J/A+A/323/71 J/A+A/323/71 Line spectra of Liners M Contini Astron. Astrophys. 323 71 1997 1997A&A...323...71C Galaxies, spectra galaxies: active galaxies: Seyfert galaxies: starburst radiation mechanisms: non-thermal shock waves The physical conditions which characterize individual Liners are obtained by fitting the observational spectra of the Ho et al. (1993ApJ...417...63H) sample by model calculations. Composite models which consistently account both for shocks, accompanying the radial outward motion of the gaseous clouds, and a photoionizing radiation flux are used. Power-law or black body radiation is considered, depending on the characteristics of the line spectra. The SUMA code is used. The contributions of the different ionization mechanisms to the spectrum emitted by each object are calculated and compared with the observations. The most significant line ratios of Liner spectra are analyzed to show the relative importance of photoionization by radiation from the active center or from starbursts, of photoionization by diffuse radiation, and of collisional ionization by shocks. Model results show that [Ne V] lines can be strong due to collisional ionization and/or photoionization. Lines from the II and III ionization levels are usually due to photoionization, but a strong contribution by collisional ionization appears in case of high densities and/or of a strong shock. Neutral lines are enhanced by diffuse radiation. The contribution of high density gas to the line intensities in Liner spectra is very small, indicating that the high density region, located between the NLR and the BLR, is also small. The results show that shocks play an important role, even if a photoionizing flux is present. On average, higher than cosmic N/H and lower S/H are indicated. The physical characteristics of Seyfert galaxies and of starburst galaxies are confirmed. The satisfactory results obtained interpreting the heterogeneous observational sample by SUMA strengthen the hypothesis that shock signature in AGN spectra is due to cloud motions in galaxies.

Model Model number=1 M0: Shock dominated model (F=0) M1: Model with low shock velocity (Vs), preshock density (n0) and photoionization flux (F) M2: Model with low Vs and n0, but relatively higher F M3: Model with low Vs and n0, but relatively higher F M4: Model showing the effect of a low high-energy cut-off M5: Model characterized by higher Vs and n0 which are higher limits deduced by observations of Liners spectra M1d: Model characteristic of higher density M3d: Model characteristic of higher density M6: represent starburst model M7: represent starburst model --- [NeV] Line intensity of [Ne V] 3426 (Hbeta=1) --- [OII] Line intensity of [O II] 3727+ (Hbeta=1) --- [NeIII] Line intensity of [Ne III] 3869+ (Hbeta=1) --- [OIII] Line intensity of [O III] 4363 (Hbeta=1) --- HeII Line intensity of He II 4686 (Hbeta=1) --- [OIII]b Line intensity of [O III] 5007+ (Hbeta=1) --- [NI] Line intensity of [N I] 5200+ (Hbeta=1) --- HeI Line intensity of He I 5876 (Hbeta=1) --- [OI] Line intensity of [O I] 6300+ (Hbeta=1) --- [NII] Line intensity of [N II] 6583+ (Hbeta=1) --- [SII] Line intensity of [S II] 6717 (Hbeta=1) --- [SII]b Line intensity of [S II] 6730 (Hbeta=1) --- [OII]b Line intensity of [O II] 7322+ (Hbeta=1) --- [SIII] Line intensity of [S III] 9402+ (Hbeta=1) --- Hbeta Hbeta flux mW/m2 R[OIII] Line ratio [O III]5007+/[O III]4363 --- R[OII] Line ratio [O II]3727+/[O II]7322 --- R[SII] Line ratio [S II]6717/[S II]6730 --- RN Line ratio [NII]/[N I] line ratio --- RHe Line ratio [He II]/[He I] line ratio --- Vs Shock velocity km/s n0 Preshock density cm-3 U Ionization parameter --- F Photoionizing power law radiation flux ph/cm+2/s/eV Ec High energy cutoff of radiation flux eV T Stellar temperature K Ion Ion --- Line Line --- NGC Galaxy name --- Obs Observed line intensity --- Obs2 Observed line intensity from Ho et al. (1996ApJ...462..183H), NGC 3031 only. --- Calc Calculated line intensity --- Calc2 Calulated line intensity --- Calc3 Calculated line intensity --- NGC Galaxy name --- HbObs Observed Hbeta flux mW/m2 HbCal Calculated Hbeta flux mW/m2 Vs Shock velocity km/s n0 Preshock density cm-3 T Stellar temperature K U Ionization parameter --- F Photoionizing power law radiation flux ph/cm+2/s/eV B0 Preshock magnetic field 10-4T N/H N/H line ratio --- O/H O/H line ratio --- Ne/H Ne/H line ratio --- S/H S/H line ratio --- No Number referring to diagnostic diagram --- NGC NGC number --- Type Classification number=1 H: H II region L: Liner S: Seyfert --- Vs Shock velocity km/s n0 Photoionizing power law radiation flux cm-3 F Photoionizing power law radiation flux ph/cm+2/s/eV U Ionization parameter --- T Star temperature K N/H Relative N/H ratio to cosmic one number=2 c: cosmic <: lower than cosmic >: higher than cosmic >=: higher or equal to cosmic value --- Ne/H Relative Ne/H ratio to cosmic one number=2 c: cosmic <: lower than cosmic >: higher than cosmic >=: higher or equal to cosmic value --- S/H Relative S/H ratio to cosmic one number=2 c: cosmic <: lower than cosmic >: higher than cosmic >=: higher or equal to cosmic value --- Flux Type of ionizing radiation responsible for heating and ionization of the emitting gas number=3 bb: black body os: only shock pl: power law --- tables.texLaTeX version of the tables Patricia Bauer CDS 1996Dec03Marcella Contini <contini@post.tau.ac.il> J_A+A_323_71.xml