We study the influence of convection on the asymmetries and Doppler shifts of \ion Fei spectral lines in the metal-poor red giant HD 122563 .
To this end , we compute theoretical \ion Fei line shifts and line bisectors using 3D hydrodynamical model atmosphere of HD 122563 calculated with the CO ^ { 5 } BOLD code .
We then make a detailed comparison of the theoretical line shifts and bisectors with those derived from the high quality HARPS spectrum of HD 122563 taken from the ESO Science Archive Facility ( R = 115 000 , average signal-to-noise ratio , S/N \approx 310 ) .
In general , we find a good agreement between the theoretically predicted and observed Doppler shifts of \ion Fei line cores , with somewhat larger discrepancies seen in the case of weaker ( equivalent width W < 5 pm ) and stronger lines ( W > 11 pm ) .
Both observed and theoretical coreshifts cover a range between 0 and -1 km/s , with increasingly stronger blueshifts for weaker lines and slight hints of a coreshift dependence on wavelength .
Theoretical bisectors reproduce the observed ones reasonably well too , however , theoretical bisectors of the weak red ( \lambda > 600 nm ) \ion Fei lines have blueshifts that are by up to \sim 200 m/s larger than observed .
The obtained results therefore suggest that the current CO ^ { 5 } BOLD models are capable of reproducing the large-scale velocity fields in the atmosphere of HD 122563 sufficiently well .
Nevertheless , further efforts are needed in order to understand the physical reasons behind the discrepancies in theoretical predictions and observed properties of the weakest and strongest \ion Fei lines .