利用哈勃前沿领域空间分辨恒星形成识别和区分熄灭星系
Identifying and Distinguishing Quenching Galaxies with Spatially Resolved Star Formation in the Hubble Frontier Fields
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中文总结 AI 辅助
研究哈勃前沿领域特定星系不同熄灭特征，通过空间分辨光谱能量分布拟合及形态学指标、$k$近邻算法，区分出由内而外和由外而内熄灭路径，发现不同路径星系在质量、所处环境及与下落时间关系上的差异。
中文摘要 AI 辅助
我们通过使用\texttt{FAST++}进行空间分辨光谱能量分布拟合，研究了哈勃前沿领域中1437个恒星质量$M_{*} \geqslant 10^{8}~\mathrm{M}_{\odot}$且恒星形成率$\text{SFR} \geqslant 10^{-3}~M_{\odot}~\text{yr}^{-1}$的星系不同熄灭特征的性质和普遍性。我们用形态学指标量化恒星形成分布，用$k$近邻算法将熄灭星系分类到不同熄灭路径，包括由内而外和由外而内路径。发现129个星系形态符合由内而外路径，70个符合由外而内路径。由内而外熄灭星系比由外而内的质量大$0.8^{+0.2}_{-0.1}~\text{dex}$，两者在星团中都比在星系场中质量大$0.8^{+0.3}_{-0.1}~\text{dex}$。由内而外熄灭星系在星团中更常见（106/129），由外而内的较少（25/70）。在星团中，由内而外熄灭星系的比例随质量强烈增加，在高质量时占非熄灭星系群体的约30%，在星系场中演化较平缓。由外而内熄灭星系的比例与质量无关，在星团和星系场中均占非熄灭群体的约10%。除了大质量由内而外熄灭星系比例随预估下落时间增加外，我们发现各群体比例与预估下落时间无强烈依赖关系。
英文摘要
We investigate the nature and prevalence of different quenching signatures for 1437 galaxies with $M_{*} \geqslant 10^{8}~\mathrm{M}_{\odot}$ and $\text{SFR} \geqslant 10^{-3}~M_{\odot}~\text{yr}^{-1}$ in the Hubble Frontier Fields through spatially resolved spectral energy distribution fitting with \texttt{FAST++}. We use the morphological metrics previously presented in our series of investigations to quantify the distribution of star formation, and use a $k$-nearest neighbors algorithm to classify quenching galaxies into different quenching pathways, including an inside-out pathway and an outside-in pathway. We find 129 galaxies have morphologies consistent with an inside-out quenching pathway, and 70 are consistent with an outside-in pathway. Inside-out quenching galaxies are $0.8^{+0.2}_{-0.1}~\text{dex}$ more massive compared to outside-in quenching galaxies, where both populations are more massive in clusters than the field, by $0.8^{+0.3}_{-0.1}~\text{dex}$. Inside-out quenching galaxies are found more often in clusters (106/129), compared to outside-in quenching galaxies (25/70). In clusters, the fraction of inside-out quenching galaxies strongly increases with mass, representing ${\sim}$30% of the non-quenched galaxy population at high masses. A milder evolution is seen in the field. The fraction of outside-in quenching galaxies is independent of mass, representing ${\lesssim}$10% of the non-quenched population, in both the cluster and field. We find no strong dependence for the fraction of any population with estimated infall time, except massive inside-out quenching galaxies, which increase in fraction with increasing infall time.
