different nature of the galaxies in the two samples.

![Comparison of observed and estimated  based on the  calibration of Zhang et al. (2009), given by Eq.\[eq-zhnag\]. The mean offset between the estimated and observed  and the scatter ($\sigma$) therein are shown in each plot. The gray dashed line shows the one-to-one relation of  ($_{est}) =$($_{obs})$.[]{data-label="fig-zhang-valid"}](fig-01-1.pdf "fig:"){width="6.7cm" height="5.2cm"} ![Comparison of observed and estimated  based on the  calibration of Zhang et al. (2009), given by Eq.\[eq-zhnag\]. The mean offset between the estimated and observed  and the scatter ($\sigma$) therein are shown in each plot. The gray dashed line shows the one-to-one relation of  ($_{est}) =$($_{obs})$.[]{data-label="fig-zhang-valid"}](fig-01-2.pdf "fig:"){width="6.7cm" height="5.2cm"} ![Comparison of observed and estimated  based on the  calibration of Zhang et al. (2009), given by Eq.\[eq-zhnag\]. The mean offset between the estimated and observed  and the scatter ($\sigma$) therein are shown in each plot. The gray dashed line shows the one-to-one relation of  ($_{est}) =$($_{obs})$.[]{data-label="fig-zhang-valid"}](fig-01-3.pdf "fig:"){width="6.7cm" height="5.2cm"} ![Comparison of observed and estimated  based on the  calibration of Zhang et al. (2009), given by Eq.\[eq-zhnag\]. The mean offset between the estimated and observed  and the scatter ($\sigma$) therein are shown in each plot. The gray dashed line shows the one-to-one relation of  ($_{est}) =$($_{obs})$.[]{data-label="fig-zhang-valid"}](fig-01-4.pdf "fig:"){width="6.7cm" 