# Assessment Instructions: Problem Set 06 — Galaxy Classification, AGN, and Galaxy Evolution

## Inputs to Inspect
Student submission, this problem set, the solution key, the corresponding lecture slides/notes, and the referenced dataset(s) under `materials/ASTR230/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 reduction steps should not.

## Problem-Level Criteria
- Problem 1: 15 points — Correct classification with physically grounded justification.
- Problem 2: 15 points — Correct application of the M-sigma scaling exponent.
- Problem 3: 15 points — Correct light-travel-time argument and unit conversion.
- Problem 4: 15 points — Correct, specific explanation of the unified AGN model’s viewing-angle and accretion-rate dependence.

## 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
- Classifying by shape alone without connecting to gas content or star-formation history.
- Using the wrong exponent in the M-sigma scaling (e.g., squaring instead of raising to the 4th power).
- Treating the unified model as claiming different AGN types are physically different objects rather than the same structure viewed differently.