Title (click for abstract)
IfA Hilo; 2:30pm
University of Cape Town
Carnegie Institution for Science
IfA Hilo; 2:30pm
David Jones & Zach Hartman
IfA Hilo; 2:30pm
Universities Space Research Association
Carnegie Mellon University
UTSA & Subaru
Arizona State University
Nov 7 (Tues)
Institute of Space Sciences (ICE-CSIC)
A Cosmic Infrared Passage
University of Cape Town / iYunivesithi yaseKapa / Universiteit van Kaapstad
In this talk I will showcase several of the most powerful scientific applications made possible by the infrared as I highlight the research that I have done over the years, starting as a postdoc developing the Palomar Prime Focus Infrared Camera, through my years as a NASA mission scientist working on IRAS, 2MASS, ISO, Spitzer, Herschel, and WISE, with sideways adventures with the WIRO, Kuiper, IRTF, HST-NICMOS, Palomar-WIRC, and most recently with JWST. I will then focus on my primary research in the field of galaxy evolution in the Cosmic Web, using WISE, optical redshifts, and radio HI surveys. I will finish with my perspective on the IRTF’s role in the coming age of the great NEO and transient surveys.
Unveiling the early stages of planet formation
Institute of Planetology and Astrophysics of Grenoble & Lagrange, Nice, France
Recent observing campaigns have revealed a great diversity in exoplanetary systems whose origin is yet to be understood. How and when planets form, and how they evolve and interact with their birth environment, the protoplanetary disks, are major open questions. Protoplanetary disks evolve and dissipate rapidly while planets are forming, implying a direct feedback between the processes of planet formation and disk evolution. These mechanisms leave clear imprints on the disk structure that can be directly observed. In the past few years, high-resolution observations of protoplanetary disks obtained in the infrared scattered light and in the millimeter regime have led to exquisite images and shown that small scale structures are ubiquitous in protoplanetary disks, and could result from the dynamical interaction with embedded planets. I will present recent observational results on protoplanetary disks that allow us to probe the disk structure and the dynamics of solids, and in particular, in the so far unique system that hosts two directly imaged protoplanets, PDS70. I will conclude on the exciting perspectives in the field of planet formation, driven by the development of new instrumentation.
Dawn of the JWST Era: A New Chapter in Exoplanet Characterization
Carnegie Institution for Science
With the successful launch and commencement of science operations of JWST, the characterization of exoplanet atmospheres has entered a new era. In this talk, I will first give an overview of the exciting programs that have and will be executed by JWST in cycle 1, and then go in-depth into a few of those programs, including discussing the key science results from the Transiting Exoplanet Early Release Science Program and the General Observer program targeting the mysterious sub-Neptune, GJ 1214b. These programs showcase the power of JWST’s high precision and extended wavelength range in revealing atmospheric composition, thermal structure, and the presence and characteristics of clouds and hazes.
The IRTF over the next 10 years: Continuing to serve the community and exceeding expectations
University of California, Davis
For a 3m telescope, the IRTF has consistently been able to “punch above its weight”. Much of this ability is due to clever instrumentation strategies, responsive operations, and a deeply embedded “can-do” attitude. We are now in the JWST/ALMA era with ELTs visible on the horizon. By building on its strengths and capabilities, I believe the IRTF will continue to be productive into the future. Of personal importance to me is ensuring that TEXES, the visitor instrument from UT Austin that first observed at the IRTF in October 2000, is readily available to the IRTF community in the future. The high spectral resolution of TEXES makes it unique and consequential even in the JWST era. Among the lessons from my experience with TEXES (and EXES on SOFIA) are the value of near realtime data reduction pipelines and the potential benefit from atmospheric modeling in data reduction. These software capabilities should be a priority for every IRTF instrument going forward. With the continued spirit of the IRTF community, I have no doubt that the observatory will be productive in the future.
Mapping dust in 3D: A billion parameter inference problem
Professor of Astronomy and of Physics
Physical processes in the interstellar medium happen in 3 spatial dimensions, but most of our ISM maps are either 2D, or 3D where the third dimension is velocity. A true 3D map is hard to come by! My group has pursued two different approaches to inferring the ISM dust density in 3D by using the brightnesses and colors of billions of stars. One is optimized for angular resolution and larger distances (Bayestar) and one is optimized for high distance resolution, but only within 1.25 kpc. I will describe how we construct these maps and the data sets they are based on.
The Race to the Bottom: The Search for Planets around Ever Smaller Hosts
Perkins Telescope Observatory
Data from NASA’s Kepler and TESS Missions show that low-mass stars, specifically M dwarf stars, are swarming with terrestrial exoplanets. The results have inspired several surveys for exoplanets orbiting stars at the bottom of the main sequence and have led to a renewed interest in the fundamental properties of low-mass stars. I will present recent results from the Low-mass Star Group at Boston University in these areas. We are particularly interested in measuring M dwarf elemental abundances; however, this is confounded by the role of the stellar carbon-to-oxygen ratio and Zeeman enhancement of individual absorption lines. I also will present recent results on the M dwarf mass-radius relationship. Lastly, I will discuss a new search for transiting planets and satellites around L and T dwarfs called the Perkins Infrared Exosatellite Survey, or PINES. L and T dwarfs can be either stars, brown dwarfs or planetary-mass objects, all of which have proto-planetary disks early in their lives. Their disks, combined with the increase in exoplanet occurrence with decreasing host mass seen in M dwarfs, suggest that L and T dwarfs may also be swarming with planets and moons, which motivates the PINES project. I will describe the survey and present our latest results.
Introduction to Gemini Observatory in the 2020s: How to Propose for Time, Complete your Program, and Reduce your Data
Gemini Science Fellow
For the past two decades, Gemini Observatory’s twin telescopes have provided the astronomical community with telescope access to the entire sky. With a full range of observing capabilities from the optical to NIR, Gemini allows scientists from around the world to conduct ground-breaking science from the Galactic center to exoplanets to cosmology, and its capabilities and support infrastructure will be improving significantly over the coming years. In this talk, we present an update on Gemini’s capabilities, proposal process, observing queue system, data reduction software, and user support system. Our goal is to help the UH community 1) take advantage of Gemini for their science needs and 2) provide resources for working with Gemini staff to make the best use of Gemini capabilities and data.
The Revitalization of Gemini Observatory
For two decades, the International Gemini Observatory has powered astronomical discovery for the entire U.S. community and the international Gemini partnership. Gemini’s twin 8.1m optical/infrared telescopes provide nightly access to both hemispheres of the sky, and host a wide suite of imaging, spectroscopic, and adaptive optics capabilities. Gemini Observatory is one of the world’s most flexible and agile 8m class observatories, enabled by remote nightly queue operations, instrument swapping on timescale of minutes, and responsive scheduling of observations.
In the next decade, Gemini seeks to provide transformational capabilities to fuel discovery in the fields of planetary systems, compact objects, cosmology, and galaxy assembly. Gemini is undergoing a major revitalization of its instrumentation suite, AO facilities, and user support infrastructure. With the advent of Rubin Observatory and LSST, Gemini is well-poised to lead the follow-up of the time-varying sky, and is developing the capabilities to ensure success in the time domain while preserving access for static universe studies.
Hoʻoleilana: An Individual Baryon Acoustic Oscillation?
University of Hawaiʻi Institute for Astronomy
Theory of the physics of the early hot universe leads to a prediction of baryon acoustic oscillations (BAOs) that has received confirmation from the pairwise separations of galaxies in samples of hundreds of thousands of objects. Evidence is presented here for the discovery of a remarkably strong individual contribution to the BAO signal at z = 0.068, an entity that is given the name Hoʻoleilana. The radius of the 3D structure is 155/h75 Mpc. At its core is the Boötes supercluster. The Sloan Great Wall, Center for Astrophysics Great Wall, and Hercules complex all lie within the BAO shell. The interpretation of Hoʻoleilana as a BAO structure with our preferred analysis implies a value of the Hubble constant of 76.9 km/s/Mpc.
NASA Citizen Science: Kamiokande to The Last Starfighter
Research Astrophysicist & Citizen Science Officer
NASA Goddard Space Flight Center
NASA’s citizen scientists—amateur scientists—have discovered hundreds of exoplanets and planetary-mass objects, most of the known comets, the Yellowball star forming regions, the Dipper star phenomenon, the Peter Pan protoplanetary disk phenomenon, the first extreme T subdwarfs, the oldest analog of our solar system, every known sample of interstellar dust, and much more. What made these discoveries possible was a change in the ways scientists work with the public, a revolution that has unlocked a powerful, addictive new research mode. I’ll tell the epic story of this development and NASA’s role in it, informed by a neutrino experiment and a classic 80s space opera.
Let’s go get the data!
SOFIA Science Center, Universities Space Research Association
The Infrared Telescope Facility faces both great opportunities and challenges. The launch of the JWST is a momentous event for mid-infrared astronomy. It provides amazing capabilities as well as a large and well-funded user community. While IRTF cannot compete head-to-head with JWST, there are numerous unique and complementary observational methods and capabilities of the IRTF, that provide important synergies. IRTF can also leverage the well-funded JWST user community to enhance its own research, and support.
Some of the unique capabilities of the IRTF are high-resolution spectroscopy, as well as IFUs, and MIR polarimetry capabilities. It provides more nimble time-domain capabilities for transient events and larger sky availability for monitoring observations, with a [much] smaller Sun avoidance angle than space-based observatories, crucial for e.g. Venus and comet observations. IRTF can take advantage of on-going instrument and detector development, to enhance existing instruments and provide new capabilities. Continuing its nimble operations, targeting unique (and new) instruments and deep community contacts (instrument developers and users), the IRTF will remain a vital player in 21st century IR astronomy.
Low-mass globular clusters from stripped dark matter halos
NASA Hubble Fellow
University of Hawaiʻi Institute for Astronomy
The origin and formation of globular clusters has remained a mystery. I present a formation scenario for ancient globular cluster-like objects that form in ultra-high resolution simulations (smallest cell size <0.1pc, mass resolution Mcell = 4M☉). The simulations are cosmological zoom-in simulations of dwarf galaxies within the stellar mass range 106-7 M☉ that match Local Group dwarf properties well. I will show these globular clusters host ancient stellar populations and are characterized by a lack of dark matter in the present epoch. The clusters exhibit short, episodic star formation histories, occasionally marked by the presence of multiple stellar generations. The metallicity distributions show a widening, encompassing stars with solar metallicities. The presence of these objects is attributable to star formation occurring within low-mass dark matter halos (Mhalo ~ 106 M☉) during the early stages of the Universe, preceding Reionization (z > 7). As these clusters are accreted into dwarf galaxies, dark matter is preferentially subjected to tidal stripping, with an average accretion redshift of z ~ 5.
Probing the Universe’s expansion with multi-messenger astronomy
Carnegie Mellon University
The synergy between gravitational wave (GW) experiments, such as LIGO/Virgo, and optical sky surveys is prominent in the discovery of electromagnetic counterparts to GW events and the application of the standard siren method, which has already enabled several measurements of the Hubble Constant. Dark Energy Camera (DECam) follow-up observations of the first binary neutron star merger detected by LIGO/Virgo enabled the discovery of the first optical counterpart to a GW event and the first standard siren measurement, which we have updated using the latest afterglow constraints. We will continue searching for optical counterparts in the upcoming years with the Gravitational Wave Multi-Messenger Astronomy DECam Survey (GW-MMADS), which I will introduce. We have also extended the standard siren analysis to compact object binary merger events without electromagnetic counterparts using galaxy catalogs, for which I will present the latest results. In the last part of the seminar, I will talk about an interesting possibility for the formation of binary black hole mergers in disks of Active Galactic Nuclei, and how these could be used for cosmology. I will show how the various standard siren measurements presented could be promising tools to shed light on the Hubble constant tension in the coming years.
Directly Imaging Extrasolar Planets with the Subaru Coronagraphic Extreme Adaptive Optics Project: Steps Towards Seeing Another Earth
University of Texas at San Antonio
The Subaru Coronagraphic Extreme Adaptive Optics Project (SCExAO) coupled to the CHARIS integral field spectrograph is the most advanced high-contrast imaging platform in the northern hemisphere. This talk summarizes direct imaging results obtained with SCExAO/CHARIS, over the past two years. SCExAO/CHARIS imaging reveals the signatures of planets imprinted on the structures of protoplanetary disks around young stars and has yielded evidence for at least one protoplanet on a wide separation around the star AB Aurigae. With SCExAO/CHARIS, we are carrying out a new search for imaging planets around nearby stars, using precision astrometry to determine which targets may host an exoplanet we can image. This survey has led to the first joint direct imaging + astrometric discovery of an exoplanet, enabled us to find exoplanets at a faster rate than before, and allowed us to study the planets’ atmospheres, weigh them, and track their orbits all at once. Finally, I describe SCExAO’s new upgrades, which will allow us to break new ground in exoplanet discovery and atmospheric characterization, help the project play a critical role in NASA’s future exoplanet programs, and demonstrate key technologies needed for imaging rocky planets around nearby stars with future extremely large telescopes like TMT and GMT.
Trojan Odyssey: NASA’s Lucy Discovery Mission and the Quest for Solar System Origins
Arizona State University
The Trojan asteroids are a large and enigmatic population of small bodies that orbit in the L4 and L5 Lagrange points of the Jupiter-Sun system, roughly 60 degrees ahead of and behind the giant planet. Asteroids are the remnants—the fossils, if you will—of solar system formation, and the small and distant Trojans are hypothesized to be among the remnants of early giant planet formation, in particular. But what we can tell of them from telescopes paints a picture of a diverse community of small bodies that appear to have formed in many different parts of the solar system, from the Main Belt close to the Sun out to well beyond the orbits of Neptune and Pluto. One hypothesis, broadly referred to as the
Nice Model, is that the Trojans were scattered from their original formation locations by the gravitational effects of the early migration of the orbits of Jupiter and the other giant planets. But such hypotheses can’t be properly tested from telescopes alone—we need to visit the Trojans up close to study their geology, composition, and other properties to learn more. NASA’s Lucy Discovery mission was competitively selected in 2017 to do just that. Lucy (named after the famous African fossil of human origins), which launched in October 2021, will flyby eight Trojans (including a large binary pair and two tiny moons) to conduct the first detailed examination of representatives of this population. Jim Bell is a member of the Lucy science team, and in this presentation he will talk about the scientific motivation behind the mission, and what the team hopes to achieve and discover during the 2027 to 2033 flybys.
The Milky Way Galactic Center – A Laboratory for Extreme Astrophysics Revealed with Adaptive Optics
Keck All-sky Precision Adaptive Optics (KAPA) Postdoctoral Scholar
The Milky Way Galactic Center is the closest nuclear star cluster to us. Despite its proximity, stars at the very center of the nuclear star cluster are difficult to observe due to extreme stellar crowding. Adaptive optics has enabled precision astrometry and spectroscopy of Galactic Center stars, leading to measured stellar orbits that confirmed the existence of a supermassive black hole. During my talk, I will describe how the UCLA Galactic Center Group has continued to monitor stars at the very heart of our galaxy and how we investigate questions about extreme physics and stellar populations near a supermassive black hole. I will also describe how developments in adaptive optics will improve our ability to learn more about the Galactic Center.
Charting the Chemistry of Galaxies Across Cosmic Time: JWST and Beyond
A central goal of modern astrophysics is to understand how galaxies grow and change over the 14 Gyr of cosmic history. To achieve this goal, it is necessary to disentangle the competing effects of the many baryonic processes that govern galaxy evolution alongside the dark matter-dominated growth of large-scale structure—including accretion of gas from the cosmic web, as well as outflows and feedback driven by massive stars and accreting supermassive black holes. These processes are difficult to observe directly, and an added complication is that much of what we know about the galaxy population is based on the present-day Universe (z ~ 0), even though the vast majority of stars in galaxies were formed at much earlier times (z > 1, more than ~7 Gyr ago). Fortunately, using new facilities like the James Webb Space Telescope (JWST) and premier ground-based observatories like the Keck Telescopes, we are now on the cusp of being able to study galaxies in detail at all cosmic times. I will share recent progress in characterizing the galaxy population during the peak of galaxy assembly 10-12 Gyr ago (z ~ 2–3), including efforts by my group to use ultra-deep Cycle 1 JWST/NIRSpec observations to accurately determine the chemical abundances in these distant galaxies. I will also preview science that will soon be possible with a large upcoming galaxy survey using the new Prime Focus Spectrograph (PFS) on the Subaru Telescope, which will target hundreds of thousands of galaxies during the period 5-10 Gyr ago when many were transitioning from highly star-forming to relatively quiescent, like the majority of galaxies today.
Measuring Stellar Properties Using Stellar Oscillations
Beatrice Watson Parrent Fellow
University of Hawaiʻi Institute for Astronomy
Measuring key stellar properties, like age, radius, and mass, can provide strong foundations for several important areas in galactic, stellar, and exoplanetary research. Asteroseismology, the study of stellar oscillations, probes the internal structure of stars and has been shown to be a powerful tool to obtain accurate stellar properties, thanks to recent breakthroughs in observations. However, these data also highlight major deviations from our theoretical expectations. These include mismatches in oscillation frequencies due to improper modeling of stellar surface layers, and incorrect estimates of mass and age for metal-poor stars, among many other issues. In this presentation, I will outline strategies for enhancing our understanding and improvement of several asteroseismic tools, including the asteroseismic scaling relations and stellar modeling approaches. These advancements will deliver improved stellar parameters and lay the groundwork for new and exciting discoveries.
Environmental studies of supernovae with integral field spectroscopy
Ramón y Cajal Fellow
Institute of Space Sciences (ICE-CSIC) & Institut d’Estudis Espacials de Catalunya (IEEC)
Integral Field Spectroscopy (IFS) applied to supernova (SN) environmental studies have shown the potential of this technique to directly characterize the galactic environmental parameters at SN locations, compare them to those at different locations of the galaxy, and put constraints on progenitor stars for different SN types. Here, I will summarize past efforts of studying supernova environments with either global/local photometry/spectroscopy, and current efforts for improvement from the two largest SN host galaxy surveys with IFS: PISCO which was built from the selected sample of SN hosts from the CALIFA survey, and AMUSING, which has used more than 600h of VLT time with MUSE to compile a sample of SN host galaxies.
Measuring the Hubble Constant with a Triply-Imaged Type Ia Supernova Observed by JWST at z = 1.78
NASA Einstein Fellow
Space Telescope Science Institute
There is a 5σ disagreement between local measurements of the Hubble constant from Type Ia supernovae (SNe Ia), and the value inferred from late universe cosmic microwave background (CMB) constraints. Independent measurements are critical to understanding the source of this tension. Gravitationally lensed SNe provide a new high-precision, single-step probe that directly constrains the Hubble constant and is fully independent of SNe Ia or CMB cosmology. These objects are extremely rare, with only one lensed SN measurement of the Hubble constant to date. The most distant (z = 1.78) lensed supernova SN Ia was recently discovered in JWST/NIRCam imaging in the PLCK G165.7+67.0 (G165) galaxy cluster, named “H0pe.” SN H0pe is triply-imaged and provides the first opportunity to measure the Hubble constant with a multiply-imaged SN Ia. I will present on the JWST imaging, spectroscopy, and analysis of the exciting SN H0pe, as well as the status and future of lensed SN cosmology.
The Keck Wide-Field Imager: The most powerful wide-field camera for the foreseeable future and what it can do for you
Swinburne University of Technology
Deep optical wide-field imaging is essential in nearly every area of astronomy and for all wavelength (radio through gamma-ray), particle, and gravitational wave science. The Keck Wide-Field Imager (KWFI) is a 1-degree diameter field of view UV-sensitive optical prime focus camera for Keck. KWFI will be the most powerful wide-field camera on Earth or in space for the foreseeable future (decades) and the only such 8m-class camera sensitive from 1 micron down to 3000 Å. KWFI will reach game-changing magnitudes of m ~ 28–30 (~25–4 nano-Jy) depths, including the u-band, as a result of KWFI’s extremely high throughput, Keck’s 10m aperture and Maunakea’s 4100m elevation, to enable world-leading science that cannot be done on any other telescope, not even 30-metre telescopes. In addition, KWFI will perform a critical role for the main science aims of existing and upcoming research facilities such as JWST, NASA Roman, ESA Euclid, the ELTs, the Square Kilometre Array, the Cherenkov Telescope Array, KN3Net, LIGO/Virgo/KAGRA, LISA, and many more, and will extend their reach. In this talk, I will discuss some of these science cases, the instrument, its status, and the path forward.