Cosmic Shear constraints from HSC Year 3 with clustering calibration of the tomographic redshift distributions from DESI
J. Choppin de Janvry, B. Dai, S. Gontcho A Gontcho, U. Seljak, T. Zhang
A reanalysis of HSC Year 3 shear data using new DESI-based clustering-redshift calibration. The updated redshift priors lift the central S8 value toward the Planck result while tightening the uncertainty substantially. Uses both importance sampling of the original HSC chains and a full rerun with updated n(z) priors. Reports S8 = 0.805 +/- 0.018, improving the precision of the original HSC Y3 result.
Full calibration of the tomographic redshift distribution from the HSC PDR3 Shape Catalog with DESI
J. Choppin de Janvry, S. Gontcho A Gontcho, U. Seljak et al.
This paper performs a full DESI-based clustering-redshift calibration of all four HSC weak-lensing tomographic bins, including the high-redshift sources that previous calibrations could not fully constrain. Extends calibration to ELG and QSO reference samples above z = 1.2. Finds smaller redshift shifts than those assumed in the original HSC Year 3 cosmic-shear analysis.
Simulating Spectral Confusion in SPHEREx Photometry and Redshifts
Z. Huai, J. Choppin de Janvry et al.
A Monte Carlo study of how source confusion and beam blending propagate into SPHEREx forced photometry and spectrophotometric redshifts, especially in the deep fields. Builds a confusion library from COSMOS2020 spectral energy distributions. Shows confusion is small at full-sky depth but relevant in the deep fields.
James J. Bock et al., including Jean Choppin de Janvry
The mission overview paper describes SPHEREx as the first all-sky near-infrared spectral survey, detailing the instrument, mission design, public data products, and the science cases driving the survey strategy. Covers the 102-band spectral survey from 0.75 to 5.0 microns. Links mission design to inflation, galaxy-evolution, and Galactic ice science.
The SPHEREx Sky Simulator: Science Data Modeling for the First All-Sky Near-Infrared Spectral Survey
B. P. Crill et al., including Jean Choppin de Janvry
The simulator paper describes the software used to generate realistic SPHEREx infrared sky scenes, including astrophysical emission, instrument effects, noise, and survey strategy models. Explains the pre-flight simulator architecture used throughout mission preparation. Provides pre-launch point-source sensitivity predictions across the full wavelength range.
Data-driven photometric redshift estimation using Dictionary Learning for SPHEREx
S. Bryan et al., including Jean Choppin de Janvry
An in-preparation line of work on dictionary-learning methods for SPHEREx photometric redshifts, tied directly to mission pipeline development at JPL. Uses sparse, data-driven spectral bases to estimate redshifts. Connects machine-learning methods to production cosmology infrastructure.