SPACE
Three iron rings in a planet-forming disk
A three-ringed structure in the planet-forming zone of a circumstellar disk where metals and minerals serve as a reservoir of planetary building blocks
IMAGE:
OBSERVATIONS WITH THE EUROPEAN SOUTHERN OBSERVATORY’S (ESO) VERY LARGE TELESCOPE INTERFEROMETER (VLTI) FOUND VARIOUS SILICATE COMPOUNDS AND POTENTIALLY IRON, SUBSTANCES WE ALSO FIND IN LARGE AMOUNTS IN THE SOLAR SYSTEM’S ROCKY PLANETS.
view moreCREDIT: © JENRY
The origin of Earth and the Solar System inspires scientists and the public alike. By studying the present state of our home planet and other objects in the Solar System, researchers have developed a detailed picture of the conditions when they evolved from a disk made of dust and gas surrounding the infant sun some 4.5 billion years ago.
Three rings hinting at two planets
With the breathtaking progress made in star and planet formation research aiming at far-away celestial objects, we can now investigate the conditions in environments around young stars and compare them to the ones derived for the early Solar System. Using the European Southern Observatory’s (ESO) Very Large Telescope Interferometer (VLTI), an international team of researchers led by József Varga from the Konkoly Observatory in Budapest, Hungary, did just that. They observed the planet-forming disk of the young star HD 144432, approximately 500 light-years away.
“When studying the dust distribution in the disk’s innermost region, we detected for the first time a complex structure in which dust piles up in three concentric rings in such an environment,” says Roy van Boekel. He is a scientist at the Max Planck Institute for Astronomy (MPIA) in Heidelberg, Germany and a co-author of the underlying research article to appear in the journal Astronomy & Astrophysics. “That region corresponds to the zone where the rocky planets formed in the Solar System“, van Boekel adds. Compared to the Solar System, the first ring around HD 144432 lies within Mercury’s orbit, and the second is close to Mars’s trajectory. Moreover, the third ring roughly corresponds to Jupiter’s orbit.
Up to now, astronomers have found such configurations predominantly on larger scales corresponding to the realms beyond where Saturn circles the Sun. Ring systems in the disks around young stars generally point to planets forming within the gaps as they accumulate dust and gas on their way. However, HD 144432 is the first example of such a complex ring system so close to its host star. It occurs in a zone rich in dust, the building block of rocky planets like Earth. Assuming the rings indicate the presence of two planets forming within the gaps, the astronomers estimated their masses to resemble roughly that of Jupiter.
Conditions may be similar to the early Solar System
The astronomers determined the dust composition across the disk up to a separation from the central star that corresponds to the distance of Jupiter from the Sun. What they found is very familiar to scientists studying Earth and the rocky planets in the Solar System: various silicates (metal-silicon-oxygen compounds) and other minerals present in Earth’s crust and mantle, and possibly metallic iron as is present in Mercury’s and Earth’s cores. If confirmed, this study would be the first to have discovered iron in a planet-forming disk.
“Astronomers have thus far explained the observations of dusty disks with a mixture of carbon and silicate dust, materials that we see almost everywhere in the Universe,” van Boekel explains. However, from a chemical perspective an iron and silicate mixture is more plausible for the hot, inner disk regions. And indeed, the chemical model that Varga, the main author of the underlying research article, applied to the data yields better-fitting results when introducing iron instead of carbon.
Furthermore, the dust observed in the HD 144432 disk can be as hot as 1800 Kelvin (approx. 1500 degrees Celsius) at the inner edge and as moderate as 300 Kelvin (approx. 25 degrees Celsius) farther out. Minerals and iron melt and recondense, often as crystals, in the hot regions near the star. In turn, carbon grains would not survive the heat and instead be present as carbon monoxide or carbon dioxide gas. However, carbon may still be a significant constituent of the solid particles in the cold outer disk, which the observations carried out for this study cannot trace.
Iron-rich and carbon-poor dust would also fit nicely with the conditions in the Solar System. Mercury and Earth are iron-rich planets, while the Earth contains relatively little carbon. “We think that the HD 144432 disk may be very similar to the early Solar System that provided lots of iron to the rocky planets we know today,” says van Boekel. ”Our study may pose as another example showing that the composition of our Solar System may be quite typical.”
Interferometry resolves tiny details
Retrieving the results was only possible with exceptionally high-resolution observations, as provided by the VLTI. By combining the four VLT 8.2-metre telescopes at ESO’s Paranal Observatory, they can resolve details as if astronomers would employ a telescope with a primary mirror of 200 metres in diameter. Varga, van Boekel and their collaborators obtained data using three instruments to achieve a broad wavelength coverage ranging from 1.6 to 13 micrometres, representing infrared light.
MPIA provided vital technological elements to two devices, GRAVITY and the Multi AperTure mid-Infrared SpectroScopic Experiment (MATISSE). One of MATISSE’s primary purposes is to investigate the rocky planet-forming zones of disks around young stars. “By looking at the inner regions of protoplanetary disks around stars, we aim to explore the origin of the various minerals contained in the disk – minerals that later will form the solid components of planets like the Earth,” says Thomas Henning, MPIA director and co-PI of the MATISSE instrument.
However, producing images with an interferometer like the ones we are used to obtaining from single telescopes is not straightforward and very time-consuming. A more efficient use of precious observing time to decipher the object structure is to compare the sparse data to models of potential target configurations. In the case of the HD 144432 disk, a three-ringed structure represents the data best.
How common are structured, iron-rich planet-forming disks?
Besides the Solar System, HD 144432 appears to provide another example of planets forming in an iron-rich environment. However, the astronomers will not stop there. “We still have a few promising candidates waiting for the VLTI to take a closer look at”, van Boekel points out. In earlier observations, the team discovered a number of disks around young stars that indicate configurations worth revisiting. However, they will reveal their detailed structure and chemistry using the latest VLTI instrumentation. Eventually, the astronomers may be able to clarify whether planets commonly form in iron-rich dusty disks close to their parent stars.
Background information
The MPIA researchers involved in this study are Roy van Boekel, Marten Scheuck, Thomas Henning, Jacob W. Isbell, Ágnes Kóspál (also HUN-REN Research Centre for Astronomy and Earth Sciences, Konkoly Observatory, Budapest, Hungary [Konkoly]; CSFK, MTA Centre of Excellence, Budapest, Hungary [CSFK]; ELTE Eötvös Loránd University, Budapest, Hungary [ELTE]), Alessio Caratti o Garatti (also INAF-Osservatorio Astronomico di Capodimonte, Naples, Italy).
Other contributors are: J. Varga (Konkoly; CSFK; Leiden Observatory, The Netherlands [Leiden]), L. B. F. M. Waters (Radboud University, Nijmegen, The Netherlands; SRON, Leiden, The Netherlands), M. Hogerheijde (Leiden; University of Amsterdam, The Netherlands [UVA]), A. Matter (Observatoire de la Côte d’Azur/CNRS, Nice, France [OCA]), B. Lopez (OCA), K. Perraut (Univ. Grenoble Alpes/CNRS/IPAG, France [IPAG]), L. Chen (Konkoly; CSFK), D. Nadella (Leiden), S. Wolf (University of Kiel, Germany [UK]), C. Dominik (UVA), P. Abraham (Konkoly; CSFK; ELTE), J.-C. Augereau (IPAG), P. Boley (OCA), G. Bourdarot (Max Planck Institute for Extraterrestrial Physics, Garching, Germany), F. Cruz-Saénz de Miera (Konkoly; CSFK; Université de Toulouse, France), W. C. Danchi (NASA Goddard Space Flight Center, Greenbelt, USA), V. Gámez Rosas (Leiden), K.-H. Hofmann (Max-Planck Institute for Radio Astronomy, Bonn, Germany [MPIfR]), M. Houllé (OCA), W. Jaffe (Leiden), T. Juhász (Konkoly; CSFK; ELTE), V. Kecskeméthy (ELTE), J. Kobus (UK), E. Kokoulina (University of Liège, Belgium; OCA), L. Labadie (University of Cologne, Germany), F. Lykou (Konkoly; CSFK), F. Millour (OCA), A. Moór (Konkoly; CSFK), N. Morujão (Universidade de Lisboa and Universidade do Porto, Portugal), E. Pantin (AIM, CEA/CNRS, Gif-sur-Yvette, France), D. Schertl (MPIfR), L. van Haastere (Leiden), G. Weigelt (MPIfR), J. Woillez (European Southern Observatory, Garching, Germany), P. Woitke (Space Research Institute, Austrian Academy of Sciences, Graz, Austria), MATISSE and GRAVITY Collaborations
JOURNAL
Astronomy and Astrophysics
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Mid-infrared evidence for iron-rich dust in the multi-ringed inner disk of HD 144432
ARTICLE PUBLICATION DATE
8-Jan-2024
Final supernova results from Dark Energy Survey offer unique insights into the expansion of the universe
VIDEO:
AN EXAMPLE OF A SUPERNOVA DISCOVERED BY THE DARK ENERGY SURVEY WITHIN THE FIELD COVERED BY ONE OF THE INDIVIDUAL DETECTORS IN THE DARK ENERGY CAMERA. THE SUPERNOVA EXPLODED IN A SPIRAL GALAXY WITH REDSHIFT = 0.04528, WHICH CORRESPONDS TO A LIGHT-TRAVEL TIME OF ABOUT 0.6 BILLION YEARS. IN COMPARISON, THE QUASAR AT THE RIGHT HAS A REDSHIFT OF 3.979 AND A LIGHT-TRAVEL TIME OF 11.5 BILLION YEARS.
view moreCREDIT: IMAGE: DES COLLABORATION
In 1998, astrophysicists discovered that the universe is expanding at an accelerating rate, attributed to a mysterious entity called dark energy that makes up about 70% of our universe. While foreshadowed by earlier measurements, the discovery was somewhat of a surprise; at the time, astrophysicists agreed that the universe’s expansion should be slowing down because of gravity.
This revolutionary discovery, which astrophysicists achieved with observations of specific kinds of exploding stars, called type Ia (read “type one-A”) supernovae, was recognized with the Nobel Prize in Physics in 2011.
Now, 25 years after the initial discovery, the scientists working on the Dark Energy Survey have released the results of an unprecedented analysis using the same technique to further probe the mysteries of dark energy and the expansion of the universe. They placed the strongest constraints on the expansion of the universe ever obtained with the DES supernova survey.
In a presentation at the 243rd meeting of the American Astronomical Society on Jan. 8 and in a paper submitted to the Astrophysical Journal in January titled, "The Dark Energy Survey: Cosmology results with ~1500 new high-redshift type Ia supernovae using the full 5-year dataset,” DES astrophysicists report results that are consistent with the now-standard cosmological model of a universe with an accelerated expansion. Yet, the findings are not definitive enough to rule out a possibly more complex model.
Taking a unique approach to analysis
The Dark Energy Survey is an international collaboration comprising more than 400 astrophysicists, astronomers and cosmologists from over 25 institutions led by members from the U.S. Department of Energy’s Fermi National Accelerator Laboratory. DES mapped an area almost one-eighth the entire sky using the Dark Energy Camera, a 570-megapixel digital camera built by Fermilab and funded by the DOE Office of Science. It was mounted on the Víctor M. Blanco Telescope at the National Science Foundation’s Cerro Tololo Inter-American Observatory, a Program of NSF’s NOIRLab in 2012. DES scientists took data for 758 nights across six years.
To understand the nature of dark energy and measure the expansion rate of the universe, DES scientists perform analyses with four different techniques, including the supernova technique used in 1998.
This technique requires data from type Ia supernovae, which occur when an extremely dense dead star, known as a white dwarf, reaches a critical mass and explodes. Since the critical mass is nearly the same for all white dwarfs, all type Ia supernovae have approximately the same actual brightness and any remaining variations can be calibrated out. So, when astrophysicists compare the apparent brightnesses of two type Ia supernovae as seen from Earth, they can determine their relative distances from us.
Astrophysicists trace out the history of cosmic expansion with large samples of supernovae spanning a wide range of distances. For each supernova, they combine its distance with a measurement of its redshift — how quickly it is moving away from Earth due to the expansion of the universe. They can use that history to determine whether the dark energy density has remained constant or changed over time.
“As the universe expands, the matter density goes down,” said DES director and spokesperson Rich Kron, who is a Fermilab and University of Chicago scientist. “But if the dark energy density is a constant, that means the total proportion of dark energy must be increasing as the volume increases.”
The culmination of a decade of effort
The standard cosmological model is ΛCDM, or Lambda Cold Dark Matter, or Lambda Cold Dark Matter, a model based on the dark energy density being constant over cosmic time. It tells us how the universe evolves, using just a few features, such as the density of matter, type of matter and behavior of dark energy. The supernova method constrains two of these features very well: matter density and a quantity called w, which indicates whether the dark energy density is constant or not.
According to the standard cosmological model, the density of dark energy in the universe is constant, which means it doesn’t dilute as the universe expands. If this is true, the parameter represented by the letter w should equal –1.
When the DES collaboration internally unveiled their supernova results, it was a culmination of a decade’s worth of effort and an emotional time for many of the astrophysicists involved. “I was shaking,” said Tamara Davis, a professor at the University of Queensland in Australia and co-convener of DES’s supernova working group. “It was definitely an exciting moment.”
The results found w = –0.80 +/- 0.18 using supernovae alone. Combined with complementary data from the European Space Agency’s Planck telescope, w reaches –1 within the error bars.
“w is tantalizingly not exactly on –1, but close enough that it’s consistent with –1,” said Davis. “A more complex model might be needed. Dark energy may indeed vary with time.”
To come to a definitive conclusion, scientists will need more data. But DES won’t be able to provide that; the survey stopped taking data in January 2019. The supernova team, led by many Ph.D. students and postdoctoral fellows, will soon have extracted all they can from the DES observations.
“More than 30 people have been involved in this analysis, and it is the culmination of almost 10 years of work,” said Maria Vincenzi, a research fellow at Duke University who co-led the cosmological analysis of the DES supernova sample. “Some of us started working on this project when we were barely at the beginning of our Ph.D., and we are now starting faculty positions. So, the DES Collaboration contributed to the growth and professional development of an entire generation of cosmologists.”
Pioneering a new approach
This final DES supernova analysis made many improvements upon DES’s first supernova result released in 2018 that used just 207 supernovae and three years of data.
For the 2018 analysis, DES scientists combined data about the spectrum of each supernova to determine their redshifts and to classify them as type Ia or not. They then used images taken with different filters to identify the flux at the peak of the light curve — a method called photometry. But spectra are hard to acquire, requiring lots of observing time on the largest telescopes, which will be impractical for future dark energy surveys like the Legacy Survey of Space and Time, LSST, to be conducted at the Vera C. Rubin Observatory, operated jointly by NSF’s NOIRLab and DOE’s SLAC National Accelerator Laboratory.
The new study pioneers a new approach to use photometry — with an unprecedented four filters — to find the supernovae, classify them and measure their light curves. Follow-up spectroscopy of the host galaxy with the Anglo-Australian Telescope provided precise redshifts for every supernova. The use of the additional filters also enabled data that is more precise than previous surveys and is a major advancement compared to the Nobel-winning supernovae samples, which only used one or two filters.
DES researchers used advanced machine-learning techniques to aid in supernova classification. Among the data from about two million distant observed galaxies, DES found several thousand supernovae. Scientists ultimately used 1,499 type Ia supernovae with high-quality data, making it the largest, deepest supernova sample from a single telescope ever compiled. In 1998, the Nobel-winning astronomers used just 52 supernovae to determine that the universe is expanding at an accelerating rate. “It’s a really massive scale-up from 25 years ago,” said Davis.
There are minor drawbacks of the new photometric approach compared to spectroscopy: Since the supernovae do not have spectra, there is greater uncertainty in classification. However, the much larger sample size enabled by the photometric approach more than makes up for this.
The innovative techniques DES pioneered will shape and further drive future astrophysical analyses. Projects like Rubin’s LSST and NASA’s Nancy Grace Roman Space Telescope will pick up where DES left off. “We’re pioneering these techniques that will be directly beneficial for the next generation of supernova surveys,” said Kron.
“This new supernova result is exciting because this means we can really tie a bow on it and hand it out to the community and say, ‘This is our best attempt at explaining how the universe is working,’” said Dillon Brout, an assistant professor at Boston University who co-led the cosmological analysis of the DES Supernova sample with Vincenzi. “These constraints will now be the gold standard in supernova cosmology for quite some time.”
Even with more advanced dark energy experiments forthcoming, DES scientists emphasized the importance of having theoretical models to explain dark energy in addition to their experimental observations. “All of this is really unknown territory,” said Kron. “We do not have a theory that puts dark energy into a framework that relates to other physics that we do understand. For the time being, we in DES are working to constrain how dark energy works in practice with the expectation that, later on, some theories can be falsified.”
DES scientists continue to use the supernova results in more analyses by integrating them with results obtained with the other DES techniques. “Combining the DES supernova information with these other probes will even better inform our cosmological model,” said Davis.
“Even if we measure dark energy infinitely precisely, it doesn’t mean we know what it is,” she said. “Dark energy is still out there to be discovered.”
Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, Funding Authority for Funding and Projects in Brazil, Carlos Chagas Filho Foundation for Research Support of the State of Rio de Janeiro, Brazilian National Council for Scientific and Technological Development and the Ministry of Science and Technology, the German Research Foundation and the collaborating institutions in the Dark Energy Survey.
The U.S. National Science Foundation's National Optical-Infrared Astronomy Research Laboratory (NOIRLab) operates the Cerro Tololo Inter-American Observatory (CTIO) and Vera C. Rubin Observatory (operated in cooperation with the U.S. Department of Energy’s SLAC National Accelerator Laboratory). The research community is honored to have the opportunity to conduct research on Cerro Tololo and Cerro Pachón in Chile. We recognize and acknowledge the very significant cultural role and reverence that these sites have to the local communities in Chile.
Based in part on data acquired at the Anglo-Australian Telescope for the Dark Energy Survey by OzDES. We acknowledge the traditional custodians of the land on which the AAT stands, the Gamilaraay people, and pay our respects to elders past and present.
JOURNAL
The Astrophysical Journal
METHOD OF RESEARCH
Data/statistical analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
The Dark Energy Survey: Cosmology results with ~1500 new high-redshift type Ia supernovae using the full 5-year dataset
Space oddity: Uncovering the origin of the universe’s rare radio circles
Outflowing galactic winds from exploding stars may explain the enormous rings
Peer-Reviewed PublicationVIDEO:
COMPUTER SIMULATION OF AN OUTFLOWING GALACTIC WIND LAUNCHED WITH AN INITIAL VELOCITY OF 450 KILOMETERS PER SECOND AND A MASS OUTFLOW RATE OF 200 SOLAR MASSES PER YEAR, WHICH BLOWS GAS OUT OF THE GALAXY FOR 200 MILLION YEARS INTO THE SURROUNDING CIRCUMGALACTIC MEDIUM. THE LEFT PANEL SHOWS THE GAS TEMPERATURE AND THE RIGHT PANEL SHOW THE GAS DENSITY. THIS SIMULATION PROVIDES A POSSIBLE EXPLANATION FOR THE ORIGIN OF ODD RADIO CIRCLES.
view moreCREDIT: CASSANDRA LOCHHAAS / SPACE TELESCOPE SCIENCE INSTITUTE
It’s not every day astronomers say, “What is that?” After all, most observed astronomical phenomena are known: stars, planets, black holes and galaxies. But in 2019 the newly completed ASKAP (Australian Square Kilometer Array Pathfinder) telescope picked up something no one had ever seen before: radio wave circles so large they contained entire galaxies in their centers.
As the astrophysics community tried to determine what these circles were, they also wanted to know why the circles were. Now a team led by University of California San Diego Professor of Astronomy and Astrophysics Alison Coil believes they may have found the answer: the circles are shells formed by outflowing galactic winds, possibly from massive exploding stars known as supernovae. Their work is published in Nature.
Coil and her collaborators have been studying massive “starburst” galaxies that can drive these ultra-fast outflowing winds. Starburst galaxies have an exceptionally high rate of star formation. When stars die and explode, they expel gas from the star and its surroundings back into interstellar space. If enough stars explode near each other at the same time, the force of these explosions can push the gas out of the galaxy itself into outflowing winds, which can travel at up to 2,000 kilometers/second.
“These galaxies are really interesting,” said Coil, who is also chair of the Department of Astronomy and Astrophysics. “They occur when two big galaxies collide. The merger pushes all the gas into a very small region, which causes an intense burst of star formation. Massive stars burn out quickly and when they die, they expel their gas as outflowing winds.”
Massive, rare and of unknown origin
Technological developments allowed ASKAP to scan large portions of the sky at very faint limits which made odd radio circles (ORCs) detectable for the first time in 2019. The ORCs were enormous — hundreds of kiloparsecs across, where a kiloparsec is equal to 3,260 light years (for reference, the Milky Way galaxy is about 30 kiloparsecs across).
Multiple theories were proposed to explain the origin of ORCs, including planetary nebulae and black hole mergers, but radio data alone could not discriminate between the theories. Coil and her collaborators were intrigued and thought it was possible the radio rings were a development from the later stages of the starburst galaxies they had been studying. They began looking into ORC 4 — the first ORC discovered that is observable from the Northern Hemisphere.
Up until then, ORCs had only been observed through their radio emissions, without any optical data. Coil’s team used an integral field spectrograph at the W.M. Keck Observatory on Maunakea, Hawaii, to look at ORC 4, which revealed a tremendous amount of highly luminous, heated, compressed gas — far more than is seen in the average galaxy.
With more questions than answers, the team got down to detective work. Using optical and infrared imaging data, they determined the stars inside ORC 4 galaxy were around 6 billion years old. “There was a burst of star formation in this galaxy, but it ended roughly a billion years ago,” stated Coil.
Cassandra Lochhaas, a postdoctoral fellow at the Harvard & Smithsonian Center for Astrophysics specializing in the theoretical side of galactic winds and a co-author on the paper, ran a suite of numerical computer simulations to replicate the size and properties of the large-scale radio ring, including the large amount of shocked, cool gas in the central galaxy.
Her simulations showed outflowing galactic winds blowing for 200 million years before they shut off. When the wind stopped, a forward-moving shock continued to propel high-temperature gas out of the galaxy and created a radio ring, while a reverse shock sent cooler gas falling back onto the galaxy. The simulation played out over 750 million years — within the ballpark of the estimated one-billion-year stellar age of ORC 4.
“To make this work you need a high-mass outflow rate, meaning it’s ejecting a lot of material very quickly. And the surrounding gas just outside the galaxy has to be low density, otherwise the shock stalls. These are the two key factors,” stated Coil. “It turns out the galaxies we’ve been studying have these high-mass outflow rates. They’re rare, but they do exist. I really do think this points to ORCs originating from some kind of outflowing galactic winds.”
Not only can outflowing winds help astronomers understand ORCs, but ORCs can help astronomers understand outflowing winds as well. “ORCs provide a way for us to ‘see’ the winds through radio data and spectroscopy,” said Coil. “This can help us determine how common these extreme outflowing galactic winds are and what the wind life cycle is. They can also help us learn more about galactic evolution: do all massive galaxies go through an ORC phase? Do spiral galaxies turn elliptical when they are no longer forming stars? I think there is a lot we can learn about ORCs and learn from ORCs.”
JOURNAL
Nature
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Ionized Gas Extended Over 40 kpc in an Odd Radio Circle Host Galaxy
ARTICLE PUBLICATION DATE
8-Jan-2024
COSMIC: The SETI Institute is unlocking the mysteries of the universe with breakthrough technology at the Karl G. Jansky Very Large Array
COSMIC could soon cover more stars, explore new frequencies, and enhance our understanding of the vast cosmic tapestry.
IMAGE:
IMAGE SHOWING THE POSITIONS OF ALL THE STARS TARGETED BY COSMIC THUS FAR WITH DATA RECORDED INTO A DATABASE OF POTENTIAL SIGNALS. WE HAVE COLLECTED DATA ON OVER 485,000 SOURCES ACROSS THE FREQUENCY RANGE OF 2 TO 45GHZ. THE COORDINATES OF EACH SMALL DOT ARE A TARGETED STAR AND THE FILLED-IN PATCHES OF THE SKY REPRESENT REGIONS MAPPED THROUGH THE VLA SKY SURVEY, WHICH SURVEYED THE SKY AT A RATE OF 2000 SOURCES PER HOUR.
view moreCREDIT: SETI INSTITUTE
January 8, 2024, Mountain View, CA -- In a groundbreaking cosmic quest, the SETI Institute’s Commensal Open-Source Multimode Interferometer Cluster (COSMIC) at the Karl G. Jansky Very Large Array (VLA) is expanding the search for extraterrestrial intelligence (SETI). This cutting-edge technology is not a distinct telescope; it’s a detector. COSMIC searches for extraterrestrial signals and paves the way for future science using a copy of the raw data from the telescope’s observations. At the heart of COSMIC’s mission is pursuing the age old question: Are we alone in the universe? Project scientist Dr. Chenoa Tremblay and the team detailed the project in a paper published in The Astronomical Journal.
What sets COSMIC apart is its adaptability to the future. The system is designed for future upgrades, ensuring it remains at the forefront of cosmic exploration. With the potential to expand its capabilities, COSMIC could soon cover more stars, explore new frequencies, and enhance our understanding of the vast cosmic tapestry. It is important to note that COSMIC’s capabilities go beyond searching for extraterrestrial intelligence. Future upgrades could unlock new explorations, from finding fast radio bursts with a submillisecond temporal resolution to studying spectral line science and axionic dark matter.
“COSMIC introduces modern Ethernet-based digital architecture on the VLA, allowing for a test bed for future technologies as we move into the next generation era,” said Tremblay. “Currently, the focus is on creating one of the largest surveys for technological signals, with over 500,000 sources observed in the first six months. However, the flexibility of the design allows for a wide range of other scientific opportunities, such as studying fast radio burst pulse structures and searching for axion dark matter candidates. We hope to open opportunities for other scientists to use our high time (nanoseconds) or our high spectral resolution (sub-Hz) to complete their research. It is an exciting time for increasing the capabilities of this historic telescope.”
COSMIC stands on the shoulders of giants like Project Phoenix, with the capacity to search millions of stars and the potential to expand to tens of millions—a leap in scope and sensitivity. Currently operational on the VLA, COSMIC is searching using observations from the Very Large Array Sky Survey (VLASS), which will map 80% of the sky in three phases over two years and catalog approximately 10 million radio sources.
COSMIC’s Ethernet-based system adds a new collaborative element to the cosmos. The multicasting technology allows other commensal systems to access COSMIC’s processing power, enabling a collaborative scientific ecosystem to develop. Imagine multiple telescopes working together to unlock the universe’s most profound mysteries.
“The COSMIC system greatly enhances the VLA’s scientific capabilities. Its main goal of detecting extraterrestrial technosignatures addresses one of the most profound scientific questions ever. This topic was previously not possible with the VLA,” said Dr. Paul Demorest, National Radio Astronomy Observatory. “By operating in parallel with projects such as the VLA Sky Survey, COSMIC will accomplish one of the largest SETI surveys ever while still allowing the VLA to carry out its usual program of other astronomical research.”
As we embark on this cosmic journey with COSMIC, the possibilities are as vast as the universe. Whether searching for signals from distant civilizations or unraveling the mysteries of dark matter, COSMIC is not just a detector on a telescope; it is a cosmic companion in our quest for knowledge.
COSMIC is supported by NRAO and Breakthrough Listen.
For more information including about the system design and early testing results, the paper is available here: https://iopscience.iop.org/article/10.3847/1538-3881/ad0fe0
About the SETI Institute
Founded in 1984, the SETI Institute is a non-profit, multi-disciplinary research and education organization whose mission is to lead humanity’s quest to understand the origins and prevalence of life and intelligence in the universe and share that knowledge with the world. Our research encompasses the physical and biological sciences and leverages data analytics, machine learning, and advanced signal detection technologies. The SETI Institute is a distinguished research partner for industry, academia, and government agencies, including NASA and the National Science Foundation.
JOURNAL
The Astronomical Journal
ARTICLE TITLE
COSMIC: An Ethernet-based Commensal, Multimode Digital Backend on the Karl G. Jansky Very Large Array for the Search for Extraterrestrial Intelligence
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