| AGNCLASS |
DESCRIPTION |
| Q |
Quasi-stellar objects. Have very high luminosities
(Mabs<-23) and broad emission lines (FWHM=5,000- 30,000km/s)
with a large red-shift ( VCV-12
). |
| BL |
BL Lacertae type object. No emission or absorption lines
deeper than ~ 2% are seen in any part of the optical spectrum,
or only extremely week absorption and/or emission lines are
observed, as a rule at minimum of their very highly variable
phase. So that their redshifts can only be determined from
features in the spectral of their host galaxies. They show
polarization and are strong radio sources (
Lawrence 1987 , ,Miller et al. 1978). |
| HP |
Highly polarized objects (
VCV-12 ). |
| S1 |
Broad-line Seyfert 1. Have broad permitted Balmer HI lines
(FWHM=1000-10000km/s, typical is 2000-6000km/s) and narrow
forbidden lines (FWHM=300-1000km/s). Physically are the same
objects as QSOs, but having smaller luminosities
(Mabs>-23). According to
Winkler (1992),Hb/[OIII]5007>5.0.
|
| S1n |
Narrow-line Seyfert 1. Defined by
Osterbrock & Pogge
(1985) as soft X-ray sources, having narrow permitted lines only
slightly broader than the forbidden ones; many FeI, FeII, FeIII,
and often strong [FeVII] and [FeX] emission lines present,
unlike what is seen in Seyfert 2s. FWHM(Hb)<2000km/s
(
Goodrich 1989).
|
| S1i |
S1 with a broad Paschen Hbeta line, indicating the presence
of a highly reddened BLR (
Goodrich et al. 1994 ).
|
| S1h |
S2 which show S1 like spectra in polarized light (
Antonucci & Miller 1985 ;
Miller & Goodrich 1990 ; Tran et al. 1992 ).
|
| S2 |
Show relatively narrow (compared to S1) emission in both
permitted Balmer and forbidden lines, with almost the same FWHM,
typically in the range of 300-1000 km/s. No broad component is
visible. A secondary classification criterion is
[OIII]5007/Hb>=3 , to distinguish against S1n (
Khachikian & Weedman 1974 ,
Veilleux and Osterbrock 1987 ,
Lawrence 1987 ). |
| S2? |
Probable S2 galaxy (
VCV-12 ). |
| S1.2 |
AGN which share parameters that are intermediate between
those of classical Sy1 and Sy2 galaxies. According to
Winkler (1992) , 2.0<Hb/[OIII]5007<5.0. Often related to S1n. |
| S1.5 |
AGN which share parameters that are intermediate between
those of classical Sy1 and Sy2 galaxies; have easily discernible
narrow HI profile superposed on broad wings. According to
Winkler (1992), 0.333<Hb/[OIII]5007<2.0. |
| S1.8 |
AGN which share parameters that are intermediate between
those of classical Sy1 and Sy2 galaxies; have relatively weak
broad Ha and Hb components superposed on strong narrow
lines. According to
Winkler (1992), Hb/[OIII]5007<0.333. |
| S1.9 |
AGN which share parameters that are intermediate between
those of classical Sy1 and Sy2 galaxies; have relatively weak
broad Ha component superposed on a strong narrow line. The broad
component of Hb is not seen. According to
Winkler (1992),
Hb/[OIII]5007<0.333. |
| S |
AGN objects without classification (
VCV-12). |
| S? |
Possibly Seyfert galaxies (
VCV-12 ). |
| S3 |
LINERS or Low-Ionization Nuclear Emission-line
Region. Introduced by
Heckman (1980) , they are low activity
AGN. Have S2-like spectra with relatively strong low-ionization
lines
(OI,OII).
I([OII]3727)/I([OIII]5007)>=1,I([OI]6300)/I([OIII]5007)>=1/3.
[NII]6584/Ha>0.6 . |
| S3b |
S3 with broad Balmer lines (
Ho, Filippenko & Sargent
1997 ). |
| S3h |
S3 with broad Balmer lines seen only in polarized light
(
VCV-12 ). |
| H2 |
Extragalactic HII regions. Have spectra with strong narrow
(FWHM<=300km/s) emission line spectrum, but with a ratio
[OIII]/Hb>=3 and ([NII]6584/)Ha<0.5, coupled with a blue
continuum (
Veilleux and Osterbrock 1987). |
| SB |
Starburst nuclei or Starburst. The major observable feature
that distinguishes SB form Sy is their strong narrow emission lines
(FWHM<=300km/s). According to Balzano (1983), SB is a spiral galaxy with a
bright, blue nucleus that emits a strong narrow emission line spectrum
similar to low-ionization HII region spectra. They have strong, narrow
(FWHM<=250km/s) low-ionization ([OIII]/Hb<3) emission lines. Absolute
luminosities are -17.5>M>-22.5. Characterized them conspicuous stellar or semistellar nuclei.
|
| em |
Object with emission line spectrum. No further precision.
|