J/A+A/323/71 Line spectra of Liners (Contini 1997)
Line spectra of Liners. The contribution of the different ionization mechanisms.
Contini M.
<Astron. Astrophys. 323, 71 (1997)>
=1997A&A...323...71C 1997A&A...323...71C (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, spectra
Keywords: galaxies: active - galaxies: starburst - galaxies: Seyfert -
radiation mechanisms: nonthermal - shock waves
Abstract:
The physical conditions which characterize individual Liners are
obtained by fitting the observational spectra of the Ho et al.
(1993ApJ...417...63H 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.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1 160 10 Line intensities relative to Hbeta
table2p1 60 288 Comparison of calculated spectra with
observations (table2, part. 1)
table2p2 80 32 Comparison of calculated spectra with
observations (table2, part. 2)
table3 51 32 Summary of the results presented in table2
tables.tex 81 533 LaTeX version of the tables
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Model Model (1)
5- 12 E8.3 --- [NeV] Line intensity of [Ne V] 3426 (Hbeta=1)
14- 18 F5.2 --- [OII] Line intensity of [O II] 3727+ (Hbeta=1)
20- 23 F4.2 --- [NeIII] Line intensity of [Ne III] 3869+ (Hbeta=1)
25- 30 F6.4 --- [OIII] Line intensity of [O III] 4363 (Hbeta=1)
32- 36 F5.3 --- HeII Line intensity of He II 4686 (Hbeta=1)
38- 42 F5.2 --- [OIII]b Line intensity of [O III] 5007+ (Hbeta=1)
44- 49 F6.4 --- [NI] Line intensity of [N I] 5200+ (Hbeta=1)
51- 54 F4.2 --- HeI Line intensity of He I 5876 (Hbeta=1)
56- 59 F4.2 --- [OI] Line intensity of [O I] 6300+ (Hbeta=1)
61- 65 F5.2 --- [NII] Line intensity of [N II] 6583+ (Hbeta=1)
67- 70 F4.2 --- [SII] Line intensity of [S II] 6717 (Hbeta=1)
72- 76 F5.3 --- [SII]b Line intensity of [S II] 6730 (Hbeta=1)
78- 82 F5.2 --- [OII]b Line intensity of [O II] 7322+ (Hbeta=1)
84- 87 F4.2 --- [SIII] Line intensity of [S III] 9402+ (Hbeta=1)
89- 95 E7.2 mW/m2 Hbeta Hbeta flux
97-101 F5.1 --- R[OIII] Line ratio [O III]5007+/[O III]4363
103-107 F5.2 --- R[OII] Line ratio [O II]3727+/[O II]7322
109-112 F4.2 --- R[SII] Line ratio [S II]6717/[S II]6730
114-119 F6.2 --- RN Line ratio [NII]/[N I] line ratio
121-124 F4.2 --- RHe Line ratio [He II]/[He I] line ratio
126-128 I3 km/s Vs Shock velocity
130-135 E6.5 cm-3 n0 Preshock density
137-142 E6.1 --- U ? Ionization parameter
144-148 E5.4 ph/cm+2/s/eV F ? Photoionizing power law radiation flux
150-153 I4 eV Ec ? High energy cutoff of radiation flux
155-158 E4.3 K T ? Stellar temperature
--------------------------------------------------------------------------------
Note (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
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2p1
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Ion Ion
10- 14 A5 --- Line ? Line
16- 22 A7 --- NGC Galaxy name
24- 29 F6.3 --- Obs ? Observed line intensity
31- 34 F4.2 --- Obs2 ? Observed line intensity from Ho et al.
(1996ApJ...462..183H 1996ApJ...462..183H), NGC 3031 only.
36- 43 F8.5 --- Calc ? Calculated line intensity
46- 53 F8.5 --- Calc2 ? Calulated line intensity
56- 60 F5.3 --- Calc3 ? Calculated line intensity
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2p2
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- NGC Galaxy name
9- 12 E4.3 mW/m2 HbObs ? Observed Hbeta flux
14- 19 E6.1 mW/m2 HbCal ? Calculated Hbeta flux
21- 23 I3 km/s Vs Shock velocity
25- 27 I3 cm-3 n0 Preshock density
29- 33 E5.1 K T ? Stellar temperature
35- 40 E6.1 --- U ? Ionization parameter
42- 46 E5.4 ph/cm+2/s/eV F ? Photoionizing power law radiation flux
48- 51 E4.3 10-4T B0 Preshock magnetic field
53- 58 E6.1 --- N/H N/H line ratio
60- 65 E6.1 --- O/H O/H line ratio
67- 72 E6.1 --- Ne/H Ne/H line ratio
74- 79 E6.1 --- S/H S/H line ratio
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- No Number referring to diagnostic diagram
4- 7 I4 --- NGC NGC number
10 A1 --- Type [HLS] Classification (1)
13- 15 I3 km/s Vs Shock velocity
17- 19 I3 cm-3 n0 Photoionizing power law radiation flux
21- 24 E4 ph/cm+2/s/eV F ? Photoionizing power law radiation flux
26- 31 E6.1 --- U ? Ionization parameter
33- 38 E6.1 K T ? Star temperature
40 A1 --- N/H [><c] Relative N/H ratio to cosmic one (2)
42- 43 A2 --- Ne/H [≥c ] Relative Ne/H ratio to cosmic one (2)
46 A1 --- S/H [<>c] Relative S/H ratio to cosmic one (2)
48 -49 A2 --- Flux [plbbos] Type of ionizing radiation
responsible for heating and ionization of
the emitting gas (3)
--------------------------------------------------------------------------------
Note (1): H: H II region
L: Liner
S: Seyfert
Note (2): c: cosmic
<: lower than cosmic
>: higher than cosmic
≥: higher or equal to cosmic value
Note (3): bb: black body
os: only shock
pl: power law
--------------------------------------------------------------------------------
Acknowledgements: Marcella Contini
(End) Patricia Bauer [CDS] 03-Dec-1996