AI 中文总结
研究Ibn型超新星2023tsz，通过紫外到近红外分光光度法获取数据，与氦星爆炸辐射传输模型比较，发现其光谱特征，得出至少部分Ibn型超新星源于低质量氦星且受双星相互作用影响的结论。
AI 中文摘要
Ibn型超新星是剥离包层爆炸，其光谱显示与致密、富氦贫氢的星际物质（CSM）相互作用，是晚期质量损失和前身星剥离的重要探针。我们展示了Ibn型超新星2023tsz广泛的紫外到近红外分光光度法，包括两个时期的哈勃太空望远镜/空间望远镜成像光谱仪（HST/STIS）紫外光谱以及地面光学和近红外后续观测。光谱在最大光度后的所有阶段都以中等宽度发射线为主，表明大部分光度源于由抛射物与CSM相互作用形成的冷致密壳（CDS）。我们将观测结果与氦燃烧开始时质量为4个太阳质量的氦星爆炸的一维非局部热力学平衡辐射传输模型进行比较。模型再现了强光学和近红外He I线，并且需要添加X射线辐照场来匹配高电离紫外特征。光谱由X射线辐照功率约为\(10^8 L_{\odot}\) 的模型最佳再现，优选模型倾向于CDS半径约为\((1.5 - 2)×10^{15}\) cm，速度约为\(5×10^7\) cm s\(^{-1}\)，相互作用功率为\(10^{42}\) erg s\(^{-1}\) 的几倍。在光学波段，优选模型从早期的较高相互作用功率和较小半径转变为后期的较低功率和较大半径。这些结果进一步证明至少一些Ibn型超新星源于质量较低的氦星，其最终演化受双星相互作用影响。
英文摘要
Type Ibn supernovae are stripped-envelope explosions whose spectra indicate interaction with dense, helium-rich and hydrogen-poor circumstellar material (CSM), making them important probes of late-stage mass loss and progenitor stripping. We present extensive ultraviolet-to-near-infrared spectrophotometry of the Type Ibn SN 2023tsz, including two epochs of HST/STIS ultraviolet (UV) spectroscopy and ground-based optical and near-infrared follow-up observations. The spectra are dominated by intermediate-width emission lines at all phases after maximum light, suggesting that much of the luminosity originates in a cold dense shell (CDS) formed by interaction between the ejecta and CSM. We compare the observations to one-dimensional non-local-thermodynamic-equilibrium radiative-transfer models of a helium-star explosion with a mass of $4 M_{\odot}$ at the onset of helium burning. The models reproduce the strong optical and near-infrared He I lines and require an added X-ray irradiation field to match the highly ionized UV features. The spectra are best reproduced by models with an X-ray irradiation power of $L_X \approx 10^8 L_{\odot}$, with the preferred models favoring CDS radii of order $(1.5$--$2) \times 10^{15}$ cm, velocities of $\sim 5 \times 10^7$ cm s$^{-1}$, and interaction powers of a few times $10^{42}$ erg s$^{-1}$. In the optical, the preferred models shift from higher interaction power and smaller radii at early times to lower power and larger radii at later times. These results add to the growing evidence that at least some SNe Ibn arise from lower-mass helium stars whose final evolution is shaped by binary interaction.
CommentsSubmitted to ApJ
