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Record W4297834322 · doi:10.1051/0004-6361:20011074

ISOCAM observations of the Ursa Major cirrus:

2002· article· en· W4297834322 on OpenAlexaff
M.-A. Miville-Deschênes, F. Boulanger, G. Joncas, É. Falgarone

Bibliographic record

VenueAstronomy and Astrophysics · 2002
Typearticle
Languageen
FieldPhysics and Astronomy
TopicAstrophysics and Star Formation Studies
Canadian institutionsUniversité Laval
Fundersnot available
KeywordsCirrusPhysicsAstrophysicsMolecular cloudInfraredCosmic dustOptical depthAstronomyAtmospheric sciencesStars

Abstract

fetched live from OpenAlex

We present mid-IR imaging observations of a high Galactic latitude cirrus obtained with the ISO camera ISOCAM at 6'' angular resolution. The observations were done with two filters LW2 (5–8.5 μm) and LW3 (12–18 μm) that measure respectively the aromatic carbon bands and the underlying continuum emission from small dust particles. Three 0.05 square degree images sample atomic and molecular sections in the Ursa Major cirrus. These images are compared with Hi, CO and IRAS observations. In such a cloud transparent to stellar light () the mid-infrared to 100 μm and the mid-IR emissivity per hydrogen are related to the abundance and the optical properties of small dust particles independently of any modelling of the penetration of the radiation. Within the atomic section of the cloud, the comparison between ISOCAM images and 21 cm interferometric data highlights an enhancement of the mid-IR emitters abundance by a factor ∼5 in an Hi filament characterized by a large transverse velocity gradient suggestive of rotation. Furthermore, a drop in the abundance of the same mid-IR emitters is observed at the interface between the atomic and molecular cirrus sections. We propose that these abundance variations of the mid-IR emitters are related to the production of small dust particles by grain shattering in energetic grain-grain collisions generated by turbulent motions within the cirrus and inversely by their disappearance due to coagulation on large grains. At the Hi-H2 interface we also observe a change in the (LW2)/(LW3) ratio by a factor 2. This color variation indicates that the amplitude of the continuum near 15 μm, relative to the aromatic bands, rises inside the molecular region. It could result from a modification of the dust size distribution or of the intrinsic optical properties of the small dust particles.

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 score0.002
Threshold uncertainty score0.005

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 studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0010.001

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 head0.017
GPT teacher head0.203
Teacher spread0.186 · 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

Citations44
Published2002
Admission routes1
Has abstractyes

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