The CFHT Legacy Survey: stacked images and catalogs

TL;DR

This paper details the creation and dissemination of stacked images and catalogs from the CFHT Legacy Survey, including calibration, processing, and access methods for the astronomical data.

Contribution

It introduces the data processing pipeline and public access tools for the CFHT Legacy Survey's deep and wide field imaging data.

Findings

Produced extensive image stacks and catalogs for the survey fields

Achieved deep magnitude limits with millions of sources cataloged

Provided multiple web interfaces for data access

Abstract

This paper describes the image stacks and catalogs of the CFHT Legacy Survey produced using using the MegaPipe data pipeline at the Canadian Astronomy Data Centre. The Legacy Survey is divided into to two parts: The Deep Survey consists of 4 fields each of 1 square degree, with magnitude limits of u=27.5, g=27.9, r=27.7, i=27.4, and z=26.2, and contains 1.6 million sources. The Wide Survey consists of 171 square degree pointings split over 4 fields, with magnitude limits of u=26.0, g=26.5, r=25.9, i=25.7, and z=24.6, and contains 30 million sources. This paper describes the calibration, image stacking and catalog generation process. The images and catalogs are available on the web through several interfaces: normal image and text file catalog downloads, a Google Sky interface, an image cutout service, and a catalog database query service.