Wine and Cheese Spring 2026

This page records the schedule, titles and abstracts of the JHU/STScI CAS Astrophysics Wine & Cheese Series in Spring 2026.

Wine and Cheese sessions with one speaker will have a 50 minute talk with 10 minutes for questions. Sessions with two speakers will have two 25 minute talks, each with 5 minutes for questions.

26 January

Colin Hamill (AAS)

Astronomy on the Hill: Federal Funding and Dark & Quiet Skies Policy
The landscape of federal science policy has shifted dramatically over the past year. As the FY2026 federal funding cycle concludes, this talk will provide a brief overview of the current fiscal situation for the astronomical sciences, as well as an outlook for FY2027 and beyond. We will then examine the Dark & Quiet Skies initiative, a global effort to preserve the night sky from light pollution and radio frequency interference from satellites. We will review recent regulatory developments in the space environment and highlight how the astronomical community works with commercial space operators and the federal government to ensure a sustainable orbital environment. The talk concludes with a discussion of how scientists at all career stages can engage with policymakers to ensure astronomy and science remains a priority on Capitol Hill.

09 February

Chris Nagele (JHU)

Radiation Transfer Simulations of Black Hole Spectra
Spectra from accreting black holes are one of our most powerful tools for understanding these enigmatic objects. These spectra, however, are not well understood. For example, stellar mass black holes and supermassive black holes exhibit different spectral properties, with the stellar mass black holes changing between different spectral states (hard and soft states) while the supermassive black holes have more uniform spectral slopes. We run radiation transfer post-processing of general relativistic magnetohydrodynamical simulations of black hole accretion, in order to generate spectral predictions. We use two radiation transfer codes, Pandurata and PTransX, to solve for thermal balance and ionization balance in different parts of the simulation. Our spectra are remarkably similar to observed trends, with a clear hard/soft dependence on accretion rate at M = 10 Msun and uniformly flat spectra in the supermassive regime. We also compute high resolution spectra in order to simulate emission lines coming from the accretion disk near the black hole. Our spectra contain Fe Kalpha lines with equivalent widths (50-200 eV) and line shapes consistent with observations. We find, however, that the breadth of these lines is due to several factors, and not simply to extreme relativistic motions near the black hole, as is almost always assumed. We discuss how physical quantities from our simulations can be incorporated into models which perform black hole parameter inference, thereby breaking some of the degeneracy associated with these models.

Stephen Schmidt (JHU)

Hot Jupiters are Inflated Primarily by Shallow Heating
The unexpectedly large radii of transiting hot Jupiters have led to many proposals for the physical mechanisms responsible for heating their interiors. While it has been shown that hot Jupiters reinflate as their host stars brighten due to heating deep in planetary interiors, young hot Jupiters also exhibit signs of delayed cooling possibly related to heating closer to their surfaces. To investigate this tension, we enhance our previously published hot Jupiter thermal evolution model by adding a parameter that allows for both deep heating and delayed cooling. We fit our thermal evolution models to a homogeneous, physically self-consistent catalog of accurate and precise hot Jupiter system properties in a hierarchical Bayesian framework. We find that hot Jupiters' interior cooling rates are reduced on average by 95%--98% compared to simpler anomalous heating models. The most plausible explanation for this inference is substantial shallow heating just below their radiative--convective boundaries that enables reinflation with much less deep heating. Shallow heating by Ohmic dissipation and/or temperature advection are therefore important components of accurate models of hot Jupiter atmospheres, especially in circulation models. If hot Jupiters are inflated primarily by shallow heating as we propose, then we predict that their observed phase curve offsets should increase with temperature in the range T_eq <~ 1500 K, peak in the range 1500 K <~ T_eq <~ 1800 K, and decrease in the range T_eq >~ 1800 K.

16 February

Jessica A. Gaskin (GSFC)

Preparing for the Next Astronomy and Astrophysics Decadal Survey (Astro2030)
The Astronomy and Astrophysics Decadal Survey, conducted once every ten years, establishes the community’s highest-priority ground- and space-based science goals and provides strategic guidance for future investments. NASA relies heavily on this guidance when shaping its long-term mission portfolio and budget. For the 2020 Decadal Survey, NASA supported a suite of community-led mission concept studies that articulated compelling science cases, assessed technical readiness, defined design reference missions, and developed high-level cost estimates, ensuring that the Decadal Committee was equipped with a robust and well-informed basis for its deliberations. As preparations begin for the next survey, Astro2030, NASA is again engaging the community to inform its planning. This includes soliciting broad feedback and convening two workshops—one in the spring and one in the fall of this year—to incorporate the evolving space environment, emerging technologies, and growing commercial capabilities before initiating any new NASA-sponsored mission concept formulation activities. This talk will provide an overview of the Decadal Survey process and outline NASA’s current plans and rough timeline for preparing for Astro2030.

23 February

Eileen Meyer (UMBC)

Crossing the Radio Divide: Radio Studies of Changing-Look AGN
While astronomers first discovered that super-massive black holes (SMBH) can launch jets of relativistic plasma over 60 years ago, we are still searching for the 'trigger' that turns a non-jetted SMBH into a jetted one. Given typical lifetimes of millions of years (if not longer), it might seem highly improbable to catch a black hole 'in the act' of launching a brand-new relativistic jet. Yet that is exactly what we believed happened in the case of 1ES 1957+654, a nearby 'changing-look' active galaxy where long-term VLBA monitoring caught a sudden radio brightening in spring of 2023 which we now understand to be a new-born jet. Nearly 2 years on, we can now follow the evolution of the plasma structures as seen in high-resolution radio imaging, and speculate on the likely cause (and future) of this unusual jet. I will place these findings in the larger context of recent discoveries which blur the line between jetted/non-jetted (or radio-quiet/radio-loud) black holes and show these types are more changeable than we might have first believed. I will also make connections between black hole outflows at all scales and in very different conditions -- from TDEs to X-ray binaries, and speculate on what may ultimately be the key to a successful jet launch.

02 March

Rajes Ghosh (JHU)

Gravitational Waves as Probe of New Physics
A decade after LIGO’s historic detection of GW150914, gravitational wave astronomy has matured into a powerful tool for uncovering new physics beyond the standard paradigm. In this spirit, I will present a novel approach to testing the Kerr paradigm using the ringdown phase of binary mergers, where the final black hole relaxes by emitting quasi-normal modes. While most existing works assume that deviations from Kerr preserve its defining symmetries, e.g., stationarity, axisymmetry, and circularity, these assumptions can indeed be broken in the presence of environmental effects or dynamical modifications of gravity. I will focus in particular on potential violations of Kerr circularity and demonstrate how quasi-normal mode spectroscopy can be used to probe such departures. Using GW150914 as a case study, we place stringent observational constraints on such deviations. This symmetry-based test also offers a novel avenue for assessing the robustness of various foundational results, like black hole uniqueness and no-hair theorems, in the context of astrophysical black holes.

09 March

Michael Eracleous (PSU)

The Central Engines of LINERs
Low-Ionization Nuclear Emission-line Regions (LINERs) have been a puzzle and the subject of debate since their identification in 1980. They are defined through the strengths of their low-ionization oxygen emission lines and are very common (found in about half o nearby galaxies). Their optical emission-line spectra can be attributed to shocks, or photoionization by a hard continuum from an active nucleus, or photoionization by unusually hot stars. I will discuss, in historical perspective, the work I have been doing with my collaborators and students trying to identify the power source in LINERs and present the emerging picture: LINERs are seemingly feeble active nuclei that can photoionize the circumnuclear gas in their immediate vicinity (within a few tens of parsec) but also produce outflows that shock the interstellar gas at larger distances (within several hundred parsec). As such, they are mechanical feedback machines whose influence on their host galaxies remains to be fully appreciated.

23 March

Yifan Zhou (UVa)

Dynamical Processes in Planetary Atmospheres: A Time-Resolved Perspective
Planetary atmospheres are highly dynamic systems. Atmospheric circulation, cloud formation, and radiative transfer drive persistent variability. The discovery and characterization of exoplanets have dramatically expanded our ability to study these dynamical processes across multiple dimensions. These dimensions include the evolutionary stage, energy budget, and rotation rate. Time-resolved direct spectroscopy provides the most powerful tool for tracing atmospheric dynamics. My group uses this approach to observe planetary and substellar objects across a wide range of evolutionary stages. This allows us to identify and characterize the physical processes that shape these worlds. In this talk, I will present case studies using high-precision monitoring data from HST and JWST. These studies probe accretion processes in forming protoplanets, atmospheric dynamics in mature giant planets and brown dwarfs, and rotation measurements of directly imaged exoplanets. I will also discuss one particularly revealing case: highly irradiated substellar companions to white dwarfs. These objects play a critical role in bridging different regimes of atmospheric physics and offer unique insights into post-main-sequence planetary systems. I aim to initiate new collaborations with experts across these fields to develop a unified framework for understanding atmospheric dynamics throughout planetary evolution.

30 March

F. Scott Porter (GSFC)

Laboratory astrophysics and atomic spectroscopy in the age of XRISM and NewAthena
Laboratory astrophysics has long been important in order to place the spectral synthesis codes, and the underlying atomic physics, on a sound experimental footing. Spectral synthesis codes are used to fit the observational data and extract the physical characteristics of the source. This has recently become even more important with the launch of XRISM and the preparation for NewAthena. The XRISM observatory was launched in 2023 and opened the X-ray midband, including the important K shell emission from Fe, to high-resolution spectroscopy. NewAthena and the high resolution XIFU instrument will follow in the mid to late 2030s and will add higher resolution spectroscopy with significantly higher throughput. However, higher resolution, and higher statistics measurements will place more stress on the precision of the spectral synthesis codes, the underlying atomic databases, and the laboratory measurements that vet them. We will discuss the role and process of X-ray laboratory astrophysics and, in addition, the laboratory measurements that support XRISM and NewAthena observations.

06 April

Soghu Wang (IU)

Towards a Unified Picture of the Origin of Hot Jupiters
While the exoplanetary field is replete with remarkable discoveries, perhaps the most intriguing findings has been the detection of hot Jupiters – giant planets orbiting perilously close to their parent stars. The mere existence of these worlds was wholly unpredicted based on the expectations gleaned from centuries of observations of our own solar system. This talk will examine the demographics and orbital architectures of these exoplanets, and discuss how subtle observational clues have guided us toward a unified framework for hot Jupiter formation.

13 April

TBD

Title
Abstract

20 April

Sarah Tuttle (UW)

Ground & Space-based instruments to Map Cosmic Ecosystems
In this talk I will talk about two instruments - one currently being built for the APO 3.5m, one proposed as a small mission explorer (SMEX). Ocotillo is a fiber-fed three channel optical spectrograph being built for the APO 3.5m. Ocotillo will initially use a single integral field unit (of ~300 fibers over a small field), with a future expansion to robotic fiber positioners with smaller IFUs (~19 fibers per robot) across the full 3.5m field (~10'). DISCO is a far ultraviolet two channel spectrograph designed to map the interactions between nearby star forming galaxies and their circumgalactic medium. We'll discuss the designs of each instrument and talk briefly about the targeted science around galaxy evolution and beyond.

27 April

Konstantin Batygin (CalTech)

Determination of Jupiter’s Primordial Radius, Accretion Rate, and Magnetic Field
The formation and early evolution of Jupiter played a pivotal role in sculpting the large-scale architecture of the solar system, intertwining the narrative of Jovian early years with the broader story of the solar system’s origins. The details and chronology of Jupiter’s formation, however, remain elusive, primarily due to the inherent uncertainties of accretionary models, highlighting the need for independent constraints. In this talk, I will show that by analyzing the dynamics of Jupiter’s satellites concurrently with its angular momentum budget, we can infer Jupiter’s radius and interior state at the time of proto-solar nebula’s dissipation. In particular, our calculations reveal that Jupiter was twice as large as it is today (corresponding to an interior entropy of S ~ 10 kB per baryon), 3.8 million years after the formation of the first solids in the solar system. Our model further indicates that young Jupiter possessed a magnetic field of approximately B ~ 210 Gauss and was accreting material through a circum-Jovian disk at a rate of ~ 1.2 Jupiter masses per million years. These findings are fully consistent with the core-accretion theory of giant planet formation and provide an evolutionary snapshot that pins down properties of the Jovian system at the end of the protosolar nebula’s lifetime. If time allows, I will also give a brief update on where things stand with Planet 9.

04 May

Anwesh Majumder (Waterloo)

The Role of Turbulence in Galaxy Clusters: A XRISM Perspective
The high-resolution X-ray spectral capability of the recently launched XRISM telescope has enabled measurements of gas motions in galaxy clusters, helping address questions such as how much of this motion is turbulent. I will briefly present recent XRISM results on gas motions in objects like the Centaurus cluster, Hydra A, and Cygnus A, and discuss implications for the role of turbulence.

Turbulence in clusters can be driven by AGN-inflated bubbles or large-scale motions such as sloshing due to mergers. Significant AGN turbulence injection requires velocity dispersions rising radially toward the center. However, in many clusters (e.g., Centaurus and Hydra A), XRISM finds no strong evidence of such trends. In Hydra A, dispersions remain nearly constant (140–160 km/s) with radius toward the Northern direction, where giant bubbles exist. The dispersion is furthermore asymmetric (80–260 km/s) when the XRISM field of view is divided, with regions of higher dispersion coincident with expanding cavity structures. These results suggest that unresolved bulk motion in XRISM dispersion measurements may explain the absence of clear radial trends. Even in clusters like Cygnus A, where much higher core dispersions are detected (261 ± 13 km/s), bulk motions may be a primary contributor. The XRISM dispersions are therefore upper limits on turbulence.

Finally, I will present a buoyancy-driven model describing the conditions under which cavities inject turbulence at different scales to balance cooling, and apply it to several clusters observed so far with XRISM.