AI 中文总结
本研究利用CatWISE、2MASS与Gaia DR3数据识别出约11800个极冷天体与褐矮星候选体，采用混合MG-MW1 Sigmoid函数近似光谱型，后续计划扩展采样并验证候选体。
AI 中文摘要
本研究利用CatWISE（W1、W2波段）、2MASS（J、Hs、K波段）及Gaia DR3（G、GRP波段，三角视差π，自行μα、μδ）的多波段与天体测量数据，识别距离太阳≤125秒差距、银纬绝对值大于8度的极冷天体与褐矮星候选体。经颜色与绝对星等标准（如G-W2≥1.75(G-J)-2.25）联合约束后，共得到约11800个候选体，其中约350个源未收录于Gaia极冷矮星（UCD）星表。研究采用混合MG-MW1 Sigmoid函数近似光谱型，该函数在部分情况下可提供更广的温度覆盖范围。后续工作或可将采样扩展至覆盖部分银道面的更深近红外VVVX天区，长期目标为对Gaia UCD星表缺失的候选体进行光谱验证或证伪。
英文摘要
Ultracool and brown dwarf candidates ($d_{\odot}\lesssim 125$ pc, $|b|>8^{\circ}$) were identified via multiband and astrometric data from CatWISE ($W_1W_2$), 2MASS ($JHK_s$), and Gaia DR3 ($G$, $G_{RP}$, $π$, $μ_α$, $μ_δ$). $N\approx 11.8 \times 10^3$ candidates emerged once simultaneously constrained by color and absolute magnitude criteria (e.g., $G-W_2 \ge 1.75(G-J)-2.25$), whereby $\simeq 350$ sources are absent from the Gaia Ultracool Dwarf (UCD) catalog. Spectral types were approximated using a hybrid $M_G-M_{W_1}$ sigmoid that offers additional temperature coverage in certain cases. Subsequent efforts may focus on extending sampling to the deeper NIR VVVX footprint that partly encompasses the Galactic plane, and over the long-term spectroscopically (in)validating candidates missing from the Gaia UCD database.
CommentsTo appear in publication
