea ice throughout the summer

Astronomers have cataloged over 500 gamma-ray bursts, which are some of the most violent explosions in the cosmos.

Uterus transplants are becoming more common, opening up the possibility of pregnancy and parenthood to people with certain health conditions

Video: 00:03:12

There’s a mystery out there in deep space – and solving it will make Earth safer. That’s why the European Space Agency’s Hera mission is taking shape – to go where one particular spacecraft has gone before.

On 26 September 2022, moving at 6.1 km/s, NASA’s DART spacecraft crashed into the Dimorphos asteroid. Part of our Solar System changed. The impact shrunk the orbit of the Great Pyramid-sized Dimorphos around its parent asteroid, the mountain-sized Didymos.

This grand experiment was performed to prove we could defend Earth against an incoming asteroid, by striking it with a spacecraft to deflect it. DART succeeded. But that still leaves many things scientists don’t know: What is the precise mass and makeup of Dimorphos? What did the impact do to the asteroid? How big is the crater left by DART’s collision? Or has Dimorphos completely cracked apart, to be held together only by its own weak gravity?

That’s why we’re going back – with ESA’s Hera mission. The spacecraft will revisit Dimorphos to gather vital close-up data about the deflected body, to turn DART’s grand-scale experiment into a well-understood and potentially repeatable planetary defence technique.

The mission will also perform the most detailed exploration yet of a binary asteroid system – although binaries make up 15% of all known asteroids, one has never been surveyed in detail.

Hera will also perform technology demonstration experiments, including the deployment ESA’s first deep space ‘CubeSats’ – shoebox-sized spacecraft to venture closer than the main mission then eventually land – and an ambitious test of 'self-driving' for the main spacecraft, based on vision-based navigation.

By the end of Hera’s observations, Dimorphos will become the best studied asteroid in history – which is vital, because if a body of this size ever struck Earth it could destroy a whole city. The dinosaurs had no defence against asteroids, because they never had a space agency. But – through Hera – we are teaching ourselves what we can do to reduce this hazard and make space safer.

The new interconnected breed of autocrats gains and retains power by deception, globally undermining democracies through their own institutions

Cave fish develop taste buds on their head and below their chin—and even in humans, taste cells grow in truly unexpected locations

New observations from the MeerKAT radio survey suggest our estimates of the cosmic dipole effect are actually in line with the large scale structure of the universe.

This week’s news roundup explores how the brain is affected by pregnancy, the way “scuba diving” lizards breathe underwater, and much more.

Find out what's going on at the International Space Station.

The Sentinel-1B satellite, the second satellite of the Copernicus Sentinel-1 mission, completed its disposal process – which included lowering its orbit and passivating its systems to ensure re-entry into Earth’s atmosphere within 25 years.

This careful operation highlights the European Union’s and ESA’s commitment to space safety and sustainability and provides valuable experience for the disposal of current and future spacecraft.

CAPTCHA tests are supposed to distinguish humans from bots, but an AI system mastered the problem after training on thousands of images of road scenes

CAPTCHA tests are supposed to distinguish humans from bots, but an AI system mastered the problem after training on thousands of images of road scenes

A gravitational lens is the ultimate funhouse mirror of the Universe. It distorts the view of objects behind them but also supplies amazing information about distant galaxies and quasars. Astronomers using Hubble Space Telescope (HST) recently released a new image of one of these weird apparitions called “The Carousel Lens”. It’s a rare alignment of seven background galaxies that all appear distorted by an intervening galaxy cluster.

According to Berkeley Lab senior scientist David Schlegel, this gravitational lens is a great find for astronomers. “This is an amazingly lucky ‘galactic line-up’—a chance alignment of multiple galaxies across a line-of-sight spanning most of the observable universe,” he said. “Finding one such alignment is a needle in the haystack. Finding all of these is like eight needles precisely lined up inside that haystack.”

The Carousel Lens was uncovered in Dark Energy Survey data a few years ago. Now astronomers are zeroing in on it to measure its mass and the effects on the images of more distant galaxies. This gravitational lens alignment of seven galaxies and a foreground galaxy cluster could well provide new insights into the early Universe via the high-redshift galaxy sources, the properties of the lensing cluster, and unanswered questions in cosmology.

An example of the Carousel gravitational lens found in the DESI Legacy Surveys data. There are four sets of lensed images in DESI-090.9854-35.9683. They correspond to four distinct background galaxies — from the outermost giant red arc to the innermost bright blue arc. All of them appear gravitationally warped — or lensed — by the orange galaxy at the very center. Deconstructing the Carousel Gravitational Lens

Typical large-scale gravitational lenses in the Universe consist of a “lensing object” and more distant objects behind it. Generally, those distant objects are galaxies and quasars. (Small-scale gravitational lenses occur when a planet passes in front of its star, for example.) However, the Carousel Lens is more “cosmic” in nature, covering objects millions of light-years apart. In particular, the cluster doing the lensing is about 5 billion light-years from Earth. It’s also designated as DESI-090.9854-35.9683 and has at least four large galaxy members as well as several other possible cluster members.

The Carousel lenses at least seven distant galaxies. They lie anywhere from 7.62 to 12 billion light-years away from Earth. Their alignment with the lensing cluster resulted in multiple images of each of the more distant galaxies. Their shapes are the result of the “funhouse mirror” effect that stretches their apparitions. The galaxy labeled “4a, 4b, 4c, 4d” actually forms a nearly perfect “Einstein Cross”, which shows the symmetrical distribution of mass in the lens.

The Carousel is a great example of a “strong lens” in the Universe, according to Xiaoshang Huang, who is part of the team at Berkeley studying it. “Our team has been searching for strong lenses and modeling the most valuable systems,” said Huang. “The Carousel Lens is an incredible alignment of seven galaxies in five groupings that line up nearly perfectly behind the foreground cluster lens. As they appear through the lens, the multiple images of each of the background galaxies form approximately concentric circular patterns around the foreground lens, as in a carousel. It’s an unprecedented discovery, and the computational model generated shows a highly promising prospect for measuring the properties of the cosmos, including those of dark matter and dark energy.”

The Carousel Lens as seen by the HST marked up by the galaxies. The “L” indicators near the center (La, Lb, Lc, and Ld) show the most massive galaxies in the lensing cluster. Seven unique galaxies (numbered 1 through 7) – located an additional 2.6 to 7 billion light years beyond the lens – appear in multiple, distorted “fun-house mirror” iterations (indicated by each number’s letter index, e.g., a through d), as seen through the lens. (Credit: William Sheu (UCLA) using HST data.) What Makes this Lens So Special?

In their recently released paper, Schlegel, Huang, and others described modeling the Carousel Lens to understand its structure. They point out that it shows nearly every lensing configuration that astronomers see in such apparitions. There are various arcs, diamond shapes, the Einstein Ring, and double lensing.

The big spread of distances between the lens itself and the galaxies it’s distorting also presents some interesting cosmological areas of study. In particular, the science team hopes to do more spectral studies to understand the lensing cluster’s matter distribution. At least seven lensed sources will help constrain the amount of matter in the cluster and aid in understanding the amounts of dark and baryonic matter in such systems.

In addition to matter distribution, the team can also use this lensing system as a way to understand the characteristics of the distant lensed sources. This is important because the most distant ones give insight into conditions in their various epochs of cosmic history. For example, source 7 is an interesting “nearby” source that could be a very high-redshift “quiescent” galaxy. It appears to be very “red” in infrared measures and others of this sort have been observed by HST. Source 7 could be an efficient example of what’s called “early galaxy quenching”.

That occurs when star formation shuts down and the galaxy becomes quiescent. There are several ways that could happen, but the most common is some kind of feedback loop between the central supermassive black hole and outlying regions. This could occur as a result of galaxy mergers, for example, which were very common in the early Universe. The Carousel Lens (and others of its type) provides a special way to study that epoch of cosmic history and the events that shaped the galaxies we see today.

For More Information

Magnifying Deep Space Through the ‘Carousel Lens
The Carousel Lens: A Well-modeled Strong Lens with Multiple Sources Spectroscopically Confirmed by VLT/MUSE

Gravitational lens found in the DESI Legacy Surveys data

The post This Might Be the Best Gravitational Lens Ever Found appeared first on Universe Today.

Solar flares are a fascinating thing and have a profound effect on what astronomers refer to as “space weather.” These events vary with the Sun’s 11-year solar cycle, releasing immense amounts of radiation across the electromagnetic spectrum (from extreme ultraviolet to X-rays) into space. The effects of flares have been observed since time immemorial, which include aurorae at high latitudes (Aurora Borealis and Australis), but have only been the subject of study and prediction for about a century and a half. Still, there is much that remains unknown about these dramatic events.

For instance, flares are known to affect the Sun’s atmosphere, from the visible surface (photosphere) to its outermost layer (corona). However, there are still questions about how these events influence the lower layers of the atmosphere. In a recent study led by the University of Colorado, Boulder, a team of researchers documented the rotation of two very small sunspots of the Sun’s surface (pores) using the Daniel K. Inouye Solar Telescope (DKIST) at Mauna Kea. These pores were linked to a less powerful flare and moved in a way that has never been observed, suggesting that the dynamics of the Sun’s atmosphere are more complex than previously thought.

The study was led by Rahul Yadav, a Research Scientist from the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder (UC Boulder). He was joined by colleagues from UC Boulder’s Department of Astrophysical and Planetary Sciences, the U.S. National Science Foundation’s (NSF) National Solar Observatory (NSO), and the Institute of Solar-Terrestrial Physics of SB RAS. The paper that details their findings, “Photospheric Pore Rotation Associated with a C-class Flare from Spectropolarimetric Observations with DKIST,” recently appeared in the Astrophysical Journal Letters.

The NSO Daniel K. Inouye Solar Telescope atop Mauna Kea, Hawaii. Credit: NSF/NSO/AURA

Solar flares are thought to occur when stored magnetic energy in the Sun’s atmosphere accelerates charged particles in the surrounding plasma. They occur in active regions and are often accompanied by a significant amount of plasma being ejected into space – a Coronal Mass Ejection (CME) – and the release of accelerated particles – a Solar Particle Event (SPE). These can play havoc with satellites in Earth’s orbit, and interfere with radio antennas and electronic grids on the surface, which is why scientists are interested in learning more about them.

Flares are classified according to their strength: B-class is the weakest, C and M-class are slightly more energetic, and X is the strongest. Previous studies have shown how intense solar flares can lead to large sunspots rapidly rotating and distorting active regions on the Sun’s surface. But as Dr. Yadav explained in an NSO press release, what they observed was quite unexpected. “[T]his study marks the first time that such rotation has been observed on a smaller scale—less than 2,000 kilometers [~1,245 mi] across—associated with a less intense C-class flare,” he said.

In addition, previous observations have found that rotational movements of sunspots occur directly at the flare ribbon, where the most intense emissions occur during a flare event. This time, the team observed a pre-flare rotation located a short distance from the flare ribbon, which suggests that the coupling between different layers of the Sun’s atmosphere during flares may be more complex than previously thought. Yadav and his colleagues suggest that the process they observed is driven by changes in the Lorentz force caused by interactions between solar charged particles (aka. solar wind) and its magnetic fields.

As Prof. Maria Kazachenko, an NSO scientist and co-author of the study, explained:

“As the magnetic field lines in the corona reorganize, they could induce changes in the lower atmosphere, leading to the observed rotation. This discovery adds a new dimension to our understanding of the complex magnetic interactions that occur during solar flares.”

This animation shows the temporal evolution of a solar flare region and the surrounding sunspots/pores as observed by the VBI instrument on the Inouye Solar Telescope. Credit: NSO–NSF

The unique observations the team made using the Inouye telescope offer new insights into the mechanisms through which solar flares influence the lower layers of the Sun’s atmosphere. For example, past observations have revealed much about sunspot rotations that occurred during more powerful flares (M—or X-class). However, the Inouye data revealed that similar rotational movements can occur with less intense flares and on smaller scales. These findings could lead to new research avenues and help refine our models of solar activity.

This will have implications for the growing constellations of telecom, research, internet, and Earth observation satellites in Earth’s orbit. Predicting space weather, which affects everything in the Solar System to the very edge of the Heliosphere, is also important for long-duration missions in space. For astronauts working on the Moon and Mars and transiting through deep space, knowing more about flare activity will help mitigate the risk of radiation exposure.

Further Reading: NSO, AJL

The post High-Resolution Images of the Sun Show How Flares Impact the Solar Atmosphere appeared first on Universe Today.

Why does this large crater on Mercury have two rings and a smooth floor?

When you get close to a black hole, things can get pretty intense. The tremendous gravity can squeeze gas to ionizing temperatures, and fierce magnetic fields can accelerate plasma into jets speeding at nearly the speed of light. That’s a lot of power, and wherever there is power someone will figure out how to harness it.

Back in 1969 Roger Penrose noted that you could theoretically extract energy from a black hole simply by dumping garbage into it. The idea was to pack a spaceship full of junk, fly really close to a black hole so that you travel within the region of strongly twisted space known as the ergosphere, then simply dump your trash. The trash gets consumed by the black hole and your spaceship gets a boost of energy. No need to reduce, reuse, recycle, just toss it down the cosmic hole.

How to turn trash into energy. Credit: Atomic Rockets, adapted from Misner, Thorne and Wheeler

While this should work in principle, the engineering needed to carry it off would be challenging, and harnessing energy from a fast-moving rocket wouldn’t be very efficient. Fortunately there should be another way, just using electromagnetic waves. In 1971 Yakov Zeldovich demonstrated how a rotating black hole could amplify electromagnetic waves. Essentially if you beam light toward a rotating black hole, some of the light will be ampified due to the frame dragging of gravity.

At least in theory.

Therein lies the problem. While all of this is theoretically sound, we don’t have a spare black hole lying around to prove it. Luckily the Zeldovich effect works for more than just black holes. Zeldovich showed that the effect should work for any rotating body that absorbs a bit of the energy aimed at it. So you should be able to bounce light against a rotating cylinder and see the effect. No black hole needed. The only problem is that the cylinder would need to rotate at relativistic speeds and the effect would be tiny. Then in 2020 a team showed how a similar effect worked with sound waves. They beamed low-frequency sound waves into an absorptive rotating disk and measured an increase in acoustic energy, proving the Zeldovich effect worked for sound.

Measuring the electromagnetic Zeldovich effect. Credit: Braidotti, et al

Now the team is back with a new paper showing the effect with electromagnetic waves.[^4] The way they did it was to adapt a resonant circuit. The circuit could focus an oscillating magnetic wave through a through an aluminum cylinder. By itself the cylinder would act as a simple resistor and dampen the magnetic field, but when the team rotated the cylinder in a particular way the magnetic field was amplified just as Zeldovich predicted. Since aluminum isn’t magnetic, the isn’t due to some dynamo effect. Thus the team could demonstrate it is a new effect.

So we now know rotating bodies, including black holes, can amplify electromagnetic fields. What’s also interesting about this experiment is how surprisingly straight forward it is. The design is similar to an induction generator used in wind turbines. The experiment could have been done decades ago, it’s just that no one had thought of it before. Sometimes the answer to a scientific question is right in front of you.

Reference: Braidotti, M. C., et al. “Amplification of electromagnetic fields by a rotating body.” Nature Communications 15.1 (2024): 5453.

The post Researchers Mimic Extracting Energy From Black Holes in the Lab appeared first on Universe Today.