使用AstroSat对ELAIS N1区域进行深远紫外观测：源目录、光谱能量分布建模和恒星形成
Deep far-UV observations of the ELAIS N1 field using AstroSat: Source catalogue, spectral energy distribution modelling and star formation
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中文总结 AI 辅助
利用AstroSat的UVIT对ELAIS N1深场进行FUV光度学研究，处理数据得到源目录，排除AGN后用CIGALE建模，得出恒星形成率等随红移的关系，发现SFR随红移增加，年轻与总恒星质量比在一定红移范围大致恒定。
中文摘要 AI 辅助
我们利用AstroSat上的紫外成像望远镜（UVIT）对ELAIS N1深场进行了远紫外（FUV）光度学研究，在F154W滤光片（$\lambda_{\rm eff} = 1541$\,Å）下观测，总源上曝光时间为30\,ksec。使用CCDLAB v3.0对一级数据进行了处理，得到了1637个3$\sigma$源目录和458个5$\sigma$源目录，极限星等分别为$25.69\,m_{AB}$和$25.13\,m_{AB}$。FUV位置与跨越光学和红外波长的多波长目录进行了交叉匹配，红移来自光谱和光度学源。通过既定的多波长标准识别并排除了活动星系核（AGN），留下了一个纯净的恒星形成星系（SFG）样本。使用CIGALE进行光谱能量分布（SED）建模，采用延迟恒星形成历史并可选择后期爆发，Bruzual & Charlot恒星种群合成，Calzetti尘埃消光，以及SKIRTOR AGN模块。从最佳拟合模型中，我们得出了恒星形成率（SFRs）、总恒星质量和年轻恒星质量随红移的函数关系。SFR随红移单调增加，与恒星形成主序列（SFMS）的演化一致。在$0 < z \lesssim 0.76$范围内，年轻恒星质量与总恒星质量的比值大致保持恒定，这证实了该样本主要由经历稳定、自我调节恒星形成的长期演化系统组成，而不是由星暴驱动的事件组成。
英文摘要
We present a far-ultraviolet (FUV) photometric study of the ELAIS N1 deep field using the Ultra-Violet Imaging Telescope (UVIT) onboard AstroSat, observed in the F154W filter ($λ_{\rm eff} = 1541$\,Å) with a total on-source exposure time of 30\,ksec. Level 1 data were reduced using CCDLAB v3.0, yielding source catalogues of 1637 objects at $3σ$ and 458 objects at $5σ$, with limiting magnitudes of $25.69\,m_{AB}$ and $25.13\,m_{AB}$ respectively. FUV positions are cross-matched against multiwavelength catalogues spanning optical and infrared wavelengths, with redshifts drawn from spectroscopic and photometric sources. Active galactic nuclei (AGN) are identified and excluded via established multiwavelength criteria, leaving a clean sample of star-forming galaxies (SFGs). Spectral energy distribution (SED) modelling is performed using CIGALE, employing a delayed star formation history with an optional late burst, Bruzual \& Charlot stellar population synthesis, Calzetti dust attenuation, and the SKIRTOR AGN module. From the best-fit models, we derive star formation rates (SFRs), total stellar masses, and young stellar masses as a function of redshift. The SFR increases monotonically with redshift, consistent with the evolution of the Star Formation Main Sequence (SFMS). The ratio of young-to-total stellar mass remains approximately constant across $0 < z \lesssim 0.76$, confirming that the sample consists predominantly of secularly evolving systems undergoing steady, self-regulated star formation rather than starburst-driven episodes.
