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

Abstract

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 EWs of optical lines HβNLR and FeII, increase as well; ii) as MIR spectral index increases, EW([OIII]) decreases, while fractional contribution of AGN (RAGN) is not connected with EW([OIII]); iii) The log([OIII]5007/HβNLR) 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 BPT 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.

Kinematic differences between NLS1 and BLAGN sources

“…Regarding the FWHM(Hβ )-RPAH trend for NLS1s ( Fig. 1), it was already noticed in [14] and references within, but for the whole BLAGN and NLS1 sample. FWHM(Hβ )-LHβ b trend (Fig.…”

Narrow vs. broad-line Seyfert 1 galaxies: X-ray, optical, and mid-infrared AGN characteristics

“…82 objects from the sample were already analysed in Lakićević et al (2017) and therefore we took the optical and MIR parameters from that work. For the rest of the data, we calculated MIR parameters (see below), and adopted the optical data (FWHM(Hβ) and L5100) from the literature ( Table 1).…”

“…This routine, written in IDL, performs the decomposition of spectra to AGN, PAH and stellar part. More about this analysis can be found in Lakićević et al (2017). The products of the fitting were MIR parameters: fractional contributions of AGN, PAH and stellar components to the integrated 5-15µm luminosity, named RAGN, RPAH and RSTR, respectively (RAGN + RPAH+ RSTR=1), spectral index of the AGN componentα, the silicate strength -S SIL 2 , χ 2 , the coefficient of variation of the rms error (CV RMSE ) and monochromatic luminosity of the source at 6 µm, hereafter L6 (Hernán-Caballero et al 2015;Lakićević et al 2017).…”

“…The resulting MIR parameters are given in Table 1. The luminosities of the Hβ broad line (the sum of intermediate line region -ILR and very broad line region -VBLR components) for the sources from Lakićević et al (2017) are the only optical parameters calculated for this work (Table 1). Their optical data are available in the SDSS Data Release 12 (DR12) (see more in Lakićević et al 2017).…”

“…The MIR and optical data for the NLS1s and BLAGNs, respectively. Column (1) -source name, (2) -redshift, (3) -FWHM(Hβ) = FWHM of broad Hβ component, (4) -logarithm of AGN luminosity at 5100Å, multiplied with 5100, (5) and (6) -fractional contributions of AGN and PAH components to the integrated MIR luminosity, respectively, (7) -silicate strength, (8) -spectral index, (9) -monochromatic luminosity of the source at 6µm, (10)-Luminosity of Hβ broad line (ILR+VBLR -see the text) for the sources from Lakićević et al (2017), (11) (2006). A full version is available in the electronical form.…”