Table · dataset · 2024
Extreme radio variability in early-stage AGN
Listed in IVOA Registry (Virtual Observatory)
We report on the discovery of one of the most extreme cases of high-frequency radio variability ever measured in active galactic nuclei (AGNs), observed on time-scales of days and exhibiting variability amplitudes of 3-4 orders of magnitude.
Description
These sources, all radio-weak narrow-line Seyfert 1 (NLS1) galaxies, were discovered some years ago at Aalto University Metsahovi Radio Observatory (MRO) based on recurring flaring at 37 GHz, strongly indicating the presence of relativistic jets.
In subsequent observations with the Karl G. Jansky Very Large Array (JVLA) at 1.6, 5.2, and 9.0GHz no signs of jets were seen. To determine the cause of their extraordinary behaviour, we observed them with the JVLA at 10, 15, 22, 33, and 45GHz, and with the Very Long Baseline Array (VLBA) at 15GHz. These observations were complemented with single-dish monitoring at 37 GHz at MRO, and at 15GHz at Owens Valley Radio Observatory (OVRO).
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Intriguingly, all but one source either have a steep radio spectrum up to 45GHz, or were not detected at all. Based on the 37GHz data, the time-scales of the radio flares are a few days, and the derived variability brightness temperatures and variability Doppler factors are comparable to those seen in blazars. We discuss alternative explanations for their extreme behaviour, but so far no definite conclusions can be made.
These sources exhibit radio variability at a level rarely, if ever, seen in AGN. They might represent a new type of jetted AGN, or a new variability phenomenon, and thus deserve our continued attention.
Links
Where it is published
- Reference page cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/532/3069 ↗
landing page · from IVOA Registry
Documentation and papers
- ADS 2024MNRAS.532.3069J ui.adsabs.harvard.edu/abs/2024MNRAS.532.3069J ↗
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/532/3069 ↗
catalogue entry · from IVOA Registry
Topics
- Stated by source
- Radio
- From keywords
- Astronomy & Astrophysics
- Inferred from text
- Astronomical sciences 71%
Provenance · 1 source records, 9 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| IVOA Registry (Virtual Observatory) | ivo://cds.vizier/j/mnras/532/3069 | 13 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 (71%) |
| concepts[field].local:field:astronomy | mapping · IVOA Registry | connector:ivoa_registry@1.0.0 | |
| concepts[modality].ivoa_waveband:radio | 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 |