The article explains what it means for objects to be gravitationally bound in an expanding universe, discussing how structures like stars, galaxies, and clusters are held together by gravity despite the universe's overall expansion, and explores how dark energy influences the future of these structures.
Astronomers have discovered the most distant and powerful Odd Radio Circle (ORC), a double-ring structure in space, using citizen science and radio telescopes, which may provide insights into galaxy and black hole evolution.
Astronomers, with citizen scientists, discovered the most powerful and distant odd radio circle (ORC), named J131346.9+500320, featuring two intersecting rings likely formed by black hole winds or shocks, providing insights into galaxy and black hole co-evolution.
Astronomers have identified a massive, ring-like structure called the Big Ring, spanning about 1.3 billion light-years, which challenges current cosmological models that predict the universe's large-scale matter distribution should be more uniform. This discovery, along with findings about the Milky Way's larger gravitational basin, suggests the universe may contain more extensive and complex structures than previously thought, prompting a reevaluation of existing theories.
The James Webb Space Telescope (JWST) has captured its most extreme gravitational lensing image yet, focusing on galaxy cluster Abell S1063. This deep field observation reveals detailed features of distant, magnified galaxies, showcasing the power of JWST's advanced infrared capabilities to study cosmic structures, dark matter distribution, and galaxy interactions billions of light-years away.
Astronomers using the ASKAP telescope discovered 15 new Giant Radio Galaxies, some over 12 million light-years wide, which are the largest single objects in the universe. These galaxies feature supermassive black holes that emit powerful jets, creating vast radio lobes, and their study helps understand galaxy growth and black hole activity cycles.
The largest known galaxy in the universe is IC 1101, located at the center of the Abell 2029 galaxy cluster. It spans an impressive 5.5 million light-years across, containing over 100 trillion stars and a mass nearly equivalent to a quadrillion suns. This giant elliptical galaxy dwarfs others, including the Milky Way and Andromeda, highlighting the vast diversity of cosmic structures.
The Euclid mission, launched by the European Space Agency, aims to study dark matter and dark energy, which make up the majority of the universe but are undetectable using traditional telescopes. Euclid will observe the distortion of distant galaxies to study dark matter and create a three-dimensional map of more than one-third of the sky, encompassing billions of galaxies. The mission, equipped with one of the largest cameras ever sent into space, will continue its study of the dark universe over the next six years.
Scientists from the University of Michigan have discovered that the growth of large cosmic structures, such as galaxy clusters and filaments, is slower than predicted by the standard model of cosmology based on Einstein's theory of general relativity. This challenges our understanding of the universe and could be explained by the presence of a new type of dark matter or dark energy, or a modification of our understanding of gravity. The findings could help explain the sigma-8 tension, a discrepancy in the distribution of matter in the universe.
Astronomers using the Webb Space Telescope have identified three objects that could be "dark stars," theoretical objects powered by dark matter. These objects, which date back to when the universe was between 320 million and 400 million years old, were initially identified as galaxies but may actually be never-before-seen dark stars. Dark stars would be powered by the collisions of dark matter particles rather than nuclear fusion and could be millions of times the mass of our Sun. Further observations with the Webb Space Telescope will provide more insights into these ancient sources of light and help scientists understand the evolution of cosmic structures.