Images of four selected sample galaxies from the first epoch of COSMOS-Web NIRCam observations, highlighting the variety of structures that can be seen.

Images of four selected sample galaxies from the first epoch of COSMOS-Web NIRCam observations, highlighting the variety of structures that can be seen. – COSMOS-WEB/KARTALTEPE ET AL.


The first images from the biggest show of the first year of the James Webb Space Telescope show many types of galaxies, gravitational lensing, and evidence of galaxy mergers.

Scientists from the COSMOS-Web program published mosaic images taken in early January by JWST’s Near Infrared Camera (NIRCam) and Mid Infrared Instrument (MIRI).

COSMOS-Web aims to map the earliest structures in the universe and will create a comprehensive and in-depth study of up to 1 million galaxies. Over the course of 255 hours of observation, COSMOS-Web will map 0.6 square degrees of the sky with NIRCam, the size of three full moonsand 0.2 degrees squared with MIRI.

“It’s incredibly exciting to get the first telescope data for COSMOS-Web,” he said. it’s a statement Principal Investigator Jeyhan Kartaltepe, Associate Professor in the School of Physics and Astronomy at the Rochester Institute of Technology (RIT). “Everything worked really well and the data is even better than we expected.”

Kartaltepe co-directs COSMOS-Web with principal investigator Caitlin Casey, an associate professor at the University of Texas at Austin. The international team is made up of around 100 astronomers from around the world.

This first snapshot of the COSMOS-Web contains about 25,000 galaxies, an incredibly larger number than the Hubble Ultra Deep Field,” explains Casey. “It’s one of the largest images ever taken by JWST. And yet that’s only 4% of the data we’ll get for the full study. When finished, this deep field will be incredibly large and incredibly beautiful.”

COSMOS-Web has three main scientific goals: to advance our understanding of the Reionization Era, approximately 200 billion to 1 billion years after the Big Bang; identify and characterize the first massive galaxies in the first 2 billion years; and studying how dark matter evolved with the stellar content of galaxies.

COSMOS-Web is the largest area that JWST will observe in its first year, allowing it to study galaxies in a wide variety of local environments. The images taken so far show incredible detail when compared to those previously taken by other observatories such as the Hubble Space Telescope and the Spitzer Space Telescope.

The mosaics were created from six telescope notes taken on January 5 and 6. The telescope will take 77 notes, about half the field, in April and May, and the remaining 69 are scheduled for December 2023 and January 2024.

“JWST has provided such stunning images of this region that sources are literally appearing in every little patch of the observed sky,” said Santosh Harish, a postdoctoral research associate at RIT.

“What were thought to be compact objects based on the best images we had so far, JWST observations are now able to resolve these objects into multiple components and in some cases even reveal the complex morphology of these extragalactic sources. first observations , we’ve barely scratched the surface of what’s to come with the completion of this program next year.”