The optical versus mid-infrared spectral properties of 82 Type 1 AGNs: coevolution of AGN and starburst

We investigated the connection between the mid-infrared (MIR) and optical spectral characteristics in a sample of 82 Type 1 active galactic nuclei (AGNs), observed with Infrared Spectrometer on Spitzer (IRS) and Sloan Digital Sky Survey (SDSS, DR12). We found several interesting correlations between optical and MIR spectral properties: (i) as starburst significators in MIR increase, the equivalent widths (EWs) of optical lines H βNLR and Fe II, increase as well; (ii) as MIR spectral index increases, EW([O III]) decreases, while fractional contribution of AGN (RAGN) is not connected with EW([O III]); (iii) The log([O III]5007/H βNLR) ratio is weakly related to the fractional contribution of polycyclic aromatic hydrocarbons (RPAHs). We compare the two different MIR and optical diagnostics for starburst contribution to the overall radiation (RPAH and Baldwin, Philips & Terlevich diagram, respectively). The significant differences between optical and MIR starburst diagnostics were found. The starburst influence to observed correlations between optical and MIR parameters is discussed.