RESEARCH

Our team studies the formation and evolution of galaxies at epochs when the Universe was only a fraction of its present age and we do so using the most powerful telescopes in space (JWST, HST, Spitzer, Euclid) and on the ground (Subaru, CFHT, and Gemini).

KEY PROJECTS

  1. JWST CANUCS:

With the Canadian NIRISS Unbiased Cluster Survey (CANUCS), we study high-redshift  galaxies using Hubble’s successor, the James Webb Space Telescope.  We have invested a massive 200 hours of JWST Cycle 1 and 2 observing time into getting JWST NIRcam imaging and NIRISS and NIRSpec spectroscopy of distant galaxies behind five intermediate-redshift massive lensing clusters. And because Webb instruments can operate in parallel, we have simultaneously taken deep medium-band NIRCam imaging a few arcminutes from the cluster cores. JWST’s superb sensitivity, further boosted by the gravitational lensing of the cluster masses, lets us detect galaxies in the Epoch of Reionization at z~7 and above, and study in detail how these galaxies subsequently grew over cosmic time.  We just completed CANUCS data acquisition (November 2023) and some initial results from this project are already out (click here, here, and here for examples).



  1. DEEP wide-area imaging:  DEUS and CLAUDS

DEUS is a large area (10 sq deg) very deep (u~27AB at SNR=5) u-band imaging survey in the Euclid Deep Field North. DEUS (which stands for Deep Euclid U-band Survey) observations are in an area of the sky that is getting very deep Euclid imaging and spectroscopy and which already contains amazing ultra-deep ancillary data, including optical imaging from Subaru/HSC and IR imaging from Spitzer/IRAC. This is going to be a truly unprecedented dataset in terms of depth, area, and wavelength coverage. The photo-z’s that the DEUS u-band imaging will enable will allow us to trace the Cosmic Web skeleton out to redshift z~3, and then study how galaxy evolution depends on a galaxy’s location in this filamentary cosmic structure. Moreover, in addition to superb photometry and Euclid imaging, Euclid slitless grism spectroscopy will let us study galaxies in a way that’s similar to what we are doing with NIRISS on JWST but over much larger areas of the sky. 


DEUS builds on CFHT Large Area U-band Deep Survey (CLAUDS), which is a very deep U-band imaging survey that overlaps with the Subaru Hyper Suprime-Cam (HSC) survey Deep/UltraDeep fields. The CLAUDS data (68 dedicated CFHT dark-time nights plus archival data) are all in hand, as are the Subaru observations. We are using these joint catalogs for a large range of scientific applications, from detailed galaxy evolutions studies over 0<z<1, to assembling large samples of galaxies, quasars and proto-clusters at z~2-3. We are working on many of these topics, and have published over 20 papers on them already, with many more in preparation.



  1. GIRMOS:


GIRMOS (Gemini InfraRed Multi-Object Spectrograph) is a next-generation instrument that we are building for the Gemini-North 8-metre telescope in Hawai`i. When it is deployed in 2027, GIRMOS will have the ability to take spatially-resolved spectra of four targets at once with light fed to it by Gemini’s new state-of-the-art GNAO adaptive optics system now also under construction as the largest component of Gemini’s GEMMA program. GIRMOS will target high-redshift (1 < z < 10) galaxies in order to study their formation and evolution, back to a time when galaxies were first forming and through to Cosmic Noon. GIRMOS will also study star-formation physics within the Milky Way Galaxy and do near-field cosmology through the study of metal-poor stars in the Milky Way’s central bulge. I am leading the team that’s developing the GIRMOS data reduction software and we look forward to using GIRMOS when it goes on the sky in 2027!


                                                                               ...read more here and here


 

SELECTED RECENT PUBLICATIONS


  1. ΛCDM not dead yet    (Desprez, Martis, Asada, Sawicki, et al. 2023)

  2. Bursty star formation and galaxy-galaxy interactions 1 Gyr after the Big Bang    (Asada, Sawicki, et al. 2023b)

  3. JWST catches the assembly of a z~5 ultra-low-mass galaxy    (Asada, Sawicki, et al. 2023a)

  4. First large catalogue of spectroscopic redshifts in JWST’s First Deep Field    (Noirot, Desprez, Asada, Sawicki et al. 2023)

  5. CLAUDS catalogs    (Desprez et al. 2023)

  6. Across the green valley with HST grisms   (Noirot, Sawicki, et al. 2022)

  7. Ionizing radiation from z>3 AGN    (Iwata, Sawicki, et al. 2021)

  8. Star/galaxy classification with XGboost    (Golob, Sawicki, et al. 2021)

  9. UV luminosity functions since z~3 with 4 million galaxies in CLAUDS+HSC    (Moutard, Sawicki, et al. 2020)

  10. The CLAUDS project    (Sawicki et al. 2019)

  11.   See here for my full publication list:  Google Scholar and SAO/NASA ADS

Home     Research     News     Team     About me     Teaching

Marcin Sawicki
Professor of Astronomy & Physics
Canada Research Chair in Astronomy