The Lyα Tomography IMACS Survey (LATIS) is survey designed to create novel 3D maps of the intergalactic medium (IGM). The maps are a new tracer of large-scale structure at cosmic noon (z~2.5) and enable a variety of applications, including the detection and characterization of protoclusters, measurements of dark halo masses, and studies of feedback. The intergalactic gas is traced by observing Lyα absorption in the spectra of faint background galaxies and quasars, a technique known as IGM or Lyα forest tomography.
LATIS is one of the largest optical spectroscopic surveys of faint high-redshift galaxies. The main observations were obtained over 59 Magellan nights from 2017-2022. Key data products include (1) 5575 high-confidence redshifts, calibrated to the systemic frame with ~100 km/s errors, (2) ~4000 spectra of z~2-3 galaxies with a typical 12 hour integration time, (3) Lyα transmission measurements in ~0.5 million pixels, (4) 3D IGM maps that cover 1.65 sq. deg. from z=2.2-2.8 at a resolution of 4 cMpc/h, and (5) mock surveys enabling the connection from the forest to the density field and its evolution. LATIS observations span three fields, with half the area in COSMOS.
LATIS Papers
Under review: LATIS: Galaxy–Environment Relations at Cosmic Noon and the Role of Sample Selection
Under review: LATIS Data Release: ∼4200 Spectra of z ∼ 2 − 3 Galaxies, Redshifts, and IGM Tomography Maps
LATIS: Comparing Galaxy and IGM Tomography Maps as Tracers of Large-scale Structure and Protoclusters at z ∼ 2.5 (Newman et al 2025, ApJ 988, 48) ADS arXiv
LATIS: A Sample of IGM-selected Protoclusters and Protogroups at z ∼ 2.5 (Newman et al 2025, ApJ 988, 47) ADS arXiv
LATIS: Constraints on the Galaxy-Halo Connection at z ~ 2.5 from Galaxy-Galaxy and Galaxy-Lyα Clustering (Newman et al 2024, ApJ 961, 27) ADS arXiv
LATIS: The Stellar Mass-Metallicity Relation of Star-forming Galaxies at z ~ 2.5 (Chartab et al 2024, ApJ 960, 73) ADS arXiv
Boosting line intensity map signal-to-noise ratio with the Ly-α forest cross-correlation (Qezlou et al 2023, MNRAS 524, 1933) ADS arXiv
A population of ultraviolet-dim protoclusters detected in absorption (Newman et al 2022, Nature 606, 475) ADS arXiv
Characterizing Protoclusters and Protogroups at z ~ 2.5 Using Lyα Tomography (Qezlou et al 2022, ApJ 930, 109) ADS arXiv
LATIS: The Lyα Tomography IMACS Survey (Newman et al 202, ApJ 891, 147) ADS arXiv