Targeting the future of spectroscopic galaxy surveys -- A cosmological study case with the Wide-field Spectroscopic Telescope

@misc{payerne2026targeting,
  title = {{Targeting the future of spectroscopic galaxy surveys -- A cosmological study case with the Wide-field Spectroscopic Telescope}},
  author = {Constantin Payerne and Antoine Rocher and Aurélien Verdier and William d'Assignies and Behnood Bandi and Sofia Contarini and Matteo Ferro and Jean-Paul Kneib and Vincenzo Mainieri and Michele Moresco and Marco Palla and Maxime Rombach and Christophe Yèche and Furkan Akbaba and Hélène Courtois and Darko Donevski and Massimo Guidi and Valentin Ivanov and Konstantinos Migkas and Ivan Minchev and Ignacio del Moral-Castro and Olcay Plevne and Mojtaba Raouf and Laurence Tresse and the WST Collaboration},
  howpublished = {arXiv},
  year = {2026},
  month = nov,
  doi = {10.48550/arxiv.2611.02828},
  eprint = {2611.02828},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2611.02828},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Targeting the future of spectroscopic galaxy surveys -- A cosmological study case with the Wide-field Spectroscopic Telescope
AU  - Constantin Payerne
AU  - Antoine Rocher
AU  - Aurélien Verdier
AU  - William d'Assignies
AU  - Behnood Bandi
AU  - Sofia Contarini
AU  - Matteo Ferro
AU  - Jean-Paul Kneib
AU  - Vincenzo Mainieri
AU  - Michele Moresco
AU  - Marco Palla
AU  - Maxime Rombach
AU  - Christophe Yèche
AU  - Furkan Akbaba
AU  - Hélène Courtois
AU  - Darko Donevski
AU  - Massimo Guidi
AU  - Valentin Ivanov
AU  - Konstantinos Migkas
AU  - Ivan Minchev
AU  - Ignacio del Moral-Castro
AU  - Olcay Plevne
AU  - Mojtaba Raouf
AU  - Laurence Tresse
AU  - the WST Collaboration
PY  - 2026
DA  - 2026/11/02
PB  - arXiv
DO  - 10.48550/arxiv.2611.02828
UR  - https://arxiv.org/abs/2611.02828
AB  - The next generation of Stage-V spectroscopic surveys are designed to measure hundreds of millions of galaxy and quasar spectra, extending precision large-scale-structure cosmology to redshifts and volumes well beyond the reach of current Stage-IV facilities. Realising this potential requires revisiting the target selection strategies and designing them explicitly around the depth, multiplexing, and survey time of the new instruments, rather than a direct extrapolation of existing recipes. This work develops and characterises new strategies for the Wide-field Spectroscopic Telescope (WST), a proposed 12-metre, highly multiplexed facility expected to operate in the 2040s. Using deep multi-band photometry, including COSMOS-field data from CLAUDS and HSC, we revisit low-redshift z<1.6 tracer selection of SDSS, BOSS/eBOSS, DESI and 4MOST-CRS -- Bright Galaxies, Luminous Red Galaxies, Emission Line Galaxies and quasars -- to photometric depth achievable in the WST era, and introduce a purely magnitude-limited sample (MagMax) exploiting three-dimensional colour-colour star-galaxy separation, and a set of Lyman-Break Galaxy dropout samples extending target selection to z>2. Using Fisher-matrix forecasts, we showcase the constraining power of a WST-like cosmological survey on BAO distance parameters α_∥ and α_⊥, the growth rate f, the evolving dark energy equation w_0w_a, the local-type primordial non-Gaussianity f_NL^loc, and the sum of the neutrino mass Σm_ν. The main outcome of this work is an optimisation framework that directly links instrumental capabilities and observing time to cosmological constraining power, providing a science-driven template applicable to the design of future generations of Stage-V spectroscopic surveys.
ER  -