Distribution of close-in exoplanets with hydrogen observations. The red points represent the exoplanets in which hydrogen has been detected in Lyα or Hα, the blue points planets with inconclusive detection in hydrogen absorption, and the black points planets in which hydrogen is not detected. Squares, circles, and stars represent planets with Lyα, Hα, and both line observations, respectively. The straight lines show the condition T_eq = T_ch and t_ion = t_rec.