Models for the evolution of close binaries with He-Star and WD components towards Type Ia supernova explosions
Models for the evolution of close binaries with He-Star and WD components towards Type Ia supernova explosions
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DOI：
10.1051/0004-6361/201527845
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发表时间：
2016-03
期刊：
影响因子：
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通讯作者：
P. Neunteufel;S.-C. Yoon;N. Langer
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文献类型：
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作者：
P. Neunteufel;S.-C. Yoon;N. Langer
Ia型超新星（SNe Ia）在相当长的一段时间内一直是天文学的重要工具;然而，它们的祖先的性质仍然有些神秘。最近的理论研究表明，碳氧白色矮星（CO WDs）的质量小于克拉塞卡质量，通过吸积的富氦物质，这将产生热核爆炸的可能性，取决于质量吸积率，质量，和WD的初始温度，光谱类似于一个正常的SN Ia或一个特殊的。本研究的目的是进一步解决的状态组成的一个sub-masekhar质量的CO WD和氦星星的双星系统在吸积诱导爆轰发生的点，并约束的初始参数空间的一部分，这种现象是可能的。预先存在的数据，通过模拟单一的，不断吸积CO WD被用作新的二元模型中的WD被视为一个点质量，其中包括非简并的合作伙伴作为一个完全解决的恒星模型的行为的指标。我们parameterized积累的氦层的点火，WD温度的变化，和CO核心质量的变化取决于传质速率。允许爆炸的初始条件在参数空间中不形成单个连续区域，其形状受到施主星星的行为的深刻影响。新星爆发造成的质量损失有利于爆炸。根据我们的标准，在这项研究中，大约10%的爆轰可以预期显示与普通超新星Ia相一致的光谱，其余的表现出特殊的功能。
Type Ia supernovae (SNe Ia) have been an important tool for astronomy for quite some time; however, the nature of their progenitors remains somewhat mysterious. Recent theoretical studies indicated the possibility of producing thermonuclear detonations of carbon-oxygen white dwarfs (CO WDs) at masses less than the Chandrasekhar mass through accretion of helium-rich matter, which would, depending on mass accretion rate, mass, and initial temperature of the WD, spectrally resemble either a normal SN Ia or a peculiar one. This study aims to further resolve the state of binary systems comprised of a sub-Chandrasekhar-mass CO WD and a helium star at the point where an accretion-induced detonation occurs and constrains the part of the initial parameter space where this kind of phenomenon is possible. Preexisting data obtained through simulations of single, constantly accreting CO WDs is used as an indicator for the behavior of new binary models in which the WD is treated as a point mass and which include the non-degenerate partner as a fully resolved stellar model. We parameterize the ignition of the accumulated helium layer, changes in the WD temperature, and changes in the CO core mass depending on the mass transfer rate. The initial conditions allowing for detonation do not form a single contiguous area in the parameter space, whose shape is profoundly influenced by the behavior of the donor star. Mass loss due to Nova outbursts acts in favor of detonation. According to our criteria, about 10% of the detonations in this study can be expected to show spectra consistent with ordinary SNe Ia; the rest exhibit peculiar features.