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name: astro-observation-report description: "Skill for writing gravitational-wave observational results papers for compact binary coalescence events (BNS, BBH, NSBH) detected by LIGO, Virgo, or KAGRA. Covers paper architecture, first-page layout, parameter estimation figures, uncertainty notation, credible region plots, statistical conventions, and running headers in Physical Review X two-column journal style."

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Gravitational-Wave Observational Results Writing Guide

A markdown-driven skill encoding document structure, presentation patterns, and statistical conventions from LIGO/Virgo/KAGRA collaboration SOTA papers.

Reference Source

• Reference type: Uploaded PDF artifact (Physical Review X journal article)
• Reference artifact type: PDF (peer-reviewed physics journal)
• Reference File Type: PDF
• Supported outputs: PDF, DOCX, PPTX
• Default output: PDF (academic journal manuscript, two-column layout)

First-Page Layout (Critical)

The Physical Review X format places ALL of the following on page 1:

1. Journal header line: "PHYSICAL REVIEW X 9, 011001 (2019)" (centered, small caps)
2. Title (bold, centered, ~14pt)
3. Author line: "B. P. Abbott et al." with collaboration in parentheses
4. Received/revised/published dates
5. Abstract (single paragraph, ~200-250 words, full width or two-column)
6. DOI line and Subject Areas
7. Beginning of I. INTRODUCTION (small-caps heading)

There is NO separate title page or abstract page. The introduction starts immediately after the abstract on the same page.

Core Workflow

1. Establish paper scope -- Identify event(s), detector network, analysis epoch. Determine measurable parameters (masses, spins, tides, location, inclination) and what is not measurable (postmerger signal).

2. Structure the manuscript -- Follow section hierarchy in references/structure_contract.md. Architecture: compact first page with abstract + intro -> Methods -> Results (by parameter class) -> Postmerger limits -> Conclusions -> Appendices -> Full author list.

3. Write the Abstract -- Single paragraph: detection statement (SNR, detectors, event name, source type), multimessenger context, key parameter constraints with numerical values, model comparison, postmerger upper limits.

4. Write Methods -- Bayesian framework, data (PSD, calibration), waveform models (comparison table in Table I), prior choices (high-spin vs low-spin).

5. Present results by parameter class -- Canonical order: Localization -> Masses -> Spins -> Tidal parameters -> Postmerger limits. Each class: physical motivation, posterior figures, numerical constraints, model comparison.

6. Create figures and tables -- Follow taxonomy and caption conventions in references/observational_results_patterns.md. Every results section must have figures. Tables use booktabs style. See the figure list below.

7. Write conclusions and back matter -- Summary, comparison to previous work, waveform systematics, future outlook. Follow with Acknowledgments, Appendices (additional model results + injection/recovery), and full author list with affiliations.

Required Figures (15+ Total)

Every GW observational results paper must include figures. The reference contains the following figure types. Even placeholder or simplified versions must be created.

Fig #	Type	Content
1	PSD plot	Detector sensitivity curves (LIGO Hanford, Livingston, Virgo)
2	Model comparison	Relative amplitude and phase differences between waveform models
3	Sky map	Localization with 50%/90% credible regions and EM counterpart
4	2D posterior	Inclination vs luminosity distance (GW-only and EM-informed)
5	2D posterior	Component masses (m1-m2) for high-spin and low-spin priors
6	1D PDF	Effective spin parameter for high-spin and low-spin priors
7	2D posterior	Effective spin vs mass ratio (degeneracy illustration)
8	Polar plot + PDF	Spin orientations and precession parameter (high-spin)
9	Polar plot + PDF	Spin orientations and precession parameter (low-spin)
10	2D posterior	Tidal deformability parameters with EOS curves (two panels)
11	1D PDF	Combined tidal parameter with EOS predictions (two panels)
12	2D posterior	Tidal parameter vs mass ratio (high-spin vs low-spin)
13	Upper limits	Postmerger strain and radiated energy (two panels)
14-15	Injection study	Parameter recovery validation plots (Appendix B)

Running Headers and Page Numbers

• Even pages (left header): Shortened article title in small caps (e.g., "PROPERTIES OF THE BINARY NEUTRON STAR MERGER ...")
• Odd pages (right header): Journal citation in small caps (e.g., "PHYS. REV. X 9, 011001 (2019)")
• Page numbers: Bottom center, format "011001-N" where N is sequential
• Page 1 only: Has journal header "PHYSICAL REVIEW X 9, 011001 (2019)" and article ID footer "2160-3308/19/9(1)/011001(32)" + "Published by the American Physical Society"

Statistical Conventions

• Uncertainty notation: Median with asymmetric credible intervals: x^{+upper}_{-lower} (e.g., 2.73^{+0.04}_{-0.01} M_\odot).
• One-sided limits: x \in (lower, upper) for 90% credible intervals bounded by priors.
• HPD intervals: Smallest interval containing 90% probability, for asymmetric posteriors.
• Credible regions: 50% (inner, dashed) and 90% (outer, solid) contours for 2D posteriors.
• Bayes factors: Evidence ratios between competing models.

Font and Typography

• Reference fonts: Times-based serif family (Times-Roman, Times-Italic, Times-Bold from the journal), with Computer Modern math symbols.
• Substitute font strategy: When unavailable, use Times New Roman, TeX Gyre Termes, or STIX Two Text. For CJK content, use a CJK-capable serif font (SimSun, Noto Serif CJK) consistently across the entire document.
• Section headings: Small caps (e.g., "I. INTRODUCTION"), bold for main sections.
• Subsection headings: Bold title case (e.g., "A. Bayesian method").
• Math typesetting: Numbered display equations, key equations explicitly shown.

Key Reference Files

File	When to Read
references/structure_contract.md	When planning the paper outline and section hierarchy
references/observational_results_patterns.md	When writing specific sections, figures, tables, captions
references/style_contract.md	When formatting the final document or resolving layout questions