{"id":787421,"date":"2024-08-17T09:00:51","date_gmt":"2024-08-17T14:00:51","guid":{"rendered":"https:\/\/spaceweekly.com\/?p=787421"},"modified":"2024-08-17T09:00:51","modified_gmt":"2024-08-17T14:00:51","slug":"galaxies-in-denser-regions-up-to-25-larger-than-those-in-less-crowded-locations","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=787421","title":{"rendered":"Galaxies in denser regions up to 25% larger than those in less crowded locations"},"content":{"rendered":"
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A new study discovered that galaxies in denser astronomical surroundings are up to 25% larger than those in less crowded locations. This study, published on August 14, 2024, in The Astrophysical Journal, stressed the importance of ambient density in galaxy size, refuting prior theories that focused solely on internal processes.<\/strong><\/p>\n
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The study was led by Aritra Ghosh, with contributions from Meg Urry and Frank van den Bosch, and international teams from ESO and NAOJ.<\/li>\n
The researchers used the Galaxy Morphology Posterior Estimation Network (GaMPEN), a cutting-edge machine-learning technology, to handle and evaluate large amounts of astronomical data. High-resolution imagery from the Very Large Telescope (VLT) and the Subaru Telescope, as well as data from the Hyper Suprime-Cam Subaru Strategic Program, enabled them to conduct a thorough examination of 8 million galaxies.<\/li>\n<\/ul>\n
The new study was led by Aritra Ghosh, a former Yale doctoral student and current LSST-DA Catalyst postdoctoral fellow at the University of Washington, and included contributions from international researchers at the European Southern Observatory (ESO) and the National Astronomical Observatory of Japan (NAOJ). The research also benefited from Meg Urry, the Israel Munson Professor of Physics and Astronomy at Yale University, and Frank van den Bosch, associate professor of Astronomy at Yale University. Their combined efforts provided new light on galaxy structure and evolution.<\/p>\n
\u201cThis comprehensive study represents an important step in resolving decades of contradictory results on the correlation between galaxy size and environmental density beyond z \u2265 0.2. Our findings emphasize that earlier works were limited in their scope, examining a narrow segment of all galaxies rather than a comprehensive overview,\u201d the researchers stated.<\/p>\n
The study, published on August 14, 2024, in The Astrophysical Journal,\u00a0 shows that galaxies in denser cosmic environments, such as galaxy clusters, are up to 25% larger than those in less crowded locations. This observation challenges previous models that relied heavily on internal processes such as star formation and black hole activity. Instead, the study directs the importance towards ambient density on galaxy size, employing a novel machine-learning tool known as the Galaxy Morphology Posterior Estimation Network (GaMPEN), which processes massive amounts of astronomical imaging data with unparalleled precision.<\/p>\n
\nProjected two-dimensional densities are shown for W04 GAMA12H, one of the five HSC-Wide fields used in this study. Each row corresponds to a different redshift slice within which the densities are measured. Colors indicate the density excess in standard deviation within r = 10 cMpc as denoted by the color bars on the right. For reference, a fixed scale of 25 cMpc is shown in each redshift slice. The white regions demarcate bright-star masks used during density measurement. Note that mask corrections are already incorporated into the density measurements used in this work, and we refer the interested reader to Shimakawa et al. (2021b) for more details. Credit: The Astronomical Journal\/Authors<\/figcaption><\/figure>\n<\/div>\n
The study utilized high-resolution imaging data from the Very Large Telescope (VLT) at the Paranal Observatory in Chile and the Subaru Telescope at the Mauna Kea Observatory in Hawaii. Additionally, the study observed and analyzed data from the Hyper Suprime-Cam Subaru Strategic Program, which covered 1,400 square degrees of the sky. This rich dataset allowed for detailed comparisons of galaxies in various astronomical conditions.<\/p>\n
The research provides new evidence on how environmental factors influence the growth of the galaxy. While internal phenomena like gravitational collapse and gas accretion were previously assumed to be responsible for galaxy size, the study shows that external factors such as the density of the surrounding cosmic environment play an important impact. The bigger size of galaxies in denser places indicates that they have more substantial gravitational interactions, which contribute to their increased size.<\/p>\n
The animation below, from Shy Genel & the Illustris collaboration, shows the wide range of physics at play in a typical dense region of the universe. Studying the structural parameters of millions of galaxies and correlating them with the density of their environments allows astronomers to develop a better understanding of how galaxies form and evolve.<\/p>\n