COSMOS-Web Releases Deepest Yet View Into the Universe

COSMOS-Web provides the most expansive and deepest observations of the universe to date. Now, the team behind this work - which includes several members from The University of Texas at Austin - has released the data and images associated with its full survey, all processed and ready for analysis (see images, specifically, here). Astronomers and members of the public are invited to make full use of the resource, which represents over 250 hours of observations on the world’s most powerful telescope: the James Webb Space Telescope.

When JWST launched in 2021, COSMOS-Web received more observing time during the telescope’s first year than any other project. The team set out with three primary goals: furthering our understanding of the Reionization Era, roughly 200,000 to 1 billion years after the Big Bang; identifying and characterizing early massive galaxies in the first two billion years; and studying how dark matter has evolved with the stellar content of galaxies.

By publishing its catalogue and images, COSMOS-Web hopes to effectively crowd-source that research, while also opening the door to unrelated discoveries. “A big part of this project is the democratization of science and making tools and data from the best telescopes accessible to the broader community,” said UC Santa Barbara physics professor Caitlin Casey, who co-leads the COSMOS-Web team.

Though COSMOS-Web data was made public almost immediately after it was gathered, it was available only in its raw form. This meant it was only useful to those with the specialized technical knowledge and the supercomputer access to process and interpret it. In 2023, the team released a polished sample of its data and imagery, covering an impressive 25,000 galaxies – but that was only a small percentage of the project’s true scope. The full release includes data on a whopping 800,000 galaxies!

“This was an ambitious undertaking that required the development of innovative technologies,” said Marko Shuntov, postdoctoral researcher at Cosmic DAWN Center. “Building the catalog required tremendous teamwork, and it was all worth it because ultimately it has delivered some of the highest quality redshifts and physical parameters of galaxies that will enable groundbreaking science.”

“The full COSMOS-Web image and data set has incredible potential!” added Olivia Cooper, a research fellow at UT Austin. “Our catalog is intended to be used by all astronomers and is especially optimized for extragalactic astronomers interested in the most massive and extreme galaxies.”

The COSMOS-Web survey mapped 0.54 square degrees of the sky (about the area of three full moons) with the telescope’s Near Infrared Camera (NIRCam) and a 0.2 square degree area with the Mid Infrared Instrument (MIRI). While previous surveys have aimed to help astronomers map and understand what exists in the vast universe, the advanced instruments of JWST have allowed COSMOS-Web to study galaxy evolution through a long range of history.

“The sensitivity of JWST lets us see much fainter and more distant galaxies than ever before, so we’re able to find galaxies in the very early universe and study their properties in detail,” said Jeyhan Kartaltepe of the Rochester Institute of Technology, who co-leads the project with Casey. “The quality of the data still blows us away. It is so much better than expected.”

While the data will be of particular interest to astronomers, average citizens can also access it and the impressive images that accompany. “Almost every bright spot you'll see is a galaxy,” said Cooper. “And these galaxies come in all sorts of shapes, sizes, colors, and amount of spacetime away from us.”

“We combined over 10,000 images of the sky together to form the largest contiguous image available from the JWST,” added Maximilien Franco, postdoctoral researcher at Université Paris-Saclay. “It was incredible to reveal galaxies that were previously invisible, and very gratifying to finally see them appear on our computers.”

The result is a profound view of the cosmos that is both beautiful in its imagery and astounding in scope. 

The COSMOS-Web images, catalog, and interactive viewer are all available through the team’s data release website. For more information on COSMOS-Web, please visit the program’s website.

Adapted from a press release by Rochester Institute of Technology.