SwRI-led team addresses mystery of heavy elements in galactic cosmic rays
MMS data reveal a mechanism for accelerating heavy ions
2021-07-06
(Press-News.org) SAN ANTONIO -- July 6, 2021 -- Scientists have used data from the Southwest Research Institute-led Magnetospheric Multiscale (MMS) mission to explain the presence of energetic heavy elements in galactic cosmic rays (GCRs). GCRs are composed of fast-moving energetic particles, mostly hydrogen ions called protons, the lightest and most abundant elements in the universe. Scientists have long debated how trace amounts of heavy ions in GCRs are accelerated.
The supernova explosion of a dying star creates massive shockwaves that propagate through the surrounding space, accelerating ions in their path to very high energies, creating GCRs. How heavy ions are energized and accelerated is important because they affect the redistribution of mass throughout the universe and are essential for the formation of even heavier and more chemically complex elements. They also influence how we perceive astrophysical structures.
"Heavy ions are thought to be insensitive to an incoming shockwave because they are less abundant, and the shock energy is overwhelmingly consumed by the preponderance of protons. Visualize standing on a beach as waves move the sand under your feet, while you remain in place," said SwRI's Dr. Hadi Madanian, the lead author of the paper about this research published in Astrophysical Journal Letters. "However, that classical view of how heavy ions behave under shock conditions is not always what we have seen in high-resolution MMS observations of the near-Earth space environment."
Shock phenomena also occur in the near-Earth environment. The Sun's magnetic field is carried through interplanetary space by the supersonic solar wind flow, which is obstructed and diverted by the Earth's magnetosphere, a bubble of protection around our home planet. This interaction region is called the bow shock due to its curved shape, comparable to the bow waves that occur as a boat travels through water. The Earth's bow shock forms at a much smaller scale than supernova shocks. However, at times, conditions of this small shock resemble those of supernova remnants. The team used high-resolution in-situ measurements from the MMS spacecraft at the bow shock to study how heavy ions are accelerated.
"We observed intense amplification of the magnetic field near the bow shock, a known property associated with strong shocks such as supernova remnants. We then analyzed how different ion species behaved as they encountered the bow shock," Madanian said. "We found that these enhanced fields significantly modify the trajectory of heavy ions, redirecting them into the acceleration zone of the shock."
While this behavior was not expected to occur for heavy ions, the team identified direct evidence for this process in alpha particles, helium ions that are four times more massive than protons and have twice the charge.
"The superb resolution of MMS observations has given us a much clearer picture of how a shockwave energizes the heavy elements. We will be able to use this new understanding to improve our computer models of cosmic ray acceleration at astrophysical shocks," said David Burgess, a professor of mathematics and astronomy at Queen Mary University of London and a coauthor of the paper. "The new findings have significant implications for the composition of cosmic rays and the observed radiation spectra from astrophysical structures."
INFORMATION:
NASA's four MMS satellites use the near-Earth environment as a laboratory to study various space physics phenomena. Goddard Space Flight Center built, integrated and tested the four MMS spacecraft and is responsible for overall mission management and mission operations. The principal investigator for the MMS instrument suite science team is based at SwRI in San Antonio, Texas. Science operations planning and instrument commanding are performed at the MMS Science Operations Center at the University of Colorado's Laboratory for Atmospheric and Space Physics in Boulder.
The paper, "Direct Evidence for Magnetic Reflection of Heavy Ions from High Mach Number Collisionless Shocks," was published July 2, 2021, in Astrophysical Journal Letters and can be accessed at DOI: 10.3847/2041-8213/ac0aee.
For more information, visit https://www.swri.org/heliophysics.
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-07-06
A research group at the University of Cordoba has conducted study focused on evaluating the potential of the Sentinel-2 sensor system's configuration to predict the amount of forage on permanent Mediterranean grasslands.
Pasture quality assessment in permanent grasslands is essential for their conservation and management, as it can facilitate real-time decision-making regarding livestock management. In this regard, the Sentinel-2 satellite constellation, launched in 2015, has proven to be a promising tool for permanent grassland monitoring. This is a sensor system developed by the European Space Agency (ESA) and that provides free and available data worldwide, with a review time of five days, and 13 spectral bands. The spectral configuration of Sentinel-2, ...
2021-07-06
Scientists from the European Molecular Biology Laboratory (EMBL) and the German Cancer Research Center (DKFZ) have presented a new method for generating metabolic profiles of individual cells. The method, which combines fluorescence microscopy and a specific form of mass spectroscopy, can analyze over a hundred metabolites and lipids from more than a thousand individual cells per hour. Researchers expect the method to better answer a variety of biomedical questions in the future.
Today, many biomedical disciplines focus their attention on the metabolites of individual cells. While in the past these were considered simply as degradation products or else building blocks for the synthesis of complex cellular molecules, ...
2021-07-06
Changes in the colour and intensity of light pollution over the past few decades result in complex and unpredictable effects on animal vision, new research shows.
Insect attraction to light is a well-known phenomenon, but artificial lighting can also have more subtle consequences for species that rely on night-time vision for their behaviour.
To explore these effects, University of Exeter researchers examined the impact of more than 20 kinds of lighting on the vision of moths, and birds that eat them.
The study found that elephant hawkmoth vision was enhanced by some types of lighting and disrupted by others, while the vision of birds ...
2021-07-06
While atomic force microscopy and scanning electron microscopy have already provided information on the morphology of bitumen surfaces in the past, for a long time it was not known whether surface and chemical composition correlate with each other. However, the chemical composition of the surface is of particular interest because oxidation processes take place there, triggered by oxygen-containing molecules in the air such as ozone, nitrogen oxides or hydroxyl radicals. The oxidation process accelerates the aging of the material - the bitumen becomes porous and damage develops.
The materials ...
2021-07-06
Metals with similar chemical properties are usually extracted together, which limits the opportunities to separate high-purity metals. To increase those opportunities, it's important to understand how different metal species act during the solvent extraction process.
Researchers from the Institute of Process Engineering (IPE), of the Chinese Academy of Sciences, have developed a new strategy to characterise polymeric transition metal species in acidic solution, which may help to separate those high-purity metals.
Their study, which was published in the KeAi journal Green Chemical Engineering (GreenChE) employed a high-resolution electrospray ionization ...
2021-07-06
A multidisciplinary research team, led by the CSIC biologist at CRAG, Ana I. Caño Delgado, and the physicist from the University of Barcelona, Marta Ibañes, has discovered that two plant stem cell proteins, known for their role in the correct development of the root, physically interact and regulate each other to avoid cellular division. The study, result of fifteen years of continued research carried out by the two researchers, reveals that these two proteins, known as BRAVO and WOX5, act in a specific manner in a small group of stem cells, and that their interaction is key to the plant's survival under genomic and environmental stress factors like extreme cold, heat, or floods. The results, obtained with the model plant Arabidopsis thaliana, have recently been published in the ...
2021-07-06
A team of researchers at the Department of Chemistry and Pharmacy at Friedrich-Alexander University Erlangen-Nürnberg (FAU) has successfully solved the problem of finding a straightforward, cost-effective process for producing hexaarylbenzene molecules with six different aromatic rings. These molecules are important functional materials. The results were published in the reputable journal Angewandte Chemie.
Until now, it has been possible to use certain chemical procedures to produce simple, symmetrical hexaarylbenzene (HAB) molecules, in which the hydrogen atoms of the benzene are replaced by the same atomic groups. However, only very little HAB was produced in this way.
The team of researchers led by Prof. Dr. Svetlana Tsogeva and Prof. Dr. Norbert Jux, both professors of organic ...
2021-07-06
The paper describes amperometric biosensors developed for the determination of diclofenac based on planar platinum electrodes modified with carbon nanotubes (CNTs) in chitosan, fullerene C60 in Boltorn H20, gold nanoparticles (Au NPs) in chitosan, and immobilized tyrosinase enzyme. It was found that diclofenac is a reversible tyrosinase inhibitor (a decrease in the analytical signal is observed), which makes it possible to determine it using appropriate biosensors modified with nanomaterials in the concentration range from 10 pM to 1 μM with CH 5 pM. Modification with composites of CNT / Au NPs and fullerene C60 / Au NPs made it possible to improve the analytical characteristics of the developed biosensors, in particular, ...
2021-07-06
A new study by researchers at the University of Eastern Finland shows for the first time that blood-based measurement of glial fibrillary acidic protein (GFAP) enables distinguishing patients with frontotemporal dementia from those with primary psychiatric disorders or healthy individuals.
Frontotemporal dementia is the second most common cause of dementia in the working age population. Its diagnostics are complicated by the similar symptoms presented by patients with psychiatric disorders or other neurodegenerative diseases as well as the lack of reliable diagnostic tools for differentiating these patients from each other.
A new study by researchers at the University of Eastern Finland ...
2021-07-06
The international collaborative team of Tokyo University of Agriculture and Technology (TUAT) in Japan and Indian Institute of Technology Ropar (IIT Ropar) in India has explored, for the first time, viscous fingering (VF, one of classical interfacial hydrodynamics) of annular ring where VF in fluid of finite volume grow radially through combination of experiment and numerical simulation. They demonstrate that the VF of an annular ring is a persistent phenomenon in contrast to the transient nature of VF of a slice where VF in fluid of finite volume grow rectilinearly.
The researchers published their results ...
LAST 30 PRESS RELEASES:
[Press-News.org] SwRI-led team addresses mystery of heavy elements in galactic cosmic rays
MMS data reveal a mechanism for accelerating heavy ions