论文标题
II型超新星的极化信号证实的外部星系中灰尘特性的多样性
Diversity of dust properties in external galaxies confirmed by polarization signals from Type II supernovae
论文作者
论文摘要
研究外部星系中的星际(IS)尘埃特性不仅重要,不仅要推断天文物体的内在特性,而且要了解星系中的恒星/行星形成。从在红色的IA型超新星(SNE)中观察到的非蜂窝路样灭绝和星际极化(ISP),已经提出,它们的宿主星系包含尘埃谷物,其特性与乳状通道(MW)灰尘大不相同。重要的是要研究宇宙中这种非MW状尘埃的普遍性。在这里,我们报告了两种高度效果II型SNE(SN 2022aa和SN 2022ame)的光谱极化。 SN 2022aau在较短的波长处显示了极化最大化,而MW恒星也可以在某种类型的IA SNE中观察到。这是其宿主星系中存在非MW样粉尘(即NGC 1672)中存在的明确证据。这一事实意味着,这种非MW状尘埃在某些环境中可能比预期更普遍,因此它可能会影响恒星/行星形成的情况。另一方面,SN 2022ame显示了类似MW的ISP,这意味着其宿主星系中存在MW状尘埃(即NGC 1255)。我们的发现证实了星系的尘埃特性是多种多样的,无论是局部还是全球。目前的工作表明,使用高度降低的SNE的极化法进一步研究了外部星系中的灰尘特性,这是有希望的,这为研究了宇宙中这种非MW样尘埃谷物的普遍性提供了绝佳的机会。
Investigating interstellar (IS) dust properties in external galaxies is important not only to infer the intrinsic properties of astronomical objects but also to understand the star/planet formation in the galaxies. From the non-Milky-Way-like extinction and interstellar polarization (ISP) observed in reddened Type Ia supernovae (SNe), it has been suggested that their host galaxies contain dust grains whose properties are substantially different from the Milky-Way (MW) dust. It is important to investigate the universality of such non-MW-like dust in the universe. Here we report spectropolarimetry of two highly-extinguished Type II SNe (SN 2022aau and SN 2022ame). SN 2022aau shows a polarization maximum at a shorter wavelength than MW stars, which is also observed in some Type Ia SNe. This is clear evidence for the existence of non-MW-like dust in its host galaxy (i.e., NGC 1672). This fact implies that such non-MW-like dust might be more common in some environments than expected, and thus it might affect the picture of the star/planet formation. On the other hand, SN 2022ame shows MW-like ISP, implying the presence of MW-like dust in its host galaxy (i.e., NGC 1255). Our findings confirm that dust properties of galaxies are diverse, either locally or globally. The present work demonstrates that further investigation of IS dust properties in external galaxies using polarimetry of highly-reddened SNe is promising, providing a great opportunity to study the universality of such non-MW-like dust grains in the universe.