SHOCK BREAKOUT FROM TYPE Ia SUPERNOVA
SHOCK BREAKOUT FROM TYPE Ia SUPERNOVA
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DOI：
10.1088/0004-637x/708/1/598
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发表时间：
2009-09
期刊：
影响因子：
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通讯作者：
A. Piro;P. Chang;N. Weinberg
中科院分区：
文献类型：
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作者：
A. Piro;P. Chang;N. Weinberg
Ia 型超新星（SNe Ia）的爆炸燃烧模式仍然是一个突出的问题。通常认为它以亚音速爆燃开始，但这可能会转变为超音速爆炸（延迟爆炸转变，DDT）。我们认为，这种转变会导致爆发性冲击，这将提供滴滴涕发生的第一个明确证据。其主要特征是持续~10−2 s的硬X射线闪光（∼20 keV），总辐射能量为∼1040 erg，随后是冷却尾部。这在可见光曲线中产生了一个明显的特征，与镍衰变不同。该冷却尾部在 ≈1 天时具有最大绝对视星等 MV ≈ -9 至 -10，这最敏感地取决于 DDT 时的白矮星半径。随着热扩散波的移动，这些表面层的成分可能会被印记为光谱特征，这将有助于辨别 SN Ia 祖模型。由于这个特征应该伴随每个 SNe Ia，未来的深度勘测（例如，m = 24）将看到它的距离约为 80 Mpc，最大速率为 ∼60 yr-1。档案数据集还可用于研究由冲击加热决定的早期上升（在最大 B 波段光之前约 20 天）。在中子星吸积引起的塌缩过程中，类似且稍亮的事件也可能伴随着核心反弹，但发生率较低。
The mode of explosive burning in Type Ia supernovae (SNe Ia) remains an outstanding problem. It is generally thought to begin as a subsonic deflagration, but this may transition into a supersonic detonation (the delayed detonation transition, DDT). We argue that this transition leads to a breakout shock, which would provide the first unambiguous evidence that DDTs occur. Its main features are a hard X-ray flash (∼20 keV) lasting ∼10−2 s with a total radiated energy of ∼1040 erg, followed by a cooling tail. This creates a distinct feature in the visual light curve, which is separate from the nickel decay. This cooling tail has a maximum absolute visual magnitude of MV ≈ −9 to −10 at ≈1 day, which depends most sensitively on the white dwarf radius at the time of the DDT. As the thermal diffusion wave moves in, the composition of these surface layers may be imprinted as spectral features, which would help to discern between SN Ia progenitor models. Since this feature should accompany every SNe Ia, future deep surveys (e.g., m = 24) will see it out to a distance of ≈80 Mpc, giving a maximum rate of ∼60 yr-1. Archival data sets can also be used to study the early rise dictated by the shock heating (at ≈20 days before maximum B-band light). A similar and slightly brighter event may also accompany core bounce during the accretion-induced collapse to a neutron star, but with a lower occurrence rate.