activity
20242026
collaborators

9 papers

astro-ph.HE2026

Energy shift of Fe-K fluorescence lines due to low ionization demonstrated with XRISM in Centaurus X-3

Yutaro Nagai, Teruaki Enoto, Masahiro Tsujimoto +13

The Fe K fluorescence line at 6.4 keV is a powerful probe of cold matter surrounding X-ray sources and has been widely used in various astrophysical contexts. The X-ray microca…

astro-ph.SR2025

Chandra/HETG and NuSTAR Observations of V750 Ara, a Cas-type Star

David P. Huenemoerder, Sean J. Gunderson, Richard Ignace +6

We present 197 ks HETG and 95 ks NuSTAR spectra of the Cas-type object V750 Ara. The high-resolution X-ray spectra show that the target is similar to other objects of this cl…

astro-ph.SR2025

A Multiwavelength View of Oph I: Resolving the X-ray Source Between A and B

Sean J. Gunderson, Jackson Codd, Walter W. Golay +12

We present a multiwavelength analysis of the central stellar pair of Oph, components A and B. Using recent high-resolution \textit{Chandra X-ray Observatory} observations, we d…

astro-ph.SR2025

X-ray Polarimetry of Accreting White Dwarfs: A Case Study of EX Hydrae

Sean J. Gunderson, Swati Ravi, Herman L. Marshall +5

We present the first first X-ray polarization measurements of a white dwarf, the intermediate polar EX Hya. We measured significant polarization only in the 2 -- 3 keV energy band…

astro-ph.HE2025

Benchmark of the Fe XXV R ratio in photoionized plasma during eclipse of Centaurus X-3 with XRISM/Resolve

Yuto Mochizuki, Masahiro Tsujimoto, Maurice A. Leutenegger +6

The R ratio is a useful diagnostic of the X-ray emitting astrophysical plasmas defined as the intensity ratio of the forbidden over the inter-combination lines in the K line co…

astro-ph.SR2025

Carbon-rich dust injected into the interstellar medium by Galactic WC binaries survives for hundreds of years

Noel D. Richardson, Micaela Henson, Emma P. Lieb +23

Some carbon-rich Wolf-Rayet stars (WC stars) show an infrared excess from dust emission. Dust forms in the collision of the WC wind with a companion star's wind. As this dust is ca…