Spatially-resolved star-formation main sequence in the local massive spiral galaxies

Abdurrouf Abdurrouf

In order to examine the origin of the main sequence of star-forming galaxies seen in the global properties, we evaluate the spatially-resolved SFRs and stellar masses of 111 massive spiral galaxies in the local universe through pixel-to-pixel SED fitting with ~1kpc resolution. We confirm the tight relation between SFR and stellar mass seen in the global properties still holds in the resolved properties with 0.2 dex scatter. As a result, radial profiles of specific SFR show flat distributionin the disk regions of the spiral galaxies. On the contrary, there are systematic offsets from the relationcaused by the global property and local structure. More massive galaxies have the average sSFR in the disk region lower than less massive galaxies; this suggests the down-sizing trend seen in the global properties holds in the local scale. It is also found that the spiral arm regions show higher sSFR and the inner regions of barred galaxies show lower sSFR, and such local variation cause scatter of the star-formation main sequence.