# Assessment Instructions: Problem Set 07 — Shocks, Cosmic Rays, and Magnetic Fields

## Inputs to Inspect
Student submission, this problem set, the solution key, the corresponding lecture slides/notes, and the referenced dataset(s) under `materials/ASTR360/data/`.

## Grading Standard
Award credit for correct method and units first, then for the specific numeric result. A student who shows correct reasoning with a small arithmetic slip should receive most of the available credit; a student with a correct-looking number but no visible derivation steps should not. Because this is a 300-level quantitative interstellar-medium course, full marks require a genuine derivation wherever the problem set asks for one, and a genuinely reasoned (not merely asserted) interpretation wherever the problem asks for scientific judgment (e.g., honestly characterizing an idealized model's disagreement with a real object).

## Problem-Level Criteria
- Problem 1: verify correct post-shock temperature arithmetic and percentage-comparison direction.
- Problem 2: verify correct power-law ratio arithmetic for both the above- and below-knee indices.
- Problem 3: verify the Crutcher B-n scaling is applied correctly (denser core has stronger field, not weaker).
- Problem 4: verify the gamma^2 scaling is used correctly (factor-of-100 gamma decrease gives factor-of-10,000 frequency decrease).

## Resubmission Policy
Students may resubmit within one week of receiving feedback. A resubmission must show a corrected derivation, not only a corrected final number, and should reference the specific feedback comment it addresses. Regrade to a maximum of 90% of the original point value unless the error was a grading mistake.

## Common Errors to Flag
- Sign errors in percentage-comparison direction (Cas A vs Tycho).
- Confusing which cosmic-ray spectral index (above or below the knee) applies to which energy range.
- Arithmetic errors in the gamma^2 synchrotron-frequency scaling (a common error is using gamma instead of gamma^2).