Latest news with #AnastasiaFialkov
Yahoo
25-06-2025
- Science
- Yahoo
Radio signals from the dawn of time could help 'weigh' the universe's 1st stars
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers could use specific radio signals from the universe's earliest epoch to "weigh" the first stars in the cosmos. The investigation could reveal more about the so-called Cosmic Dawn, the period of the universe during which darkness lifted and light became free to first stars, or "Population III" (Pop III) stars, can't be seen even with the most powerful telescopes because their light was prevented from traveling by a dense cosmic fog spread between star-forming regions that consisted mostly of hydrogen. However, during this period, around 100 million years after the Big Bang, this hydrogen created a radio signal called "the 21-centimeter signal." An international team of astronomers now suggests this signal could be used to determine how light from the first stars interacted with this cosmic fog, helping to lift it. "This is a unique opportunity to learn how the universe's first light emerged from the darkness," team leader and University of Cambridge researcher Anastasia Fialkov said in a statement. "The transition from a cold, dark universe to one filled with stars is a story we're only beginning to understand." Fialkov heads up the Radio Experiment for the Analysis of Cosmic Hydrogen (REACH) project, a radio antenna that studies the faint glow of the 21-centimeter signal to reveal more about Cosmic Dawn. Still in its calibration stage, REACH will soon be joined in its investigation of the first stars by the Square Kilometre Array (SKA), a massive array of antennas under construction in Australia and South Africa. Together, SKA and REACH will investigate the masses, luminosities, and distribution of the universe's earliest stars. In preparation for this investigation, Fialkov and colleagues developed a model to predict what observations of the 21-centimeter signal will look like for both projects. This revealed that this signal is influenced by stellar masses. "We are the first group to consistently model the dependence of the 21-centimeter signal of the masses of the first stars, including the impact of ultraviolet starlight and X-ray emissions from X-ray binaries produced when the first stars die," said Fialkov. "These insights are derived from simulations that integrate the primordial conditions of the universe, such as the hydrogen-helium composition produced by the Big Bang." While developing the model, the team studied how the mass distribution of Pop III stars influenced the 21-centimeter signal. This revealed that the connection between this signal and the first stars has been underestimated in prior research because these studies had failed to account for the number of systems composed of a dense dead star, usually a white dwarf, and an ordinary star, so-called "X-ray binaries" among Pop III stars. "The predictions we are reporting have huge implications for our understanding of the nature of the very first stars in the universe," REACH telescope Principal Investigator Eloy de Lera Acedo said. "We show evidence that our radio telescopes can tell us details about the mass of those first stars and how these early lights may have been very different from today's stars." Related Stories: — How the Rubin observatory could detect thousands of 'failed stars' — Tiny 'primordial' black holes created in the Big Bang may have rapidly grown to supermassive sizes — Could dark matter have been forged in a 'Dark Big Bang?' — Astronomers discover ultrapowerful black hole jet as bright as 10 trillion suns lit by Big Bang's afterglow REACH and SKA won't see these first stars as a telescope like the James Webb Space Telescope (JWST) does. They instead rely on scientists performing statistical analysis of the data they provide. The effort can pay dividends as it provides information about entire populations of stars, X-ray binary systems and galaxies. "It takes a bit of imagination to connect radio data to the story of the first stars, but the implications are profound," Fialkov concluded. The team's research was published on Friday (June 20) in the journal Nature Astronomy.
Yahoo
22-06-2025
- Science
- Yahoo
A radio signal from the beginning of the universe could reveal how everything began
A radio signal from the early universe could allow us to understand how everything that surrounds us began. The signal – known as the 21-centimetre signal – could finally let us understand how the first stars and galaxies switched on, and brought the universe from darkness to light. 'This is a unique opportunity to learn how the universe's first light emerged from the darkness,' said co-author Anastasia Fialkov from Cambridge University, in a statement. 'The transition from a cold, dark universe to one filled with stars is a story we're only beginning to understand.' The signal comes to us from more than 13 billion years ago, just a hundred million years after the Big Bang. The faint glow is created by hydrogen atoms that fill up the space between regions of space where stars are being formed. Scientists now believe they will be able to use the nature of that signal to better understand the early universe. They will do that with a radio antenna called REACH – the Radio Experiment for the Analysis of Cosmic Hydrogen – which will try and capture radio signals to reveal data about the beginnings of the universe. To better understand how that project might work, researchers created a model that predicted how REACH as well as another project called the Square Kilometre Array will be able to provide information about the masses and other details of the first stars. 'We are the first group to consistently model the dependence of the 21-centimetre signal of the masses of the first stars, including the impact of ultraviolet starlight and X-ray emissions from X-ray binaries produced when the first stars die,' said Professor Fialkov. 'These insights are derived from simulations that integrate the primordial conditions of the universe, such as the hydrogen-helium composition produced by the Big Bang.' 'The predictions we are reporting have huge implications for our understanding of the nature of the very first stars in the Universe,' said co-author Eloy de Lera Acedo, Principal Investigator of the REACH telescope. 'We show evidence that our radio telescopes can tell us details about the mass of those first stars and how these early lights may have been very different from today's stars. 'Radio telescopes like REACH are promising to unlock the mysteries of the infant Universe, and these predictions are essential to guide the radio observations we are doing from the Karoo, in South Africa.' The work is described in a new paper, 'Determination of the mass distribution of the first stars from the 21-cm signal', published in the journal Nature Astronomy.
Yahoo
22-06-2025
- Science
- Yahoo
Scientists Working to Decode Signal From Earliest Years of Universe
As mysterious as the Big Bang that gave birth to the universe is the brief but tumultuous period that immediately followed it. How did the cosmos transform from a uniform sea of darkness into a chaotic swirl brimming with radiant stars? What were these first stars like, and how were they born? So far, we have very strong suspicions, but no hard answers. One reason is that the light from this period, called the cosmic dawn, is extremely faint, making it nearly impossible to infer the traits of these first cosmic objects, let alone directly observe them. But that's about to change, according to a team of international astronomers. In a new study published in the journal Nature Astronomy, the astronomers argue that we're on the verge of finally decoding a radio signal that was emitted just one hundred millions years after the Big Bang. Known as the 21 centimeter signal, which refers to its distinct wavelength, this burst of radiation was unleashed as the inchoate cosmos spawned the earliest stars and black holes. "This is a unique opportunity to learn how the universe's first light emerged from the darkness," said study co-author Anastasia Fialkov, an astronomer from the University of Cambridge in a statement about the work. "The transition from a cold, dark universe to one filled with stars is a story we're only beginning to understand." After several hundred thousand years of cooling following the Big Bang, the first atoms to form in the universe were overwhelmingly neutral hydrogen atoms made of one positively charged proton and one negatively charged electron. But the formation of the first stars unbalanced that. As these cosmic reactors came online, they radiated light energetic enough to reionize this preponderance of neutral hydrogen atoms. In the process, they emitted photons that produced light in the telltale 21 centimeter wavelength, making it an unmistakeable marker of when the first cosmic structures formed. Deciphering these emissions would be tantamount to obtaining a skeleton key to the dawn of the universe. And drum roll, please: employing the Radio Experiment for the Analysis of Cosmic Hydrogen telescope, which is currently undergoing calibration, and the enormous Square Kilometer Array, which is under construction Australia, the researchers say they've developed a model that can tease out the masses of the first stars, sometimes dubbed Population III stars, that are locked inside the 21 centimeter signal. While developing the model, their key revelation was that, until now, astronomers weren't properly accounting for the impact of star systems called x-ray binaries among these first stars. These are systems where a black hole or neutron star is stripping material off a more ordinary star that's orbiting it, producing light in the x-ray spectrum. In short, it appears that x-ray binaries are both brighter and more numerous than what was previously thought. "We are the first group to consistently model the dependence of the 21-centimeter signal of the masses of the first stars, including the impact of ultraviolet starlight and X-ray emissions from X-ray binaries produced when the first stars die," said Fialkov. "These insights are derived from simulations that integrate the primordial conditions of the universe, such as the hydrogen-helium composition produced by the Big Bang." All told, it's another promising leap forward in the field of radio astronomy, where recent advances have begun to reveal an entire "low surface brightness" universe — and a potentially profound one as well, with the promise to illuminate our understanding of the cosmic dawn as never never before. "The predictions we are reporting have huge implications for our understanding of the nature of the very first stars in the universe," said co-author Eloy de Lera Acedo, a Cambridge astronomer and a principal investigator of the REACH telescope. "We show evidence that our radio telescopes can tell us details about the mass of those first stars and how these early lights may have been very different from today's stars." More on astronomy: Scientists Investigating Small Orange Objects Coating Surface of the Moon
Yahoo
20-06-2025
- Science
- Yahoo
A radio signal from the beginning of the universe could reveal how everything began
A radio signal from the early universe could allow us to understand how everything that surrounds us began. The signal – known as the 21-centimetre signal – could finally let us understand how the first stars and galaxies switched on, and brought the universe from darkness to light. 'This is a unique opportunity to learn how the universe's first light emerged from the darkness,' said co-author Anastasia Fialkov from Cambridge University, in a statement. 'The transition from a cold, dark universe to one filled with stars is a story we're only beginning to understand.' The signal comes to us from more than 13 billion years ago, just a hundred million years after the Big Bang. The faint glow is created by hydrogen atoms that fill up the space between regions of space where stars are being formed. Scientists now believe they will be able to use the nature of that signal to better understand the early universe. They will do that with a radio antenna called REACH – the Radio Experiment for the Analysis of Cosmic Hydrogen – which will try and capture radio signals to reveal data about the beginnings of the universe. To better understand how that project might work, researchers created a model that predicted how REACH as well as another project called the Square Kilometre Array will be able to provide information about the masses and other details of the first stars. 'We are the first group to consistently model the dependence of the 21-centimetre signal of the masses of the first stars, including the impact of ultraviolet starlight and X-ray emissions from X-ray binaries produced when the first stars die,' said Professor Fialkov. 'These insights are derived from simulations that integrate the primordial conditions of the universe, such as the hydrogen-helium composition produced by the Big Bang.' 'The predictions we are reporting have huge implications for our understanding of the nature of the very first stars in the Universe,' said co-author Eloy de Lera Acedo, Principal Investigator of the REACH telescope. 'We show evidence that our radio telescopes can tell us details about the mass of those first stars and how these early lights may have been very different from today's stars. 'Radio telescopes like REACH are promising to unlock the mysteries of the infant Universe, and these predictions are essential to guide the radio observations we are doing from the Karoo, in South Africa.' The work is described in a new paper, 'Determination of the mass distribution of the first stars from the 21-cm signal', published in the journal Nature Astronomy.
The Independent
20-06-2025
- Science
- The Independent
A radio signal from the beginning of the universe could reveal how everything began
A radio signal from the early universe could allow us to understand how everything that surrounds us began. The signal – known as the 21-centimetre signal – could finally let us understand how the first stars and galaxies switched on, and brought the universe from darkness to light. 'This is a unique opportunity to learn how the universe's first light emerged from the darkness,' said co-author Anastasia Fialkov from Cambridge University, in a statement. 'The transition from a cold, dark universe to one filled with stars is a story we're only beginning to understand.' The signal comes to us from more than 13 billion years ago, just a hundred million years after the Big Bang. The faint glow is created by hydrogen atoms that fill up the space between regions of space where stars are being formed.
