HSC Subaru Strategic Program

HSC Subaru Strategic Program
Name	HSC Subaru Strategic Program
Location	Mauna Kea
Telescope	Subaru Telescope
Instrument	Hyper Suprime-Cam
Startdate	2014
Status	Ongoing

HSC Subaru Strategic Program The program is a wide-field imaging survey conducted with the Subaru Telescope on Mauna Kea using the Hyper Suprime-Cam instrument and coordinated by institutions such as the National Astronomical Observatory of Japan, the University of Tokyo, and the Kavli Institute for the Physics and Mathematics of the Universe. The survey complements efforts by projects like the Sloan Digital Sky Survey, the Dark Energy Survey, and the Pan-STARRS project while addressing topics pursued by collaborations including the Euclid (spacecraft), the Nancy Grace Roman Space Telescope, and the Large Synoptic Survey Telescope. It integrates strategies from legacy programs such as the Canada–France–Hawaii Telescope surveys, the COSMOS project, and the Hubble Space Telescope deep fields.

Overview

The project conducts multi-band optical imaging across nested layers—Wide, Deep, and UltraDeep—using the Hyper Suprime-Cam mounted on the Subaru Telescope at Mauna Kea, engaging teams from the National Astronomical Observatory of Japan, the Princeton University, the University of California, Santa Cruz, the Instituto de Astrofísica de Canarias, and the Kavli Institute for the Physics and Mathematics of the Universe. Its goals intersect with research pursued by the Planck (spacecraft), the Wilkinson Microwave Anisotropy Probe, the Atacama Cosmology Telescope, the South Pole Telescope, and the Gaia mission, targeting weak gravitational lensing, galaxy evolution, and transient discovery. The survey's footprint and depth were designed to provide synergy with catalogs from the Sloan Digital Sky Survey, the Two Micron All Sky Survey, the Wide-field Infrared Survey Explorer, and the Galaxy And Mass Assembly survey.

Survey Design and Instrumentation

The instrument suite centers on Hyper Suprime-Cam, a wide-field prime-focus camera developed by a consortium including the National Astronomical Observatory of Japan, the International Astronomical Union, and partners at institutions such as University of Hawaii, Princeton University, and the University of Tokyo, using CCD technology influenced by designs from the Subaru Telescope engineering teams and informed by precedents like Suprime-Cam and MegaCam. The optical filter set and focal plane layout were specified to optimize compatibility with photometric systems used by the Sloan Digital Sky Survey, the Pan-STARRS, and the Hubble Space Telescope photometry, facilitating cross-calibration with datasets from the Gaia mission and the Two Micron All Sky Survey. The camera's readout and cooling systems were developed in collaboration with engineering groups at the National Astronomical Observatory of Japan, the Kavli Institute for the Physics and Mathematics of the Universe, and the Institute of Astronomy, Cambridge, enabling survey strategies akin to those employed by the Dark Energy Survey.

Observing Strategy and Data Processing

The survey employs nested observing tiers—Wide, Deep, UltraDeep—with cadence and exposure patterns coordinated among teams at the Subaru Telescope operations, the National Astronomical Observatory of Japan, the University of Tokyo, and the Kavli Institute for the Physics and Mathematics of the Universe to support transient work similar to that of the Zwicky Transient Facility and the Pan-STARRS transient search. Data reduction pipelines were developed drawing on software practices from the Sloan Digital Sky Survey, the Hyper Suprime-Cam collaboration, and algorithms used in the Dark Energy Survey and LSST frameworks, incorporating tools related to Astrometry.net, SExtractor, and bespoke image subtraction and coaddition modules. Photometric calibration leverages cross-matching with catalogs from the Gaia mission, the Pan-STARRS1 survey, and the Two Micron All Sky Survey, while shape measurement and weak lensing analysis build on methods tested in the CFHTLenS and the DES Year 1 analyses.

Science Goals and Key Results

Primary science aims include precision weak gravitational lensing constraints on dark matter distribution and dark energy parameters, galaxy formation and evolution studies across cosmic time, supernova and transient discovery, and identification of high-redshift quasars and galaxies; these goals align with priorities set by the Dark Energy Survey, the Euclid (spacecraft), and the Roman Space Telescope. Key results include high-significance measurements of cosmic shear compatible with results from the Planck (spacecraft) cosmology analyses and comparisons to the Kilo-Degree Survey and DES findings, catalogs of galaxy clusters cross-validated with South Pole Telescope and Atacama Cosmology Telescope samples, deep multi-band photometry advancing work begun in the COSMOS field and informing studies by the Hubble Space Telescope and Spitzer Space Telescope. The survey has also produced samples of high-redshift quasars for follow-up by facilities like the Keck Observatory, the Very Large Telescope, and the Gemini Observatory, while transient discoveries have been coordinated with teams from the Zwicky Transient Facility and the Pan-STARRS consortium.

Data Releases and Access

Public data releases were staged and coordinated by the National Astronomical Observatory of Japan and partner institutions including the University of Tokyo and Princeton University, with data products distributed to archives used by the NASA/IPAC Infrared Science Archive, the Centre de Données astronomiques de Strasbourg, and science teams associated with the International Virtual Observatory Alliance. Releases provided calibrated images, photometric catalogs, and shape catalogs designed for use alongside datasets from the Sloan Digital Sky Survey, the Pan-STARRS1 catalogs, and the Gaia database, and were accompanied by documentation and software tools developed by the Hyper Suprime-Cam collaboration and data centers at the National Astronomical Observatory of Japan.

Collaborations and Related Surveys

The program is a collaboration among the National Astronomical Observatory of Japan, the University of Tokyo, the Kavli Institute for the Physics and Mathematics of the Universe, Princeton University, University of California, Santa Cruz, and international partners echoing consortia such as DES, Pan-STARRS, Euclid Consortium, and the LSST Science Collaboration. Its science and calibration strategies are coordinated with surveys and facilities including the Sloan Digital Sky Survey, the COSMOS project, the Hubble Space Telescope programs, the Spitzer Space Telescope, the Atacama Cosmology Telescope, the South Pole Telescope, and spectroscopic follow-up efforts at the Keck Observatory, the Very Large Telescope, and the Subaru Telescope instrumentation groups.

Legacy and Future Plans

The survey's legacy includes extensive multi-band imaging, weak lensing catalogs, and transient archives intended to serve the communities involved in projects like the Euclid (spacecraft), the Nancy Grace Roman Space Telescope, and the Vera C. Rubin Observatory; future plans emphasize deeper observations in the UltraDeep fields, spectroscopic follow-up with facilities such as the Keck Observatory and the Very Large Telescope, and methodological synergy with the LSST and Euclid analyses to refine cosmological parameters and galaxy evolution models.

Category:Astronomical surveys