The catalog-to-cosmology framework for weak lensing and galaxy clustering for LSST

TL;DR

This paper introduces TXPipe, a modular pipeline for analyzing LSST data to measure weak lensing and galaxy clustering, validated with simulations to ensure accurate cosmological parameter estimation.

Contribution

The paper presents TXPipe, a flexible, automated pipeline for two-point measurements in LSST data, validated with simulations and adaptable for future science probes.

Findings

Accurately measures data vectors and recovers input cosmology in simulations.

Validated pipeline performance with Gaussian and realistic mock data.

Establishes a baseline framework for LSST cosmology analyses.

Abstract

We present TXPipe, a modular, automated and reproducible pipeline for ingesting catalog data and performing all the calculations required to obtain quality-assured two-point measurements of lensing and clustering, and their covariances, with the metadata necessary for parameter estimation. The pipeline is developed within the Rubin Observatory Legacy Survey of Space and Time (LSST) Dark Energy Science Collaboration (DESC), and designed for cosmology analyses using LSST data. In this paper, we present the pipeline for the so-called 3x2pt analysis -- a combination of three two-point functions that measure the auto- and cross-correlation between galaxy density and shapes. We perform the analysis both in real and harmonic space using TXPipe and other LSST-DESC tools. We validate the pipeline using Gaussian simulations and show that it accurately measures data vectors and recovers the input cosmology to the accuracy level required for the first year of LSST data under this simplified scenario. We also apply the pipeline to a realistic mock galaxy sample extracted from the CosmoDC2 simulation suite (Korytov et al. 2019). TXPipe establishes a baseline framework that can be built upon as the LSST survey proceeds. Furthermore, the pipeline is designed to be easily extended to science probes beyond the 3x2pt analysis.