Research Interests of KIPAC Senior Members

Tom Abel : Numerical Cosmology

Tom's current research focuses on studying the formation and evolution of galaxies with new numerical techniques, however, he enjoys all areas of non-linear physics which can be addressed using supercomputer calculations! His research interests span dark matter dynamics, the physics of collisionless shocks, investigating the role that cosmic rays and magnetic fields play in the formation and evolution of galaxies, modeling the formation of stars and black holes as well as turbulence, and applications of numerical general relativity.

Visualizations of Dark Matter / Large Scale Structure by R. Kähler and T. Abel. Simulation credit to O. Hahn and T. Abel.

Daniel Akerib : Dark Matter

Together with Tom Shutt, Dan works on the LUX and LZ dark matter experiments to search for dark matter in the form of Weakly Interacting Massive Particles, or WIMPs. The detectors use liquid xenon as a target medium in a time projection chamber, or TPC. The Large Underground Xenon (LUX) experiment is currently operating a 250-kg target in the former Homestake gold mine in the Black Hills of South Dakota. Preparations are underway at SLAC to design and build the 7-ton successor, known as LUX-ZEPLIN (LZ). The group is involved in many aspects of data analysis, detector design, xenon purification, control andreadout systems, and detector performance studies.

Steven Allen : X-ray Astronomy and Observational Cosmology (XOC)

Steve is interested in the physics of the most massive objects in the Universe and how we can use them to probe how the Universe evolved. Steve and his group are currently focused on understanding the astrophysics of galaxies and of galaxy clusters using multi-wavelength observations, and on using large, statistical samples of these objects to probe the natures of dark matter, dark energy and fundamental physics. More information regarding ongoing research and a list of Steve's current group members can be found here.

Roger Blandford : Theoretical Astrophysics

Roger has broad interests in astrophysics, cosmology and physics. His current research interests in high energy astrophysics include interpreting Fast Radio Bursts (FRB) as a consequence of magnetar (neutron stars with up too a 100 Giga Tesla magnetic field), modeling the black hole shadow observed in M87 by the EHT as a ergomagnetosphere that drives away the infalling gas through an ejection disk, explaining the highest energy cosmic rays as being accelerated at accretion shocks surrounding nearby clusters of galaxies and developing “magnetoluminescent” mechanisms of the most rapid particle acceleration in cosmic sources. His cosmological interests include using the microwave backgrounds and large surveys to make a largest scale map of the actual universe we inhabit and exploring the potential of FRB to make competitive cosmological measurements. His main physics interest centers on accounting for biological homochirality using spin-polarized cosmic rays.

Patricia Burchat : Observational Cosmology, LSST Dark Energy Science Collaboration, Gravitational Lensing

Pat and her research group are major contributors to the Legacy Survey of Space & Time (LSST) Dark Energy Science Collaboration (DESC).  DESC is preparing to explore cosmology and fundamental physics with the massive astronomical data set that will come from Rubin Observatory, which is close to the completion of construction in Chile. Pat’s group is focused on the challenges that need to be overcome to do both precise and accurate measurements of "weak gravitational lensing". Her group is using analytic calculations, simulations, modeling, and analysis of existing astronomical images to thoroughly understand and then correct potential systematic biases. Current projects include detailed understanding and modeling of the correlations in the point spread function across the very large field of view of the Rubin telescope, and the understanding and reducing negative impacts of blended objects.

NASA/ESA image of strong lensing due to the galaxy cluster Abell 2218.

Robert L. Byer : Lasers and Nonlinear Optics

Bob's current research is directed towards precision laser measurements which are used in support of the detection of gravitational waves and in laser particle acceleration. Bob's group and others are involved in developing nanostructured chips, smaller than a grain of rice, in which electrons can be accelerated at a rate 10 times higher than conventional technology.

Blas Cabrera : Dark Matter

Blas's main research efforts are directed towards the search for dark matter in the form of WIMPs or Weakly Interacting Massive Particles. Blas is Spokesperson for SuperCDMS Collaboration. The SuperCDMS Soudan experiment is now operating in northern Minnesota and the SuperCDMS SNOLAB experiment has just been approved by NSF & DOE as one of two second generation WIMP search experiments.

super dms
One of SuperCDMS's state-of-the-art detectors. 



Sarah Church : Cosmic Microwave Background Radiation

Sarah's group builds instrumentation to observe the Cosmic Microwave Background radiation (CMB) at millimetre wavelengths. The CMB is a virtually pristine relic of conditions in the universe approximately 400,000 years after the Big Bang and by studying it we can test our understanding of the laws of physics in the extreme conditions that occurred in the first few moments after the Big Bang. Sarah's group use telescopes located at the best sites in the world for millimetre wavelength astronomy, including the South Pole, the Chilean Andes, and Mauna Kea in Hawaii.

Susan Clark : Astrophysical Magnetism and the Interstellar Medium

Susan is broadly interested in astrophysical magnetism and the physics of the interstellar medium (ISM), from diffuse gas to dense, star-forming regions. Susan’s research tackles open questions like the structure of the Milky Way’s magnetic field, the nature of interstellar turbulence, and the role of magnetism in star formation. These big questions demand multiwavelength observations and new data analysis techniques. Susan is particularly interested in deciphering the magnetic ISM using sensitive measurements of synchrotron and polarized dust emission made by cosmic microwave background experiments like the Atacama Cosmology Telescope (ACT) and the Simons Observatory (SO).

Starlight polarization aligned with diffuse neutral hydrogen structures.
Starlight polarization aligned with diffuse neutral hydrogen structures.


Peter Graham : Beyond the Standard Model

Peter is broadly interested in theoretical physics beyond the Standard Model, including cosmology, astrophysics, general relativity, and even atomic physics. The Standard Model leaves many questions unanswered including the nature of dark matter and the origins of the fundamental fermion masses, the weak scale, and the cosmological constant. These and other clues such as the unification of the forces are a guide to building new theories beyond the Standard Model. Peter's group are interested in inventing novel experiments to uncover this new physics.

Courtesy Fermilab Visual Media Services.

Steven Kahn : Rubin Observatory and Legacy Survey of Space & Time

Steve is the Director of Rubin Observatory — a major new facility currently under construction in Chile — which will produce (over ten years) the Legacy Survey of Space & Time (LSST).  The LSST will enable a wide array of scientific investigations ranging from studies of moving objects in the solar system to the structure and evolution of the universe as a whole. Steve has played a major role in the construction of the LSST camera. Prior to his engagement with LSST, Steve was an X-ray astrophysicist, concentrating on the design of instrumentation and analysis of data associated with high resolution X-ray spectroscopy of cosmic sources. He maintains an interest in that field, although at a low level, given his commitments to Rubin Observatory.

Rubin Observatory


Chao-Lin Kuo : Cosmic Microwave Background Radiation: Instrumentation and Cosmology

Chao-Lin’s group use the most ancient light, the Cosmic Microwave Background (CMB) radiation, emitted when the universe was in its infancy to shed light on the question of how the universe began. Currently Chao-Lin's group are involved in a number of experiments such as BICEP/BICEP2/Keck Array and have been working hard on detecting primordial B-mode polarization. His group are involved in both he design and construction of instruments as well as the data analysis and theoretical interpretation.

BICEP2 first detection of B-modes. Credit the BICEP and Keck Array Team.

Bruce Macintosh : Adaptive Optics and Extrasolar Planet Imaging

Bruce's main focus is the direct detection and characterization of extrasolar planets and the use of adaptive optics technology to control light. Bruce is Principal Investigator for the Gemini Planet Imager (GPI) instrument which was commissioned and saw first light in late 2013. Bruce will lead a 600-star survey to discover and spectroscopically characterize young giant extrasolar planets around nearby stars. A new laboratory will be used for  developing exoplanet instrumentation for future ground and space-based telescopes, and applying adaptive optics to other applications such as microscopy. Bruce is also involved in preparations for the proposed exoplanet coronagraph on the WFIRST-AFTA telescope and other approaches to studying extrasolar planets.

Roger Romani : Neutron Stars and Black Holes: Observations, Modelling and Theory

Roger is interested in a variety of topics in high energy astrophysics and cosmology. Much of Roger's group are currently focused on understanding the cosmic gamma-ray sources discovered by the Fermi Space telescope, principally pulsars and blazars. This inherently multi-wavelength question requires them to use telescopes all over the world and in space in order to assemble data on these objects and then to develop and test theoretical models to explain what we see. 

Aaron Roodman : Observational Cosmology

Aaron's current research focus is the study of dark energy using images from the ongoing Dark Energy Survey (DES) and the  future Large Synoptic Survey Telescope (LSST). He is interested in studying dark energy using both galaxy clusters and weak gravitational lensing. His research group connects instrumental work, in particular active optics and wavefront measurements at DES and a program of camera-wide testing at LSST,  with cosmology measurements. For example, they are developing a new method to characterize the telescope+camera point spread function using optical data, to be part of the weak lensing data analysis at both DES and LSST.

Laura Schaefer : Exoplanet Atmospheres

Laura's research focuses on understanding how atmospheres on rocky planets, both exoplanets and those within the solar system, form and evolve over time. Her group investigates topics ranging from tidal heating, asteroidal bombardment, to long-term weathering cycles and how they influence atmospheres and habitability. Other topics of interest include the physics and chemistry of core formation, atmosphere-interior exchange, mantle convection, atmospheric escape, and N-body simulations of planet formation.

Philip Scherrer : Solar Physics

Phil's main research interests are in the structure and dynamics of the interior of the sun, how this affect solar activity and through this its effects on terrestrial systems. Phil's group’s primary emphasis is on the structure and dynamics of the solar interior using techniques of helioseismology. His group are interested in both developing instrumentation for solar observatories and in the data analysis of solar magnetic fields from space and from the ground.

Rafe Schindler : Large Synoptic Survey Telescope

Rafe and his group are working hard on the development and commissioning of the upcoming Large Synoptic Survey Telescope (LSST) a next generation ground based optical survey telescope. The LSST group at KIPAC are working both in the lab, developing the state-of-the-art technologies necessary to preserve the LSST camera’s image quality during operation and building computer simulations of the camera and telescope performance -- a  novel area being pioneered by LSST.

Dustin Schroeder : Ice Penetrating Radar

The Stanford Radio Glaciology research group is led by Dustin Schroeder and focuses on advancing the scientific and technical foundations of geophysical ice penetrating radar and its use in observing and understanding the interaction of ice and water in the solar system.  We are actively engaged with the flow of information through each step of the observational science process; from instrument and experiment design, through data processing and analysis, to modeling and inference.  This work contributes to both the observation of Earth's rapidly changing ice sheets and the subsurface exploration of icy moons. Dustin is also a Science Team Member with the REASON instrument and co-leads the Interiors Working Group on NASA’s Europa Clipper Mission.

NASA image of Europa

NASA image of Europa

Leonardo Senatore : Early Universe Cosmology; Growth of Structure

Leonardo is interested in understanding how the universe began and evolved to its present form. Cosmological observations are providing us with a huge amount of data, which allows us to test our theories about inflation, eternal inflation and its alternatives, and about the growth of structures in our universe, to an unprecedented level. Leonardo and his group are involved in both developing the theory and analysis of cosmological data and are working to bridge the gap between theories of the early universe and current and future data.

Thomas Shutt : Dark Matter

Together with Dan Akerib, Tom works on the LUX and LZ dark matter experiments to search for dark matter in the form of Weakly Interacting Massive Particles, or WIMPs. The detectors use liquid xenon as a target medium in a time projection chamber, or TPC. The Large Underground Xenon (LUX) experiment is currently operating a 250-kg target in the former Homestake gold mine in the Black Hills of South Dakota. Preparations are underway atSLAC to design and build the 7-ton successor, known as LUX-ZEPLIN (LZ). The group is involved in many aspects of data analysis, detector design, xenon purification, control andreadout systems, and detector performance studies.

The LUX detector situated in its water shield at the 4850' level of the Sanford Underground Research Facility.

Risa Wechsler : Computational Cosmology and Galaxy Surveys

Risa and her group work on a range of topics in cosmology and astrophysics, with a focus on the formation of cosmological structure in the Universe, its impact on galaxy formation, and its use in determining the nature of dark matter and dark energy. Risa's group builds and analyzes numerical simulations and develops models of galaxy formation for comparison with large observational datasets, and develops new techniques to learn about the dark side of the Universe from these data.  Her group is actively involved in the ongoing Dark Energy Survey (DES), as well as the largest future planned surveys including the Dark Energy Spectroscopic Instrument (DESI) and the Large Synoptic Survey Telescope (LSST).

Galaxy cluster formation. Visualization: R. Kaehler. Simulation: H. Wu, O. Hahn, R. Wechsler.

Research interests of KIPAC Scientific Staff

Zeeshan Ahmed : Cosmic Microwave Background

Zeesh is an observational cosmologist who studies the relic blackbody radiation of the early universe, called the Cosmic Microwave Background (CMB), to understand the origin and composition of the Universe and find answers to some perplexing questions in fundamental physics. With CMB team members at KIPAC, SLAC and Stanford, Zeesh builds CMB cameras and analyzes data generated by them. He is a member of the BICEP/Keck, South Pole Telescope (SPT-3G), Simons Observatory and CMB-S4 scientific collaborations. His current research interests include experimental bounds on cosmic inflation from CMB polarization, searches for dark matter using CMB data, and development of next-generation CMB camera readout technologies. Recent hardware development in SLAC’s CMB lab, with a focus on GHz superconducting microresonators, has cross cutting applications in CMB imaging, X-ray and particle detection, and beyond-SQL measurements.


Noah Kurinsky : Quantum Sensing for Dark Matter Detection

Noah’s current interests are directed toward developing large particle detectors with sensitivity to meV-scale excitations. Noah is the R&D coordinator for the SuperCDMS collaboration, and leads development for the single-electron sensitive HVeV detector program. He also has ongoing programs to use novel quantum materials with meV-scale bandgaps to detect small energy deposits, as well as qubit and KID-based sensors for low-energy phonon and THz photon detection. Noah is also a new PI in the QNEXT quantum institute, where he focuses on mitigating radiation effects in qubits from radioactivity by studying phonon transport in different qubit architectures.

Grzegorz M. Madejski : X-ray and Gamma-ray Astronomy and Astrophysics

Greg's research interests are mainly in extragalactic high-energy astrophysics. This includes (1) studies of active galactic nuclei, and an associated formation and evolution of relativistic jets; and (2) studies of clusters of galaxies, and in particular the processes responsible for the heating of the X-ray emitting intra-cluster gas. Besides taking advantage of data from the Fermi Gamma-ray Observatory, Greg is involved in analysing and interpreting observations performed with NuSTAR, a recently-launched NASA satellite, sensitive in the hard X-ray band.

Phil Marshall : Observational Cosmology

Phil's research interests are in observational cosmology using gravitational lensing: weighing galaxies, and measuring the expansion rate of the Universe. He is a member of the H0LiCOW and STRIDES collaborations, modeling time delay lenses in order to measure the Hubble constant, and is active in the LSST DESC Strong Lensing working group, helping design and implement its strong lensing science analysis. LSST presents astronomers with a new scale of Big Data problems, the solutions to which will necessarily involve either innovations in automated inference, or large numbers of people, or both: Phil's research is focused on strong lensing, but the methods he is investigating with the KIPAC students and postdocs have much wider applicability.

W.L. Kimmy Wu : Cosmic Microwave Background (CMB)

Kimmy is a cosmologist focusing on using observations of the cosmic microwave background (CMB) to understand the history of the universe—from its earliest moments through the present day. Using data from the South Pole Telescope and from the BICEP/Keck Array telescopes, Kimmy and her collaborators develop methods and algorithms to look for signatures from primordial gravitational waves, to test the standard cosmological model LCDM, and to constrain new physics using both the primary CMB and its lensing signal. To harvest more information from this relic light from the universe, they, along with the broader CMB community, are currently planning the next-generation ground-based CMB experiment, CMB-S4.

Research interests of KIPAC Emeritus Faculty

Elliott D. Bloom : Fermi LAT; Indirect Searches for Dark Matter

Elliott spends most of his research time working on the analysis of Fermi-LAT data, the Large Area Telescope on the Fermi Gamma-ray space observatory which was constructed right here at SLAC! He is primarily interested in high energy searches for dark matter and new physics, and in understanding the diffuse gamma-ray background. 

David Burke : Observational Cosmology with Large Surveys: DES and LSST

David's current projects are focusing on the development of scientific analyses for the Dark Energy Survey (DES). The DES is an exciting, broad ground-based optical survey which started taking data in 2013. It is measuring cosmological parameters through the use of gravitational lensing, studies of clusters and large scale structure of galaxy populations. Presently David's work is aimed at optimizing the performance of instrument operations and data reduction, and development of scientific analysis techniques using​ simulations and the survey data set. 

The Blanco 4-meter Dark Energy Survey telescope which holds the Dark Energy Camera at the Cerro Tololo Inter-American Observatory in Chile. 

Robert V. Wagoner : Theoretical Astrophysics

Bob has wide research interests in the field of gravitational astrophysics. Bob is interested in oscillations of accretion disks around black holes, and other signatures of very strong gravitational fields, sources of gravitational radiation, and their detection by LIGO and other facilities, scalar-tensor theories of gravitation and physics of the early universe.

A black hole accretion disk. Credit C. Perez.