  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.
