X-ray spectroscopy in the microcalorimeter era 4: Optical depth effects on the soft X-rays studied with CLOUDY

Abstract

In this paper, we discuss atomic processes modifying the soft X-ray spectra in from optical depth effects like photoelectric absorption and electron scattering suppressing the soft X-ray lines. We also show the enhancement in soft X-ray line intensities in a photoionized environment via continuum pumping. We quantify the suppression/enhancement by introducing a "line modification factor ($f_{\mathrm{mod}}$)." If 0 $\le$ $f_{\mathrm{mod}}$ $\le$ 1, the line is suppressed, which could be the case in both collisionally-ionized and photoionized systems. If $f_{\mathrm{mod}}$ $\ge$ 1, the line is enhanced, which occurs in photoionized systems. Hybrid astrophysical sources are also very common, where the environment is partly photoionized and partly collisionally-ionized. Such a system is V1223 Sgr, an intermediate polar binary. We show the application of our theory by fitting the first-order Chandra MEG spectrum of V1223 Sgr with a combination of \textsc{Cloudy}-simulated additive cooling-flow and photoionized models. In particular, we account for the excess flux for O~VII, O~VIII, Ne~IX, Ne~X, and Mg~XI lines in the spectrum found in a recent study, which could not be explained with an absorbed cooling-flow model.

References in corpus (12)

• Two new Intermediate Polars with a soft X-ray component
• Stout: Cloudy's Atomic and Molecular Database
• The first broadband X-ray view of the narrow line Seyfert 1 Ton S180
• A Cloudy/Xspec Interface
• X-ray spectroscopy in the microcalorimeter era I: Effects of Fe XXIV Resonance Auger Destruction on Fe XXV K$\alpha$ spectra
• The role of complex ionized absorber in the soft X-ray spectra of Intermediate Polars
• Chandra HETG line spectroscopy of the Non-magnetic Cataclysmic Variable SS Cyg
• X-ray spectroscopy in the microcalorimeter era II: A new Diagnostic on Column Density from the Case A to B Transition in H- and He-like Iron
• Implications of Coronal Line Emission in NGC 4696
• Looking through the photoionisation wake: Vela X-1 at ${\phi }_{\mathrm{orb}}\approx 0.75$ with Chandra/HETG
• Application of a new X-ray reflection model to V1223 Sagittarii
• Cloudy in the microcalorimeter era: improved energies for Si and S K$\alpha$ fluorescence lines

Cited by in corpus (4)

• X-ray metal line emission from the hot circumgalactic medium: probing the effects of supermassive black hole feedback
• Scientific Objectives of the Hot Universe Baryon Surveyor (HUBS) Mission
• R-matrix electron-impact excitation data for the H- and He-like ions with Z=6-30
• Probing extreme black-hole outflows on short timescales via high spectral-resolution X-ray imagers