标题： 在SDSS大弧星系巡天中发现的两个z∼3莱曼破缺透镜星系 显示英文标题

标题： Two Lensed z~3 Lyman Break Galaxies Discovered in the SDSS Giant Arcs Survey

摘要： 我们报告了两个红移约为3的强引力透镜化Lyman断层星系（LBGs）的发现，它们作为u波段紫外dropout被发现于SDSS大弧线巡天（SGAS）中。 第一个星系，SGAS J122651.3+215220，位于z=2.9233，由一个复杂的致密星团中的多个亚团块之一SDSS J1226+2152引力透镜化，该星团的红移为z=0.43。 它的(g, r, i)星等值为(21.14, 20.60, 20.51)，对应表面亮度mu_{g, r, i}分别为(23.78, 23.11, 22.81)。 第二个星系，SGAS J152745.1+065219，位于z=2.7593，由前景的SDSS J1527+0652（红移z=0.39）引力透镜化，其(g, r, z)星等值为(20.90, 20.52, 20.58)，表面亮度mu_{g, r, z}为(25.15, 24.52, 24.12)。 中等分辨率光谱确认了由测光断层所提示的红移，并展示了典型的LBGs吸收和发射特征。 从结合成像与光谱学得到的透镜质量模型显示，SGAS J122651.3+215220是一个高度放大源（M~40），而SGAS J152745.1+065219的放大倍数不超过M~15。 与LBGs巡天结果（Steidel等人，2003年）相比，其亮度和透镜校正后的星等表明SGAS J122651.3+215220是该样本中最暗的20%的LBGs之一。 另一方面，SGAS J152745.1+065219似乎更具有代表性，类似于“宇宙之眼”。 显示英文摘要

摘要： We report the discovery of two strongly-lensed z ~ 3 Lyman Break Galaxies (LBGs) discovered as u-band dropouts as part of the SDSS Giant Arcs Survey (SGAS). The first, SGAS J122651.3+215220 at z = 2.9233 is lensed by one of several sub-clusters, SDSS J1226+2152, in a complex massive cluster at z = 0.43. Its (g, r, i) magnitudes are (21.14, 20.60, 20.51) which translate to surface brightnesses, mu_{g,r,i}, of (23.78, 23.11, 22.81). The second, SGAS J152745.1+065219, is an LBG at z = 2.7593 lensed by the foreground SDSS J1527+0652 at z = 0.39, with (g, r, z)=(20.90, 20.52, 20.58) and mu_{g,r,z}=(25.15, 24.52, 24.12). Moderate resolution spectroscopy confirms the redshifts suggested by photometric breaks, and shows both absorption and emission features typical of LBGs. Lens mass models derived from combined imaging and spectroscopy reveal that SGAS J122651.3+215220 is a highly magnified source (M ~40), while SGAS J152745.1+065219 is magnified by no more than M ~ 15. Compared to LBG survey results (Steidel et al. 2003), the luminosities and lensing-corrected magnitudes suggest that SGAS J122651.3+215220 is among the faintest 20% of LBGs in that sample. SGAS J152745.1+065219, on the other hand, appears to be more representative of the average LBG, similar to the "Cosmic Eye".