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Record W2784316442 · doi:10.1051/0004-6361/201732286

Is 4C+29.48 a <i>γ</i>-ray source?

2018· article· en· W2784316442 on OpenAlexfundno aff

Bibliographic record

VenueAstronomy and Astrophysics · 2018
Typearticle
Languageen
FieldPhysics and Astronomy
TopicAstrophysics and Cosmic Phenomena
Canadian institutionsnot available
FundersLawrence Berkeley National LaboratoryBrookhaven National LaboratoryYouth Innovation Promotion AssociationJet Propulsion LaboratoryOffice of ScienceHungarian Scientific Research FundChinese Academy of SciencesYork UniversityNew Mexico State UniversityAssociated UniversitiesCarnegie Mellon UniversityUniversity of ArizonaCollege of Engineering, Michigan State UniversityPrinceton UniversityAlfred P. Sloan FoundationUniversity of WashingtonEuropean Space AgencyJohns Hopkins UniversityMagyar Tudományos AkadémiaU.S. Department of EnergyNational Radio Astronomy ObservatoryHarvard UniversityOhio State UniversityUniversity of California, Los AngelesUniversity of PortsmouthYale UniversityVanderbilt UniversityNational Science FoundationNemzeti Kutatási Fejlesztési és Innovációs HivatalCalifornia Institute of TechnologyNational Aeronautics and Space Administration
KeywordsVery-long-baseline interferometryBlazarSkyActive galactic nucleusRedshiftBrightnessTelescopeVery Long Baseline ArrayRadio telescopeBrightness temperature

Abstract

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Context. The Fermi Large Area Telescope revealed that the extragalactic γ-ray sky is dominated by blazars, active galactic nuclei (AGN) whose jet is seen at very small angle to the line of sight. To associate and then classify the γ-ray sources, data have been collected from lower frequency surveys and observations. Since those have superior angular resolution and positional accuracy compared to the γ-ray observations, some associations are not straightforward. Aims. The γ-ray source 3FGL J1323.0+2942 is associated with the radio source 4C+29.48 and classified as a blazar of unknown type, lacking optical spectrum and redshift. The higher-resolution radio data showed that 4C+29.48 comprises three bright radio-emitting features located within a ~1′-diameter area. We aim to reveal their nature and pinpoint the origin of the γ-ray emission. Methods. We (re-)analyzed archival Very Large Array (VLA) and unpublished very long baseline interferometry (VLBI) observations conducted by the Very Long Baseline Array (VLBA) and the European VLBI Network of 4C+29.48. We also collected data form optical, infrared and X-ray surveys. Results. According to the VLBI data, the northernmost complex of 4C+29.48 contains a blazar with a high brightness temperature compact core and a steep-spectrum jet feature. The blazar is positionally coincident with an optical source at a redshift of 1.142. Its mid-infrared colors also support its association with a γ-ray emitting blazar. The two other radio complexes have steep radio spectra similar to AGN-related lobes and do not have optical or infrared counterparts in currently available surveys. Based on the radio morphology, they are unlikely to be related to the blazar. There is an optical source between the two radio features, also detected in infrared wavebands. We discuss the possibilities whether the two radio features are lobes of a radio galaxy, or gravitationally lensed images of a background source. Conclusions. We propose to associate the γ-ray source 3FGL J1323.0+2942 in subsequent versions of the Fermi catalog with the blazar residing in northernmost complex. We suggest naming this radio source J1323+2941A to avoid misinterpretation arising from the fact that the coordinates of the currently listed radio counterpart 4C+29.48 is closer to a most probably unrelated radio source.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.010
Threshold uncertainty score0.021

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0010.001
Science and technology studies0.0010.001
Scholarly communication0.0010.001
Open science0.0010.001
Research integrity0.0010.000
Insufficient payload (model declined to judge)0.0030.001

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.006
GPT teacher head0.200
Teacher spread0.194 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations2
Published2018
Admission routes1
Has abstractyes

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