Special Talk

• Special Talks

  Speaker: Ian Wong (STScI)
  Title: Exploring the Compositional Diversity of Small Bodies in the Solar System with JWST ​​​​​​​
  Abstract: Small bodies lie at the nexus of many foundational questions in planetary science. From near-Earth asteroids to far-flung Kuiper belt objects and Oort cloud comets, these primitive planetesimals represent the primordial building blocks of the Solar System, encoding the chemical and thermophysical conditions across the protoplanetary disk and the myriad evolutionary processes that have shaped their interiors and surfaces across 4.5 Gyr. Systematic explorations of their composition and physical properties are highly informative for our fundamental understanding of planet formation and planetary dynamics across the galaxy. Over the past four years, JWST has been revolutionizing the study of solar system small bodies. By leveraging the cutting-edge capabilities of the onboard instruments, the planetary science community has made a slew of spectacular new discoveries that have substantially refined our knowledge of the various small body populations in the Solar System. The expansive wavelength coverage and exquisite sensitivity of NIRSpec in particular has enabled unprecedented analyses of the compositional inventories of icy bodies and is helping to synthesize a refined compositional atlas of the middle and outer Solar System. JWST observations have provided critical constraints on the formation and evolutionary trajectories of planetesimals, uncovering new molecular detections and physical processes. In this talk, I will provide a high-level overview of major highlights from recent JWST observations of small bodies, with a focus on connecting individual results to broad ensemble insights and interpreting these findings within the overarching framework of solar system formation and evolution models.

  Speaker: Chris Nagele​​​​​​​ (JHU)
  Title: Radiative Transfer Post-Processing of AthenaK Simulations of Eddington Accretion onto Stellar Mass Black Holes​​​​​​​
  Abstract: We present post-processing calculations which solve for thermal balance, ionization balance and radiative transfer in simulation snapshots taken from the general relativistic magnetohydrodynamics radiation code AthenaK (Zhang+26). These simulations are the first to implement genuine radiation pressure in disks of black hole accretion flows, thereby allowing the study of higher accretion rates than ever before. We present the thermal/ionization balance solutions, as well as the spectral and polarization signals predicted by our calculations. We compare to existing observation of ultra-luminous X-ray sources. We also discuss the implications of the hard X-ray weakness in these simulations for the dearth of observed X-rays in little red dots.