01/01/2026 - High-Energy

The Feasibility of Using Fe XXIII Metastable Transitions as a Density Diagnostic for Low-mass X-Ray Binary Disk Winds

Low-mass X-ray binaries (LMXBs) occasionally show signs of outflowing material from the accretion disk. Studying these outflows can inform the understanding of the geometry of the systems, as well as the dynamics and energetics of accretion. One key variable for determining the location of these disk winds is the density of the outflowing material. In…

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01/01/2026 - High-Energy

XRISM Observations of the Prototypical Cold Front in A3667

We present high-resolution X-ray spectroscopy of the merging galaxy cluster A3667 with XRISM/Resolve. Two observations, targeting the cluster X-ray core and the prototypical cold front, were performed with exposures of 105 and 276 ks, respectively. We find that the gas in the core is blueshifted by vz ∼ −200 km s−1 relative to the brightest…

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01/01/2026 - Exoplanets

Hot and cloudy: High temperature clouds in super-Earths and sub-Neptunes

JWST observations provide for the first time evidence for an atmosphere on a rocky exoplanet – 55 Cnc e. The atmosphere of 55 Cnc e is hot with Teq > 2000 K and shows strong variability, for which cloud formation above a molten crust could be one possible explanation. The composition of the atmosphere of…

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