ASTR 470 Lab 05: Compactness and neutron-star radius

Lectures 06-07 ยท high-energy data activity

Objectives

Materials and setup

Use Python 3, the supplied neutron_star_models.csv, and the source documentation named below. The supplied record is clearly labeled in data/README.md. Record file hash, row count, columns, units, processing state, and provenance level.

Computed check: r_L approximately 0.36034 pc The estimate uses pc approximately equal to E/c and shows why Galactic magnetic fields erase arrival directions.

Procedure

  1. Inspect the file and make a schema table before filtering or fitting.
  2. Reproduce the baseline calculation with units and an independent hand-derived formula.
  3. Apply the activity-specific task: compare mass-radius models with compactness and redshift observables.
  4. Perform one perturbation or alternative-model test and report the direction of change.
  5. Write a caption that identifies data, transformation, inference, uncertainty, and limitation.

Measurement and analysis record

RecordRequired entry
InputFile, source, release or access date, columns, units, and provenance level.
ModelEquation, parameter values, boundary conditions, and approximation.
UncertaintyStatistical term plus calibration, distance, response, or model sensitivity.
ValidationIndependent recomputation, limiting-case check, and comparison direction.

Deliverables and assessment

Submit code or notebook, provenance manifest, one labeled figure or table, a 700-word methods memo, and a revision note. Full credit requires traceable input, correct units, explicit assumptions, uncertainty treatment, and a specific limitation. Resubmission with a change log is encouraged.

Sources and provenance

Evaluate three model rows at 1.4 Msun and identify how a 10% radius uncertainty changes z. Reference anchor: NICER About page and OpenStax 24.1.. Level-1 mission facts are listed separately from level-2 literature/object parameters and level-3 teaching records.