We present our spectroscopic data around H \beta of the symbiotic star V1016 Cyg obtained with the Bohyunsan Echelle Spectrograph , in order to secure the broad emission feature at around 4850 Å , which is formed through Raman scattering of He II \lambda 972 .
The total cross section around Ly \gamma is approximately given by \sigma ( \lambda ) \simeq 1.7 \times 10 ^ { -28 } [ \lambda _ { Ly \gamma } / ( \lambda - \lambda _ { % Ly \gamma } ) ] ^ { 2 } { cm ^ { 2 } } , with \lambda _ { Ly \gamma } being the line centre wavelength of Ly \gamma .
We find a centre shift redward by an amount \Delta \lambda = +0.64 { \AA } in the Raman scattered He II \lambda 4850 .
This redward centre shift is exactly analogous to the effect for the Raman scattered He II \lambda 6545 blueward of H \alpha discussed in our previous study .
We compute the branching ratios of Raman scattering into the level 2 s and levels 3 s, and 3 d , which are subsequently incorporated in our Monte Carlo code .
Using this code , we present the centre shift of the 4850 feature as a function of the neutral hydrogen column density in the scattering region .
Assuming that He II \lambda 972 emission is characterized by a single Gaussian profile , the redward peak shift observed in the Raman scattered He II 4850 feature corresponds to the neutral column density N _ { HI } = 1.2 \times 10 ^ { 21 } { cm ^ { -2 } } .
Assuming that the covering factor \sim 0.1 of the scattering region with respect to the He II emission region and adopting a simple spherical stellar wind model , we may place an upper bound \dot { M } \leq 3.6 \times 10 ^ { -7 } { M _ { \odot } yr ^ { -1 } } for the mass loss rate of the giant component of V1016 Cyg .
Our estimate can be severely affected by the kinematics of the scattering and He II emission regions and the exact atomic physics , about which brief discussions are presented .