连接光度和光谱颗粒信号与Cheops和浓缩咖啡

论文标题

连接光度和光谱颗粒信号与Cheops和浓缩咖啡

Connecting photometric and spectroscopic granulation signals with CHEOPS and ESPRESSO

论文作者

Sulis, S., Lendl, M., Cegla, H., Diaz, L. F. Rodriguez, Bigot, L., Van Grootel, V., Bekkelien, A., Cameron, A. Collier, Maxted, P. F. L., Simon, A. E., Lovis, C., Scandariato, G., Bruno, G., Nardiello, D., Bonfanti, A., Fridlund, M., Persson, C. M., Salmon, S., Sousa, S. G., Wilson, T. G., Krenn, A., Hoyer, S., Santerne, A., Ehrenreich, D., Alibert, Y., Alonso, R., Anglada, G., Bárczy, T., Navascues, D. Barrado y, Barros, S. C. C., Baumjohann, W., Beck, M., Beck, T., Benz, W., Billot, N., Bonfils, X., Borsato, L., Brandeker, A., Broeg, C., Cabrera, J., Charnoz, S., van Damme, C. Corral, Csizmadia, Sz., Davies, M. B., Deleuil, M., Deline, A., Delrez, L., Demangeon, O. D. S., Demory, B. -O., Erikson, A., Fortier, A., Fossati, L., Gandolfi, D., Gillon, M., Güdel, M., Heng, K., Isaak, K. G., Kiss, L. L., Laskar, J., Etangs, A. Lecavelier des, Magrin, D., Munari, M., Nascimbeni, V., Olofsson, G., Ottensamer, R., Pagano, I., Pallé, E., Peter, G., Piotto, G., Pollacco, D., Queloz, D., Ragazzoni, R., Rando, N., Rauer, H., Ribas, I., Rieder, M., Santos, N. C., Ségransan, D., Smith, A. M. S., Steinberger, M., Steller, M., Szabó, Gy. M., Thomas, N., Udry, S., Walton, N. A., Wolter, D.

论文摘要

恒星颗粒在光度和光谱数据中产生波动，其特性取决于恒星类型，组成和进化状态。在这项研究中，我们旨在检测主序列恒星的恒星颗粒，链路光谱和光度特征的特征，以及来自3D流体动力模型的测试预测。我们第一次观察到两个明亮的恒星（Teff = 5833 K和6205 K），并与Cheops和浓缩咖啡同时进行了高精度观测。我们分析了每个单个数据集中恒星粒状信号的性能。我们将它们与开普勒观测和3D流体动力模型进行了比较。通过衰减P模式振荡信号来隔离肉芽诱导的变化，我们研究了光度法和光谱可观察物之间的关系。检测到恒星颗粒的特征，并精确地针对Cheops和浓缩咖啡观测中的较热的F星。对于冷却器G星，我们仅在Cheops数据集中获得清晰的检测。苔丝观察结果对此恒星信号视而不见。基于Cheops的观察，我们表明，恒星颗粒的推断性质与开普勒观察和流体动力学模型一致。比较它们的周期图，我们观察到光谱和光度观测值之间的牢固联系。但是，由于信号到噪声依赖性变化，很难隔离该恒星信号在时域（磁通与RV）和特定光谱可观察物（互相关函数的形状）的相关性。在即将到来的柏拉图任务和极端精确的RV调查的背景下，需要对恒星颗粒信号的性质进行透彻的理解。 Cheops和Espresso观察为详细分析了这一出色的过程铺平了道路。

Stellar granulation generates fluctuations in photometric and spectroscopic data whose properties depend on the stellar type, composition, and evolutionary state. In this study, we aim to detect the signatures of stellar granulation, link spectroscopic and photometric signatures of convection for main-sequence stars, and test predictions from 3D hydrodynamic models. For the first time, we observed two bright stars (Teff = 5833 K and 6205 K) with high-precision observations taken simultaneously with CHEOPS and ESPRESSO. We analyzed the properties of the stellar granulation signal in each individual data set. We compared them to Kepler observations and 3D hydrodynamic models. While isolating the granulation-induced changes by attenuating the p-mode oscillation signals, we studied the relationship between photometric and spectroscopic observables. The signature of stellar granulation is detected and precisely characterized for the hotter F star in the CHEOPS and ESPRESSO observations. For the cooler G star, we obtain a clear detection in the CHEOPS dataset only. The TESS observations are blind to this stellar signal. Based on CHEOPS observations, we show that the inferred properties of stellar granulation are in agreement with both Kepler observations and hydrodynamic models. Comparing their periodograms, we observe a strong link between spectroscopic and photometric observables. Correlations of this stellar signal in the time domain (flux vs RV) and with specific spectroscopic observables (shape of the cross-correlation functions) are however difficult to isolate due to signal-to-noise dependent variations. In the context of the upcoming PLATO mission and the extreme precision RV surveys, a thorough understanding of the properties of the stellar granulation signal is needed. The CHEOPS and ESPRESSO observations pave the way for detailed analyses of this stellar process.

下载PDF全文

下载文献需遵守相关版权规定

论文标题