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Fe XXV resonant scattering

Model the Fe XXV w line near 6.7 keV with AtomDB emission and ion fractions, then compare intrinsic and scattered radiation. This example uses TNG-Cluster target 0 at z = 0.

Intrinsic and scattered Fe XXV w maps and annular spectra. Intrinsic and scattered Fe XXV w maps and annular spectra.

The intrinsic (optically thin) and scattered surface brightness maps show similar structure. The annular spectra reveal suppressed inner emission and redistribution of photons into the outskirts, reflected in the scattered-to-intrinsic ratio (S / I).

Run

Download the AtomDB table (37 MiB; checksums) and unpack it:

xz -dc atomdb-3.1.3-cie-ag89-fe-k-v1-atomdb.h5.xz.part0000 > cluster-cie.h5

Download fexxv-w.yaml, set the snapshot paths and atomdb.table_path to the unpacked file, and run:

OMP_NUM_THREADS=8 ACPP_VISIBILITY_MASK=omp thor fexxv-w.yaml

The model includes thermal broadening and gas bulk velocities. It follows only the w line, without continuum, neighboring lines, or an instrument response.

Outputs

The run saves intrinsic and scattered maps and aperture spectra. “Scattered” includes photons that reach the observer without scattering. Maps are stored in erg s⁻¹ cm⁻² arcsec⁻². See reading and converting the outputs for photon surface brightness, photon-luminosity spectra, and annular spectra.