A new quadruple gravitational lens from the Hyper Suprime-Cam Survey: the puzzle of HSC J115252+004733
A new quadruple gravitational lens from the Hyper Suprime-Cam Survey: the puzzle of HSC J115252+004733
复制标题
来自 Hyper Suprime-Cam Survey 的新型四重引力透镜：HSC J115252 004733 之谜
DOI：
10.1093/mnras/stw2924
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
S. (8th author in 19 authors) et. al
中科院分区：
文献类型：
--
作者：
More;A.;More;S. (8th author in 19 authors) et. al
We report the serendipitous discovery of a quadruply lensed source atzs= 3.76, HSC J115252+004733, from the Hyper Suprime-Cam (HSC) Survey. The source is lensed by an early-type galaxy atzl= 0.466 and a satellite galaxy. Here, we investigate the properties of the source by studying its size and luminosity from the imaging and the luminosity and velocity width of the Ly-α line from the spectrum. Our analyses suggest that the source is most probably a low-luminosity active galactic nucleus (LLAGN) but the possibility of it being a compact bright galaxy (e.g. a Lyman-α emitter or lyman break galaxy) cannot be excluded. The brighter pair of lensed images appears point-like except in the HSCiband (with a seeing ∼0.5 arcsec). The extended emission in thei-band image could be due to the host galaxy underneath the AGN, or alternatively, due to a highly compact lensed galaxy (without AGN) which appears point-like in all bands except iniband. We also find that the flux ratio of the brighter pair of images is different in theKsband compared to optical wavelengths. Phenomena such as differential extinction and intrinsic variability cannot explain this chromatic variation. While microlensing from stars in the foreground galaxy is less likely to be the cause, it cannot be ruled out completely. If the galaxy hosts an AGN, then this represents the highest redshift quadruply imaged AGN known to date, enabling study of a distant LLAGN. Discovery of this unusually compact and faint source demonstrates the potential of the HSC survey.
