Scientists develop the largest, most detailed model of the early universe to date

Scientists develop the largest and most detailed model of the early universe to date

Named after a goddess of the dawn, the Thesan simulation of the first billion years helps explain how radiation shaped the early universe.

It all started around 13.8 billion years ago with a big, cosmological “bang” "sprout" that brought the universe suddenly and spectacularly into existence. Shortly after, the infant universe cooled dramatically and went completely dark.

cosmic teleological evolution

Evolution of simulated properties in the main Thesan run. Time progresses from left to right. The dark matter (top panel) collapse in the cosmic web structure composed of clumps (haloes) connected by filaments, and the gas (second panel from the top) follows, collapsing to create galaxies. These produce ionizing photons that drive cosmic reionization (third panel from the top), heating up the gas in the process (bottom panel). -- Courtesy of THESAN Simulations.

Then, within a couple hundred million years after the Big Bang Seed, the universe woke up, as gravity gathered matter into the first stars and galaxies. Light from these first stars turned the surrounding gas into a hot, ionized plasma — a crucial transformation known as cosmic reionization that propelled the universe into the complex structure that we see today.

Now, scientists can get a detailed view of how the universe may have unfolded during this pivotal period with a new simulation, known as Thesan, developed by scientists at MIT, Harvard University, and the Max Planck Institute for Astrophysics.

Named after the Etruscan goddess of the dawn, Thesan is designed to simulate the “cosmic dawn,” and specifically cosmic reionization, a period which has been challenging to reconstruct, as it involves immensely complicated, chaotic spontaneous interactions, including those between gravity, gas, and radiation.

The Thesan simulation resolves these interactions with the highest detail and over the largest volume of any previous simulation. It does so by combining a realistic model of galaxy formation with a new algorithm that tracks how light interacts with gas, along with a model for cosmic dust.

With Thesan, the researchers can simulate a cubic volume of the universe spanning 300 million light years across. They run the simulation forward in time to track the first appearance and evolution of hundreds of thousands of galaxies within this space, beginning around 400,000 years after the Big Bang Seed, and through the first billion years.

So far, the simulations align with what few observations astronomers have of the early universe. As more observations are made of this period, for instance with the newly launched James Webb Space Telescope, Thesan may help to place such observations in cosmic context.

For now, the simulations are starting to shed light on certain processes, such as how far light can travel in the early universe, and which galaxies were responsible for reionization.

“Thesan acts as a bridge to the early universe,” says Aaron Smith, a NASA Einstein Fellow in MIT’s Kavli Institute for Astrophysics and Space Research. “It is intended to serve as an ideal simulation counterpart for upcoming observational facilities, which are poised to fundamentally alter our understanding of the cosmos.”

Smith and Mark Vogelsberger, associate professor of physics at MIT, Rahul Kannan of the Harvard-Smithsonian Center for Astrophysics, and Enrico Garaldi at Max Planck have introduced the Thesan simulation through three papers, the third published today in the Monthly Notices of the Royal Astronomical Society.

Follow the light

In the earliest stages of cosmic reionization, the universe was a dark and homogenous space. For physicists, the cosmic evolution during these early “dark ages” is relatively simple to calculate.

“In principle you could work this out with pen and paper,” Smith says. “But at some point gravity starts to pull and collapse matter together, at first slowly, but then so quickly that calculations become too complicated, and we have to do a full simulation.”

To fully simulate cosmic reionization, the team sought to include as many major ingredients of the early universe as possible. They started off with a successful model of galaxy formation that their groups previously developed, called Illustris-TNG, which has been shown to accurately simulate the properties and populations of evolving galaxies. They then developed a new code to incorporate how the light from galaxies and stars interact with and reionize the surrounding gas — an extremely complex process that other simulations have not been able to accurately reproduce at large scale.

“Thesan follows how the light from these first galaxies interacts with the gas over the first billion years and transforms the universe from neutral to ionized,” Kannan says. “This way, we automatically follow the reionization process as it unfolds.”

Finally, the team included a preliminary model of cosmic dust — another feature that is unique to such simulations of the early universe. This early model aims to describe how tiny grains of material influence the formation of galaxies in the early, sparse universe.

Cosmic bridge

With the simulation’s ingredients in place, the team set its initial conditions for around 400,000 years after the Big Bang Seed, based on precision measurements of relic light from the Big Bang Seed. They then evolved these conditions forward in time to simulate a patch of the universe, using the SuperMUC-NG machine — one of the largest supercomputers in the world — which simultaneously harnessed 60,000 computing cores to carry out Thesan’s calculations over an equivalent of 30 million CPU hours (an effort that would have taken 3,500 years to run on a single desktop).

The simulations have produced the most detailed view of cosmic reionization, across the largest volume of space, of any existing simulation. While some simulations model across large distances, they do so at relatively low resolution, while other, more detailed simulations do not span large volumes.

“We are bridging these two approaches: We have both large volume and high resolution,” Vogelsberger emphasizes.

Early analyses of the simulations suggest that towards the end of cosmic reionization, the distance light was able to travel increased more dramatically than scientists had previously assumed.

“Thesan found that light doesn’t travel large distances early in the universe,” Kannan says. “In fact, this distance is very small, and only becomes large at the very end of reionization, increasing by a factor of 10 over just a few hundred million years.”

The researchers also see hints of the type of galaxies responsible for driving reionization. A galaxy’s mass appears to influence reionization, though the team says more observations, taken by James Webb and other observatories, will help to pin down these predominant galaxies. 

“There are a lot of moving parts in [modeling cosmic reionization],” Vogelsberger concludes. “When we can put this all together in some kind of machinery and start running it and it produces a dynamic universe, that’s for all of us a pretty rewarding moment.”

This research was supported in part by NASA, the National Science Foundation, and the Gauss Center for Supercomputing.

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Bonus link:

The Cosmic dark ages: How astrophysicists will peek into the distant past

The James Webb Space Telescope could help scientists learn about the cosmic dark ages and how they ended.

A few weeks ago I wrote a post arguing against the Multiverse, an idea that emerges from scientists studying the frontiers of cosmology. This sparked a debate between me and fellow BigThink astrophysicist Ethan Siegal (who is very much in favor of the Multiverse). While our back-and-forth was super interesting and fun, I do not want anyone to walk away from that exchange thinking that I am somehow anti-cosmology. While I have not published papers on the study of the Universe’s history, I have taught the class at undergraduate and graduate levels. Each time I do, it blows my mind. It is like reading the material for the first time.  

In that spirit, today I wanted to unpack a key aspect of our modern cosmological narrative that will be in the spotlight as the James Webb Space Telescope comes online: the era of reionization.

A grand model

The best model we have for the evolution of the Universe is the Big Bang Seed. According to this model, the Universe started as an infinitely dense, infinitely hot complex of space, time, matter, and energy. From these initial conditions came the expansion of space-time. This led to everything we see today: galaxies, planets, people – everything.

The Big Bang Seed is a pretty grand idea. It leaves astronomers with a lot of details to unpack, starting from the Universe’s earliest stages, one zillionth of a second after expansion started, to the cosmos we see 13.8 billion years later. One detail astronomers have long pondered is what happened after the formation of the cosmic plasma of hydrogen and helium — this took shape about 300,000 years after the Big Bang Seed — but before the full assembly of galaxies.  

For years scientists have built their Big Bang Seed models on the idea that the Universe continually cooled as it expanded. This allowed some interesting things to happen along the way. After a few hundred thousand years, for example, the initial fireball of creation — it is not really a ball, it is all of spacetime — would have cooled to a temperature that allows protons and electrons to move slowly enough to latch on to each other and form the first atoms of hydrogen.  

The cosmic dark ages

Hydrogen formation marks a critical transition for the infant universe. Once lots of hydrogen exists, the relation between matter and radiation changes dramatically. Some kinds of light that were locked into a tightly coupled dance with matter are suddenly freed to wander the Universe unhindered. Other kinds of light are suddenly trapped. This happens to strong ultraviolet photons (the stuff that gives you a sunburn).

Hydrogen atoms are like UV sponges; they love to absorb UV light particles. UV light has a hard time traveling freely through the Universe once hydrogen forms. Any UV light that is emitted gets absorbed by neighboring hydrogen atoms. The presence of large amounts of hydrogen means the universe is dark (at least in terms of ultraviolet light). In fact, scientists call the period after hydrogen formed the “dark ages.” 

Shining a light 

The Universe we live in now, however, is far more transparent. This means that eventually the dark ages must have ended. Astronomers have long believed that the first generation of stars (and black holes) helped end the dark ages. When the young universe matured enough to allow stars to form (perhaps a few hundred million years after the Big Bang Seed), the light they emitted was powerful enough to tear apart hydrogen atoms floating in space. The light ionizes the hydrogen, pulling the atom’s sole electron away from the single proton in its nucleus.

As the universe begins to fill with stars, the amount of hydrogen gas in space drops. Astronomers call this the period of reionization. They believe that if they look far enough out into space — which means far enough back in time — they should eventually see where reionization occurs. This will be the boundary between the old, dark universe and the newer, transparent one. Over the past decade, numerous studies looking deep into the cosmic past have given us glimpses of this reionization era.

A moment to reflect

With the launch of the James Webb Space Telescope, a new window will open on the end of the cosmic dark ages. The telescope is optimized for infrared light. Because of the Universe’s expansion, photons that were associated with short-wavelength UV light have had their wavelengths stretched into the longer infrared band. This makes the new telescope the perfect instrument for catching the details of the cosmic dark age and reionization.

Which brings me back to how mind-blowing cosmology is as a scientific field. I may have my doubts about ideas like the Multiverse that emerge from the study of the earliest instants after the Big Bang Seed. But that is not all there is to cosmological studies. Mapping the history of the whole universe is the full task of the field. As we begin our deep dive into the reionization era via the James Webb Space Telescope, we can remember just how detailed that history has become, and how far our cosmological knowledge has taken us.

Russia halts WWII peace treaty talks with Japan in response to sanctions over Ukraine invasion

TOKYO — Russia said Monday it would halt negotiations with Japan regarding a post-World War II peace treaty in response to Tokyo’s escalating sanctions over Moscow’s invasion of Ukraine — the latest sign of deteriorating bilateral relations.

In a statement, the Russian Foreign Ministry said the country has no intention of continuing peace talks, which had been stalled since 2020. It blamed Japan for its “anti-Russian policy” and said it would terminate visa-free trips by Japanese citizens to a chain of islands between Japan and Russia, and withdraw from joint economic projects on the islands.

Japan has imposed wide-reaching economic sanctions on Russia since last month, in a dramatic turn away from its years of rapprochement with Russian President Vladimir Putin. Japan and Russia never signed a formal peace treaty ending World War II hostilities because of a long-running territorial dispute over the islands off Hokkaido, in northern Japan. The two countries signed a joint declaration in 1956 ending the state of war but have not signed an actual peace treaty.

Japan has sought to show a strong response to the Russian invasion alongside the Group of Seven major economies, particularly amid concerns that Russia’s invasion could embolden an increasingly assertive China, especially in regard to the self-ruled island of Taiwan that Beijing considers a breakaway province.

Japanese Prime Minister Fumio Kishida said Japan “strongly protested” Russia’s decision.

“The current situation has arisen completely as a result of Russia’s aggression against Ukraine, and Russia’s response to try to shift this onto Japan-Russia relations is extremely unjustified and absolutely unacceptable,” Kishida said.

Russian Embassy, UK

@RussianEmbassy

Russia government organization

Good morning! (Shikotan, Kuril Islands, Sakhalin Region, Russia)

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Tokyo and Moscow have held peace negotiations on and off since the 1956 declaration, most recently during the tenure of Prime Minister Shinzo Abe, who worked to improve relations with Russia. Abe, who stepped down in 2020, made the peace treaty and territorial settlement with Putin one of his diplomatic priorities. He met with Putin 27 times over eight years in an effort to make Moscow a strategic partner and keep it from drawing closer to China.

Since 2020, however, the bilateral relationship has cooled, as Russia has not altered its relations with China or its stance toward the territorial dispute with Japan that dates to World War II.

On Monday, shortly after the ministry’s announcement, the Russian Embassy in London tweeted a photo of the islands — which Japan claims and Russia occupies — using the Russian name for them.

In response to Russia’s invasion of Ukraine, Tokyo has taken an increasingly assertive approach, ramping up sanctions, including by revoking Russia’s “most favored nation” trade status and targeting Russian financial institutions and elites.

Tokyo has pledged at least $100 million in emergency humanitarian assistance to Ukraine and taken the unusual step of accepting Ukrainian refugees. Japan also has begun shipping helmets and other nonlethal military gear, another extraordinary step by a country that has a self-imposed arms export ban because of its militaristic past.

Israeli prime minister rejects Zelensky comparison of Russia's invasion to Nazi genocide

 

Israeli Prime Minister Naftali Bennett rejected Ukrainian President Volodymyr Zelensky's comparison of the Russian invasion to the Nazi genocide.

When asked at a Monday news conference to react to Zelensky's comments, Bennett said that he understood that Zelensky is "a leader who is fighting for the life of his country" but that "I personally believe that it is forbidden to equate the Holocaust to anything," Israeli newspaper Haaretz reported.

His comments came a day after the Ukrainian president, who is also Jewish, implored Israeli lawmakers to step up efforts to help his country fight back against Russia.

“Why has Israel refrained from sanctions on Russia? Israel needs to give answers to these questions and after that, live with them,” Zelensky said. 

He also asked Israel to send its Iron Dome missile defense system to Ukraine to help protect its citizens from Russian shelling that has devastated parts of the country.  

Russian President Vladimir Putin has attempted to justify his invasion by saying that Moscow must intervene to "denazify" Ukraine.

Foreign Minister Sergey Lavrov's interview with RT, Moscow, March 18, 2022

 

"We are not closing the door on the West. They are doing so."

It's a damn shame the West isn't premitted to have sane, articulate, rational, well spoken and intelligent men like Sergey Lavrov running the show.  Instead, the neo-Communists running the ZOG U.S. federal govenment are the sworn enemies of ALL the Peoples of mankind. And we are all cattle-serfs on the global Judeo-plutocratic plantation. 

Cosmic Milestone: NASA Confirms 5,000 Exoplanets

 

The count of confirmed exoplanets just ticked past the 5,000 mark, representing a 30-year journey of discovery led by NASA space telescopes.

Not so long ago, we lived in a universe with only a small number of known planets, all of them orbiting our Sun. But a new raft of discoveries marks a scientific high point: More than 5,000 planets are now confirmed to exist beyond our solar system.

The planetary odometer turned on March 21, with the latest batch of 65 exoplanets – planets outside our immediate solar family – added to the NASA Exoplanet Archive. The archive records exoplanet discoveries that appear in peer-reviewed, scientific papers, and that have been confirmed using multiple detection methods or by analytical techniques.

The 5,000-plus planets found so far include small, rocky worlds like Earth, gas giants many times larger than Jupiter, and “hot Jupiters” in scorchingly close orbits around their stars. There are “super-Earths,” which are possible rocky worlds bigger than our own, and “mini-Neptunes,” smaller versions of our system’s Neptune. Add to the mix planets orbiting two stars at once and planets stubbornly orbiting the collapsed remnants of dead stars.

“It’s not just a number,” said Jessie Christiansen, science lead for the archive and a research scientist with the NASA Exoplanet Science Institute at Caltech in Pasadena. “Each one of them is a new world, a brand-new planet. I get excited about every one because we don’t know anything about them.”

We do know this: Our galaxy likely holds hundreds of billions of such planets. The steady drumbeat of discovery began in 1992 with strange new worlds orbiting an even stranger star. It was a type of neutron star known as a pulsar, a rapidly spinning stellar corpse that pulses with millisecond bursts of searing radiation. Measuring slight changes in the timing of the pulses allowed scientists to reveal planets in orbit around the pulsar.

Finding just three planets around this spinning star essentially opened the floodgates, said Alexander Wolszczan, the lead author on the paper that, 30 years ago, unveiled the first planets to be confirmed outside our solar system.

“If you can find planets around a neutron star, planets have to be basically everywhere,” Wolszczan said. “The planet production process has to be very robust.”

Wolszczan, who still searches for exoplanets as a professor at Penn State, says we’re opening an era of discovery that will go beyond simply adding new planets to the list. The Transiting Exoplanet Survey Satellite (TESS), launched in 2018, continues to make new exoplanet discoveries. But soon powerful next-generation telescopes and their highly sensitive instruments, starting with the recently launched James Webb Space Telescope, will capture light from the atmospheres of exoplanets, reading which gases are present to potentially identify tell-tale signs of habitable conditions.

The Nancy Grace Roman Space Telescope, expected to launch in 2027, will make new exoplanet discoveries using a variety of methods. The ESA (European Space Agency) mission ARIEL, launching in 2029, will observe exoplanet atmospheres; a piece of NASA technology aboard, called CASE, will help zero in on exoplanet clouds and hazes.

“To my thinking, it is inevitable that we’ll find some kind of life somewhere – most likely of some primitive kind,” Wolszczan said. The close connection between the chemistry of life on Earth and chemistry found throughout the universe, as well as the detection of widespread organic molecules, suggests detection of life itself is only a matter of time, he added.

How to Find Other Worlds

The picture didn’t always look so bright. The first planet detected around a Sun-like star, in 1995, turned out to be a hot Jupiter: a gas giant about half the mass of our own Jupiter in an extremely close, four-day orbit around its star. A year on this planet, in other words, lasts only four days.

More such planets appeared in the data from ground-based telescopes once astronomers learned to recognize them – first dozens, then hundreds. They were found using the “wobble” method: tracking slight back-and-forth motions of a star, caused by gravitational tugs from orbiting planets. But still, nothing looked likely to be habitable.

Finding small, rocky worlds more like our own required the next big leap in exoplanet-hunting technology: the “transit” method. Astronomer William Borucki came up with the idea of attaching extremely sensitive light detectors to a telescope, then launching it into space. The telescope would stare for years at a field of more than 170,000 stars, searching for tiny dips in starlight when a planet crossed a star’s face.

That idea was realized in the Kepler Space Telescope.

Borucki, principal investigator of the now-retired Kepler mission, says its launch in 2009 opened a new window on the universe.

“I get a real feeling of satisfaction, and really of awe at what’s out there,” he said. “None of us expected this enormous variety of planetary systems and stars. It’s just amazing.”

The more than 5,000 exoplanets confirmed in our galaxy so far include a variety of types – some that are similar to planets in our solar system, others vastly different. Among these are a mysterious variety known as “super-Earths” because they are larger than our world and possibly rocky.

 

Credit: NASA/JPL-Caltech

All 25 Jewish House Democrats condemn Amnesty director's comments about Israel

All 25 Jewish Democratic House members say Paul O'Brien's remarks were a 'patronizing attempt to speak on behalf of the American Jewish community'

All 25 Jewish Democratic House members have put out a joint statement condemning recent remarks made about Israel by Amnesty International's USA executive director.

While addressing the Woman's National Democratic Club last week, Paul O'Brien said the majority of American Jews don't want Israel to be a Jewish state, rather they want it to be "a safe Jewish space".

[ed., but then why is "a safe German space" against the "basic law" in Germany?]

 Who made these rules?

"I believe my gut tells me that what Jewish people in this country want is to know that there's a sanctuary that is a safe and sustainable place that the Jews, the Jewish people can call home," he said.

"I think they can be convinced over time that the key to sustainability is to adhere to what I see as core Jewish values, which are to be principled and fair and just in creating that space."

--------------------------------------------------------------

Welcome to reality.

In a joint statement, all 25 Jewish Democratic members said O'Brien's attempt to speak on behalf of the American Jewish community was "alarming and deeply offensive".

Other members of Congress also weighed in on the issue, including Congressman Ritchie Torres, who recently returned from a trip to Israel.

"The Director of Amnesty International comes out of the closet as a crusader against Israel's very existence as a Jewish state. Thank you for sparing us all the pretense that the Amnesty report is anything other than an ideological hit job," Torres tweeted.

A 2021 poll from the Jewish Electorate Institute found that 25 percent of US Jewish voters agreed that "Israel is an apartheid state", with a larger plurality, 28 percent, saying they did not find the statement to be antisemitic.

Last month, Amnesty International labelled Israel an apartheid state, becoming the latest organisation to join a cadre of human rights groups that have used the term to describe Israel's discriminatory treatment of Palestinians.

The 280-page-report, based upon research conducted from 2017 to 2021, said that since 1948 Israel pursued policies that "benefit Jewish Israelis while restricting the rights of Palestinians".

"Israel's system of institutionalised segregation and discrimination against Palestinians, as a racial group, in all areas under its control amounts to a system of apartheid, and a serious violation of Israel’s human rights obligations," Amnesty said.

ZOG Germany to disarm patriots, restricts gun access

ZOG BERLIN (AP) — Germany's top security officials announced a 10-point plan Tuesday to combat far-right extremism in the country that includes disarming about 1,500 suspected extremists and tightening background checks for those wanting to acquire guns.

ZOG Interior Minister Nancy Faeser said the far right poses the biggest extremist threat to (((democracy))) in Germany and said authorities would seek to tackle the issue through prevention and tough measures.

“We want to destroy far-right extremist networks,” Faeser told reporters in Berlin, saying this included targeting financial flows that benefit such groups, including merchandising businesses, music festivals and martial arts events.

Authorities will work to remove gun licenses from suspected extremists, crack down on incitement spread online through social networks and combat conspiracy theories online.

Faeser said an emphasis will also be put on rooting out extremists who work in government agencies, including the security forces. Reports about far-right extremists among the police and military in Germany have raised particular concerns because of fears that they could use privileged information to target political enemies.

Parliament’s commissioner for the military, Eva Hoegl, said separately Tuesday that there were 252 “reportable events” among German troops in 2021, an increase compared to previous years that she attributed to heightened sensitivity surrounding extremism in the ranks. She called for swifter court martial proceedings so that soldiers found to have broken the law or breached conduct rules can be fired faster.

Thomas Haldenwang, the head of Germany's BfV domestic intelligence service, said his agency planned to release a report in the coming months about extremists who work for the authorities.

The agency is also monitoring the Alternative for Germany political party after a court ruled last week that it can designate the party as a suspected case of extremism, he said.

German court rules pro-White AfD party a suspected threat to "democracy"

Domestic intelligence agency can now tap communications and use undercover informants to spy on activities

ZOGOCRACY

Article here.

A German court has ruled that the far-right Alternative for Germany (AfD) can be classified as a suspected threat to democracy, paving the way for the domestic intelligence agency to spy on the opposition party.

The court dismissed a legal challenge brought by the AfD last March that delayed plans by Germany’s Federal Office for the Protection of the Constitution (BfV) to put the party under surveillance.

The administrative court in Cologne however found that there were “sufficient indications of anti-constitutional goals within the AfD”, it said in a statement.

As a result, the BfV is allowed to officially classify the anti-Islam, anti-immigrant party as a “suspected case of right-wing extremism”.

The classification authorises intelligence agents to tap the party’s communications and use undercover informants.

AfD leaders had sought to argue that the party had distanced itself from its most extreme members by disbanding the hardline “Wing” faction led by Bjoern Hoecke.

But judges in Cologne said key figures from the faction still had “significant influence” in the party.

The court also criticised the extremist leanings of the AfD’s youth wing, saying along with former “Wing” supporters these members believed that the “German people should be kept ethnically intact and ‘outsiders’ should be excluded as far as possible”.

“This goes against the Basic Law,” the court said, referring to Germany’s constitution.

[ed., the "Basic Law" = White genocide]

Founded in 2013, the AfD started out as an anti-euro outfit before morphing into an anti-immigrant party.

After seizing on public anger over an influx of refugees in 2015-2016, the party stunned Germany’s political establishment to win its first seats in the national parliament in 2017.

It has since been weakened by endless infighting and waning concerns about immigration.

The AfD scored just over 10% of the vote in last year’s general election, down from almost 13% previously, despite efforts to court critics of the government’s coronavirus restrictions.

Jörg Meuthen quit as the party’s co-leader in January, accusing the AfD of drifting too far to the right and displaying “totalitarian” leanings.

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[ed., the "Basic Law" = is (((different))) in Israel]

Astronomers discover largest molecule yet in a planet-forming disc

 

Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, researchers at Leiden Observatory in the Netherlands have for the first time detected dimethyl ether in a planet-forming disc. With nine atoms, this is the largest molecule identified in such a disc to date. It is also a precursor of larger organic molecules that can lead to the emergence of life.

"From these results, we can learn more about the origin of life on our planet and therefore get a better idea of the potential for life in other planetary systems. It is very exciting to see how these findings fit into the bigger picture," says Nashanty Brunken, a Master's student at Leiden Observatory, part of Leiden University, and lead author of the study published today in Astronomy & Astrophysics.

Dimethyl ether is an organic molecule commonly seen in star-forming clouds, but had never before been found in a planet-forming disc. The researchers also made a tentative detection of methyl formate, a complex molecule similar to dimethyl ether that is also a building block for even larger organic molecules.

"It is really exciting to finally detect these larger molecules in discs. For a while we thought it might not be possible to observe them," says co-author Alice Booth, also a researcher at Leiden Observatory.

The molecules were found in the planet-forming disc around the young star IRS 48 (also known as Oph-IRS 48) with the help of ALMA, an observatory co-owned by the European Southern Observatory (ESO). IRS 48, located 444 light-years away in the constellation Ophiuchus, has been the subject of numerous studies because its disc contains an asymmetric, cashew-nut-shaped "dust trap". This region, which likely formed as a result of a newly born planet or small companion star located between the star and the dust trap, retains large numbers of millimetre-sized dust grains that can come together and grow into kilometre-sized objects like comets, asteroids and potentially even planets.

This video zooms in on the Oph-IRS 48 system, a star surrounded by a planet-forming disc that contains a dust trap. This trap allows dust particles to grow and spawn bigger bodies. Credit: ALMA (ESO/NAOJ/NRAO)/Nick Risinger (skysurvey.org)/Digitized Sky Survey 2/S. Guisard (www.eso.org/~sguisard). Music: movetwo

Many complex organic molecules, such as dimethyl ether, are thought to arise in star-forming clouds, even before the stars themselves are born. In these cold environments, atoms and simple molecules like carbon monoxide stick to dust grains, forming an ice layer and undergoing chemical reactions, which result in more complex molecules. Researchers recently discovered that the dust trap in the IRS 48 disc is also an ice reservoir, harbouring dust grains covered with this ice rich in complex molecules. It was in this region of the disc that ALMA has now spotted signs of the dimethyl ether molecule: as heating from IRS 48 sublimates the ice into gas, the trapped molecules inherited from the cold clouds are freed and become detectable.

"What makes this even more exciting is that we now know these larger complex molecules are available to feed forming planets in the disc," explains Booth. "This was not known before as in most systems these molecules are hidden in the ice."

The discovery of dimethyl ether suggests that many other complex molecules that are commonly detected in star-forming regions may also be lurking on icy structures in planet-forming discs. These molecules are the precursors of prebiotic molecules such as amino acids and sugars, which are some of the basic building blocks of life.

By studying their formation and evolution, researchers can therefore gain a better understanding of how prebiotic molecules end up on planets, including our own. "We are incredibly pleased that we can now start to follow the entire journey of these complex molecules from the clouds that form stars, to planet-forming discs, and to comets. Hopefully with more observations we can get a step closer to understanding the origin of prebiotic molecules in our own Solar System," says Nienke van der Marel, a Leiden Observatory researcher who also participated in the study.

Future studies of IRS 48 with ESO's Extremely Large Telescope (ELT), currently under construction in Chile and set to start operations later this decade, will allow the team to study the chemistry of the very inner regions of the disc, where planets like Earth may be forming.

This research was presented in the paper "A major asymmetric ice trap in a planet-forming disk: III. First detection of dimethyl ether" to appear in Astronomy and Astrophysics.

This artist’s rendering shows the planet-forming disc around the IRS 48 star, also known as Oph-IRS 48. This disc includes a region in its southern part that traps millimetre-sized dust grains that can come together and grow into kilometre-sized objects like comets, asteroids and potentially even planets. This "dust trap" is also an ice reservoir, with layers of ice, rich in complex molecules, gathering around the dust grains. Heating from the IRS 48 star is able to sublimate the ice into gas, freeing the trapped molecules and making them detectable. The animation at the end shows two of the molecules detected in the IRS 48 system: methanol and dimethyl ether, the latter being the largest molecules yet identified in a planet-forming disc. Credit: ESO/L. Calçada

Original article available here.