论文标题
phangs-jwst首先结果:NGC628中气泡演化的统计视图
PHANGS-JWST First Results: A statistical view on bubble evolution in NGC628
论文作者
论文摘要
JWST对附近星系的第一批观察结果揭示了大量的气泡,这些气泡追踪了负责其创造的恒星反馈机制。因此,研究这些气泡使我们能够绘制出恒星反馈与星际介质之间的相互作用,以及在全球调节恒星形成过程所需的较大银河流。我们介绍了NGC628中的第一个气泡目录,并使用Miri F770W Phangs-JWST观测来视觉识别,并使用它们来统计评估气泡特性。我们将1694个结构分类为6-552 PC之间的气泡。其中31%的边缘至少包含一个较小的气泡,表明前几代恒星形成对新恒星形成的位置有局部影响。在大尺度上,大多数气泡位于螺旋臂附近,与上游相比,它们的半径下游增加。此外,气泡朝着与螺旋式脊脊线相似的方向拉长。这些方位角趋势表明,恒星形成与螺旋臂通道密切相关。最后,气泡尺寸分布遵循索引$ p = -2.2 \ pm0.1 $的幂律,该索引比理论值略低于1-3.5 $σ$,该值不包括气泡合并。在较大气泡的壳中鉴定出的气泡的比例表明气泡合并是一个常见的过程。因此,我们的分析使我们能够量化受早期影响的星形形成区域的数量,以及反馈过程在设定全球恒星形成率方面具有的角色。使用完整的phangs-jwst样品,我们可以为更多星系做到这一点。
The first JWST observations of nearby galaxies have unveiled a rich population of bubbles that trace the stellar feedback mechanisms responsible for their creation. Studying these bubbles therefore allows us to chart the interaction between stellar feedback and the interstellar medium, and the larger galactic flows needed to regulate star formation processes globally. We present the first catalog of bubbles in NGC628, visually identified using MIRI F770W PHANGS-JWST observations, and use them to statistically evaluate bubble characteristics. We classify 1694 structures as bubbles with radii between 6-552 pc. Of these, 31% contain at least one smaller bubble at their edge, indicating that previous generations of star formation have a local impact on where new stars form. On large scales, most bubbles lie near a spiral arm, and their radii increase downstream compared to upstream. Furthermore, bubbles are elongated in a similar direction to the spiral arm ridge-line. These azimuthal trends demonstrate that star formation is intimately connected to the spiral arm passage. Finally, the bubble size distribution follows a power-law of index $p=-2.2\pm0.1$, which is slightly shallower than the theoretical value by 1-3.5$σ$ that did not include bubble mergers. The fraction of bubbles identified within the shells of larger bubbles suggests that bubble merging is a common process. Our analysis therefore allows us to quantify the number of star-forming regions that are influenced by an earlier generation, and the role feedback processes have in setting the global star formation rate. With the full PHANGS-JWST sample, we can do this for more galaxies.