Asymmetries in core-collapse supernovae from maps of radioactive ${}^{44}$Ti in CassiopeiaA

Abstract

Asymmetry is required by most numerical simulations of stellar core-collapse explosions, but the form it takes differs significantly among models. The spatial distribution of radioactive 44Ti, synthesized in an exploding star near the boundary between material falling back onto the collapsing core and that ejected into the surrounding medium, directly probes the explosion asymmetries. CassiopeiaA is a young, nearby, core-collapse remnant from which 44Ti emission has previously been detected but not imaged. Asymmetries in the explosion have been indirectly inferred from a high ratio of observed 44Ti emission to estimated 56Ni emission, from optical light echoes, and from jet-like features seen in the X-ray and optical ejecta. Here we report spatial maps and spectral properties of the 44Ti in Cassiopeia A. This may explain the unexpected lack of correlation between the 44Ti and iron X-ray emission, the latter being visible only in shock-heated material. The observed spatial distribution rules out symmetric explosions even with a high level of convective mixing, as well as highly asymmetric bipolar explosions resulting from a fast-rotating progenitor. Instead, these observations provide strong evidence for the development of low-mode convective instabilities in core-collapse supernovae.

32 pages, Figures Embedded

References in corpus (6)

• The Cassiopeia A Supernova was of Type IIB
• The Expansion Asymmetry and Age of the Cassiopeia A Supernova Remnant
• A new method for determining the sensitivity of X-ray imaging observations and the X-ray number counts
• The signature of 44Ti in Cassiopeia A revealed by IBIS/ISGRI on INTEGRAL
• Hydrodynamical Neutron Star Kicks in Three Dimensions
• The Polar Regions of Cassiopeia A: The Aftermath of a Gamma Ray Burst?

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