. | . |
New light on baryonic matter and gravity on cosmic scales by Staff Writers La Laguna, Spain (SPX) Mar 26, 2021
Scientists estimate that dark matter and dark energy together are some 95% of the gravitational material in the universe while the remaining 5% is baryonic matter, which is the "normal" matter composing stars, planets, and living beings. However for decades almost one half of this matter has not been found either. Now, using a new technique, a team in which the Instituto de Astrofisica de Canarias (IAC) has participated, has shown that this "missing" baryonic matter is found filling the space between the galaxies as hot, low density gas. The same technique also gives a new tool that shows that the gravitational attraction experienced by galaxies is compatible with the theory of General Relativity. This research is published in three articles in the journal Monthly Notices of the Royal Astronomical Society (MNRAS). In designing this new technique they have analyzed the changes in the electromagnetic spectrum, its shift to the red, caused by the reddening of the light from the galaxies as they speed away from us. In the Universe, the sources which move away show a redder spectrum, and those which approach us show a bluer spectrum. This effect has given essential data for the development of modern cosmology. Almost a century ago, Edwin Hubble discovered that the redshifts of galaxies are bigger the further away from us they are, and this was the initial evidence which eventually led to the Big Bang model of the universe. Since then these redshifts have been used to find the distances to the galaxies and to build three dimensional maps of their distribution in the Universe. In the work we are reporting here a new method has been developed, which studies the statistics of the redshifts of galaxies, without converting them to distances. In their first article, the team shows that these maps are sensitive to the gravitational attraction between galaxies on cosmological scales. In a second article, the same team compare the maps with observations of the cosmic microwave background,, and they permit, for the first time, a complete census of the baryonic matter during 90% of the life of the Universe. "Most of this 'ordinary' matter is invisible to us because it is not sufficiently hot to emit energy. However, by using maps of the redshifts of the galaxies we find that all of this matter fills the space between them", explains Jonas Chaves-Montero, a researcher at the Donostia International Physics Center (DIPC) and first author of this article. Finally, as found in a third article, the researchers have also used the redshift maps of the galaxies to study the nature of gravity. "In contrast to previous approaches, our new method is not based on any conversion of redshift to distance, and it is shown to be robust agains noise and data impurities. Thanks to that it allow us to conclude with high accuracy, that the observations are compatible with Einstein's theory of gravity", notes Carlos Hernandez-Monteagudo, an IAC researcher who is the first author on this third article. These studies have been performed by researchers Carlos Hernandez-Monteagudo, Jonas Chaves-Montero, Raul Angulo and Giovanni Arico, who designed the research during their time at the Centre for Studies of Cosmic Physics of Aragon (CEFCA), even though now they are working at other Spanish research centres, such as the Instituto de Astrofisica de Canarias, and the Donostia International Physics Center. In one of the articles there was participation also by J. D. Emberson, a Canadian researcher at the Argonne National Laboratory, Illinois, USA.
Research Report: "Angular Redshift Fluctuations: a New Cosmological Observable"
A brighter future for gravitational-wave astronomy Potsdam, Germany (SPX) Mar 18, 2021 Future gravitational-wave detectors on Earth will use laser light with even higher power than in current instruments. Researchers from the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI), the Laser Zentrum Hannover e.V. (LZH), and Leibniz University Hannover have now developed a new laser system for this purpose. They combined the custom tailored light from two high-power lasers so precisely that it meets the requirements for use in gravitational-wave detectors. In ... read more
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |