The distances of millions of distant galaxies with unprecedented precision, have been unveiled today by an international team of astronomers. The catalog, a result of the Physics of the Accelerating Universe Survey (PAUS), is set to revolutionize our understanding of how the universe formed and evolved.
Led by the Institute of Space Sciences (ICE-CSIC), part of Spain's Ministry of Science, Innovation, and Universities (MICIU), PAUS is a global collaboration involving 14 institutions from six countries, including the University of Portsmouth. After four years of data collection using the PAUCam camera on the William Herschel Telescope in La Palma, the catalog is now publicly available on the PAUS website and the CosmoHub web portal.
Spanning 50 square degrees of the sky—an area equivalent to 250 full moons—the catalog includes data on 1.8 million astronomical objects. Its precise distance measurements will enable astronomers to build more accurate maps of the universe, shedding light on the forces that shape cosmic structures and influencing future studies of dark matter and dark energy.
A Game-Changer for Cosmic Mapping
"The PAU Survey offers a groundbreaking approach to creating cosmic maps, made possible through the design and development of a novel instrument and a dedicated survey to collect and analyze data in ways never done before," said Enrique Gaztañaga, Director of the PAU Survey and Professor at the University of Portsmouth's Institute of Cosmology and Gravitation. "It has been a privilege to collaborate with such a talented and dependable group."
The catalog's precision is crucial for understanding the accelerated expansion of the universe, which astronomers attribute to dark energy—an enigmatic force comprising 70% of the universe's total energy. With data extending over 10 billion light-years, the PAU Survey offers invaluable insights into the early universe and its expansion.
Unlocking the Secrets of Dark Energy and Matter
Despite making up the majority of the universe, the nature of dark energy remains one of the greatest mysteries in cosmology. By providing highly accurate measurements of galaxy distances, the PAU catalog will help astronomers delve deeper into the effects of dark energy and how it drives the universe’s expansion.
The PAUCam, a camera specially designed for this survey, plays a key role in the project's success. Its cutting-edge technology, which uses 40 color filters to measure light in narrow bands across the optical spectrum, allows researchers to calculate galaxy distances with remarkable precision through photometric redshift measurements. This technique involves observing how light from distant galaxies shifts toward the red end of the spectrum as it travels through the expanding universe.
"The great advantage of PAUS is that it combines information from 40 different filters, allowing for highly accurate distance measurements," explained David Navarro-Gironés, a Ph.D. student at ICE-CSIC and lead author of the research paper. "This level of precision is crucial for studying the structure of the universe, which in turn requires data from a large number of galaxies."
Building on a Legacy of Cosmic Surveys
PAUS builds upon previous surveys such as the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS) and the Kilo-Degree Survey (KiDS), enhancing existing data to achieve precise measurements of distant galaxies. By combining this new dataset with previous cosmic observations, the PAUS catalog has expanded our knowledge of cosmic distances and time in ways previously unattainable.
Published in two papers in the *Monthly Notices of the Royal Astronomical Society*, the catalog's release is set to become a vital tool for the astronomical community, assisting with the scientific analysis and calibration of other major cosmological surveys.
University of Portsmouth. “New Cosmic Distance Catalog Could Unlock the Mysteries of Universe Formation.” Phys.org, Phys.org, 18 Sept. 2024, phys.org/news/2024-09-cosmic-distance-mysteries-universe-formation.html. Accessed 19 Sept. 2024.
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