A team of international astronomers reported the discovery of a new ultra-high energy (UHE) gamma-ray source in the Galactic plane named LHAASO J0341+5258. It is an extended source with a width of 0.29° and emission from it reaches up to 200 TeV. Their study recently appeared in Arxiv.
Cosmic rays are charged particles, mainly protons and helium nuclei, that arrive isotropically (i.e. exhibiting the same behaviour in all directions) from space and continuously bombard Earth’s atmosphere. They were discovered by Victor Hess in 1912, when he measured an increasing radiation level in the atmosphere with altitude, using his balloon to reach a height of 5.3 km. He rightly postulated the extraterrestrial origin of cosmic rays and was awarded the Nobel Prize in Physics in 1936 for his discovery.
Decades of measurements helped to construct the energy spectrum of cosmic rays observed from Earth. It is one of the most famous plots of modern physics, exhibiting a remarkable power law in energy over several orders of magnitude (see inset in Figure 1). This power law has a break in energy at a few Peta-electronvolts (PeV, 1015 eV), which is referred to as the knee. Below the knee, cosmic rays are believed to be of Galactic origin, but the sources where they are produced are still unknown. Sources capable of accelerating particles up to at least PeV energies are called PeVatrons, and astronomers are actively on the hunt for these extreme accelerators within our Galaxy in order to shed more light on their properties.
Now, by using China’s Large High Altitude Air Shower Observatory (LHAASO) a team of international astronomers found a new source of this type called LHAASO J0341+5258. It was detected during an obervational campaign between December 2019 and November 2020.
“Since December 2019, the half of LHAASO-KM2A experiment has monitored the sky in the declination band from -15° to 75 degrees above tens of TeV with high duty cycle. An excess with a pre-trial significance of 8.2σ was detected from the direction of LHAASO J0341+5258 using events with energy above 25 TeV,” they said.
It was found from observations that LHAASO J0341+5258 is an extended source with angular size of approximately 0.29°. The gamma-ray emission from this source reaches values of nearly 200 TeV (0.2 PeV).
Their results showed that the integrated energy flux of gamma-ray emissions for LHAASO J0341+5258 above 25 TeV is 1.44 × 10¯14 (cm¯2s¯1), which accounts for about 20 percent of the flux from the Crab Nebula. In addition, the energy spectrum of this source can be described by a power-law, even though there is a hint of curvature at around 50 TeV.
Moreover, they found that LHAASO J0341+5258 is positionally coincident with a known GeV gamma-ray source 4FGL J0340.4+5302. Therefore, the researchers assume that both sources may have a unified origin.
Summing up the results, they noted that LHAASO J0341+5258 could be an extended emission of a pulsar wind nebula (PWN) and/or a pulsar halo. However, the challenge of this scenario is the lack of a reported powerful pulsar.
“Interestingly, such a pulsar could be the gamma-ray source 4FGL J0340.4+5302 with a characteristic spectrum below 1 GeV. The detection of pulsed radio emission from this source would support the IC (inverse Compton) origin of the UHE gamma-ray emission,” they explained.
Finally, they added that the hadronic origin of the UHE emission from LHAASO J0341+5258 can be interpreted as an ‘echo’ from molecular clouds. This is the result of interactions of protons with dense gas regions in the proximity of an old supernova remnant.
Featured image: The significance map of LHAASO J0341+5258 above 25 TeV. The green circle marks the position of 4FGL J0340.4+5302, and the blue cross marks the position of the pulsar PSR J0343+5312. Credit: Cao et al.
Reference: LHAASO Collaboration, “Discovery of a new γ-ray source LHAASO J0341+5258 with emission up to 200TeV”, arXiv:2107.02020 [astro-ph.HE] arxiv.org/abs/2107.02020
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After years of research, the molecular structure of the enzyme that is responsible for a large part of the worldwide nitrate and nitrogen production by bacteria is known. The anammox bacteria, among others, use this enzyme to convert toxic nitrite into nitrate. Now that it has been clarified exactly how this enzyme works, this creates new possibilities for making better use of the anammox bacteria for power generation from wastewater and the production of rocket fuel. Researchers from Radboud University and the Max Planck Institutes in Heidelberg and Frankfurt are publishing about it today in Nature Microbiology .
Nitrogen-eating bacteria such as anammox require the enzyme nitrite oxidoreductase (NXR) to convert the toxic nitrite to nitrate. The enzyme plays a central role in the nitrogen cycle in nature. For example, through fertilizer use in agriculture, a lot of ammonium ends up in the soil, which is then converted to nitrate. Nitrate is easily soluble in water, which means that it is easily washed away in ground and surface water. That process is an important reason why too much nitrogen has such a big environmental impact.
‘Despite the fact that the enzyme is so important for the nitrogen cycle, we knew very little about how it works,’ says Mike Jetten , professor of Microbial Ecology at Radboud University. ‘It took us more than ten years to map out the molecular structure of this enzyme in the anammox bacterium.’
‘NXR turns out to be complicated and to contain unexpected parts,’ says Thomas Barends of the Max Planck Institute for Medical Research in Heidelberg. ‘Together with our colleagues in Frankfurt, we have found a building block in it that ensures that the protein joins together into long threads. We have now also gained more insight into how proteins can organize themselves in the cell in general.’
Wastewater and rocket fuel
The fact that it is now finally known how NXR works helps, among other things, in using the anammox bacterium for interesting applications. Jetten: ‘Anammox needs this enzyme to grow, but naturally grows very slowly. Now we may be able to remove the bottlenecks in the growth process, so that we can use the bacterium in smaller and faster installations.’
Nijmegen microbiologists have been studying the properties of the special anammox bacterium for a long time. This is because it is the only one in the world capable of converting harmful ammonium into harmless nitrogen gas without using oxygen. Since the discovery of the bacterium, anammox has been widely used for wastewater treatment.
A year ago, the microbiologists discovered that the bacteria can help generate electricity from wastewater. ‘We made this – initially impossible – reaction possible by bypassing the NXR enzyme. It is also still on our bucket list to have anammox produce rocket fuel on a large scale. It is also useful for this if we know how we can better circumvent the enzyme: then the bacterium will focus less on growth, but more on making the by-product hydrazine, a raw material for rocket fuel. ‘
‘Architecture of the Intracellular Superstructure-Forming Nitrite Oxidoreductase’, Tadeo Moreno Chicano et al., Nature Microbiology . DOI: 10.1038/s41564-021-00934-8
High-dose buprenorphine therapy, provided under emergency department care, is safe and well tolerated in people with opioid use disorder experiencing opioid withdrawal symptoms, according to a study supported by the National Institutes of Health’s National Institute on Drug Abuse (NIDA) through the Helping to End Addiction Long-term Initiative, or the NIH HEAL Initiative.
Lower doses of buprenorphine, a medication approved by the U.S. Food and Drug Administration to treat opioid use disorder, are the current standard of care. However, elevated doses of the medication may provide a critical extended period of withdrawal relief to people after being discharged from the emergency department that may help them navigate barriers to obtaining medications as well as accessing care for the treatment of opioid use disorder. The findings appeared today in JAMA Network Open.
“Emergency departments are at the front lines of treating people with opioid use disorder and helping them overcome barriers to recovery such as withdrawal,” said Nora D. Volkow, M.D., director of NIDA. “Providing buprenorphine in emergency departments presents an opportunity to expand access to treatment, especially for underserved populations, by supplementing urgent care with a bridge to outpatient services that may ultimately improve long-term outcomes.”
Some emergency departments already use higher doses of buprenorphine for the treatment of withdrawal and opioid use disorder in response to the increasing potency of the illicit opioid drug supply and commonly encountered delays in access to follow-up care, but this practice has not been evaluated previously.
In this study, researchers used a retrospective chart review to analyze data from electronic health records documenting 579 emergency department visits at the Alameda Health System?Highland Hospital in Oakland, California, made by 391 adults with opioid use disorder in 2018. Many of the patients were from vulnerable populations, with 23% experiencing homelessness and 41% having a psychiatric disorder. Most patients were male (68%). Forty-four percent of patients were Black, and 15% were Hispanic or Latino.
The data analysis showed that in 63% of cases, the clinicians administered more than the standard upper limit of 12 mg of sublingual buprenorphine during emergency department induction, and in 23% of cases, patients were given 28 mg or more. Higher doses of buprenorphine were safe and tolerable, and among those given the higher doses, there were no reports of respiratory problems or drowsiness – possible side effects of the medication. The small number of serious adverse events that occurred were determined to be unrelated to high-dose buprenorphine therapy.
Studies have shown that initiating buprenorphine in emergency departments improves engagement in treatment and is cost effective, but barriers to the medication’s use persist. At the time of the study, there were strict controls on buprenorphine prescribing. While clinicians could dispense the medication in the emergency department, only those who had fulfilled the federal certification requirements related to training and ancillary services needed to obtain a buprenorphine prescribing waiver could provide a prescription upon discharge. Patients discharged without a prescription for buprenorphine may experience a return of withdrawal symptoms before they have a chance to access follow-up care. Recent changes to prescribing guidelines by the U.S. Department of Health and Human Services now allow some clinicians treating up to 30 patients to prescribe buprenorphine without the previous training and services criteria.
“Once discharged, many people have difficulty linking to follow-up medical care,” said study leader Andrew A. Herring, M.D., of Highland Hospital Department of Emergency Medicine. “Adjusting the timing and dosage of buprenorphine in the emergency department, along with resources and counseling aimed at facilitating the transition to outpatient services, may provide the momentum needed to access continuing care.”
“This study enhances the evidence we know about emergency-department buprenorphine induction, and could be a gamechanger, particularly for vulnerable populations who would likely benefit from a rapid induction at the time of the visit,” says study author Gail D’Onofrio, M.D., of Yale University, New Haven, Connecticut, who published the original studies on emergency department-initiated buprenorphine, as well as recent consensus recommendations on the treatment of opioid use disorder in the emergency department.
While the researchers note that their findings need to be prospectively confirmed in other emergency departments, this study suggests that with proper support and training, emergency medicine providers may safely and effectively initiate high-dose buprenorphine therapy.
This work was supported by NIDA’s Clinical Trials Network (UG1DA015831), a nationwide consortium aimed at testing drug use interventions and delivering evidence-based therapies to diverse patient populations. Additional support was also provided by the NIH HEAL Initiative.
The Helping to End Addiction Long-term Initiative, or the NIH HEAL Initiative, are registered trademarks and service marks, respectfully, of the U.S. Department of Health and Human Services.
Project offers new step toward study of emergence, ‘materials by design,’ and future nanomagnets
Using a D-Wave quantum-annealing computer as a testbed, scientists at Los Alamos National Laboratory have shown that it is possible to isolate so-called emergent magnetic monopoles, a class of quasiparticles, creating a new approach to developing “materials by design.”
“We wanted to study emergent magnetic monopoles by exploiting the collective dynamics of qubits,” said Cristiano Nisoli, a lead Los Alamos author of the study. “Magnetic monopoles, as elementary particles with only one magnetic pole, have been hypothesized by many, and famously by Dirac, but have proved elusive so far.”
They realized an artificial spin ice by using the superconducting qubits of the quantum machine as a magnetic building block. Generating magnetic materials with exotic properties in this way is ground-breaking in many ways. Their process used Gauss’s law to trap monopoles, allowing the scientists to observe their quantum-activated dynamics and their mutual interaction. This work demonstrates unambiguously that magnetic monopoles not only can emerge from an underlying spin structure, but can be controlled, isolated and studied precisely.
“It was shown in the last decade or so that monopoles can emerge as quasiparticles to describe the excitation spin ices of various geometries. Previously, the National High Magnetic Field Laboratory’s Pulsed Field Facility here at Los Alamos was able to ‘listen’ to monopole noise in artificial spin ices. And now, utilizing a D-Wave quantum annealing system, we have enough control to actually trap one or more of these particles and study them individually. We saw them walking around, getting pinned down, and being created and annihilated in pairs of opposite magnetic charge. And we could thus confirm our quantitative theoretical predictions, that they interact and in fact screen each other,” said Nisoli.
“D-Wave’s processors are designed to excel in optimization, but can also be used as quantum simulators. By programming the desired interactions of our magnetic material into D-Wave’s qubits, we can perform experiments that are otherwise extremely difficult,” said Andrew King, director of Performance Research at D-Wave and an author on the paper. “This collaborative, proof-of-principle work demonstrates new experimental capabilities, improving the power and versatility of artificial spin ice studies. The ability to programmatically manipulate emergent quasiparticles may become a key aspect to materials engineering and even topological quantum computing; we hope it will be foundational for future research.”
Nisoli added, “We have only scratched the surface of this approach. Previous artificial spin ice systems were realized with nanomagnets, and they obeyed classical physics. This realization is instead fully quantum. To avoid leapfrogging we concentrated so far on a quasi-classical study, but in the future, we can really crank up those quantum fluctuations, and investigate very timely issues of decoherence, memory, quantum information, and topological order, with significant technological implications.”
“These results also have technological consequences particularly relevant to DOE and Los Alamos, specifically in the idea of materials-by-design, to produce future nanomagnets that might show advanced and desirable functionality for sensing and computation. Monopoles, as binary information carriers, can be relevant to spintronics. They also contribute significantly to Los Alamos D-Wave investments,” noted Alejandro Lopez-Bezanilla of Los Alamos, who works on the D-Wave processor and assembled the team.
Nisoli, moreover, suggests that beside fruitful applications, these results could perhaps also provide food for thought to fundamental physics.
“Our fundamental theories of particles are parametrized models. One wonders: what is a particle? We show here experimentally that not only particles but also their long-range interactions can be a higher-level description of a very simple underlying structure, one only coupled at nearest-neighbors. Could even ‘real’ particles and interactions that we consider fundamental, such as leptons and quarks, instead be construed as an emergent, higher-level description of a more complex lower-level binary substratum, much like our monopoles emerging from a bunch of qubits?”
Funding: This project was funded under a Los Alamos National Laboratory Directed Research grant.
Han and colleagues investigated the influence of pre-hydration levels on circulating bubble formation for scuba divers and evaluated the appropriate volume of water intake for reducing the risk of decompression sickness (DCS). They demonstrated that pre-hydration with 30% of the recommended daily water intake before scuba diving effectively suppressed the formation of bubbles after diving and decreased the risk of DCS. Their study recently appeared in the Journal Int. J. Environ. Res. Public Health.
Decompression sickness, also called generalized barotrauma or the bends, refers to injuries caused by a rapid decrease in the pressure that surrounds you, of either air or water. It occurs most commonly in scuba or deep-sea divers, although it also can occur during high-altitude or unpressurized air travel.
DCS results in the production of venous gas emboli from the release of inert gas that may evolve in the tissues or blood due to super-saturation during decompression. Bubbles excessively generated in the blood and super-saturated tissues potentially cause severe neurological damage. It is considered a pathological condition caused by intravascular and extravascular gas bubbles, and its symptoms range from mild discomfort, such as painful joints and skin rashes, to neurological consequences including cognitive impairment, sensorimotor dysfunction, and death.
Previous study suggested that pre-dive oral hydration can be an easy means of reducing the risk of DCS. However, the appropriate level of hydration was not provided in the study. Thus, Han and colleagues now investigated the appropriate volume of hydration before scuba diving contributing to the reduction of circulating vascular bubbles using a Doppler device.
They classified twenty scuba divers into four groups according to the volume of water taken in before scuba diving as follows: no-water-intake group (NWIG), 30%-water-intake group (30WIG), 50%-water intake group (50WIG), and 100%-water-intake group (100WIG). Then, they measured the circulating bubbles using movement status by Doppler on the right and left subclavian veins and precordial regions at pre-dive, post-dive, and 30 min after diving to a depth of 30 m for a duration of 25 min at the bottom.
They found that drinking 30% of daily water intake before scuba diving contributed to a reduced Spencer grade. Most of the participants who drank 30% (0.69 L) of daily water intake 2h before scuba diving showed the lowest (I) or the second-lowest (II) Spencer grade (as shown in Table 1).
From these results, one can inferred that drinking 30% of daily water intake before scuba diving effectively removed the formation of bubbles after diving and facilitated the recovery after diving by reducing bubbles in the body.
Moreover, their study confirmed that 30% of water intake before diving is a suitable way to prevent DCS. On the other hand, drinking 100% of daily water intake before diving showed similar bubble grades to non-water intake, which further facilitated the formation of bubbles in the body. There are 6–7 L of water in the body. However, the higher the water retention amount, the higher the possibility that the bubble retention amount increases. That is, it is good to consume water only as much as the amount to be dehydrated, but as a result of analysis in this study, the amount was 30%. This means that 30% of water intake before and after diving is very important in smoothing out the air bubbles already in the blood vessels.
Featured image credit: Getty Images
Reference: Han, K.-H.; Hyun, G.-S.; Jee, Y.-S.; Park, J.-M. Amount-Effect of Water Intake before Scuba Diving on the Risk of Decompression Sickness. Int. J. Environ. Res. Public Health 2021, 18, 7601. https://doi.org/10.3390/ijerph18147601
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On July 16, 2011, NASA’s Dawn mission entered orbit around the asteroid Vesta, a first in the history of solar system exploration. “It was a magical moment, with a very strong emotion”, remembers Maria Cristina De Sanctis of INAF, scientific director of the Italian Vir spectrometer on board the probe
Ten years ago, a probe he wrote a remarkable page of history of space exploration, entering for the first time in orbit around a body in the main belt of asteroids between the orbits of Mars and Jupiter. The probe, which had left Earth nearly four years earlier (and had twice risked not leaving at all), is called Dawn , ‘dawn’ in English. His goal: to study the dawn of the solar system.
It was July 16, 2011 and Dawn, a NASA mission that boasts a strong Italian contribution with the Italian Space Agency (ASI) and the National Institute of Astrophysics (Inaf), reached its first destination : the asteroid Vesta , a body of the diameter of about 500 meters, the second largest in the main belt. It will remain in orbit there for 14 months, until 5 September 2012, before heading to Ceres , the most massive object in the main asteroid belt, elevated in 2006 to the rank of dwarf planet . Upon arrival, in 2015, Dawn will become the first probe to orbit two distinct celestial bodies in deep space, continuing to study Ceres from orbit until the mission ends., in November 2018.
Among the four experiments on board the probe is the visible and infrared spectrometer Vir (Visible and Infrared Mapping Spectrometer) under Italian responsibility, funded and coordinated by ASI under the scientific guidance of INAF, built by the Leonardo company. This instrument sent over 11 million images and 90 GB of data to Earth, making a decisive contribution to the characterization of both Vesta and Ceres and to the study of their origin and evolution.
«The arrival of Dawn in Vesta was for me a truly unique moment that I had been waiting for over ten years», Maria Cristina De Sanctis , Inaf researcher and scientific director of Vir , tells Media Inaf . “Seeing that everything was working perfectly, that the data was of extremely high quality and that we were seeing an ‘alien’ world for the first time was a magical moment with a very strong emotion. I wish all scientists to feel emotions like the one I felt in setting eyes on Dawn’s first data in Vesta ».
The observations collected by Dawn in the fourteen months in orbit around Vesta have shown that this celestial body can be counted among the protoplanets, with characteristics that make it more similar to the Moon than to other asteroids. More generally, the mission data allowed scientists to compare two planet-like worlds that evolved very differently from each other, demonstrating the importance of the relative positions of different bodies within the early Solar System for their training and evolution.
To celebrate the 10th anniversary of Dawn’s arrival in Vesta, NASA has created a poster with a mosaic of images of the asteroid obtained from the camera on board the spacecraft. The central mosaic in black and white, made from many smaller images, shows a region near the equator of Vesta, where a vast system of depressions, called Divalia Fossae , is visible , which exceeds the dimensions of the Grand Canyon and covers the surface of the asteroid for 465 km in length and 22 km in width. The image also shows the irregular, non-spherical shape of Vesta. At the origin of this there would be two major impacts, the largest of which would have produced the Rheasilva crater, visible in the color image at the bottom right, and would also be at the origin of the system of ridges and depressions at the equator, formed over a billion years ago.
Dawn has also shown that Vesta, due to the violent collisions suffered, is the progenitor of a family of smaller asteroids, the so-called vestoids , as well as a particular class of meteorites known as Hed meteorites., where Hed stands for howardites-eucrites-diogenites. A name that is all a program and that describes the origin of these meteorites respectively from the crust (howardites), from the shallow magma chambers (eucrites) or from the lower crust or upper mantle (diogenites) of the asteroid. In the color image at the bottom left, the material around the three impact craters is seen in purple whose shape vaguely resembles that of a snowman, rich in minerals found in eucrites, according to the analysis of data from Vir and of the Gamma Ray and Neutron Detector. The regions in yellow and green in the lower right image, on the other hand, at the base of the Rheasilvia crater, are rich in minerals found in the diogenites, excavated from the upper mantle of Vesta.
It was precisely the mineralogical similarities between these meteorites, studied in the laboratory, and Vesta, observed with telescopes from Earth, that in the second half of the last century renewed the scientific interest in this asteroid discovered in 1807, leading to the definition of one of the objectives of the Dawn mission.
Featured image: The Dawn probe and the asteroid Vesta. Credits: Nasa / Jpl-Caltech
The Juno Waves instrument “listened” to the radio emissions from Jupiter’s immense magnetic field to find their precise locations.
By listening to the rain of electrons flowing onto Jupiter from its intensely volcanic moon Io, researchers using NASA’s Juno spacecraft have found what triggers the powerful radio emissions within the monster planet’s gigantic magnetic field. The new result sheds light on the behavior of the enormous magnetic fields generated by gas-giant planets like Jupiter.
Jupiter has the largest, most powerful magnetic field of all the planets in our solar system, with a strength at its source about 20,000 times stronger than Earth’s. It is buffeted by the solar wind, a stream of electrically charged particles and magnetic fields constantly blowing from the Sun. Depending on how hard the solar wind blows, Jupiter’s magnetic field can extend outward as much as two million miles (3.2 million kilometers) toward the Sun and stretch more than 600 million miles (over 965 million kilometers) away from the Sun, as far as Saturn’s orbit.
Jupiter has several large moons that orbit within its massive magnetic field, with Io being the closest. Io is caught in a gravitational tug-of-war between Jupiter and the neighboring two of these other large moons, which generates internal heat that powers hundreds of volcanic eruptions across its surface.
These volcanoes collectively release one ton of material (gases and particles) per second into space near Jupiter. Some of this material splits up into electrically charged ions and electrons and is rapidly captured by Jupiter’s magnetic field. As Jupiter’s magnetic field sweeps past Io, electrons from the moon are accelerated along the magnetic field toward Jupiter’s poles. Along their way, these electrons generate “decameter” radio waves (so-called decametric radio emissions, or DAM). The Juno Waves instrument can “listen” to this radio emission that the raining electrons generate.
Video: Juno tunes into one of its favorite radio stations. Hear the decametric radio emissions triggered by the interaction of Io with Jupiter’s magnetic field. The Waves instrument on Juno detects radio signals whenever Juno’s trajectory crosses into the beam which is a cone-shaped pattern. This beam pattern is similar to a flashlight that is only emitting a ring of light rather than a full beam. Juno scientists then translate the radio emission detected to a frequency within the audible range of the human ear. Credit: University of Iowa/SwRI/NASA
The researchers used the Juno Waves data to identify the precise locations within Jupiter’s vast magnetic field where these radio emissions originated. These locations are where conditions are just right to generate the radio waves; they have the right magnetic field strength and the right density of electrons (not too much and not too little), according to the team.
“The radio emission is likely constant, but Juno has to be in the right spot to listen,” said Yasmina Martos of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, College Park.
The radio waves emerge from the source along the walls of a hollow cone aligned with and controlled by the strength and shape of the magnetic field of Jupiter. Juno receives the signal only when Jupiter’s rotation sweeps that cone over the spacecraft, in the same way a lighthouse beacon shines briefly upon a ship at sea. Martos is lead author of a paper about this research published in June 2020 in the Journal of Geophysical Research, Planets.
Data from Juno allowed the team to calculate that the energy of the electrons generating the radio waves was far higher than previously estimated, as much as 23 times greater. Also, the electrons do not necessarily need to come from a volcanic moon. For example, they could be in the planet’s magnetic field (magnetosphere) or come from the Sun as part of the solar wind, according to the team.
More about this project and the Juno Mission
The research was funded by the Juno Project under NASA Grants NNM06AAa75c and 699041X to the Southwest Research Institute in San Antonio, Texas, and NASA Grant NNN12AA01C to NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, California. The team is composed of researchers from NASA Goddard, the National Institute of Technology (KOSEN) in Tokyo, Japan; Niihama College in Niihama, Ehime, Japan, the University of Iowa, Iowa City; and the Technical University of Denmark in Kongens Lyngby, Denmark. NASA JPL manages the Juno mission for the principal investigator, Scott J. Bolton, of the Southwest Research Institute. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. Lockheed Martin Space in Denver built and operates the spacecraft.
Featured image: This processed image of Io by New Horizons shows the 290-kilometer-high (180-mile-high) plume of the volcano Tvashtar near Io’s north pole. Also visible is the Prometheus volcano’s much smaller plume in the 9 o’clock direction. The top of the Masubi volcano’s plume appears as an irregular bright patch near the bottom. Credit: NASA/JHUAPL/SwRI
Reference: Martos, Y. M., Imai, M., Connerney, J. E. P., Kotsiaros, S., & Kurth, W. S. (2020). Juno reveals new insights into Io-related decameter radio emissions. Journal of Geophysical Research: Planets, 125, e2020JE006415. https://doi.org/10.1029/2020JE006415
A newly discovered visitor to the outer edges of our Solar System has been shown to be the largest known comet ever, thanks to the rapid response telescopes of Las Cumbres Observatory. The object, which is named Comet C/2014 UN271 Bernardinelli-Bernstein after its two discoverers, was first announced on Saturday, June 19th, 2021. C/2014 UN271 was found by reprocessing four years of data from the Dark Energy Survey, which was carried out using the 4-m Blanco telescope at Cerro Tololo Inter-American Observatory in Chile between 2013 and 2019. At the time of the announcement, there was no indication that this was an active world. Anticipation was immediately high among astronomers. C/2014 UN271 was inbound from the cold outer reaches of the Solar System, so rapid imaging was needed to find out: when would the big new-found world start to show a comet’s tail?
Las Cumbres Observatory was quickly able to determine whether the object had become an active comet in the three years since it was first seen by the Dark Energy Survey. “Since the new object was far in the south and quite faint, we knew there wouldn’t be many other telescopes that could observe it,” says Dr. Tim Lister, Staff Scientist at Las Cumbres Observatory (LCO). “Fortunately LCO has a network of robotic telescopes across the world, particularly in the Southern Hemisphere, and we were able to quickly get images from the LCO telescopes in South Africa,” explained Tim Lister.
The images from one of LCO’s 1-meter telescopes hosted at the South African Astronomical Observatory, came in around 9pm PDT on Monday night June 22. Astronomers in New Zealand who are members of the LCO Outbursting Objects Key (LOOK) Project were the first to notice the new comet.
“Since we’re a team based all around the world, it just happened that it was my afternoon, while the other folks were asleep. The first image had the comet obscured by a satellite streak and my heart sank. But then the others were clear enough and gosh: there it was, definitely a beautiful little fuzzy dot, not at all crisp like its neighbouring stars!” said Dr. Michele Bannister at New Zealand’s University of Canterbury. Analysis of the LCO images showed a fuzzy coma around the object, indicating that it was active and was indeed a comet, even though it is still out at a remarkable distance of more than 1,800,000,000 miles, more than double Saturn’s distance from the Sun.
The comet is estimated to be over 100km in diameter, which is more than three times the size of the next biggest comet nucleus we know, Comet Hale-Bopp, which was discovered in 1995. This comet is not expected to become naked-eye bright: it will remain a telescopic object because its closest distance to the Sun will still be beyond Saturn. Since Comet C/2014 UN271 was discovered so far out, astronomers will have over a decade to study it. It will reach its closest approach to the Sun in January of 2031. A recent article in the New York Times about the comet details its predicted travel.
Thus Tim Lister and the other astronomers of the LOOK Project will have plenty of time to use the telescopes of Las Cumbres Observatory to study C/2014 UN271. The LOOK Project is continuing to observe the behavior of a large number of comets and how their activity evolves as they come closer towards the Sun. The scientists are also using the rapid response capability of LCO to get observations very quickly when a comet goes into an outburst.
“There are now a large number of surveys, such as the Zwicky Transient Facility and the upcoming Vera C. Rubin Observatory, that are monitoring parts of the sky every night. These surveys can provide alerts if one of the comets changes brightness suddenly and then we can trigger the robotic telescopes of LCO to get us more detailed data and a longer look at the changing comet while the survey moves onto other areas of the sky,” explains Tim Lister. “The robotic telescopes and sophisticated software of LCO allow us to get images of a new event within 15 minutes of an alert. This lets us really study these outbursts as they evolve.”
Featured image: Comet C/2014 UN271 (Bernardinelli-Bernstein), as seen in a synthetic color composite image made with the Las Cumbres Observatory 1-meter telescope at Sutherland, South Africa, on 22 June 2021. The diffuse cloud is the comet’s coma. Credit: LOOK/LCO
Argonne-driven technology is part of a broad initiative to answer fundamental questions about the birth of matter in the universe and the building blocks that hold it all together.
Imagine the first of our species to lie beneath the glow of an evening sky. An enormous sense of awe, perhaps a little fear, fills them as they wonder at those seemingly infinite points of light and what they might mean. As humans, we evolved the capacity to ask big insightful questions about the world around us and worlds beyond us. We dare, even, to question our own origins.
“The place of humans in the universe is important to understand,” said physicist and computational scientist Salman Habib. “Once you realize that there are billions of galaxies we can detect, each with many billions of stars, you understand the insignificance of being human in some sense. But at the same time, you appreciate being human a lot more.”
“To say that we understand the universe would be incorrect. To say that we sort of understand it is fine. We have a theory that describes what the universe is doing, but each time the universe surprises us, we have to add a new ingredient to that theory.” — Salman Habib, physicist and computational scientist
With no less a sense of wonder than most of us, Habib and colleagues at the U.S. Department of Energy’s (DOE) Argonne National Laboratory are actively researching these questions through an initiative that investigates the fundamental components of both particle physics and astrophysics.
The breadth of Argonne’s research in these areas is mind-boggling. It takes us back to the very edge of time itself, to some infinitesimally small portion of a second after the Big Bang when random fluctuations in temperature and density arose, eventually forming the breeding grounds of galaxies and planets.
It explores the heart of protons and neutrons to understand the most fundamental constructs of the visible universe, particles and energy once free in the early post-Big Bang universe, but later confined forever within a basic atomic structure as that universe began to cool.
And it addresses slightly newer, more controversial questions about the nature of dark matter and dark energy, both of which play a dominant role in the makeup and dynamics of the universe but are little understood.
“And this world-class research we’re doing could not happen without advances in technology,” said Argonne Associate Laboratory Director Kawtar Hafidi, who helped define and merge the different aspects of the initiative.
“We are developing and fabricating detectors that search for signatures from the early universe or enhance our understanding of the most fundamental of particles,” she added. “And because all of these detectors create big data that have to be analyzed, we are developing, among other things, artificial intelligence techniques to do that as well.”
Decoding messages from the universe
Fleshing out a theory of the universe on cosmic or subatomic scales requires a combination of observations, experiments, theories, simulations and analyses, which in turn requires access to the world’s most sophisticated telescopes, particle colliders, detectors and supercomputers.
Argonne is uniquely suited to this mission, equipped as it is with many of those tools, the ability to manufacture others and collaborative privileges with other federal laboratories and leading research institutions to access other capabilities and expertise.
As lead of the initiative’s cosmology component, Habib uses many of these tools in his quest to understand the origins of the universe and what makes it tick.
And what better way to do that than to observe it, he said.
“If you look at the universe as a laboratory, then obviously we should study it and try to figure out what it is telling us about foundational science,” noted Habib. “So, one part of what we are trying to do is build ever more sensitive probes to decipher what the universe is trying to tell us.”
To date, Argonne is involved in several significant sky surveys, which use an array of observational platforms, like telescopes and satellites, to map different corners of the universe and collect information that furthers or rejects a specific theory.
For example, the South Pole Telescope survey, a collaboration between Argonne and a number of national labs and universities, is measuring the cosmic microwave background (CMB), considered the oldest light in the universe. Variations in CMB properties, such as temperature, signal the original fluctuations in density that ultimately led to all the visible structure in the universe.
Additionally, the Dark Energy Spectroscopic Instrument and the forthcoming Vera C. Rubin Observatory are specially outfitted, ground-based telescopes designed to shed light on dark energy and dark matter, as well as the formation of luminous structure in the universe.
All the data sets derived from these observations are connected to the second component of Argonne’s cosmology push, which revolves around theory and modeling. Cosmologists combine observations, measurements and the prevailing laws of physics to form theories that resolve some of the mysteries of the universe.
But the universe is complex, and it has an annoying tendency to throw a curve ball just when we thought we had a theory cinched. Discoveries within the past 100 years have revealed that the universe is both expanding and accelerating its expansion — realizations that came as separate but equal surprises.
“To say that we understand the universe would be incorrect. To say that we sort of understand it is fine,” exclaimed Habib. “We have a theory that describes what the universe is doing, but each time the universe surprises us, we have to add a new ingredient to that theory.”
Modeling helps scientists get a clearer picture of whether and how those new ingredients will fit a theory. They make predictions for observations that have not yet been made, telling observers what new measurements to take.
Habib’s group is applying this same sort of process to gain an ever-so-tentative grasp on the nature of dark energy and dark matter. While scientists can tell us that both exist, that they comprise about 68 and 26% of the universe, respectively, beyond that not much else is known.
Observations of cosmological structure — the distribution of galaxies and even of their shapes — provide clues about the nature of dark matter, which in turn feeds simple dark matter models and subsequent predictions. If observations, models and predictions aren’t in agreement, that tells scientists that there may be some missing ingredient in their description of dark matter.
But there are also experiments that are looking for direct evidence of dark matter particles, which require highly sensitive detectors. Argonne has initiated development of specialized superconducting detector technology for the detection of low-mass dark matter particles.
This technology requires the ability to control properties of layered materials and adjust the temperature where the material transitions from finite to zero resistance, when it becomes a superconductor. And unlike other applications where scientists would like this temperature to be as high as possible — room temperature, for example — here, the transition needs to be very close to absolute zero.
Habib refers to these dark matter detectors as traps, like those used for hunting — which, in essence, is what cosmologists are doing. Because it’s possible that dark matter doesn’t come in just one species, they need different types of traps.
“It’s almost like you’re in a jungle in search of a certain animal, but you don’t quite know what it is — it could be a bird, a snake, a tiger — so you build different kinds of traps,” he said.
Lab researchers are working on technologies to capture these elusive species through new classes of dark matter searches. Collaborating with other institutions, they are now designing and building a first set of pilot projects aimed at looking for dark matter candidates with low mass.
Tuning in to the early universe
Amy Bender is working on a different kind of detector — well, a lot of detectors — which are at the heart of a survey of the cosmic microwave background (CMB).
“The CMB is radiation that has been around the universe for 13 billion years, and we’re directly measuring that,” said Bender, an assistant physicist at Argonne.
The Argonne-developed detectors — all 16,000 of them — capture photons, or light particles, from that primordial sky through the aforementioned South Pole Telescope, to help answer questions about the early universe, fundamental physics and the formation of cosmic structures.
Now, the CMB experimental effort is moving into a new phase, CMB-Stage 4 (CMB-S4). This larger project tackles even more complex topics like inflationary theory, which suggests that the universe expanded faster than the speed of light for a fraction of a second, shortly after the Big Bang.
While the science is amazing, the technology to get us there is just as fascinating.
Technically called transition edge sensing (TES) bolometers, the detectors on the telescope are made from superconducting materials fabricated at Argonne’s Center for Nanoscale Materials, a DOE Office of Science User Facility.
Each of the 16,000 detectors acts as a combination of very sensitive thermometer and camera. As incoming radiation is absorbed on the surface of each detector, measurements are made by supercooling them to a fraction of a degree above absolute zero. (That’s over three times as cold as Antarctica’s lowest recorded temperature.)
Changes in heat are measured and recorded as changes in electrical resistance and will help inform a map of the CMB’s intensity across the sky.
CMB-S4 will focus on newer technology that will allow researchers to distinguish very specific patterns in light, or polarized light. In this case, they are looking for what Bender calls the Holy Grail of polarization, a pattern called B-modes.
Capturing this signal from the early universe — one far fainter than the intensity signal — will help to either confirm or disprove a generic prediction of inflation.
It will also require the addition of 500,000 detectors distributed among 21 telescopes in two distinct regions of the world, the South Pole and the Chilean desert. There, the high altitude and extremely dry conditions keep water vapor in the atmosphere from absorbing millimeter wavelength light, like that of the CMB.
While previous experiments have touched on this polarization, the large number of new detectors will improve sensitivity to that polarization and grow our ability to capture it.
“Literally, we have built these cameras completely from the ground up,” said Bender. “Our innovation is in how to make these stacks of superconducting materials work together within this detector, where you have to couple many complex factors and then actually read out the results with the TES. And that is where Argonne has contributed, hugely.”
Down to the basics
Argonne’s capabilities in detector technology don’t just stop at the edge of time, nor do the initiative’s investigations just look at the big picture.
Most of the visible universe, including galaxies, stars, planets and people, are made up of protons and neutrons. Understanding the most fundamental components of those building blocks and how they interact to make atoms and molecules and just about everything else is the realm of physicists like Zein-Eddine Meziani.
“From the perspective of the future of my field, this initiative is extremely important,” said Meziani, who leads Argonne’s Medium Energy Physics group. “It has given us the ability to actually explore new concepts, develop better understanding of the science and a pathway to enter into bigger collaborations and take some leadership.”
Taking the lead of the initiative’s nuclear physics component, Meziani is steering Argonne toward a significant role in the development of the Electron-Ion Collider, a new U.S. Nuclear Physics Program facility slated for construction at DOE’s Brookhaven National Laboratory.
Argonne’s primary interest in the collider is to elucidate the role that quarks, anti-quarks and gluons play in giving mass and a quantum angular momentum, called spin, to protons and neutrons — nucleons — the particles that comprise the nucleus of an atom.
Video: Electrons colliding with ions will exchange virtual photons with the nuclear particles to help scientists “see” inside the nuclear particles; the collisions will produce precision 3D snapshots of the internal arrangement of quarks and gluons within ordinary nuclear matter; like a combination CT/MRI scanner for atoms. (Image by Brookhaven National Laboratory.)
While we once thought nucleons were the finite fundamental particles of an atom, the emergence of powerful particle colliders, like the Stanford Linear Accelerator Center at Stanford University and the former Tevatron at DOE’s Fermilab, proved otherwise.
It turns out that quarks and gluons were independent of nucleons in the extreme energy densities of the early universe; as the universe expanded and cooled, they transformed into ordinary matter.
“There was a time when quarks and gluons were free in a big soup, if you will, but we have never seen them free,” explained Meziani. “So, we are trying to understand how the universe captured all of this energy that was there and put it into confined systems, like these droplets we call protons and neutrons.”
Some of that energy is tied up in gluons, which, despite the fact that they have no mass, confer the majority of mass to a proton. So, Meziani is hoping that the Electron-Ion Collider will allow science to explore — among other properties — the origins of mass in the universe through a detailed exploration of gluons.
And just as Amy Bender is looking for the B-modes polarization in the CMB, Meziani and other researchers are hoping to use a very specific particle called a J/psi to provide a clearer picture of what’s going on inside a proton’s gluonic field.
But producing and detecting the J/psi particle within the collider — while ensuring that the proton target doesn’t break apart — is a tricky enterprise, which requires new technologies. Again, Argonne is positioning itself at the forefront of this endeavor.
“We are working on the conceptual designs of technologies that will be extremely important for the detection of these types of particles, as well as for testing concepts for other science that will be conducted at the Electron-Ion Collider,” said Meziani.
Argonne also is producing detector and related technologies in its quest for a phenomenon called neutrinoless double beta decay. A neutrino is one of the particles emitted during the process of neutron radioactive beta decay and serves as a small but mighty connection between particle physics and astrophysics.
“Neutrinoless double beta decay can only happen if the neutrino is its own anti-particle,” said Hafidi. “If the existence of these very rare decays is confirmed, it would have important consequences in understanding why there is more matter than antimatter in the universe.”
Argonne scientists from different areas of the lab are working on the Neutrino Experiment with Xenon Time Projection Chamber (NEXT) collaboration to design and prototype key systems for the collaborative’s next big experiment. This includes developing a one-of-a-kind test facility and an R&D program for new, specialized detector systems.
“We are really working on dramatic new ideas,” said Meziani. “We are investing in certain technologies to produce some proof of principle that they will be the ones to pursue later, that the technology breakthroughs that will take us to the highest sensitivity detection of this process will be driven by Argonne.”
The tools of detection
Ultimately, fundamental science is science derived from human curiosity. And while we may not always see the reason for pursuing it, more often than not, fundamental science produces results that benefit all of us. Sometimes it’s a gratifying answer to an age-old question, other times it’s a technological breakthrough intended for one science that proves useful in a host of other applications.
Through their various efforts, Argonne scientists are aiming for both outcomes. But it will take more than curiosity and brain power to solve the questions they are asking. It will take our skills at toolmaking, like the telescopes that peer deep into the heavens and the detectors that capture hints of the earliest light or the most elusive of particles.
We will need to employ the ultrafast computing power of new supercomputers. Argonne’s forthcoming Aurora exascale machine will analyze mountains of data for help in creating massive models that simulate the dynamics of the universe or subatomic world, which, in turn, might guide new experiments — or introduce new questions.
And we will apply artificial intelligence to recognize patterns in complex observations — on the subatomic and cosmic scales — far more quickly than the human eye can, or use it to optimize machinery and experiments for greater efficiency and faster results.
“I think we have been given the flexibility to explore new technologies that will allow us to answer the big questions,” said Bender. “What we’re developing is so cutting edge, you never know where it will show up in everyday life.”
Funding for research mentioned in this article was provided by Argonne Laboratory Directed Research and Development; Argonne program development; DOE Office of High Energy Physics: Cosmic Frontier, South Pole Telescope-3G project, Detector R&D; and DOE Office of Nuclear Physics.
Featured image: The South Pole Telescope is part of a collaboration between Argonne and a number of national labs and universities to measure the CMB, considered the oldest light in the universe. The high altitude and extremely dry conditions of the South Pole keep water vapor from absorbing select light wavelengths. (Image by Argonne National Laboratory.)