Two Distinct-Absorption X-Ray Components from Type IIn Supernovae: Evidence for Asphericity in the Circumstellar Medium

Abstract

We present multi-epoch X-ray spectral observations of three Type IIn supernovae (SNe) 2005kd, 2006jd, and 2010jl, acquired with Chandra, XMM-Newton, Suzaku, and Swift. Previous extensive X-ray studies of SN 2010jl have revealed that X-ray spectra are dominated by thermal emission, which likely arises from a hot plasma heated by a forward shock propagating into a massive circumstellar medium (CSM). Interestingly, an additional soft X-ray component was required to reproduce the spectra at a period of ~1-2 yr after the SN explosion. Although this component is likely associated with the SN, its origin remained an open question. We find a similar, additional soft X-ray component from the other two SNe IIn as well. Given this finding, we present a new interpretation for the origin of this component; it is thermal emission from a forward shock essentially identical to the hard X-ray component, but directly reaches us from a void of the dense CSM. Namely, the hard and soft components are responsible for the heavily- and moderately-absorbed components, respectively. The co-existence of the two components with distinct absorptions as well as the delayed emergence of the moderately-absorbed X-ray component would be evidence for asphericity of the CSM. We show that the X-ray spectral evolution can be qualitatively explained by considering a torus-like geometry for the dense CSM. Based on our X-ray spectral analyses, we estimate the radius of the torus-like CSM to be on the order of ~5 times 10^{16} cm.

11 pages, 3 figures, accepted for publication in The Astrophysical Journal

References in corpus (5)

• Spectropolarimetry of Supernovae
• The Dual-Axis Circumstellar Environment of the Type IIn Supernova 1997eg
• The Suzaku Observation of the Nucleus of the Radio-Loud Active Galaxy Centaurus A: Constraints on Abundances of the Accreting Material
• Long-Lasting X-Ray Emission from Type IIb Supernova 2011dh and Mass-Loss History of The Yellow Supergiant Progenitor
• Modeling the X-ray emission of SN 1993J

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