Astro-H: New Spectral Features Seen in High-Resolution X-rays

The Soft X-ray Spectrometer (SXS) microcalorimeter on Astro-H will provide the first high-resolution X-ray spectra of diffuse astrophysical sources. One key new type of science will be charge exchange spectroscopy, wherein highly-ionized metals interact with neutral hydrogen, helium, or other material. This has been detected with modest resolution in comets and planets, and is thought to be the origin of at least some of the 1/4 keV soft X-ray background. We will report on the predicted emission that the Astro-H SXS may detector from all of these sources using the recently released AtomdB Charge Exchange spectral model acx, and comment on possible other sources such as starburst galaxies. The SXS will also observe complex high-resolution spectra from other diffuse sources such as overionized supernova remnants and galaxy clusters. We will discuss these in the context of advanced spectral models using the recently released AtomDB v3.0 data and non-equilibrium models.