Extended Data Fig. 2: The mass versus [N/Fe] in our sample.

Martig et al. (2016) mapped the correlations⁴⁶ of stellar masses with ASPCAP [N/Fe] using machine learning. Their ‘predicted’ masses of the common sources in our sample are plotted as the grey dots. The red and blue dots are Li-rich RC and RGB stars in our sample, respectively. The region marked with light blue is the most clumped mass range predicted by the HeWD-RGB merger model. For the predicted mass range of 0.8-1.8 M_⊙ by the HeWD-RGB model, a fraction of stars indeed show much larger [N/Fe] (also see Fig. 3) compared to other RC stars within this mass range, but there seems no evident correlation between stars with high-mass and stars with high-[N/Fe].