从暗能量光谱仪（DESI）到欧几里得（Euclid）：通向无偏星系结构的生成桥梁
From DESI to Euclid: A Generative Bridge to Improve Measurements of Galaxy Structure
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中文总结 AI 辅助
研究利用生成模型将DESI成像转换为Euclid VIS图像，缩小地面与天基成像差距，提升分辨率并使星系结构参数去偏，发布转换结果E - BGS待公开验证。
中文摘要 AI 辅助
地面观测会给星系结构参数带来与大小相关的偏差，而消除此偏差所需的天基成像目前仅覆盖小部分天空。我们用一个生成模型填补这一差距，该模型将明亮星系巡天（BGS）目标的DESI成像转换为Euclid VIS图像。傅里叶域分析证实其能恢复至0.37''的结构（相对于DESI r波段基线的1.41''），分辨率提升约3.8倍。虽未达Euclid VIS的0.16''分辨率，但已使结构参数相对于DESI r波段测量去偏。我们将这些转换结果作为Euclid分辨率的BGS（E - BGS）在Euclid DR1覆盖区域发布，待DR1公开后可进行盲验证。
英文摘要
Ground-based seeing imprints size-dependent biases on galaxy structural parameters, yet the high-resolution space-based imaging needed to improve these measurements currently covers only a small fraction of the sky. We close this gap with a generative model that produces Euclid-like VIS predictions from DESI imaging of Bright Galaxy Survey (BGS) targets. Our predictions remain Fourier-correlated with Euclid VIS images down to 0.37'', compared with 1.41'' and 1.00'' for the DESI $r$- and $z$-band inputs, corresponding to improvements by factors of ${\sim}3.8$ and ${\sim}2.7$, respectively. Although this correlation does not extend down to 0.16'', the characteristic Euclid VIS PSF FWHM, structural measurements from these predictions already show reduced biases relative to the DESI $r$-band structure measurements: the Petrosian radius bias falls to +0.072'' (from -0.845''), independent of galaxy size; the bias in the Sérsic effective radius ($R_{\rm e}$) drops to -0.018'' (from -0.322''); and the Sérsic-index bias to +0.093 (from +0.262). We release these predictions over the Euclid DR1 footprint as the Euclid-like Predictions of BGS (\textbf{E-BGS}), which can be blindly validated once DR1 is public.
