Curving X-ray detectors for astrophysics applications

Kavli Affiliate: Catherine Grant | Summary:Next-generation X-ray optics will revolutionize high-energy astrophysics, yet they present several challenges to design a complementary focal plane. In particular, the focal surface is curved, requiring many small, flat sensors to achieve a large field. We present work building on MIT Lincoln Laboratory technology to curve the sensor itself, improving […]


Continue.. Curving X-ray detectors for astrophysics applications

JWST Reveals a Candidate Supermassive Black Hole Binary at z=4.3 in the Brightest Sub-millimeter Galaxy in COSMOS-Web

Kavli Affiliate: Kohei Inayoshi | Summary:We present JWST/NIRSpec PRISM and G395M grating spectroscopy for AzTEC-1, a massive sub-mm bright galaxy at $z=4.34$ in the COSMOS extragalactic field. The PRISM spectrum reveals strong H$α$, a significant Balmer break, and no H$β$ detection, indicating a $100-400$ Myr-old stellar population and high dust attenuation. BPT line ratios indicate […]


Continue.. JWST Reveals a Candidate Supermassive Black Hole Binary at z=4.3 in the Brightest Sub-millimeter Galaxy in COSMOS-Web

Improved Threshold for Particle-Induced Magnetic Avalanche in Single-Molecule Magnets Using Fe$_8$ Molecule

Kavli Affiliate: Tom Melia | Summary:Extending the original work on the development of a magnetic avalanche detector using Mn$_12$-ac single-molecule magnet (SMM), we report the results on a significantly lower threshold magnetic avalanche detector using Fe$_8$ SMM. Fe$_8$ has an order of magnitude smaller relaxation time that is expected to produce at least 3 orders […]


Continue.. Improved Threshold for Particle-Induced Magnetic Avalanche in Single-Molecule Magnets Using Fe$_8$ Molecule

Skyfire: A Spectroscopic Census of Little Red Dots and Broad-Line AGN in the CEERS Field

Kavli Affiliate: Kohei Inayoshi | Summary:We present the Skyfire program, a 21-hour Cycle 3 JWST/NIRSpec survey with the G395M medium-resolution grating covering five pointings in the Extended Groth Strip. The survey is designed to carry out a systematic census of faint, broad-line AGN candidates with a range of rest-optical colors identified at z > 3 […]


Continue.. Skyfire: A Spectroscopic Census of Little Red Dots and Broad-Line AGN in the CEERS Field

Weighing Little Red Dots with Transient Events

Kavli Affiliate: Mark Vogelsberger | Summary:Recent JWST observations have revealed a large population of compact red sources at $z gtrsim 4$, known as Little Red Dots (LRDs), many of which show signatures of accreting massive black holes (BHs). The physical nature of these sources and their connection to host galaxies are under debate. We propose […]


Continue.. Weighing Little Red Dots with Transient Events

You Shouldn’t Have Asked: A Pragmatics-Inspired Taxonomy for Evaluating LLM Refusals

Kavli Affiliate: Robert Cameron | Summary:Refusals are often treated as face-threatening acts in pragmatics because they can challenge the requester’s socially claimed self-image. Large language models (LLMs) are increasingly trained to refuse unsafe and inappropriate requests, and these refusals may harm users when models fail to manage this interactional cost properly. While existing work has […]


Continue.. You Shouldn’t Have Asked: A Pragmatics-Inspired Taxonomy for Evaluating LLM Refusals

Host Dependence and Line-of-Sight Effects on Galaxy-Galaxy Strong Lensing in Clusters

Kavli Affiliate: Mark Vogelsberger | Summary:The cross section for galaxy-galaxy strong lensing (GGSL) events in galaxy clusters has repeatedly been found to be higher in observations than in cosmological simulations. We revisit this discrepancy using updated simulation methodology and investigate the dependence of the GGSL probability, $P_rm GGSL$, on host-cluster lensing properties, baryonic physics, and […]


Continue.. Host Dependence and Line-of-Sight Effects on Galaxy-Galaxy Strong Lensing in Clusters

When 3D Gaussian Splatting Recovers Real Surfaces

Kavli Affiliate: David W. Miller | Summary:When does 3D Gaussian Splatting (3DGS) recover the true scene surface rather than just overfitting view-dependent appearance? We answer this by developing a mathematical framework based on a first-hit rendering abstraction that cleanly isolates geometry from appearance. We prove that geometric misalignment forcefully converts spatial textures into high-frequency angular […]


Continue.. When 3D Gaussian Splatting Recovers Real Surfaces

Advancing Fundamental Physics and Cosmology with high-resolution X-ray imaging

Kavli Affiliate: Herman Marshall | Summary:Black Holes are the key to solving many unanswered questions in fundamental physics: in particular, the very extreme properties shown by supermassive black holes at the centers of galaxies make them obvious candidates for testing gravity theories in the strong-field regime. Since X-rays are generated by matter under extreme physical […]


Continue.. Advancing Fundamental Physics and Cosmology with high-resolution X-ray imaging

The Structural Abundance Crisis of Massive Galaxies in Current Cosmological Simulations

Kavli Affiliate: Luis Ho | Summary:The internal structure of galaxies encodes the complex baryon cycle driven by gas accretion, star formation, and feedback, together with secular evolution and environmentally driven processes such as mergers and tidal interactions. We present a population-level census of massive nearby galaxies ($log(M_star/M_odot) > 10$) by comparing Hyper Suprime-Cam Subaru Strategic […]


Continue.. The Structural Abundance Crisis of Massive Galaxies in Current Cosmological Simulations