论文标题
Zeeman-Doppler成像中低估的场强会影响旋转扭矩估计值多少？
How much do underestimated field strengths from Zeeman-Doppler imaging affect spin-down torque estimates?
论文作者
论文摘要
许多尝试估计低质量恒星在文献中存在角度动量的速度。一种方法是使用从Zeeman-Doppler Imaging（ZDI）和所谓的“制动法”结合使用的磁图。 ZDI地图的使用比其他方法具有优势，因为它允许将有关磁场几何形状的信息纳入估计值。然而，已知ZDI低估了由于磁通效应而导致的光谱场强度。最近，Lehmann等。 （2018年）在一组通量传输模拟上进行了合成的ZDI重建，以帮助量化ZDI低估相对缓慢旋转和弱活性太阳能恒星的田间强度的数量。在本文中，我们评估了基于ZDI图的低估角度损失率的估计是如何的。我们发现它们对于具有强磁场的恒星相对准确，但对于具有弱磁场弱的恒星，可能会低估$ \ sim 10 $ 10。此外，我们重新评估了先前使用ZDI图来研究不同磁场模式对角动量损害的相对贡献的工作。我们先前发现，偶极子组件在大多数低质量恒星中都占主导地位。即使鉴于Lehmann等人的工作，这一结论仍然是正确的。 （2018）。
Numerous attempts to estimate the rate at which low-mass stars lose angular momentum over their lifetimes exist in the literature. One approach is to use magnetic maps derived from Zeeman-Doppler imaging (ZDI) in conjunction with so-called "braking laws". The use of ZDI maps has advantages over other methods because it allows information about the magnetic field geometry to be incorporated into the estimate. However, ZDI is known to underestimate photospheric field strengths due to flux cancellation effects. Recently, Lehmann et al. (2018) conducted synthetic ZDI reconstructions on a set of flux transport simulations to help quantify the amount by which ZDI underestimates the field strengths of relatively slowly rotating and weak activity solar-like stars. In this paper, we evaluate how underestimated angular momentum-loss rate estimates based on ZDI maps may be. We find that they are relatively accurate for stars with strong magnetic fields but may be underestimated by a factor of up to $\sim$10 for stars with weak magnetic fields. Additionally, we re-evaluate our previous work that used ZDI maps to study the relative contributions of different magnetic field modes to angular momentum-loss. We previously found that the dipole component dominates spin-down for most low-mass stars. This conclusion still holds true even in light of the work of Lehmann et al. (2018).
