A survey of sodium absorption in 10 giant exoplanets with high-resolution transmission spectroscopy

The alkali metal sodium (Na) is one of the most commonly detected chemical species in upper atmospheres giant exoplanets. In this work we conducted a homogeneous survey Na diverse sample ten highly irradiated exoplanets using high-resolution transmission spectroscopy. Our includes nine planets with previous detections and new detection. We confirm assess multiple approaches for deriving line properties from spectra. homogeneously measured depths were used to constrain atmospheric heights ($H_{\text{Na}}$) respect planetary radii ($R_{\text{p}}$). an empirical trend describing relative height ($H_{\text{Na}}/R_{\text{p}}$) as function equilibrium temperature ($T_{\text{eq}}$) surface gravity ($g$), which $H_{\text{Na}}/R_{\text{p}}$ decreases exponentially $\xi \propto gT_{\text{eq}}$, approaching constant at large $\xi$. also report D2/D1 ratios across our find that seven targets have are consistent unity. Finally, net blueshifted offsets absorption lines their rest frame wavelengths all planets, corresponding day-night wind velocities few km s$^{-1}$. This suggests broad share common underlying processes govern dynamics. study highlights promising avenue spectroscopy further understanding how characteristics vary over