ABSTRACT

In this work we present the photometric and spectroscopic observations of type IIb supernova 2017gpn. This supernova was discovered in the error-box of the LIGO/Virgo G299232 gravitational-wave event. We obtained the light curves in the B and R passbands and modelled them numerically using the one-dimensional radiation hydrocode stella. The best-fitting model has the following parameters: the pre-SN star mass and the radius are M ≈ 3.5 M_⊙ and R ≈ 50 R_⊙, respectively; the explosion energy is $E_{\rm exp} \approx 1.2\times 10^{51}$ erg; the mass of radioactive nickel is $M_{\rm ^{56}Ni} \approx 0.11$ M_⊙, which is completely mixed throughout the ejecta; and the mass of the hydrogen envelope $M_{\rm H\_{env}}$ ≈ 0.06 M_⊙. Moreover, SN 2017gpn is a confirmed SN IIb that is located at the farthest distance from the centre of its host galaxy NGC 1343 (i.e. the projected distance is ∼21 kpc). This challenges the scenario of the origin of type IIb supernovae from massive stars.

中文翻译：

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IIb型超新星2017gpn的光学和光谱观测及流体动力学建模

摘要

在这项工作中，我们介绍了IIb型超新星2017gpn的光度学和光谱学观察。这个超新星是在LIGO / Virgo G299232引力波事件的误差箱中发现的。我们获得了B和R通带中的光曲线，并使用一维辐射Hydrocode Stella对其进行了数值建模。最佳拟合模型具有以下参数：预SN星质量和半径是中号 ≈的3.5M _⊙和- [R  ≈50红_⊙分别; 爆炸能量为$ E _ {\ rm exp} \约1.2 \乘以10 ^ {51} $ erg；放射性镍的质量为$ M _ {\ rm ^ {56} Ni} \约0.11 $ _M⊙，在整个弹射器中完全混合；氢包层的质量$ M _ {\ rm H \ _ {env}} $≈0.06 _M⊙。此外，SN 2017gpn是一个已确认的SN IIb，它位于距其宿主星系NGC 1343中心最远的距离（即，投影距离约为21 kpc）。这对来自大质量恒星的IIb型超新星起源的情景提出了挑战。