CHAS BEICHMAN
Executive Director of the NASA Exoplanet Science Institute (NExScI) at Caltech, NASA’s Center for exo-planet research
NASA and Keck: A Beautiful Friendship
“Louis, I think this is the beginning of a beautiful friendship” – Rick Blaine in Casablanca.
NASA has been a partner with WMKO on the Keck 10-m telescopes since 1993 when NASA agreed to help fund the construction of Keck II. Starting in 1996 NASA and WMKO collaborated through Cooperative Agreements which have been successfully renewed every 5 years. NASA offers the national community its only open, fully competed access to the full suite of Keck’s capabilities including for a comprehensive data archive. Although for the first few years, investigations were restricted to exoplanet and solar system science, NASA access soon expanded to include the full suite of astrophysics science. The 30+ years of the NASA-Keck partnership has repeatedly demonstrated the dramatic breakthroughs possible from the synergistic fusion of ground and space-based observations. I will discuss some past and present triumphs and forecast what, I am confident, will be a long and bright future for the NASA-Keck partnership.
Fiona Harrison
Harold A. Rosen Professor of Physics, Caltech
The Ultraviolet Explorer Mission
The Ultraviolet Explorer (UVEX) is a NASA Medium Class Explorer mission is built on three scientific pillars: exploring the low-mass, low-metallicity galaxy frontier; providing new views of the dynamic universe, and leaving a broad legacy of modern, deep synoptic surveys adding to the panchromatic richness of 21st century astrophysics. The UVEX local galaxy sample will be the benchmark for understanding the low mass, low metallicity systems being discovered by JWST at high redshift. UVEX will provide a new tool for exploring the dynamic universe with its first-ever rapid broad band UV transient follow-up. The UVEX deep, synoptic all-sky surveys will likely be its most important legacy, replacing GALEX with a survey that: is cadenced; includes the Galactic Plane and Magellanic Clouds; provides rapid transient alerts to the community; and achieves depths and resolution matching modern optical/IR surveys with Rubin, Roman and Euclid. In this talk I will discuss the scientific drivers and observational program, emphasizing scientific opportunities and synergies with Keck.
TOMMASO TREU
Professor of Physics & Astronomy, Vice Chair of the UCLA Division of Astronomy and Astrophysics
What’s the universe made of? Cosmology with strong gravitational lenses
The standard Lambda Cold Dark Matter model successfully reproduces many observed features of the Universe. However, two profound questions remain answered: Is this the correct model or are there missing parts? Assuming the model is correct, what are dark matter and dark energy? I will show that observations of strong gravitational lenses can address both questions. First, they can be used to infer the expansion history of the universe and thus measure the Hubble constant H0, independent of all other methods. Thus, strong lenses have the potential to settle the so-called “Hubble tension”, i.e. the statistical disagreement between local measurements of H0 and predictions from early universe probes, by revealing whether it arises from systematic uncertainties or may be indicative of new physics, e.g. new particles or early dark energy. Second, strongly lensed quasars can be used to detect dark matter subhalos independent of their stellar content. This measurement tests a fundamental prediction of the cold dark matter model, i.e. that galaxies should be surrounded by large numbers of dark satellite subhalos. I will discuss the implications of this measurement in terms of fundamental properties of dark matter, such as free streaming length and self-interaction cross section. Both measurements rely heavily on Keck data, and will be greatly enhanced by upcoming Keck capabilities such as KAPA and LIGER.