A negative stellar mass−gaseous metallicity gradient relation of dwarf galaxies modulated by stellar feedback

作者：Tie Li, Hong-Xin Zhang, Wenhe Lyu, Yimeng Tang, Yao Yao, Enci Wang, Yu Rong, Guangwen Chen, Xu Kong, Fuyan Bian, Qiusheng Gu, Evelyn J. Johnston, Xin Li, Shude Mao, Yong Shi, Junfeng Wang, Xin Wang, Xiaoling Yu, Zhiyuan Zheng · 发表于：Astronomy and Astrophysics · 年份：2025 · DOI：10.1051/0004-6361/202452978 · 被引用次数：4 · 研究领域：Phase Equilibria and Thermodynamics

Baryonic cycling is reflected in the spatial distribution of metallicity within galaxies; however, gas-phase metallicity distribution and its connection with other properties of dwarf galaxies are largely unexplored. We present the first systematic study of radial gradients of gas-phase metallicities for a sample of 55 normal nearby star-forming dwarf galaxies (stellar mass M ⋆ ranging from 10 7 to 10 9.5 M ⊙ ) based on MUSE wide-field spectroscopic observations. We find that the metallicity gradient has a significant negative correlation (Spearman’s rank correlation coefficient r ≃ −0.56) with M ⋆ , which is in contrast with the flat or even positive correlation observed for higher-mass galaxies. The negative correlation is accompanied by a stronger central suppression of metallicity compared to the outskirts in lower-mass galaxies. Among the other explored galaxy properties, including baryonic mass, star formation distribution, galaxy environment, regularity of gaseous velocity field, and effective yield of metals y eff , only the regularity of gaseous velocity field and y eff have residual correlation with metallicity gradient after controlling for M ⋆ , in the sense that galaxies with an irregular velocity field or lower y eff favor a less negative or more positive metallicity gradient. Particularly, a linear combination of logarithmic stellar mass and y eff significantly improves the correlation with metallicity gradients ( r ∼ −0.68) compared to using stellar mass alone...