T_c slopes versus surface gravity of the stars from the full sample (top) and 58 solar analogs (bottom). Gray solid lines provide linear fits to the data points.

T_c slopes versus atmospheric parameters of the stars from the full sample (left) and solar analogs (right).

T_c slopes versus age and the mean of the apo- and pericentric distances for the solar twins in our sample. Gray solid lines provide linear fits to the data points.

R_mean versus age for the full sample. Red squares represent the stars with negative T_c slopes, and the stars with positive T_c slopes are marked by blue circles. Gray solid line provides linear fits to the full data points.

[X/Fe] versus T_c at three different galactocentric distances. The [X/Fe] values derived using the Galactic abundance gradients of Galactic Cepheids from Lemasle et al. (2008, 2013). The lines with different colors represent linear fits of the data.