Can Charge Exchange Explain Anomalous Soft X-ray Emission in the Cygnus Loop?

Abstract

Recent X-ray studies have shown that supernova shock models are unable to satisfactorily explain X-ray emission in the rim of the Cygnus Loop. In an attempt to account for this anomalously enhanced X-ray flux, we fit the region with a model including theoretical charge exchange (CX) data along with shock and background X-ray models. The model includes the CX collisions of $O^{8+}$, $O7+$, $N^{7+}$, $N^{6+}$, $C^{6+}$, and $C^{5+}$ with H with an energy of 1 keV/u (438 km/s). The observations reveal a strong emission feature near 0.7 keV that cannot fully be accounted for by a shock model, nor the current CX data. Inclusion of CX, specifically $O^{7+}+H$, does provide for a statistically significant improvement over a pure shock model.

arXiv commentAccepted for publication in ApJL, 5 pages, 4 figures, 1 table

References in corpus (9)

• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• Monte-Carlo Simulator and Ancillary Response Generator of Suzaku XRT/XIS System for Spatially Extended Source Analysis
• Reproducibility of Non-X-ray Background for the X-ray Imaging Spectrometer aboard Suzaku
• Balmer-Dominated Spectra of Nonradiative Shocks in the Cygnus Loop, RCW 86 and Tycho Supernova Remnants
• Energy Spectra of the Soft X-ray Diffuse Emission in Fourteen Fields Observed with Suzaku
• The energy source of the filaments around the giant galaxy NGC1275
• Possible Charge-Exchange X-Ray Emission in the Cygnus Loop Detected with Suzaku
• Discovery of X-rays from Venus with Chandra
• Charge Exchange X-ray Emission of M82: Kα triplets of O VII, Ne IX, and Mg XI

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