High-Resolution Hard X-ray Spectroscopy with Transition Edge Sensor Microcalorimeter Arrays

Speaker

Fabian Kislat (University of New Hampshire)

Abstract

Spectroscopy of X-ray and gamma-ray lines is one of the most powerful tools of high-energy astrophysics. Gamma-ray emission originating from decays of ⁴⁴Ti, for example, allows us to study ejecta in supernova remnants in great detail and provides some of the strongest constraints on the explosion mechanism. Because ⁴⁴Ti is produced in regions where the explosion is driven (e.g., convective regions in the standard supernova engine), it is a strong probe of the supernova explosion mechanism. The isotope has a half-life of about 60 years, making it observable in historic remnants.

The shape of the iron Kα line in accreting black hole and neutron star systems carries important information about the geometry of the system, including the neutron star radius, and the accretion processes. Recently, the Resolve instrument on board the X-Ray Imaging and Spectroscopy Mission (XRISM) made it possible to detect structures in the relativistically broadened line.

I will give an overview of the scientific potential and technical challenges of a high-energy X-ray imaging telescope using an array of superconducting gamma-ray transition-edge sensor (TES) microcalorimeter detectors with a spectral resolution ~55eV. When used on a future NuSTAR follow-up mission, these detectors will allow detailed spectroscopy of the ⁴⁴Ti line in supernova remnants. Measurements of the Fe Kα line with such an instrument will have a spectral resolution that is well matched to the expected structures and at the same time provide a detailed measurement of the underlying continuum. Constraining the continuum emission is one of the main challenges of spectroscopic analyses conducted with current high-resolution instruments. I will present future satellite based and balloon-borne hard X-ray mission concepts and our approach to addressing the challenges outlined above, and the progress we have made in recent years.

Title TBA

Speaker

Casey DeRoo (University of Iowa)

Abstract

TBA

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