论文标题
利用来自最近太阳能恒星的空间数据以更好地了解径向速度数据中的恒星活动特征
Leveraging space-based data from the nearest Solar-type star to better understand stellar activity signatures in radial velocity data
论文作者
论文摘要
恒星变异性是达到使用径向速度（RV）检测方法恢复类似地球外球星网所需的灵敏度的关键障碍。为了探索类似太阳恒星的活动特征，我们提出了Solaster，这是一种公开分布的分析管道，可以将基于空间的测量结果与地面磁盘集成的RV进行比较。 Using high spatial resolution Dopplergrams, magnetograms, and continuum filtergrams from the Helioseismic and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory (SDO), we estimate 'Sun-as-a-star' disk-integrated RVs due to rotationally modulated flux imbalances and convective blueshift suppression, as well as other observables such as unsigned magnetic flux.将这些测量结果与Neid仪器的地面RV进行比较，NEID仪器每天都使用自动太阳能望远镜观察太阳，我们发现磁性活动指标与RV变化之间存在牢固的关系，并支持将无符号磁通量作为在缓慢旋转恒星中恒星活性的代理进行努力。对测量的未签名磁通量的下降使我们能够将NIID RV测量值提高约20 \％（〜50 cm/s，在正交总和中〜50 cm/s），在五个月内产生了〜60 cm/s的RMS散射。我们还探索了neID光谱和SDO衍生的磁性活性指标中个体和平均光谱线形状之间的相关性，从而激发了对这些可观察物的未来研究。最后，将隔离剂应用于金星和汞的档案行星横向，我们证明了通过直接测量Rossiter-Mclaughlin（RM）信号来恢复SDO数据中恢复小幅度（<50 cm/s）RV变化的能力。
Stellar variability is a key obstacle in reaching the sensitivity required to recover Earth-like exoplanetary signals using the radial velocity (RV) detection method. To explore activity signatures in Sun-like stars, we present SolAster, a publicly-distributed analysis pipeline that allows for comparison of space-based measurements with ground-based disk-integrated RVs. Using high spatial resolution Dopplergrams, magnetograms, and continuum filtergrams from the Helioseismic and Magnetic Imager (HMI) aboard the Solar Dynamics Observatory (SDO), we estimate 'Sun-as-a-star' disk-integrated RVs due to rotationally modulated flux imbalances and convective blueshift suppression, as well as other observables such as unsigned magnetic flux. Comparing these measurements with ground-based RVs from the NEID instrument, which observes the Sun daily using an automated solar telescope, we find a strong relationship between magnetic activity indicators and RV variation, supporting efforts to examine unsigned magnetic flux as a proxy for stellar activity in slowly rotating stars. Detrending against measured unsigned magnetic flux allows us to improve the NEID RV measurements by ~20\% (~50 cm/s in a quadrature sum), yielding an RMS scatter of ~60 cm/s over five months. We also explore correlations between individual and averaged spectral line shapes in the NEID spectra and SDO-derived magnetic activity indicators, motivating future studies of these observables. Finally, applying SolAster to archival planetary transits of Venus and Mercury, we demonstrate the ability to recover small amplitude (< 50 cm/s) RV variations in the SDO data by directly measuring the Rossiter-McLaughlin (RM) signals.
