Performance of the VLT Planet Finder SPHERE II. Data analysis and Results for IFS in laboratory
D. Mesa, R. Gratton, A. Zurlo, A. Vigan, R. U. Claudi, M. Alberi, J. Antichi, A. Baruffolo, J. -L. Beuzit, A. Boccaletti, M. Bonnefoy, A. Costille, S. Desidera,… 展开作者
D. Mesa, R. Gratton, A. Zurlo, A. Vigan, R. U. Claudi, M. Alberi, J. Antichi, A. Baruffolo, J. -L. Beuzit, A. Boccaletti, M. Bonnefoy, A. Costille, S. Desidera, K. Dohlen, D. Fantinel, M. Feldt, T. Fusco, E. Giro, T. Henning, M. Kasper, M. Langlois, A. -L. Maire, P. Martinez, O. Moeller-Nilsson, D. Mouillet, C. Moutou, A. Pavlov, P. Puget, B. Salasnich, J. -F. Sauvage, E. Sissa, M. Turatto, S. Udry, F. Vakili, R. Waters, F. Wildi
We present the performance of the Integral Field Spectrograph (IFS) of SPHERE, the high-contrast imager for the ESO VLT telescope designed to perform imaging and spectroscopy of extrasolar planets, obtained from tests performed at the Institute de Planétologie et d'Astrophysique de Grenoble facility during the integration phase of the instrument.} {The tests were performed using the instrument software purposely prepared for SPHERE. The output data were reduced applying the SPHERE data reduction and handling software, adding an improved spectral deconvolution procedure. To this aim, we prepared an alternative procedure for the spectral subtraction exploiting the principal components analysis algorithm. Moreover, a simulated angular differential imaging procedure was also implemented to estimate how the instrument performed once this procedure was applied at telescope. The capability of the IFS to faithfully retrieve the spectra of the detected faint companions was also considered.} {We found that the application of the updated version of the spectral deconvolution procedure alone, when the algorithm throughput is properly taken into account, gives us a $5σ$ limiting contrast of the order of 5$\times$$10^{-6}$ or slightly better. The further application of the angular differential imaging procedure on these data should allow us to improve the contrast by one order of magnitude down to around 7$\times$$10^{-7}$ at a separation of 0.3 arcsec. The application of a principal components analysis procedure that simultaneously uses spectral and angular data gives comparable results. Finally, we found that the reproducibility of the spectra of the detected faint companions is greatly improved when angular differential imaging is applied in addition to the spectral deconvolution.
Spectral cube extraction for the VLT/SPHERE IFS: Open-source pipeline with full forward modeling and improved sensitivity
我们提出了一个新的开源数据简化管道，从原始的SPHERE积分场光谱仪（IFS）数据重建光谱数据立方体。管道是用Python编写的，基于为CHARIS IFS开发的管道。它介绍了几个改进SPHERE数据分析，最终产生显着的改善后处理的灵敏度。我们首先使用新的数据来测量在四个激光校准波长处的SPHERE小透镜点扩散函数（PSF）。这些小透镜PSF使我们能够对SPHERE数据进行前向建模，使用最小二乘拟合提取光谱，并使用测量的小透镜PSF去除光谱串扰。我们的方法还减少了所需的插值，光谱和空间的数量，并可以保持原来的六边形小透镜的几何形状在SPHERE IFS。在最小二乘提取的情况下，不进行数据插值。我们展示了直接成像的系外行星51 Eri b和HD 2133的热白矮星伴星的观测上的新管道。HD 2133B的提取光谱与理论模型相匹配，表明分光光度校准良好到几个百分点。对两个51 Eri b数据集的后处理表明，与使用SPHERE数据中心重建的立方体相比，2015年和2017年数据的灵敏度分别提高了80%和30%。最大的改进是在观测条件较差的情况下。新的SPHERE管道在现代笔记本电脑上生成一个数据立方体只需不到三分钟的时间，因此可以重新处理所有SPHERE IFS数据。
First light of the VLT planet finder SPHERE. II. The physical properties and the architecture of the young systems PZ Tel and HD 1160 revisited
[摘要]背景。年轻的系统PZ Tel和HD 1160，拥有已知的低质量同伴，在新的行星发现者SPHERE的调试期间被观察到，具有几种成像和光谱模式。目的。我们的目标是完善这两个系统的物理特性和架构。方法.我们使用SPHERE调试数据和REM观测，以及来自VLT/SINFONI，VLT/NaCo，Gemini/NICI和Keck/NIRC 2的文献和未发表的数据。结果我们导出了新的光度学，并证实了PZ Tel A的几乎每日光度变化。使用文献数据跨越38年，我们表明，恒星也表现出长期的变化趋势。PZ Tel B的0.63-3.8 mic SED允许我们修正其性质：光谱型M7+/-1，Teff=2700+/-100 K，log（g）<4.5 dex，log（L/L_Sun）=-2.51+/-0.10 dex，质量38-72 MJ。HD 1160 B的1-3.8 mic SED表明它是一颗大质量褐矮星或低质量恒星，其光谱型为M5.5-7.0，Teff=3000+/-100 K，[M/H]=-0.5-0.0 dex，log（L/L_Sun）=-2.81+/-0.10 dex，质量为39-168 MJ。我们证实了PZ Tel B的减速和高偏心率（e>0.66）。当e<0.9时，升交点的倾角、经度和近星点通过时间都得到了很好的限制。该系统被视为接近一个边缘上的几何形状。我们排除了两个系统中0.2…
