Asymmetric Expansion of the Fe ejecta in Kepler's Supernova Remnant

Abstract

The ejecta kinematics of supernova remnants (SNRs) is one of crucial clues to understand the explosion mechanism of type Ia supernovae (SNe). In particular, the kinematic asymmetry of iron-peak elements provides the key to understanding physical processes taking place in the core of the exploding white dwarfs (WDs) although it has been poorly understood by observations. In this paper, we show for the first time the asymmetric expansion structure in the line-of-sight direction of Fe ejecta in Kepler's SNR revealed by spectral and imaging analysis using the Chandra archival data. We found that the K$\alpha$ line centroid energy and line width is relatively lower ($<$ 6.4 keV) and narrower ($\sim$80 eV) around the center of the remnant, which implies that the majority of the Fe ejecta in the central region is red-shifted. At the outer regions, we identify bright blue-shifted structures as it might have been ejected as high velocity dense clumps. Taking into account the broad population of the Fe charge states, we estimate the red-shifted velocity of ~2,000 km/s and the blue-shifted velocity of ~3,000 km/s for each velocity structure. We also present a possibility that a portion of the Fe ejecta near the center are interacting with the dense circumstellar medium (CSM) on the near side of the remnant. As the origin of the asymmetric motion of the Fe ejecta, we suggest three scenarios, (1) the asymmetric distribution of the CSM, (2) the "shadow" in Fe cast by the companion star, and (3) the asymmetric explosion.

arXiv comment19 pages, 10 figures, accepted for publication in PASJ

References in corpus (32)

• Nucleosynthesis in Chandrasekhar Mass Models for Type Ia Supernovae and Constraints on Progenitor Systems and Burning-Front Propagation
• Observational clues to the progenitors of Type-Ia supernovae
• Three-dimensional delayed-detonation models with nucleosynthesis for Type Ia supernovae
• The Diversity of Type Ia Supernovae from Broken Symmetries
• A Spatial and Spectral Study of Nonthermal Filaments in Historical Supernova Remnants: Observational Results with Chandra
• An asymmetric explosion as the origin of spectral evolution diversity in type Ia supernovae
• A Deep Chandra Observation of Kepler's Supernova Remnant: A Type Ia Event with Circumstellar Interaction
• The imprint of a symbiotic binary progenitor on the properties of Kepler's supernova remnant
• A Chandrasekhar Mass Progenitor for the Type Ia Supernova Remnant 3C 397 from The Enhanced Abundances of Nickel and Manganese
• Spitzer Space Telescope Observations of Kepler's Supernova Remnant: A Detailed Look at the Circumstellar Dust Component
• Carbon Ignition in Type Ia Supernovae: II. A Three-Dimensional Numerical Model
• Expansion Velocity of Ejecta in Tycho's Supernova Remnant Measured by Doppler Broadened X-ray Line Emission
• XMM-Newton observation of Kepler's supernova remnant
• Progenitors of type Ia supernovae
• On the Sensitivity of Deflagrations in Chandrasekhar Mass White Dwarf to Initial Conditions
• A reconnaissance of the possible donor stars to the Kepler supernova
• New Evidence for Efficient Collisionless Heating of Electrons at the Reverse Shock of a Young Supernova Remnant
• The Kinematics of Kepler's Supernova Remnant as revealed by Chandra
• Kepler's Supernova: An Overluminous Type Ia Event Interacting with a Massive Circumstellar Medium at a Very Late Phase
• Dust in a Type Ia Supernova Progenitor: Spitzer Spectroscopy of Kepler's Supernova Remnant
• X-ray Emission from Strongly Asymmetric Circumstellar Material in the Remnant of Kepler's Supernova
• Second Epoch Hubble Space Telescope Observations of Kepler's Supernova Remnant: The Proper Motions of Balmer Filaments
• A Super-Solar Metallicity for the Progenitor of Kepler's Supernova
• The Origin of the Iron-Rich Knot in Tycho's Supernova Remnant
• Direct Ejecta Velocity Measurements of Tycho's Supernova Remnant
• Forward Shock Proper Motions of Kepler's Supernova Remnant
• Is there a hidden hole in Type Ia supernova remnants?
• The Three-Dimensional Expansion of the Ejecta from Tycho's Supernova Remnant
• Freely Expanding Knots of X-ray Emitting Ejecta in Kepler's Supernova Remnant
• Doppler-Broadened Iron X-ray Lines from Tycho's Supernova Remnant
• Supernova 1604, Kepler's supernova, and its remnant
• Shadows of our Former Companions: How the Single-Degenerate Binary Type Ia Supernova Scenario Affects Remnants

Cited by in corpus (7)

• Type Ia Supernova Explosions in Binary Systems: A Review
• Spatially Resolved RGS Analysis of Kepler's Supernova Remnant
• An Ejecta Kinematics Study of Kepler's Supernova Remnant with High-Resolution $Chandra$ HETG Spectroscopy
• Genus Statistic Applied to the X-ray Remnant of SN 1572: Clues to the Clumpy Ejecta Structure of Type Ia Supernovae
• Gamma-ray Diagnostics of r-process Nucleosynthesis in the Remnants of Galactic Binary Neutron-Star Mergers
• Element Stratification in the Middle-Aged Type Ia Supernova Remnant G344.7-0.1
• Detection of the hard X-ray non-thermal emission from Kepler's supernova remnant