Local Star-forming Galaxies Build Up Central Mass Concentration Most Actively near M ?=1010 M⊙

作者：Pan, Zhizheng^*; Zheng, Xianzhong; Kong, Xu

来源：Astrophysical Journal, 2023, 958(1): 42.

DOI：10.3847/1538-4357/ad0230

• SDSS-IV MANGA
• BAND OPTICAL-PROPERTIES
• STELLAR POPULATION
• MAIN-SEQUENCE
• MERGER RATE
• BULGE
• MORPHOLOGY
• EVOLUTION
• ORIGIN
• SIZE

To understand in what mass regime star-forming galaxies (SFGs) build up central mass concentration most actively, we present a study on the luminosity-weighted stellar age radial gradient (del(age)) distribution of similar to 3600 low-redshift SFGs using the MaNGA Pipe3D data available in Data Release 17 from the Sloan Digital Sky Survey. The mean age gradient is negative, with del(age) = -0.14 log Gyr/R-e, consistent with the inside-out disk formation scenario. Specifically, SFGs with positive del(age) consist of similar to 28% at log (M-M-circle dot) < 9.5, while this fraction rises up to its peak (similar to 40%) near log (M-M-circle dot) = 10 and then decreases to similar to 15% at log (M-M-circle dot) = 11. At fixed M-*, SFGs with positive del(age) typically have more compact sizes and more centrally concentrated star formation than their counterparts, indicative of recent central mass buildup events. These results suggest that the buildup of central stellar mass concentration in local SFGs is mostly active near M-* = 10(10)M(circle dot). Our findings provide new insights into the origin of morphological differences between low-mass and high-mass SFGs.

• 单位
  中国科学院; 中国科学技术大学; 中国科学院紫金山天文台