Polycyclic Aromatic Hydrocarbons (PAHs) are ubiquitous complex molecules in the interstellar medium and are used as an indirect indicator of star-formation. On the other hand the ultraviolet (UV) emission from the young massive stars directly traces the star formation activity in a galaxy. The James Webb Space Telescope (JWST), along with the UltraViolet Imaging Telescope (UVIT), opened up a new window of opportunity to make a better understanding of the properties of the PAH molecules associated with the star-forming regions. In this study, we investigate how the resolved scale properties of PAH molecules in nearby galaxies are affected by star- formation. We analyze the PAH features observed at 3.3, 7.7, and 11.3um using F335M, F770W, and F1130W images obtained from JWST. These images help us identify and quantify the PAH molecules. Additionally, we utilize UVIT images to assess the star formation associated with these PAH emitting regions. Our study focuses on three galaxies, namely NGC 628, NGC 1365, and NGC 7496, selected based on the availability of both JWST and UVIT images. Bright PAH emission regions are identified in the JWST images, and their corresponding UV emission is estimated using the UVIT images. We quantify the star formation properties of these PAH emitting regions using the UVIT images. Furthermore, we investigate the relationship between the star formation surface density ({SIGMA}SFR) and the PAH ratios to better understand the impact of star formation on the properties of PAH molecules. Based on the resolved scale study on the PAH bright regions using JWST images, we found that the fraction of ionized PAH molecules is high in the star-forming regions with high {SIGMA}SFR. We observed that emission from smaller PAH molecules is more in the star-forming regions with higher {SIGMA}SFR. Our study suggests that the PAH molecules excited by the photons from SF regions with higher {SIGMA}SFR are dominantly smaller and ionized molecules.UV photons from the star-forming regions could be the reason for a higher fraction of the ionized PAHs. We suggest that the effect of high temperature in the star-forming regions and the formation of smaller PAH molecules in the star-forming regions might also be resulting in the higher fraction of emission in the F335MPAH band.

Cone search capability for table J/A+A/684/A71/list (Information on fits images)