论文标题
重建由超质量椭圆星系SDSS J0100+1818的多种来源的扩展结构
Reconstructing the extended structure of multiple sources strongly lensed by the ultra-massive elliptical galaxy SDSS J0100+1818
论文作者
论文摘要
我们通过完整的强镜头分析研究了偏转器SDSS J0100+1818的总质量分布。该系统由超质量的早期类型的星系组成，$ z = 0.581 $，总质量为$（1.5 \ pm 0.3）10^{12} $ m $ _ \ odot $和恒星速度分散（$ 450光谱镜以$ z = 1.880 $确认。我们利用高分辨率HST光度法和VLT/X射击器光谱法来测量多个图像的位置，并使用软件GLEE进行强大的镜头研究。我们测试了镜头的不同总质量剖面，并首先将背景源建模为类似点状，然后用作扩展对象。我们成功地预测了观察到的多个图像的位置，并在大约7200 HST像素上重建了源的复杂表面亮度分布。我们测量了镜头的累积总质量概况，并找到$（9.1 \ pm 0.1）10^{12} $ m $ $ _ \ odot $，在爱因斯坦半径内约为42 kpc，大约42 kpc，以及超过的总体分数，范围为（$ 49 \ pm 12 $）$ n $ n $ n of n $ n $ 3 $ right = $ right = $ right = right = right = right uips riptius。镜头星系，至（$ 10 \ pm 2 $）％，在外部区域（$ r = 70 $ kpc）。这些结果表明，SDSS J0100+1818的重型质量成分非常集中在其核心上，并且镜头早期型星系/组浸入了大量的暗物质晕中。这与中间红移的其他超高质量候选者中发现的内容是一致的。我们还测量了遥远来源的物理大小，将它们解析为几百个parsec。最后，我们量化并讨论了与采用的透镜总质量模型相关的背景星系的重建大小的系统不确定性的相关来源。
We study the total and baryonic mass distributions of the deflector SDSS J0100+1818 through a full strong lensing analysis. The system is composed by an ultra-massive early-type galaxy at $z=0.581$, with total stellar mass of $(1.5 \pm 0.3) 10^{12}$ M$_\odot$ and stellar velocity dispersion of ($450 \pm 40$) km s$^{-1}$, surrounded by ten multiple images of three background sources, two of which spectroscopically confirmed at $z=1.880$. We take advantage of high-resolution HST photometry and VLT/X-shooter spectroscopy to measure the positions of the multiple images and perform a strong lensing study with the software GLEE. We test different total mass profiles for the lens and model the background sources first as point-like and then as extended objects. We successfully predict the positions of the observed multiple images and reconstruct over approximately 7200 HST pixels the complex surface brightness distributions of the sources. We measure the cumulative total mass profile of the lens and find a total mass value of $(9.1 \pm 0.1) 10^{12}$ M$_\odot$, within the Einstein radius of approximately 42 kpc, and stellar-over-total mass fractions ranging from ($49 \pm 12$)%, at the half-light radius ($R_e = 9.3$ kpc) of the lens galaxy, to ($10 \pm 2$)%, in the outer regions ($R = 70$kpc). These results suggest that the baryonic mass component of SDSS J0100+1818 is very concentrated in its core and that the lens early-type galaxy/group is immersed in a massive dark matter halo. This is consistent with what found in other ultra-high mass candidates at intermediate redshift. We measure also the physical sizes of the distant sources, resolving them down to a few hundreds of parsec. Finally, we quantify and discuss a relevant source of systematic uncertainties on the reconstructed sizes of background galaxies, associated to the adopted lens total mass model.
