Abundance Inhomogeneity in the Northeastern Rim of the Cygnus Loop Revealed by Suzaku Observatory

Abstract

We present the results of a spatially resolved spectral analysis from four Suzaku observations covering the northeastern rim of the Cygnus Loop. A two-kT_e non-ionization equilibrium (NEI) model fairly well represents our data, which confirms the NEI condition of the plasma there. The metal abundances are depleted relative to the solar values almost everywhere in our field of view. We find abundance inhomogeneities across the field: the northernmost region (Region A) has enhanced absolute abundances compared with other regions. In addition, the relative abundances of Mg/O and Fe/O in Region A are lower than the solar values, while those in the other regions are twice higher than the solar values. As far as we are concerned, neither a circumstellar medium, fragments of ejecta, nor abundance inhomogeneities of the local interstellar medium around the Cygnus Loop can explain the relatively enhanced abundance in Region A. This point is left as an open question for future work.

13 pages, 6 figures

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• Monte-Carlo Simulator and Ancillary Response Generator of Suzaku XRT/XIS System for Spatially Extended Source Analysis
• Young core collapse supernova remnants and their supernovae
• The Homogeneity of Interstellar Oxygen in the Galactic Disk
• Hubble Space Telescope and Ground-Based Observations of SN 1993J and SN 1998S: CNO Processing in the Progenitors
• The Plasma Structure of the Cygnus Loop from the Northeastern Rim to the Southwestern Rim

Cited by in corpus (10)

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• Possible Charge-Exchange X-Ray Emission in the Cygnus Loop Detected with Suzaku
• Chandra Observations of the Northeastern Rim of the Cygnus Loop
• High Forbidden-to-resonance Line Ratio of OVII Discovered in the Cygnus Loop
• The Ejecta Distributions of the Heavy Elements in the Cygnus Loop
• The Plasma Structure of the Southwestern Region of the Cygnus Loop with the XMM-Newton Observatory
• Search for a Non-equilibrium Plasma in the Merging Galaxy Cluster Abell 754
• Evidence for Resonance Line Scattering in the Suzaku X-ray Spectrum of the Cygnus Loop
• The Abundance Inhomogeneity in the Northern Rim of the Cygnus Loop
• The origin of the X-ray emitting plasma in the eastern edge of the Cygnus Loop