ASTR 4020 / 8020 -- Diffuse Matter and Star Formation
Semester 1, 2023
Lecturer
Class meeting times
Tuesdays and Thursdays, 2 - 4 pm
Wooley Seminar Room
Topics
This course covers the physics and phenomenology of diffuse matter in interstellar and intergalactic space, and of how that matter undergoes gravitational collapse to form new stars. The course can roughly be divided into three parts. The first covers the basic physics of matter at low densities, including processes such as collisional excitation and thermalisation, and matter-radiation interaction. The second covers the phenomenology of diffuse, non-self-gravitating gas, and introduces the various phases of interstellar matter and their properties. The third and final part covers the behaviour of self-gravitating interstellar gas and the phenomenology of how it forms stars.
Texts
This course uses two main textbooks:
- Physics of the Interstellar and Intergalactic Medium, by Bruce Draine
- Star Formation, by Mark Krumholz
Assessments
This course has three forms of assessment:
- There will be 5 problem sets, due on the dates indicated in the schedule below. These should be submitted via the course wattle page. The problem sets together form 40% of the total assessment, and are all weighted equally. Late submissions will be accepted, at a penalty of 5% of the credit per working day, up to one week past the original due date, at which time I will distribute solution sets.
- Each student will give an in-class presentation of approximately 20-30 minutes summarising a topic from the recent research literature. Topics will be by mutual agreement between the student and the professor, and will be fixed by the midterm break. Presentations will take place during the last few meetings of the term. All students are expected to attend, and to ask questions and participate in the discussion -- such participation will be factored into the presentation grade. This item is 30\% of the total course grade. /li>
- There will be an oral final exam during the exam period, which will be scheduled individually. This exam will last approximately 45 minutes, and will consist of making rough estimates, order of magnitude calculations, scaling arguments, and similar quick calculations of the type that one is likely to encounter during a discussion at a scientific conference or similar venue. The exam is worth 30% of the total course grade.
Policy on collaboration
Group work is encouraged in this course. In particular, if your understanding is lacking in places, we strongly encourage you to discuss and debate with other students to reach a better understanding. However, this should not lead to a number of students producing identical assignments. In the end, you must work through, understand, and answer the assignment questions yourself, not simply reproduce verbatim other students’ work. See links for further information on ANU policies on plagiarism and collusion.
Schedule
Note: DX indicates chapter X from Draine, KX indicates chapter X from Krumholz.Date | Topic | Reading | Assignments due |
21 Feb | Collisional processes (Practice problems) | D1-3, K4-5 | |
23 Feb | Fluid dynamics | ||
28 Feb | Radiation-matter interactions (Practice problems) | D4-6 | |
2 Mar | Atomic and molecular structure | ||
7 Mar | The hydrogen 21 cm line | D8-9 | |
9 Mar | Absorption lines | Problem set 1 | |
14 Mar | Ionisation and recombination I | D10-11 | |
16 Mar | Ionisation and recombination II | ||
21 Mar | Collisionally-excited lines | D13-15, D21-22 | |
23 Mar | Interstellar dust | Problem set 2 | |
28 Mar | Photoionised regions I | D27-28, K7 | |
30 Mar | Photoionised regions II | Presentation topic | |
3 - 14 Apr: semester break | |||
18 Apr | Atomic gas | D29-30, D34 | |
20 Apr | Hot gas | Problem set 3 | |
25 Apr | No class -- ANZAC Day | K1, K3 | |
27 Apr | Molecular gas: microphysics | ||
2 May | Molecular gas: dynamics | K6-8 | |
4 May | Galaxy-scale star formation I | ||
9 May | Galaxy-scale star formation II | K9-11 | Problem set 4 |
11 May | Stellar clustering | ||
16 May | The initial mass function | K12-13, K16-17 | |
18 May | Protostellar evolution | ||
23 May | Final presentations | ||
25 May | Final presentations | Problem set 5 | |
1 - 17 Jun: exam period |