Raman-scattered Ne vii delta 973 at 4881 Aa in the symbiotic star V1016 Cygni

We present high-resolution spectra of the symbiotic star V1016 Cygni obtained with the Bohyunsan Optical Echelle Spectrograph in 2003 and 2005, from which we find a broad emission feature at 4881 Aa. We propose that this broad feature is formed from Raman scattering of Ne VII lambda 973 by atomic hydrogen. Thus far, the detection of Raman-scattered lines by atomic hydrogen is limited to O VI lambda lambda 1032, 1038 and He II lambda lambda 940, 972 and 1025. With the adoption of a centre wavelength 973.302 Aa for Ne VII lambda 973 and considering an air refractive index nair = 1.000 279 348, the atomic line centre of the Raman-scattered Ne VII feature is determined to be 4880.53 Aa. The total cross-section at the line centre of Ne VII lambda 973 is computed to be 2.62 x 10 super( -22) cm super( 2), with a branching ratio of 0.17. We perform Monte Carlo simulations to fit the Raman-scattered Ne VII lambda 973. Assuming that the Ne VII and He II emission regions share the same kinematics with respect to the neutral scattering region, we find that the Raman-scattered He II lambda 972 at 4850 Aa and Ne VII lambda 973 at 4881 Aa are excellently fitted. We also propose that the He II and Ne VII emission regions were stationary with respect to the H I region in 2003, but that they were receding from it with a velocity ~20 km s-1 in 2005.