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August 24, 2023 • Current spotlights

Announcing the first COSMOS-Web Public Data Release!

We’re happy to announce our first COSMOS-Web public data release, DR0.2, covering the first epoch of observations taken in January. These data were taken 2023 January 5-6 as 6 separate, contiguous pointings and have been stitched together into a single mosaic covering 77 sq. arcmin with NIRCam in the F115W, F150W, F277W, and F444W filters along with the MIRI parallel images in F77W. 
You can find the full details, along with instructions for downloading the data, here:
March 9, 2023 • Current spotlights

Press Release on First Epoch of COSMOS-Web Imaging

The first images from the largest program in the James Webb Space Telescope’s first year show many types of galaxies, including dazzling examples of spiral galaxies, gravitational lensing, and evidence of galaxy mergers. Scientists from the COSMOS-Web program released 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 of the universe and will create a wide and deep survey of up to 1 million galaxies. Over the course of 255 hours of observing time, COSMOS-Web will map 0.6 square degrees of the sky with NIRCam, roughly the size of three full moons, and 0.2 square degrees with MIRI.

November 18, 2022 • Current spotlights

COSMOS-Web overview paper is out!

COSMOS-Web is a 255 hour treasury program to be conducted by the JWST in its first cycle of observations. It observes a contiguous area of 0.54 deg2 with NIRCam imaging as well as an area of 0.19 deg2 with MIRI in parallel and builds on the rich heritage of multiwavelength observations and data products available in the COSMOS field. The design of COSMOS-Web is driven by three primary science goals:
  • discover and characterize thousands of galaxies in the Epoch of Reionization (6 < z < 11)
  • identify and study hundreds of rare quiescent galaxies at z > 4 and
  • directly measure the evolution of the stellar mass to halo mass relation out to z ~ 2.5.
Read on!
For more details on observations and science, see our COSMOS-Web overview paper: Casey & Kartaltepe et al. (2022)
COSMOS-Web map
May 9, 2022 • Current spotlights

Nick Scoville elected to National Academy of Sciences


Nick Scoville, the Francis L. Moseley Professor of Astronomy at Caltech (Emeritus), was recently elected to the National Academy of Sciences in recognition of his distinguished and continuing achievements in original research! Nick is the PI of the original COSMOS HST/ACS observations. Congratulations!



December 20, 2021 • Current spotlights

New COSMOS catalog is out!

The new COSMOS catalog is out and its accompanying paper is accepted!

The catalog contains 1 million sources measured in more than 30 photometric bands from the UV to the infrared. For the extraction of the photometry, our international team applied a new prior-based method to go even deeper and to obtain more robust measurements for blended sources. The catalog also contains photometric redshifts and other physical properties of the galaxies measured from their photometry using spectral energy distribution (SED) fitting codes like LePhare and Eazy.

This catalog is a major milestone for COSMOS, combining its multi-wavelength data consistently, and opening up new avenues to explore galaxy evolution.

You can download the catalog at to use it for your own science!

October 7, 2021 • Current spotlights

Extended radio AGN and how they bend it


A team of COSMOS researchers studied jets escaping active galactic nuclei (AGN) to investigate what causes their bending. For this, they used radio data from the VLA and X-ray observations from Chandra/XMM-Newton to measure the "bent angle", i.e., the angle the jets form to each other in a two-sided source. The angle is related to the environment in which the AGN hosts reside and compared to magnetohydrodynamic simulations. It is found that the evolution of the environment surrounding the sources affects their radio structures and allows for more space for jet interactions.

April 19, 2021 • Current spotlights

COSMOS-Webb selected as JWST’s largest Cycle 1 program

When the James Webb Space Telescope (JWST)—the long-awaited successor to the Hubble Space Telescope—becomes operational in 2022, one of its first orders of business will be mapping the earliest structures of the universe. A team of nearly 50 researchers led by scientists at Rochester Institute of Technology and University of Texas at Austin will attempt to do so through the COSMOS-Webb program, the largest General Observer program selected for JWST’s first year.

Over the course of 208.6 observing hours, the COSMOS-Webb program will conduct an ambitious survey of half a million galaxies with multi-band, high-resolution near infrared imaging and an unprecedented 32,000 galaxies in mid infrared. The scientists involved said that because COSMOS-Webb is a treasury program, they will rapidly release data to the public so it can lead to countless other studies by other researchers.