| タイトル | Asymmetries in Core Collapse Supernovae Revealed by Maps of Radioactive Titanium |
| 本文（外部サイト） | http://hdl.handle.net/2060/20150009316 |
| 著者（英） | Hailey, C. J.; Forster, K.; Zhang, W. W.; Christensen, F. E.; Madsen, K. K.; Boggs, S. E.; Wik, D. R.; Koglin, J. E.; Zoglauer, A.; Mao, P. H.; Barret, D.; Kaspi, V. M.; An, H.; Miyasaka, H.; Fryer, C. L.; Hornstrup, A.; Ellinger, C. I.; Kitaguchi, T.; Grefenstette, B. W.; Craig, W. W.; Alexander, D. M.; Harrison, F. A.; Mori, K.; Giommi, P.; Reynolds, S. P. |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2014-02-19 |
| 言語 | eng |
| 内容記述 | Asymmetry is required by most numerical simulations of stellar core collapse explosions, however the nature differs significantly among models. The spatial distribution of radioactive Ti-44, 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 explosion1asymmetries. Cassiopeia A is a young, nearby, core-collapse remnant from which Ti-44 emission has previously been detected, but not imaged. Asymmetries in the explosion have been indirectly inferred from a high ratio of observed Ti-44 emission to that estimated from (56)Ni9, from optical light echoes, and by jet-like features seen in the X-ray and optical ejecta. Here we report on the spatial maps and spectral properties of Ti-44 in Cassiopeia A. We find the Ti-44 to be distributed non-uniformly in the un-shocked interior of the remnant. This may explain the unexpected lack of correlation between the Ti-44 and iron X-ray emission, the latter only being visible 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. |
| NASA分類 | Astrophysics |
| レポートNO | GSFC-E-DAA-TN21572 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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