Lado Samushia, an associate professor of physics in Kansas State University’s College of Arts and Sciences, participates in a group that is researching dark energy, the enigmatic factor thought to be driving the universe’s quickening expansion.
The researchers using the Dark Energy Spectroscopic Instrument, or DESI, at the Kitt Peak National Observatory in Tucson, Arizona, are mapping more than 40 million galaxies, quasars, and stars. The U.S. Department of Energy’s Lawrence Berkeley National Laboratory manages the experiment.
Recently, the partnership published a number of publications relating to the early data release and released its first batch of data, which included approximately two million objects for academics to investigate. Early observations of galaxy clustering, research on unusual objects, and descriptions of the equipment and survey operations are all covered in the articles.
Our team analyzed properties of two types of galaxies luminous red galaxies and the galaxies that have quasi-stellar objects in their center and saw very clearly that the luminous red galaxies gain mass and acquire fewer satellite galaxies with time. These insights provide valuable illumination on the physics involved in the evolution of massive galaxies.
Hanyu Zhang
Hanyu Zhang, a Kansas State University doctoral student in physics supervised by Samushia, is the lead author of the paper, “The DESI One-Percent Survey: Exploring the Halo Occupation Distribution of Luminous Red Galaxies and Quasi-Stellar Objects with AbacusSummit,” which is available on the pre-print server arXiv.
“Our team analyzed properties of two types of galaxies luminous red galaxies and the galaxies that have quasi-stellar objects in their center and saw very clearly that the luminous red galaxies gain mass and acquire fewer satellite galaxies with time,” said Zhang. “These insights provide valuable illumination on the physics involved in the evolution of massive galaxies.”
DESI moves optical fibers that collect light from objects millions or billions of light-years away using 5,000 robotic positioners. It is the most potent multi-object survey spectrograph in the world, and in a single night, it can measure the light from more than 100,000 galaxies. By providing distance information, that light enables researchers to create a 3D cosmic map.
The wavelength of light is stretched as the universe grows, turning it redder. Redshift is the term for this increase in wavelength. The redshift increases in size with galactic distance.
DESI specializes in gathering redshifts that can be used to answer some of the astrophysics’ most challenging questions, including what dark energy is and how it has evolved throughout the course of the universe.
