MétaCan
Menu
← all works

Astrometric Perturbations in Substructure Lensing

2007· article· en· 61 citations· W2047352035 on OpenAlex· 10.1086/512002

Why is this work in the frame?

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

Canadian affiliationAn author listed a Canadian institution. This is the only route the usual frame has.

Full frame distilled prediction

Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

Candidate categories
none
Consensus categories
none
Domain
Candidate signal: noneConsensus signal: none
Study design
Candidate signal: ObservationalConsensus signal: Observational
Genre
Candidate signal: EmpiricalConsensus signal: Empirical
Teacher disagreement score
0.017
Threshold uncertainty score
0.459
Validation status
machine_predicted_unvalidated · codex-gemma-dda1882f352a

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0000.000
Bibliometrics0.0000.001
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.001
Insufficient payload (model declined to judge)0.0000.000

Machine scores (provisional)

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

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.

Opus teacher head0.008
GPT teacher head0.218
Teacher spread
0.210 · how far apart the two teachers sit on this one work
Validation status
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Abstract

In recent years, gravitational lensing has been used as a means to detect substructure in galaxy-sized halos, using anomalous flux ratios in quadruply-imaged lenses. In addition to causing anomalous flux ratios, substructure may also perturb the positions of lensed images at observable levels. In this paper, we numerically investigate such astrometric perturbations using realistic models of substructure distributions. Substructure distributions that project clumps near the Einstein radius of the lens result in perturbations that are the least degenerate with the best-fit smooth macromodel. Degeneracies between the center of the lens potential and astrometric perturbations suggest that milliarcsecond measurements of the center of the lensing potential boost the observed astrometric perturbations by an order of magnitude. In addition, we discuss methods of substructure detection via astrometric perturbations that avoid full lens modeling in favor of local image observables and using lens modeling of systems with luminous satellites to constrain the masses of those satellites.

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.

The record

Venue
The Astrophysical Journal
Topic
Galaxies: Formation, Evolution, Phenomena
Field
Physics and Astronomy
Canadian institutions
Canadian Institute for Theoretical AstrophysicsUniversity of WaterlooUniversity of Toronto
Funders
not available
Keywords
SubstructurePhysicsGravitational lensObservableEinstein radiusLens (geology)GalaxyStrong gravitational lensingAstrophysicsRADIUSHaloOpticsComputer science
Has abstract in OpenAlex
yes