A COMPACT DEGENERATE PRIMARY-STAR PROGENITOR OF SN 2011fe
A COMPACT DEGENERATE PRIMARY-STAR PROGENITOR OF SN 2011fe
复制标题
DOI：
10.1088/2041-8205/744/2/l17
复制
发表时间：
2011-11
期刊：
影响因子：
--
通讯作者：
J. Bloom;D. Kasen;K. Shen;P. Nugent;N. Butler;M. Graham;D. Andrew Howell;U. Kolb;S. Holmes;C. Haswell;V. Burwitz;Juan Rodriguez;M. Sullivan
中科院分区：
文献类型：
--
作者：
J. Bloom;D. Kasen;K. Shen;P. Nugent;N. Butler;M. Graham;D. Andrew Howell;U. Kolb;S. Holmes;C. Haswell;V. Burwitz;Juan Rodriguez;M. Sullivan
虽然从理论的角度来看，白色矮星（WD）是Ia型超新星（SN Ia）最可能的主星星，但许多其他候选者尚未被正式排除。沉积在任何爆炸的主包层中的冲击能量有助于早期SN亮度，并且由于这种辐射能量在爆炸后因膨胀而退化，因此扩散光度取决于初始主半径。我们提出了一个新的非检测极限附近的SN Ia 2011 fe，在爆炸后4小时内获得，使我们能够直接约束初始主半径（Rp）。结合未探测到的静态X射线对应物和推断的合成56 Ni质量，我们证明了Rp = 0.02 R返（比之前推断的小5倍），原初粒子的平均密度必须是ρp > 104 g cm−3，有效温度必须小于几× 105 K。这排除了燃烧氢的主序星和巨星。构建氦燃烧和碳燃烧的主序列，我们发现，这样的对象也被排除在外。通过排除，我们发现只有简并支持的致密天体--WD和中子星--才是SN 2011 fe的主星星。除了一些警告，我们还将伴星（次级）星星限制在Rc <$0.1 R突增，排除了罗氏瓣溢出红巨星和主序星伴星。
While a white dwarf (WD) is, from a theoretical perspective, the most plausible primary star of a Type Ia supernova (SN Ia), many other candidates have not been formally ruled out. Shock energy deposited in the envelope of any exploding primary contributes to the early SN brightness and, since this radiation energy is degraded by expansion after the explosion, the diffusive luminosity depends on the initial primary radius. We present a new non-detection limit of the nearby SN Ia 2011fe, obtained at a time that appears to be just 4 hr after explosion, allowing us to directly constrain the initial primary radius (Rp). Coupled with the non-detection of a quiescent X-ray counterpart and the inferred synthesized 56Ni mass, we show that Rp ≲ 0.02 R☉ (a factor of five smaller than previously inferred), that the average density of the primary must be ρp > 104 g cm−3, and that the effective temperature must be less than a few × 105 K. This rules out hydrogen-burning main-sequence stars and giants. Constructing the helium-burning and carbon-burning main sequences, we find that such objects are also excluded. By process of elimination, we find that only degeneracy-supported compact objects—WDs and neutron stars—are viable as the primary star of SN 2011fe. With few caveats, we also restrict the companion (secondary) star radius to Rc ≲ 0.1 R☉, excluding Roche-lobe overflowing red giant and main-sequence companions to high significance.