James Webb Space Telescope (JWST)

JWST is the largest, most powerful and complex space telescope ever built and launched into space. It has fundamentally changed our understanding of the universe. JWST has four science instruments onboard: NIRCam, NIRSpec, MIRI and NIRISS. I am a team member of the NIRCam science team, which is conducting the JWST Advanced Deep Extragalactic Survey (JADES) - the largest survey for galaxies in the early universe. We peer back in time over 13.5 billion years to see the first galaxies born after the Big Bang. By comparing the faintest, earliest galaxies to today's grand spirals and ellipticals, we will understand how galaxies assemble over billions of years.

JWST Advanced Deep Extragalactic Survey (JADES)

The JADES program is executed by a collaboration composed of NIRSpec and NIRCam instrument team Guaranteed Time Observers (GTOs). This program will substantially redefine our understanding of the high redshift universe. JADES targets two well-studied fields, GOODS-N and GOODS-S because of the wealth of ancillary data and the low galactic and zodiacal backgrounds in these directions. The figure on the left summarizes the area covered in GOODS-S. With NIRSpec, we can take spectra of very faint galaxies (to AB=29 and beyond) out to 5μm; with NIRCam, we can obtain imaging of unprecedented depth with a resolution of 0.04−0.10" from the optical to 5μm; and with MIRI, we can complement NIRCam images at wavelengths longer than 5μm. Check out the survey paper for more details. 

You can download the reduced data products here:

Key Science of JADES

JWST Extragalactic Medium-band Survey (JEMS)

Together with Christina Williams and Michael Maseda, I am the PI of JEMS, which is the first public medium-band imaging survey carried out using JWST/NIRCam and NIRISS. These observations use ~2 micron and ~4 microm medium-band filters over 15.6 square arcminutes in the Hubble Ultra Deep Field (UDF). Our chosen filters create a JWST imaging survey in the UDF that enables novel analysis of a range of spectral features potentially across the redshift range of 0.3 < z < 20, including Paschen-a, Ha+[NII], and [OIII]+Hb  emission at high spatial resolution. Check out the survey paper for more details. 

You can download the reduced data products here:

Using the JEMS data in conjuncture with MUSE, we measured the ionizing photon production efficiency at z~6 for Lyman-alpha emitters, allowing us to place constraints on the wider galaxy populations driving reionization (Simmonds, Tacchella et al. 2023).

Other JWST programs

Beside JADES and JEMS, we are involved in a range of other JWST investigations:

Archival Proposals: