Recent advancements in the technology readiness of the Lynx X-ray Microcalorimeter
Abstract
One of the Lynx X-ray telescope's three instruments is an imaging spectrometer called the Lynx X-ray Microcalorimeter (LXM), an X-ray microcalorimeter behind an X-ray optic with an angular resolution of 0.5 arc-seconds and approximately 2 m2 of area at 1 keV. This presentation will highlight recent advances in the LXM detector development and also characterization that determines the requirements for the LXM read-out. The LXM will meet the many different science-driven performance requirements of Lynx with different sub-regions of the detector array. These arrays are identified as the Main Array (MA) the Enhanced Main Array (EMA) and the Ultra-High-Resolution Array (UHRA). The MA has a field-of-view equivalent to the Athena X-ray Integral Field Unit instrument, but with a substantially smaller pixel size, necessary to exploit the X-ray Mirror Assembly half power diameter of 0.5 arc-seconds. This fine resolution will permit Lynx to observe sub-arcsecond-scale features in clusters and jets, and minimize source confusion in crowded fields. The MA will provide an energy resolution of better than 3 eV (FWHM) over the energy range of 0.2 to 7 keV with pixels sizes that vary in scale from 0.5 arc-seconds in the innermost 1-arc-minute EMA to pixels that are 1.0 arc-seconds extending out to a 5 arc-minute field-of-view. The EMA will provide 2 eV energy resolution (FWHM) as well as the better angular resolution. The UHRA will provide an energy resolution of 0.3 eV up to ∼ 0.8 keV and ∼ 2 eV resolution up to ∼ 2 keV in a 1 arc-minute region off to the side with 1 arc-second pixels. This region will allowing the measurement of turbulence in winds of individual galaxies, and is also used in a variety of other measurements of hot gases around galaxy halos. We report on the development of multi-absorber detectors referred to as 'hydras'. A hydra consists of multiple x-ray absorbers each with a different thermal conductance to a TES. Position information is encoded in the pulse shape. With some trade-off in performance, hydras enable the very large format arrays. We present first results from hydras with 25-pixels for Lynx. Designs with absorbers on a 25 um and 50 um pitch are studied. Arrays incorporate, microstrip buried wiring layers of suitable pitch and density required to readout a full-scale Lynx array. The resolution from the co-added energy histogram including all 25-pixels was ΔEFWHM = 1.66±0.02 eV and 3.34±0.06 eV at an energy of 1.5 keV for the 25 υm and 50 um absorber designs respectively. Designs of single pixels designed for the UHR array have demonstrated less than 0.3 eV energy resolution at low energies.
- Publication:
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American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23513004B