  We look into the signatures of the effective Y-bosonic strings in the gluonic
profile due to a system of three static quarks on the lattice. The gluonic
distribution is calculated in pure Yang-Mills lattice gauge theory at finite
temperature with Polyakov loops operators. The analysis of the action density
unveils a filled-$\Delta$ distribution. However, we found that these
$\Delta$-shaped action density profiles are structured from three Y-shaped
Gaussian-like flux-tubes. The length of the revealed Y-flux system increases
with the increasing of the color source separation and reaches maximum near the
deconfinement point. The lattice data for the mean-square width of the gluonic
action density have been compared to the corresponding width calculated based
on the string model at finite temperature. We assume Y-string configuration
with minimal length. The growth pattern of the action density of the gluonic
field fits well to junction fluctuations of the Y-baryonic string model for
large quark separation at the considered temperatures.
