High-spectral-resolution X-Ray Observations of the Evolved Supermassive Stellar Binary System η Carinae: Fe Kα Band Profile Revealed with XRISM

01/06/2026 - High-Energy

The supermassive binary system, η Carinae, is experiencing enormous wind-driven mass loss at a rate unparalleled in the rest of the Galaxy. Their wind─wind collision (WWC) continuously produces shock heated, X-ray-emitting plasmas. The XRISM X-ray observatory observed the system in 2023 and 2024 when the X-ray emission began to increase toward periastron passage in 2025.…

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Sensitivity of dry lava planet atmospheric emission spectra to changes in lava compositions

01/06/2026 - Exoplanets

The atmospheres of hot rocky exoplanets are among the first primary targets of the James Webb Space Telescope (JWST). Interpreting their atmospheric spectra requires understanding the link between silicate lava compositions and overlying atmospheres. We investigate the sensitivity of simulated emission spectra of dry lava planets to variations in oxide abundances in silicate melt. Our…

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Silicon, Sulfur, and Iron in the Interstellar Medium: A High-resolution X-Ray Spectral Study of GX 340+0

01/05/2026 - High-Energy

High-resolution X-ray spectroscopy provides a powerful probe of the interstellar medium (ISM), giving direct access to the composition and physical state of dust grains and atomic species in dense environments. We present a study of the gas and dust along the line of sight to the bright low-mass X-ray binary GX 340+00, which samples higher-density…

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