SLAC's Particle Astrophysics & Cosmology Division plays leading roles in the study of the high-energy universe, where cosmology and particle physics – the study of the very big and the very small – meet. In this approach to discovery, known as the Cosmic Frontier, the universe itself is their laboratory. Two of the biggest puzzles in this realm are the nature of the dark matter and dark energy that make up 95 percent of the universe. SLAC is pursuing these and other questions with telescopes on the ground and in space and a detector deep underground.
Our research is led by the joint SLAC-Stanford Kavli Institute for Particle Astrophysics and Cosmology. KIPAC serves as a bridge between the disciplines of astrophysics, cosmology and particle physics, with special emphasis on cosmic structure, dark energy, dark matter, the early universe, compact objects and natural particle accelerators. Its mission is to bring the resources of modern computational, experimental, observational and theoretical science to bear on our understanding of the universe at large.
Our current major astrophysics and cosmology projects include:
SLAC's Computational Astrophysics group seeks to bridge theoretical and experimental physics communities to bring their combined strength to bear on some of the most challenging and fascinating problems in particle astrophysics and cosmology.
SLAC is playing a key role in the Super Cryogenic Dark Matter Search experiment, a next-generation search for dark matter that will take place deep underground at Canada’s SNOLAB. We are developing the experiment’s germanium-crystal detectors. Chilled to extremely cold temperatures and shielded under 6,800 feet of rock, they will attempt to record signals from dark matter WIMPs – weakly interacting massive particles – which, as the name implies, usually pass through normal matter without leaving a trace.
The Dark Energy Survey (DES) is a new survey of distant galaxies that aims to unravel the mystery of cosmic acceleration by using multiple techniques to measure and study dark energy. SLAC is directly involved in calibrating the DES imaging data, in running massive computer simulations of the Universe and DES data, and in several aspects of the analysis and processing of the DES data. Our scientific focus at KIPAC includes weak gravitational lensing, clusters of galaxies, and galaxy evolution.
SLAC managed construction and assembly of the main instrument for the Fermi Gamma-ray Space Telescope, an international project launched by NASA in 2008 to observe the universe in gamma rays. These high-energy rays bring us invaluable information about the extreme events that caused them, such as black holes and exploding stars. They may also yield evidence for dark matter, which so far has only been seen through its gravitational influence on the growth of structures in the universe.
SLAC is leading the design and construction effort for the 3.2 gigapixel camera – the world’s biggest – planned for the Large Synoptic Survey Telescope (LSST). The LSST will photograph the entire southern sky every 3.5 days, providing a unique view of the transient universe. This will allow scientists to track the evolution of the universe and any changes in its expansion rate over time, giving us great insight into the nature of dark energy.
A leading hypothesis is that dark matter is composed of Weakly Interacting Massive Particles, or WIMPs. LUX-ZEPLIN will search for these particles by looking for evidence of WIMPs colliding with xenon nuclei inside the LZ detector, located 4850 feet underground in South Dakota's Sanford Underground Research Facility. The LZ group at SLAC plays a major role in designing, fabricating and carrying out the experiment, as well as reponsible for determining how to best purify the liquid xenon that will be used in the detector.