Astronomy Content

Simulations Explain Abundance of Bright Galaxies at Cosmic Dawn

Andy Fell — October 03, 2023 - 12:41pm

When researchers glimpsed the first images and data from the James Webb Space Telescope (JWST), humanity’s largest and most powerful space telescope, they noticed something peculiar. A large number of bright galaxies deep in the universe formed during a period called “Cosmic Dawn,” when the first stars and galaxies formed within 500 million years after the Big Bang.

Making Better Measurements of the Composition of Galaxies

Andy Fell — April 20, 2023 - 8:00am

A study using data from telescopes on Earth and in the sky resolves a problem plaguing astronomers working in the infrared and could help make better observations of the composition of the universe with the James Webb Space Telescope and other instruments. The work is published April 20 in Nature Astronomy.

Newly Discovered Gravitational Lenses Could Reveal Ancient Galaxies and the Nature of Dark Matter

Andy Fell — September 29, 2022 - 4:38pm

An international team of astronomers has discovered dozens of strong gravitational lenses that will allow astronomers to look deep into the universe, revealing ancient structures and giving insight into the nature of dark matter.

Astronomers Look Forward to Webb Telescope Projects

Andy Fell — July 13, 2022 - 11:24am

The release of the first images from NASA's James Webb Space Telescope this week has scientists and laypeople alike swooning over the quality and beauty of the images. Astronomers are also getting ready to use the JWST in their research projects.

Associate Professor Tucker Jones and postdoctoral research Ryan Sanders, both in the 51�ԹϺ�� Davis Department of Physics and Astronomy, are each leading programs that will make use of the JWST.

Long Ago, Far Away and Hard to See

Andy Fell — June 22, 2022 - 10:13am

The ancestors of galaxy clusters, the largest structures in the universe, have been identified by a team of astronomers including Brian Lemaux, who is affiliated with the 51�ԹϺ�� Davis Department of Physics and Astronomy. Galaxies in the newly identified protoclusters are surprisingly sparse and dim, which may be why they have been so difficult to find until now. The work was published June 15 in Nature.

New, Third Type of Supernova Observed

Andy Fell — June 28, 2021 - 12:00pm

An international team of astronomers has observed the first example of a new type of supernova. The discovery, confirming a prediction made four decades ago, could lead to new insights into the life and death of stars. The work is published June 28 in Nature Astronomy.

Taking the Temperature of Dark Matter

Andy Fell — January 15, 2020 - 9:24am

Warm, cold, just right? Physicists at the University of California, Davis, are taking the temperature of dark matter, the mysterious substance that makes up about a quarter of our universe.

We have very little idea of what dark matter is, and physicists have yet to detect a dark matter particle. But we do know that the gravity of clumps of dark matter can distort light from distant objects. Chris Fassnacht, a physics professor at 51�ԹϺ�� Davis, and colleagues are using this distortion, called gravitational lensing, to learn more about the properties of dark matter.

New Measurement of Hubble Constant Adds to Cosmic Mystery

Andy Fell — October 23, 2019 - 10:15am

New measurements of the rate of expansion of the universe, led by astronomers at the University of California, Davis, add to a growing mystery: Estimates of a fundamental constant made with different methods keep giving different results.

“There’s a lot of excitement, a lot of mystification and from my point of view it’s a lot of fun,” said Chris Fassnacht, professor of physics at 51�ԹϺ�� Davis and a member of the international SHARP/H0LICOW collaboration, which made the measurement using the W.M. Keck telescopes in Hawaii.

Astronomers Find a Cosmic Titan in the Early Universe

Andy Fell — October 17, 2018 - 8:55am

An international team of astronomers has discovered a titanic structure in the early universe, just 2 billion years after the Big Bang. This galaxy proto-supercluster, nicknamed Hyperion, is the largest and most massive structure yet found at such a remote time and distance.

Colliding Neutron Stars Seen by Gravity Waves and Optical Telescopes

Andy Fell — October 16, 2017 - 11:49am

For the first time, astronomers have observed a celestial event through both conventional telescopes and gravitational waves. The collision of two super-dense neutron stars just 120 million light-years from Earth was captured by both gravity wave observatories (Laser Interferometer Gravitational Observatory, LIGO in the U.S., and Virgo in Italy) and telescopes including the DLT40 survey based in Chile. The results are published Oct.