Galactic infrared (IR) bubbles, which can be seen as shell-like structures at mid-IR wavelengths, are known to possess massive stars within their shell boundaries. In our previous study, Hanaoka et al. (2019) expanded the research area to the whole Galactic plane ($0^{\circ} \leq l \leq 360^{\circ}$, $|b| \leq 5^{\circ}$) and studied systematic differences in the shell morphology and the IR luminosity of the IR bubbles between inner and outer Galactic regions. In this study, utilizing high spatial-resolution data of AKARI and WISE in the mid-IR and Herschel in the far-IR, we investigate the spatial distributions of dust components around each IR bubble to discuss the relation between the star-formation activity and the dust properties of the IR bubbles. For the 247 IR bubbles studied in Hanaoka et al. (2019), 165 IR bubbles are investigated in this study, which have the Herschel data ($|b| \leq 1^{\circ}$) and known distances. We created their spectral energy distributions on a pixel-by-pixel basis around each IR bubble, and decomposed them with a dust model consisting of polycyclic aromatic hydrocarbons (PAHs), hot dust, warm dust and cold dust. As a result, we find that the offsets of dust heating sources from the shell centers in inner Galactic regions are systematically larger than those in outer Galactic regions. Many of the broken bubbles in inner Galactic regions show large angles between the offset and the broken shell directions from the center. Moreover, the spatial variations of the PAH intensity and cold dust emissivity around the IR bubbles in inner Galactic regions are larger than those in outer Galactic regions. We discuss these results in light of the interstellar environments and the formation mechanism of the massive stars associated with the IR bubbles.

中文翻译：

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与 AKARI 和 Herschel 一起对沿银河平面的银河红外气泡进行系统研究。二、气泡周围尘埃成分的空间分布

银河红外 (IR) 气泡在中红外波长下可以被视为壳状结构，已知在其壳边界内拥有大质量恒星。在我们之前的研究中，Hanaoka 等人。(2019) 将研究领域扩展到整个银河平面 ($0^{\circ} \leq l \leq 360^{\circ}$, $|b| \leq 5^{\circ}$) 并研究系统差异内部和外部银河区域之间的红外气泡的壳形态和红外光度。在这项研究中，我们利用中红外波段 AKARI 和 WISE 和远红外波段 Herschel 的高空间分辨率数据，研究了每个红外气泡周围尘埃成分的空间分布，以讨论恒星形成活动与恒星形成活动之间的关系。红外气泡的灰尘特性。对于 Hanaoka 等人研究的 247 个 IR 气泡。(2019), 本研究调查了 165 个红外气泡，它们具有赫歇尔数据 ($|b| \leq 1^{\circ}$) 和已知距离。我们在每个 IR 气泡周围逐个像素地创建了它们的光谱能量分布，并用由多环芳烃 (PAH)、热尘埃、暖尘埃和冷尘埃组成的尘埃模型分解它们。因此，我们发现内银河区壳中心的尘埃热源偏移量系统地大于银河外区的偏移量。银河内部区域中的许多破碎气泡显示出偏离中心和破碎壳方向之间的大角度。此外，银河内区红外气泡周围的多环芳烃强度和冷尘埃发射率的空间变化大于银河外区。