Table · dataset · 2014
Type 1 AGN at low z. III.
Listed in IVOA Registry (Virtual Observatory)
We present the optical narrow-line ratios in a Sloan Digital Sky Survey (SDSS) based sample of 3175 broad H{alpha} selected type 1 active galactic nuclei (AGN), and explore their positions in the BPT diagrams as a function of the AGN and the host properties.
Description
We find the following: (1) the luminosities of all measured narrow lines (H{alpha}, H{beta}, [OIII], [NII], [SII], [OI]) show a Baldwin relation relative to the broad H{alpha} luminosity LbH{alpha}, with slopes in the range of 0.53-0.72.
(2) About 20 percent of the type 1 AGN reside within the "Composite" and "star-forming" (SF) regions of the Baldwin, Phillips & Terlevich (BPT) diagrams. These objects also show excess narrow H{alpha} and ultraviolet (UV) luminosities, for their LbH{alpha}, consistent with contribution from star formation which dominates the narrow-lines emission, as expected from their positions in the BPT diagrams. (3) The type 1 which reside within the AGN region in the BPT diagrams, are offset to lower [SII]/H{alpha} and [NII]/H{alpha} luminosity ratios, compared to type 2 AGN.
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This offset is a selection effect, related to the lower AGN/host luminosity selection of the type 2 AGN selected from the SDSS galaxy sample. (4) The [NII]/H{alpha} and [NII]/[SII] ratios in type 1 AGN increase with the host mass, as expected if the mass-metallicity relation of quiescent galaxies holds for the AGN narrow-line region (NLR). (5) The broad lines optical Fe ii is higher for a higher [NII]/H{alpha}, at a fixed Lbol and Eddington ratio L/LEdd.
This suggests that the broad line region metallicity is also related to the host mass. (6) The fraction of AGN which are low-ionization nuclear emission-line regions (LINERs) increases sharply with decreasing L/LEdd. This fraction is the same for type 1 and type 2 AGN.
(7) The BPT position is unaffected by the amount of dust extinction of the optical-UV continuum, which suggests that the extincting dust resides on scales larger than the narrow-line region (NLR).
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/431/836 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2013MNRAS.431..836S ui.adsabs.harvard.edu/abs/2013MNRAS.431..836S ↗
publication · from IVOA Registry
Catalogue records · 2
- VOResource record dc.g-vo.org/oai.xml?verb=GetRecord&metadataPrefix=ivo_vor&identifier=ivo%3… ↗
metadata API · from IVOA Registry
- Registry record (GAVO) dc.g-vo.org/I/cds.vizier/j/mnras/431/836 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Optical
- From keywords
- Astronomy & Astrophysics
- Inferred from text
- Astronomical sciences 73%
Provenance · 1 source records, 9 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/mnras/431/836 | 14 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[field].anzsrc:group:5101 | enrichment · IVOA Registry | taxonomy-embedding@1.1.0 | title+keywords+description (73%) |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:optical | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| description | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_description |
| license_text | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| publication_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| title | source · IVOA Registry | connector:ivoa_registry@1.0.0 | rr.resource.res_title |
| updated_date | source · IVOA Registry | connector:ivoa_registry@1.0.0 |