Legacy Survey of Space and Time

Legacy Survey of Space and Time
Name	Legacy Survey of Space and Time
Country	United States
Institution	National Science Foundation, Department of Energy (United States)
Telescope	Vera C. Rubin Observatory
Location	Cerro Pachón
Startdate	2024
Wavelength	Optical

Legacy Survey of Space and Time is a decade-long wide-field imaging program conducted with the Vera C. Rubin Observatory at Cerro Pachón in Chile. The project aims to map billions of objects across the southern sky to address questions in cosmology, astronomy, and planetary science while providing an unprecedented data set for the communities involved with the National Science Foundation, Department of Energy (United States), and international partners. The survey combines deep, multi-band imaging with high cadence to enable studies ranging from dark energy and dark matter to near-Earth object discovery and transient astrophysics linked to observatories like LIGO, Fermi Gamma-ray Space Telescope, and James Webb Space Telescope.

Overview

The survey deploys the Vera C. Rubin Observatory's 8.4-meter mirror and 3.2-gigapixel LSST Camera to image roughly 18,000 square degrees over ten years, creating time-domain and static sky products used by teams associated with Lawrence Berkeley National Laboratory, SLAC National Accelerator Laboratory, University of Washington, University of California, Berkeley, National Optical-Infrared Astronomy Research Laboratory, and international institutions such as INAF, Max Planck Society, and University of Cambridge. The program is designed to interface with legacy datasets from Sloan Digital Sky Survey, Pan-STARRS, and Dark Energy Survey, and to coordinate follow-up with facilities including Keck Observatory, Gemini Observatory, and Atacama Large Millimeter/submillimeter Array.

Science Goals

Primary goals link to strategic objectives in cosmology and astrophysics: to measure the equation of state of dark energy via multiple probes: weak gravitational lensing, large-scale structure, baryon acoustic oscillations, and supernova distances, leveraging methods developed by projects such as DESI, Euclid (spacecraft), and Planck (spacecraft). Secondary targets include mapping the distribution of dark matter through shear catalogs, inventorying the Solar System for near-Earth objects and trans-Neptunian objects with ties to NASA, characterizing transient phenomena including supernovae, kilonovae related to GW170817, and variable stars relevant to the Gaia (spacecraft) astrometric frame. The survey supports studies of galaxy evolution by tracing stellar populations, mergers, and active galactic nuclei identified in synergy with Chandra X-ray Observatory, XMM-Newton, and Spitzer Space Telescope archives.

Telescope and Instrumentation

The observatory features the Vera C. Rubin Observatory's unique three-mirror design developed from concepts by teams at LSST Corporation and instrument groups at SLAC National Accelerator Laboratory and Brookhaven National Laboratory. The focal plane hosts the 3.2-gigapixel LSST Camera, building on detector technologies advanced at Teledyne Technologies and testing programs involving National Optical Astronomy Observatory. The telescope systems integrate active optics and a rapid-slew mount to support 15-second exposures enabling high cadence; engineering and commissioning drew on expertise from Argonne National Laboratory, National Center for Supercomputing Applications, and Lawrence Livermore National Laboratory.

Survey Design and Operations

Survey strategy emphasizes a dual-depth wide-fast-deep cadence with roughly 18,000 square degrees in ugrizy filters, balancing uniform sky coverage and concentrated deep drilling fields modeled after approaches from Sloan Digital Sky Survey deep fields and Hubble Space Telescope legacy fields. Operations planning involves scheduling algorithms from teams at University of Arizona and University of Pennsylvania and coordination with the Southern Astrophysical Research Telescope and Subaru Telescope for target-of-opportunity follow-up. Data quality assurance, photometric calibration, and astrometric registration connect to calibrations developed using Pan-STARRS and Gaia (spacecraft) reference catalogs.

Data Processing and Releases

The project delivers calibrated images, object catalogs, difference images for transient detection, and value-added products via a science platform informed by software frameworks from LSST Science Pipelines and collaborations with National Center for Supercomputing Applications, Data Science Institute (Columbia University), and NERSC. Data releases are staged as annual public Data Releases with intermediate alert streams for transients distributed to partner networks including AMON, ANTARES (broker), and community brokers used by observers at European Southern Observatory, NOIRLab, and university groups. Processing leverages high-performance computing resources similar to those used by LIGO Scientific Collaboration and CERN computing grids.

Results and Discoveries

Early results include discovery and orbital characterization of numerous near-Earth object candidates, large catalogs of galaxies and stars enabling improved constraints on structure growth consistent with analyses from Planck (spacecraft) and DESI, detections of exotic transients comparable to events followed by Swift (satellite) and Fermi Gamma-ray Space Telescope, and maps of the Milky Way halo that complement Gaia (spacecraft) stellar streams. Teams have produced weak-lensing shear measurements, photometric redshift catalogs, and populated training sets for machine learning projects with partners such as Google DeepMind and academic groups at Massachusetts Institute of Technology and Stanford University.

Collaborations and Management

The survey is managed through a partnership model involving National Science Foundation, Department of Energy (United States), NOIRLab, national laboratories including Brookhaven National Laboratory and Lawrence Berkeley National Laboratory, and academic consortia spanning University of Chicago, Harvard University, Princeton University, California Institute of Technology, and international partners like University of Tokyo and University of Toronto. Governance includes science collaborations focused on cosmology, transient science, solar system science, and galaxy evolution, with advisory relationships to agencies such as NASA and coordination with multinational projects like Euclid (spacecraft) and Square Kilometre Array science working groups.

Category:Astronomical surveys