Title: PHANGS-JWST First Results: The Dust Filament Network of NGC 628 and its Relation to Star Formation Activity Show Chinese title

Title: PHANGS-JWST 首批结果：NGC 628 的尘埃纤维网络及其与恒星形成活动的关系

Abstract: PHANGS-JWST mid-infrared (MIR) imaging of nearby spiral galaxies has revealed ubiquitous filaments of dust emission in intricate detail. We present a pilot study to systematically map the dust filament network (DFN) at multiple scales between 25-400 pc in NGC 628. MIRI images at 7.7, 10, 11.3 and 21$\mu$m of NGC 628 are used to generate maps of the filaments in emission, while PHANGS-HST B-band imaging yields maps of dust attenuation features. We quantify the correspondence between filaments traced by MIR thermal continuum / polycyclic aromatic hydrocarbon (PAH) emission and filaments detected via extinction / scattering of visible light; the fraction of MIR flux contained in the DFN; and the fraction of HII regions, young star clusters and associations within the DFN. We examine the dependence of these quantities with the physical scale at which the DFN is extracted. With our highest resolution DFN maps (25 pc filament width), we find that filaments in emission and attenuation are co-spatial in 40% of sight lines, often exhibiting detailed morphological agreement; that ~30% of the MIR flux is associated with the DFN; and that 75-80% of HII regions and 60% of star clusters younger than 5 Myr are contained within the DFN. However, the DFN at this scale is anti-correlated with looser associations of stars younger than 5 Myr identified using PHANGS-HST near-UV imaging. We discuss the impact of these findings for studies of star formation and the ISM, and the broad range of new investigations enabled with multi-scale maps of the DFN. Show Chinese abstract

Abstract: 近邻螺旋星系的PHANGS-JWST中红外（MIR）成像揭示了尘埃发射的细丝结构，其细节非常丰富。 我们进行了一项试点研究，系统地在NGC 628中以25-400 pc的不同尺度绘制尘埃细丝网络（DFN）。 使用NGC 628在7.7、10、11.3和21$\mu$m波长的MIRI图像生成发射细丝的地图，而PHANGS-HST B波段成像则提供尘埃消光特征的地图。 我们量化了通过MIR热连续谱/多环芳烃（PAH）发射追踪的细丝与通过可见光消光/散射检测到的细丝之间的对应关系；DFN中包含的MIR通量比例；以及DFN内HII区域、年轻星团和复合体的比例。 我们研究了这些量值随DFN提取物理尺度的变化情况。 在我们最高分辨率的DFN地图（25 pc细丝宽度）中，我们发现发射和消光细丝在40%的视线方向上是共空间的，通常表现出详细的形态一致性；约30%的MIR通量与DFN有关；并且75-80%的HII区域和60%年龄小于5 Myr的星团位于DFN内。 然而，在这个尺度下，DFN与使用PHANGS-HST近紫外成像识别的年龄小于5 Myr的松散星团关联性较差。 我们讨论了这些发现对恒星形成和星际介质研究的影响，并探讨了利用多尺度DFN地图所开启的广泛新研究方向。