摘要：Context.Most of the massive star-forming galaxies are found to have “inside-out” stellar mass growth modes, which means the inner parts of the galaxies mainly consist of the older stellar population, while the star forming in the outskirt of the galaxy is still ongoing.Aims.The high-resolution HST images fromHubbleDeep UV Legacy Survey and Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey projects with the unprecedented depth in bothF275WandF160Wbands are the perfect data sets to study the forming and formed stellar distribution directly.Methods.We selected the low redshift (0.05 < zspec < 0.3) galaxy sample from the GOODS-North field where the HSTF275WandF160Wimages are available. Then we measured the half light radius inF275WandF160Wbands, which are the indicators of the star formation and stellar mass.Results.By comparing theF275WandF160Whalf light radius, we find the massive galaxies are mainly follow the “inside-out” growth mode, which is consistent with the previous results. Moreover, the HSTF275WandF160Wimages reveal that some of the low-mass galaxies (< 108 M⊙) have the “outside-in” growth mode: their images show a compact UV morphology, implying an ongoing star formation in the galaxy centre, while the stars in the outskirts of the galaxies are already formed. The two modes transit smoothly at stellar mass range about 108 − 9 M⊙with a large scatter. We also try to identify the possible neighbour massive galaxies from the SDSS data, which represent the massive galaxy sample. We find that all of the spec-zselected galaxies have no massive galaxy nearby. Thus the “outside-in” mode we find in the low-mass galaxies are not likely originated from the environment.
