The 3D shape of Type IIb SN 2011hs
The 3D shape of Type IIb SN 2011hs
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DOI：
10.1093/mnras/stz265
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发表时间：
2019-01
影响因子：
4.8
通讯作者：
H. Stevance;J. Maund;D. Baade;J. Bruten;A. Cikota;P. Höflich;L. Wang;J. Wheeler;A. Clocchiatti;J. Spyromilio;F. Patat;Y. Yang;P. Crowther
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作者：
H. Stevance;J. Maund;D. Baade;J. Bruten;A. Cikota;P. Höflich;L. Wang;J. Wheeler;A. Clocchiatti;J. Spyromilio;F. Patat;Y. Yang;P. Crowther
作者：Stevance， HF；小莫恩德;Baade D;Bruten J;Cikota,;Hoflich P;王,L;惠勒,JC;Clocchiatti,;Spyromilio J;Patat F;杨,Y;摘要：我们观测了IIb型SN 2011hs的7个光谱偏振谱期，v波段最大值为-3 ~ +40 d。探测到高度的星际偏振（高达~ 3%），其峰值位于4500 A的蓝色。类似的行为在一些Ia型超新星（SNe）中已经被观察到，但从未在IIb型超新星中被观察到。我们发现这很可能是SN附近小硅酸盐颗粒相对增强的结果。在第3天和第2天恢复了显著的本征连续偏振（p分别= 0.55±0.12%和0.75±0.11%）。我们讨论了偏振角在光谱线和连续体上的变化，作为喷射物三维结构的诊断。在v波段最大值后-2 ~ +18 d，连续偏振角逐渐旋转约-50°。He i λ5876、Hα和Ca ii红外三重态中类似的旋转似乎表明，整体几何形状对线偏振特征有很强的影响。它们在Stokes q-u平面上各自回路的演化差异表明，特定于直线的几何形状也正在被探索。可能的解释进行了讨论，并在文学背景下放置。我们发现SN 2011hs与SN 2011dh的光谱偏振特征最为相似，但存在显著差异。
Author(s): Stevance, HF; Maund, JR; Baade, D; Bruten, J; Cikota, A; Hoflich, P; Wang, L; Wheeler, JC; Clocchiatti, A; Spyromilio, J; Patat, F; Yang, Y; Crowther, P | Abstract: We observed seven epochs of spectropolarimetry in optical wavelengths for the Type IIb SN 2011hs, ranging from-3 to +40 d with respect to V-band maximum. A high degree of interstellar polarization was detected (up to ∼3 per cent), with a peak lying blueward of 4500 A. Similar behaviours have been seen in some Type Ia supernovae (SNe), but had never been observed in a Type IIb. We find that it is most likely the result of a relative enhancement of small silicate grains in the vicinity of the SN. Significant intrinsic continuum polarization was recovered at-3 and +2 d (p = 0.55 ± 0.12 per cent and 0.75 ± 0.11 per cent, respectively). We discuss the change of the polarization angle across spectral lines and in the continuum as diagnostics for the 3D structure of the ejecta. We see a gradual rotation by about-50° in the continuum polarization angle between-2 and +18 d after V-band maximum. A similar rotation in He i λ5876, Hα and the Ca ii infrared triplet seems to indicate a strong influence of the global geometry on the line polarization features. The differences in the evolution of their respective loops on the Stokes q-u plane suggest that line specific geometries are also being probed. Possible interpretations are discussed and placed in the context of literature. We find that the spectropolarimetry of SN 2011hs is most similar to that of SN 2011dh, albeit with notable differences.