The emission spectrum of the strong Fe II emitter BAL Seyfert 1 galaxy IRAS 07598+6508

The narrow-line Seyfert 1 galaxy IRAS 07598+6508 is known to be a stong Fe II emitter. The analysis of several high S/N ratio spectra shows that its spectrum is dominated by a relatively narrow “broad line” region (1780 km s -1 FWHM ) emitting not only Fe II, but also Ti II and Cr II lines. Although we were unable to find a completely satisfactory physical model, we got the best agreement with the observations with collisional rather than radiative models, with a high density ($n=10^{15}$ cm -3 ), a high column density ( N H = 10 25 cm -2 ) and a microturbulence of 100 km s -1 . This BLR is qualitatively similar to the one observed in I Zw 1. We have not found traces in IRAS 07598+6508 of the narrow line regions found in I Zw 1.