ASTR 4008 / 8008 -- Star Formation
Semester 2, 2022
Lecturers
Class meeting times
Tuesdays and Thursdays, 3 - 5 pm
Wooley Seminar Room
Topics
This course covers the basics of star formation and the transition to planet formation. We begin with a survey of the physical processes that govern star-forming clouds, including magnetohydrodyanmic turbulence, gravitational instability, non-ideal MHD effects, and radiative transfer by molecules and dust grains. We then study the star formation process starting at galactic scales and working our way down, touching on topics including: star formation laws; molecular cloud formation, evolution, and disruption; collapse, fragmentation, and the origin of the initial mass function; protostellar disks and outflows; pre-main sequence stellar evolution; massive stars and feedback; and the dispersal of disks and the onset of planet formation.
Texts
Our main reference for this class will be Star Formation, by Mark Krumholz. You can get the book in several ways:
- You can buy a paper or e-book from amazon
- You can get a free PDF copy through the Open Astrophysics Bookshelf
- The source for the book is available on github
- The ANU library has a copy on course reserve
- A version of the book is available on the arXiv
In addition to the book, we will have supplementary readings from the research literature each week. Links are below.
Assessments
This course has three forms of assessment:
- There will be 5 problem sets, due on the dates indicated in the schedule below. These can be submitted via the course wattle page, or on paper. 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 we will distribute solution sets.
- Each student will give one in-class presentation summarising a paper from the recent research literature, and lead a discussion of that paper. Presentations and discussions should be approximately 30 minutes each. Every student is expected to read the paper and to submit questions/comments for discussion to the student who is leading the discussion in advance. This item is 30% of the total course grade. Assessment will be based mainly on the presentation/discussion that each student leads, but the quality of participation in discussions led by other students will be considered as well.
- There will be an oral final exam during the exam period, which will be scheduled in- dividually. 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.
Class-by-Class Topics and Reading
| Date | Topic | Lecturer | Textbook chapter | Reading for presentation | Homework |
| 26 July | Observing the cold ISM (Practice problems) | Krumholz | 1 | ||
| 28 July | Molecular line emission (Practice problems) | Krumholz | Appendix A | ||
| 2 Aug | Observing young stars (Practice problems) | Krumholz | 2 | ||
| 4 Aug | Chemistry and thermodynamics | Krumholz | 3 | Glover et al., 2010, MNRAS, 404, 2 | |
| 9 Aug | Gas flows and turbulence | Krumholz | 4 | ||
| 11 Aug | Magnetic fields | Krumholz | 5 | Planck Collaboration, 2016, A&A, 586, A138 | Problem set 1 due |
| 16 Aug | Gravitational instability | Krumholz | 6 | ||
| 18 Aug | Feedback | Krumholz | 7 | Kim, Kim, & Ostriker, 2018, ApJ, 859, 68 | |
| 23 Aug | Giant molecular clouds | Grasha | 8 | ||
| 25 Aug | Galaxy-scale star formation: observations | Grasha | 9 | Sun et al., 2020, ApJ, 901, L8 | |
| 30 Aug | Galaxy-scale star formation: theory | Grasha | 10 | ||
| 1 Sep | Stellar clustering | Grasha | 11 | Krumholz et al., 2018, MNRAS, 477, 2716 | Problem set 2 due |
| 5 - 16 Sep: semester break | |||||
| 20 Sep | The IMF: observations | Krumholz | 12 | ||
| 22 Sep | The IMF: theory | Krumholz | 13 | Da Rio et al., 2012, ApJ, 748, 14 | |
| 27 Sep | Discs and outflows: observation | Krumholz | 14 | ||
| 29 Sep | Discs and outflows: theory | Krumholz | 15 | Kratter et al., 2014, ApJ, 708, 1585 | Problem set 3 due |
| 4 Oct | Protostar formation | Krumholz | 16 | ||
| 6 Oct | Protostellar evolution | Krumholz | 17 | Tomida et al., 2013, ApJ, 763, 6 | |
| 11 Oct | Massive star formation | Grasha | 18 | ||
| 13 Oct | The first stars | Grasha | 19 | Susa, Hasegawa, & Tominaga, 2014, ApJ, 792, 32 | |
| 18 Oct | Planet formation I | Mike Ireland (guest lecturer) | |||
| 20 Oct | Planet formation II | Mike Ireland (guest lecturer) | Problem set 4 due | ||
| 25 Oct | Dust processes in late stage discs | Krumholz | 20 | ||
| 27 Oct | Disc dispersal | Krumholz | 21 | van der Marel et al., 2015, A&A, 579, A106 | |
| 3 Nov | -- | Problem set 5 due | |||
| 3 - 19 Nov: exam period | |||||