Special Session SS2  28 June 2022

Mining the sky: searching and modeling strong lenses at galaxy and cluster scales

Aims and scope

Upcoming space missions and ground-based observatories aiming to constrain cosmology, e.g. Euclid, the LSST/Vera Rubin Observatory, and the Nancy Grace Roman Space Telescope, are designed to use lensing as one of their primary observational tools. Gravitational lensing represents one of the key and most powerful tools to understand the growth of structure and the expansion of the Universe. More globally, it traces the total matter distribution of the lenses, free of assumptions regarding their dynamical state, but also provides a unique spatially resolved view of the lensed objects. Adding to that the panchromatic imaging and hyper-spectral surveys of the lenses (X-rays, NIR/MIR, submm/mm, radio) can illuminate in particular the expansion rate of the Universe (and the much debated values of the Hubble constant), the nature of Dark Matter, and constrain the nature of Dark Energy or possible modifications to General Relativity, but also more astrophysical questions such as galaxy evolution, and feedback processes.

The importance of lensing by galaxies and galaxy clusters has been clearly appreciated in recent ambitious Hubble Space Telescope programs (e.g. SLACS, CLASH, GLASS, SGAS, HFF, RELICS, and BUFFALO), and their hyper-spectral follow-ups (e.g. with ALMA and MUSE). The identification of massive galaxy clusters thanks to wide field extragalactic surveys (e.g. Planck, SPT, KIDS, DES, VHS, LOFAR, ACT, HSC) is becoming key to increase cluster statistics (discovering new clusters), to obtain a comprehensive understanding of cluster formation and evolution, and to use them as cosmological probes. Similarly, strong lensing by galaxies is becoming an utmost probe to look at the expansion rate of the Universe, with the recent Hubble constant tension, and the low-mass end of the halo mass function in the Universe that holds the key to our understanding of dark matter. With such a wealth of data, and by combining them with the latest cosmological simulations of our Universe, we can now probe cosmological parameters in a competitive way, and test the Lambda-CDM paradigm while tracing the evolution and distribution of substructures in the Universe.

Moreover, these lenses act as `Cosmic Telescopes', offering a unique glimpse to the distant Universe, thanks to the large magnification factors produced over wide areas. As an example, well-calibrated gravitational telescopes allow us to observe well beyond the observational limits of current instrumentation: the most distant galaxies, lensed supernovae and exceptionally magnified distant stars through micro lensing.

The future of cluster and galaxy lenses is even brighter with the continuing HST surveys, the James Webb Space Telescope launch in December 2021 which already has numerous approved programs devoted to lensing, upcoming missions such as Euclid and Roman, and the new ground-based experiments such as DESI, SDSS-V, Rubin, ASKAP, MeerKAT, SKA, and the CMB-S4 experiment. These observations will provide some of the most powerful independent cosmological probes.

With this Special Session, we propose to bring together observers, modelers and theorists to discuss the latest developments and challenges focussing on multi-wavelength and large field of view observations - to address cluster physics, galaxy evolution, cosmology and the magnified Universe probing right up to the Dark Ages.

Programme

  • Lensing mass modelling & Dark Matter properties
  • The physics of galaxies and galaxy clusters
  • Lensed galaxies & Reionization
  • Long wavelength view of the distant Universe
  • Lensed transients & the Hubble constant
  • Cosmography & Simulations
  • Strong lenses (automatic) searches

Invited speakers

  • Anahita Alavi (IPAC, USA)
  • Spencer Everett (JPL, USA)
  • Alexie Leauthaud (UC Santa Cruz, USA)
  • Guillaume Mahler (Durham University, UK)
  • Anna Nierenberg (UC Mereced, USA)
  • Sherry Suyu (MPA, Germany)

Scientific organisers

  • Mathilde Jauzac (Durham University, UK) - Chair
  • Jean-Paul Kneib (EPFL, Switzerland) - co-Chair
  • Hakim Atek (IAP, France)
  • Marusa Bradac (UC Davis, USA)
  • Jose Maria Diego (Instituto de Fisica de Cantabria, Spain)
  • Matt Hilton (UKZN, South Africa)
  • Eric Jullo (LAM, France)
  • Kenda Knowles (Rhodes University, South Africa)
  • Priyamvada Natarajan (Yale University, USA)
  • Jason Rhodes (JPL, USA)
  • Keren Sharon (University of Michigan, USA)
  • Ian Smail (Durham University, UK)
  • Charles Steinhart (Neils Bohr Institute, Denmark)

    • Contact

    Please contact Mathilde Jauzac ( mathilde.jauzac @ durham.ac.uk ) if you have any questions regarding this Special Session.

    Updated on Wed Feb 09 12:17:23 CET 2022
European Astronomical Society