leda Catalogue of agn classification

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Search an object in the activity catalog

This catalogue (table a109 in the database) presents the compilation of the activity classification of objects. We have added in the database a characterization of the nuclear activity from the Véron and Véron catalogue (see Véron and Véron 2006 in VizieR, and in ADS , hereafter VCV-12). It is now possible to retrieve an activity type for the HyperLeda galaxies having this attribute, and to select list of objects from constraints on activity type. For example, one may select all Sy2 galaxies within some magnitude limits and/or redshift. The main difficulty for cross-identifying these multi-wavelength catalogues is the extremely different spatial resolution of the surveys which make automatic positional cross-identification unsafe. Fortunately, the VCV-12 already made the essential of this work and provides accurate position (typically to within 1 arcsec) for most of the sources. In many cases the redshift consistency allowed to make the proper identifications, and in some cases it was necessary to control visually the identifications using sky surveys images.

In April 2009, the table contained 88707 objects with activity classification.

In the work we have made some differences regarding to VCV-12 catalogue:
(i) For the moment, some objects from VCV-12 are still not cross-identified in HyperLeda;
(ii) For all "types" of BL which exist in VCV-12 (BL, BL?, blank and ? ) we have use the flag BL;
(iii) We denoted as Q all objects brighter than absolute magnitude Mabs=23;

Description of the field agnclass

We used for HyperLeda the activity type provided in the VCV-12:

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.

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