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New methods are developed to determine the origin of dust particles in meteorites



GRETINA in ATLAS at Argonne

Photo of GRETINA in ATLAS in Argonne. Credit: Argonne National Laboratory

The international team developed a new method for determining the origin of stardust in meteorites.

Meteorite content analysis plays an important role in enhancing our understanding of the origin and evolution of the solar system. Some meteorites also contain stardust particles. These particles predate the formation of our solar system and are now providing important insights into how elements in the universe form.

In collaboration with an international group, nuclear physicists at the United States Department of Energy’s Argonne National Laboratory (DOE) made an important discovery related to the analysis of the “pre-polarity”. Found in some meteors. This discovery shed light on the nature of star explosions and the origin of the chemical elements. It has also provided a new way of studying astronomy.

Dariusz Seweryniak, an experimental nuclear physicist in Argonne’s Physics division, said: “Precipolar particles, about one micrometer in size, are residue of star explosions in the distant past, very long before our solar system existed ”. The star debris from the explosions eventually turned into meteorites crashing into Earth.

“In turn, we can calculate the rates of different sulfur isotopes produced in stellar explosions, which will allow astrophysicists to determine if a particular pre-polar particle is present. origin of Nova or supernova ”. – Dariusz Seweryniak, an experimental physicist in the Physics department

Large star explosions are of two types. One is called “nova” related to a binary star system in which a primary star is orbiting one white dwarf star star, an extremely dense star that might be the size of Earth but the mass of our sun. Matter from the main star is constantly being pulled away by the white dwarf because of its extremely strong gravitational field. This deposited material generates a fusion explosion each first,000 arrived 100,000 years, and the white dwarf emits masses equivalent to more than thirty Earths into interstellar space. In a “supernova”, a collapsing star explodes and expels most of its mass.

Nova and supernovae are the most frequent and intense sources of stellar eruptions in our Galaxy, and for that reason they have been the subject of intense astronomical investigations for decades. . Much has been learned from them, for example, about the origins of heavier elements.

“A new way to study these phenomena is to analyze the chemical composition and isotopes of the precursors in meteorites,” explains Seweryniak. “Particularly important to our research is that a specific nuclear reaction occurs in supernovae and supernovae – capturing protons on an isotope of chlorine – which we can only study indirectly. in the laboratory. “

In conducting their research, the team pioneered a new approach to the study of astrophysics. It requires the use of the Array in the Gamma Beam Energy Tracking beam (GRETINA) combined with the Fragment Mass Analyzer at the Argonne Tandem Linac Accelerator System (ATLAS), Office User Facility DOE science for nuclear physics. GRETINA is a modern detection system that can track the path of gamma rays emitted from nuclear reactions. It is one of only two such systems in the world.

Using GRETINA, the team completed the first detailed gamma-ray spectroscopy study of an astronomically important nucleus of an isotope, argon-34. From the data, they calculated the nuclear reaction rate involved in the capture of protons per chlorine isotope (chlorine-33).

“In turn, we can calculate the proportions of different sulfur isotopes produced in stellar explosions, which will allow astrophysicists to determine if a particular pre-polar particle is present. the origin of Nova or supernova, ”Seweryniak said. The team also applied their data to better understand the synthesis of elements in stellar explosions.

The group is planning to continue research with GRETINA as part of a worldwide effort to gain a comprehensive understanding of the fusion of the elements in stellar explosions.

Reference: “The Search for Nova Presolar Grains: Ray Spectroscopy 34Ar and its relevance to astrophysics 33Reaction Cl (p, γ) ”by ARL Kennington, G. Lotay, DT Doherty, D. Seweryniak, C. Andreoiu, K. Auranen, MP Carpenter, WN Catford, CM Deibel, K. Hadyńska-Klęk, S. Hallam , DEM Hoff, T. Huang, RVF Janssens, S. Jazrawi, J. José, FG Kondev, T. Lauritsen, J. Li, AM Rogers, J. Saiz, G. Savard, S. Stolze, GL Wilson and S. Zhu, June 26, 2020, Letter of physical assessment.
DOI: 10.1103 / PhysRevLett.124.252702

In addition to Seweryniak, the authors include A.RL Kennington, G. Lotay, DT Doherty, C. Andreoiu, K. Auranen, MP Carpenter, WN Catford, CM Deibel, K. Hadynska-Klek, S. Hallam, D. Hoff , T. Huang, RVF Janssens, S. Jazrawi, J. José, FG Kondev, T. Lauritsen, J. Li, AM Rogers, J. Saiz, G. Savard, S. Stolze, GL Wilson and S. Zhu. Participating research institutions include University of Surrey (UK), York University (UK), Simon Fraser University (Canada), Louisiana State University (United States), University of North Carolina (USA), Duke University (USA), Politècnica de Catalunya University (Spain) and the Institut d’Estudis Espacials de Catalunya (Spain)).

This study is supported by the DOE Science Office.




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