We discuss the rest-frame ultraviolet emission from the starbursting galaxy HFLS3 at a redshift of 6.34. The galaxy was discovered in Herschel/SPIRE data due to its red color in the submillimeter wavelengths from 250 to 500 μm. Keck/NIRC2?K s -band adaptive optics imaging data showed two potential near-IR counterparts near HFLS3. Previously, the northern galaxy was taken to be in the foreground at z = 2.1, while the southern galaxy was assumed to be HFLS3's near-IR counterpart. The recently acquired Hubble/WFC3 and Advanced Camera for Surveys (ACS) imaging data show conclusively that both optically bright galaxies are in the foreground at z 6. A new lensing model based on the Hubble imaging data and the millimeter-wave continuum emission yields a magnification factor of 2.2 ± 0.3, with a 95% confidence upper limit on the magnification of 3.5. When corrected for lensing, the instantaneous star formation rate is 1320 M ☉?yr–1, with the 95% confidence lower limit around 830 M ☉?yr–1. The dust and stellar masses of HFLS3 from the same spectral energy distribution (SED) models are at the level of 3 × 108 M ☉ and ~5 × 1010 M ☉, respectively, with large systematic uncertainties on assumptions related to the SED model. With Hubble/WFC3 images, we also find diffuse near-IR emission about 0.5 arcsec (~3?kpc) to the southwest of HFLS3 that remains undetected in the ACS imaging data. The emission has a photometric redshift consistent with either z ~ 6 or a dusty galaxy template at z ~ 2.
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机译：我们讨论了来自星爆星系HFLS3的静止帧紫外线发射，其红移为6.34。该星系是在Herschel / SPIRE数据中发现的，这是因为它在250至500μm的亚毫米波长中呈红色。 Keck / NIRC2？K s波段自适应光学成像数据显示在HFLS3附近有两个潜在的近红外对应物。以前，北部星系在z = 2.1时位于前景中，而南部星系被假定为HFLS3的近红外对应物。最近获得的哈勃/ WFC3和高级勘测相机（ACS）成像数据表明，两个光学明亮的星系在z <6时都处于前台。基于哈勃成像数据和毫米波连续体发射量的新透镜模型放大倍数为2.2±0.3，对3.5的放大倍数有95％的置信上限。校正透镜后，瞬时恒星形成速率为1320 M Myr-1，95％置信下限约为830 M yryr-1。来自相同光谱能量分布（SED）模型的HFLS3的尘埃和恒星质量分别处于3×108 M☉和〜5×1010 M level的水平，在与SED模型相关的假设上存在较大的系统不确定性。使用哈勃/ WFC3图像，我们还发现向HFLS3西南方向约0.5 arcsec（〜3？kpc）的漫射近红外发射，在ACS成像数据中仍未检测到。发射的光度红移与z〜6或z〜2处的尘埃星系模板一致。
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