Unraveling the Origin of Overionized Plasma in the Galactic Supernova Remnant W49B
arXiv:1309.1464 · doi:10.1088/0004-637X/777/2/145
Abstract
Recent observations have shown several supernova remnants (SNRs) have overionized plasmas, those where ions are stripped of more electrons than they would be if in equilibrium with the electron temperature. Rapid electron cooling is necessary to produce this situation, yet the physical origin of that cooling remains uncertain. To assess the cooling scenario responsible for overionization, in this paper, we identify and map the overionized plasma in the Galactic SNR W49B based on a 220 ks Chandra Advanced CCD Imaging Spectrometer (ACIS) observation. We performed a spatially-resolved spectroscopic analysis, measuring the electron temperature by modeling the continuum and comparing it to the temperature given by the flux ratio of the He-like and H-like lines of sulfur and of argon. Using these results, we find that W49B is overionized in the west, with a gradient of increasing overionization from east to west. As the ejecta expansion is impeded by molecular material in the east but not in the west, our overionization maps suggest the dominant cooling mechanism is adiabatic expansion of the hot plasma.
6 pages, 4 figures, resubmitted to ApJ following referee comments
References in corpus (3)
Cited by in corpus (31)
- Gone With the Wind: Where is the Missing Stellar Wind Energy from Massive Star Clusters?
- Supernova Remnants Interacting with Molecular Clouds: X-ray and Gamma-ray Signatures
- Asymmetric Type-Ia supernova origin of W49B as revealed from spatially resolved X-ray spectroscopic study
- Are Models for Core-Collapse Supernova Progenitors Consistent with the Properties of Supernova Remnants?
- Supernova remnant W49B and its environment
- Non-equilibrium ionization in mixed-morphology supernova remnants
- The Morphology and Dynamics of Jet-Driven Supernova Remnants: the Case of W49B
- Evidence for Rapid Adiabatic Cooling as an Origin of the Recombining Plasma in the Supernova Remnant W49B Revealed by NuSTAR Observations
- Deep XMM-Newton Observations Reveal the Origin of Recombining Plasma in the Supernova Remnant W44
- The Metal-enriched Thermal Composite Supernova Remnant Kesteven 41 (G337.8-0.1) in a Molecular Environment
- ALMA CO Observations of the Mixed-Morphology Supernova Remnant W49B: Efficient Production of Recombining Plasma and Hadronic Gamma-rays via Shock-Cloud Interactions
- Chemical abundances in Sgr A East: evidence for a Type Iax supernova remnant
- Toward the Understanding of the Physical Origin of Recombining Plasma in the Supernova Remnant IC 443
- Evolutionary Models for 15 Galactic Supernova Remnants with New Distances
- The Morphologies and Kinematics of Supernova Remnants
- Recombining Plasma in the Gamma-ray Emitting Mixed-Morphology Supernova Remnant 3C 391
- XMM-Newton observation of the Galactic supernova remnant W51C (G49.1-0.1)
- A Chandra X-ray study of the mixed-morphology supernova remnant 3C400.2
- Unveiling pure-metal ejecta X-ray emission in supernova remnants through their radiative recombination continuum
- Analysis of XMM-Newton Observations of Supernova Remnant W49B and Clues to the Progenitor
- Spatially Resolved Chandra Spectroscopy of the Large Magellanic Cloud Supernova Remnant N132D
- Hitomi Observations of the LMC SNR N132D: Highly Redshifted X-ray Emission from Iron Ejecta
- Unusually high HCO+/CO ratios in and outside supernova remnant W49B
- Identification of a Jet-Driven Supernova Remnant in the Small Magellanic Cloud: Possible Evidence for the Enhancement of Bipolar Explosions at Low Metallicity
- An XMM-Newton X-ray View of Supernova Remnant W49B: Revisiting its Recombining Plasmas and Progenitor Type
- Can the Fe K-alpha Line Reliably Predict Supernova Remnant Progenitors?
- An XMM-Newton Study of the Mixed-Morphology Supernova Remnant G346.6-0.2
- Spatially-Resolved Study of Recombining Plasma in W49B Using XMM-Newton
- Element Stratification in the Middle-Aged Type Ia Supernova Remnant G344.7-0.1
- X-ray emitting structures in the Vela SNR: ejecta anisotropies and progenitor stellar wind residuals
- Investigation of the Physical Origin of Overionized Recombining Plasma in the Supernova Remnant IC 443 with XMM-Newton