LEDA 18174
Observation
| Spectrum ID | 18991982_sp1 |
|---|---|
| Alt name | g0558507-403847 |
| z | 0.0627 |
| RA, Dec | 89.7114, -40.6464 |
| MJD | 60266.67 |
| SNR/Å B/R | 14.5/22.6 |
| Obs Airmass | 1.01 |
| SMSS ID | 18991982 |
| Closest SMSS | None (< 15") |
| SMSS Mean r6"ap | 16.6 ± 0.1 |
| 2MASS Kext | 12.4 ± 0.1 |
AGN Properties
| Spectrum Type | Sy 1.2 |
|---|---|
| Quality Flag | good |
| AGN reference | 6dFGS |
| MW E(B−V) | 0.042 |
| Power law αν | 0.47 ± 0.03 |
| log L5100,AGN | 43.48 ± 0.01 |
| log HβBr/[O III] | 0.49 ± 0.11 |
| log ML5100/M☉ | 7.71 ± 0.02 |
| log MHα/M☉ | 7.53 ± 0.02 |
| log MHβ/M☉ | 7.70 ± 0.06 |
| log M[O III]/M☉ | 7.62 ± 0.03 |
Spatial extraction & sky subtraction region
Spaxel scale: 1 arcsec² — Flux units: erg s⁻¹ cm⁻² Å⁻¹
Apertures: object (solid), background (dashed)
Spectrum decomposition
Emission line measurements
| Line | log L (erg s⁻¹) | FWHM (km s⁻¹) | σ (km s⁻¹) | EW (Å) |
|---|---|---|---|---|
| Hγ Narrow | 39.57 ± 0.38 | 306 ± 64 | 208 ± 26 | 0.43 ± 0.31 |
| Hγ Broad | 41.31 ± 0.03 | 3565 ± 133 | 1171 ± 29 | 23.14 ± 0.68 |
| [O III] 4364 | 39.57 ± 0.33 | 254 ± 63 | 107 ± 25 | 0.43 ± 0.21 |
| He II Narrow | 39.76 ± 0.18 | 254 ± 63 | 107 ± 25 | 0.79 ± 0.27 |
| He II Broad | — | — | — | — |
| Hβ Narrow | 40.03 ± 0.15 | 306 ± 64 | 208 ± 26 | 1.60 ± 0.34 |
| Hβ Broad | 41.64 +0.20−0.01 | 3280 ± 45 | 1209 ± 26 | 64.95 ± 0.87 |
| [O III] 5007 | 41.15 ± 0.01 | 306 ± 64 | 208 ± 26 | 22.58 ± 0.37 |
| He I Narrow | 39.05 ± 0.41 | 254 ± 63 | 107 ± 25 | 0.27 ± 0.22 |
| He I Broad | 41.06 ± 0.03 | 4513 ± 79 | 1917 ± 32 | 27.52 ± 1.02 |
| [O I] 6300 | 39.32 ± 0.24 | 254 ± 63 | 107 ± 25 | 0.60 ± 0.23 |
| Hα Narrow | 40.61 ± 0.03 | 254 ± 63 | 107 ± 25 | 12.93 ± 0.40 |
| Hα Broad | 42.18 ± 0.01 | 2868 ± 64 | 1556 ± 33 | 481.28 ± 2.28 |
| [N II] 6585 | 40.44 ± 0.03 | 254 ± 63 | 107 ± 25 | 8.84 ± 0.36 |
| [S II] 6718 | 39.80 ± 0.09 | 254 ± 63 | 107 ± 25 | 2.10 ± 0.29 |
| [S II] 6732 | 39.59 ± 0.16 | 254 ± 63 | 107 ± 25 | 1.29 ± 0.28 |
All narrow line widths are tied to narrow [O III] 5007Å. [O III] 5007Å and narrow Hβ include a second narrow component not tied to other narrow lines.
Emission summary
| Hα Broad SNR | 24.11 |
|---|---|
| Hβ Broad SNR | 9.80 |
| Hγ Broad SNR | 5.23 |
| AGN frac | 0.66 |
| Host frac | 0.34 |
| log L5100,Host | 43.20 |
| Fe II/Hβ | — |
| Fe II/[O III] | — |
Quality flags
spurious_hab/hbb | 0.0/1 |
|---|---|
l5100 | 2 |
balmer | 0 |
balmer_snr | 0 |
hb_width | 0 |
balmer_width | 0 |
Hα mass estimates from Cho+2023. Remaining mass estimates from R–L relations in Wang & Woo 2024 and zero-points from Amrutha+2026.