Ay 102
Physics of The Interstellar / Intergalactic Medium
(Winter Term 2020)


Left: The Large Magellenic Cloud.
Middle: The Outer Milky Way.
Right: The site of star formation near Lynds 1551.

Class Logistics ...... Policies ...... Syllabus ...... Resources ...... Assignments

Class Logistics

Professor: Lynne Hillenbrand (lah@astro)
office hour: drop by, or email / talk to me after class if you would like to make an appointment

Graduate Teaching Assistant: Yuhan Yao (yyao@astro)
office hour: 2-3pm sundays / cahill 256

Purpose:
Ay102 is the advanced undergraduate "ISM" class at Caltech, complementing Ay101 on "stars".
Our other junior/senior level course is the optional Ay104 on "high energy" astrophysics.
Armed with the knowledge from Ay101 and Ay102,
plus additional background from the junior level physics curriculum for Ay or Ph majors,
undergraduates are equipped for the Ay graduate classes during senior year.

Meeting Times:
MWF 11am-12

Assignments: There will be roughly weekly problem sets.
You will be asked to do analytic work and/or plot and analyze relevant formulae
and/or data, using your favorite coding language.
In addition, there will be a class project analyzing the spectrum of a planetary nebula using concepts from class.

Exams: The mid-term assessment will be an evaluation of conceptual understanding rather than problem solving ability.
The final exam will be open note (your own notes only), closed book, and held during finals period. It will test both problem solving and conceptual understanding.


Policies

Problem sets are a critical means of learning the material, not just "busy work."
Collaboration on problem sets is permitted in the conceptual phases of completing an assigment.
However, all students are expected to work out the final solutions themselves.
Several of the problem sets will require use of computers for calculations and plotting of results.

The term project is intended to bring the theoretical concepts from lecture into practice.
It requires some background reading and then writing original code
to work with and analyze spectroscopic data.

Note that use of materials from previous versions of this class is not allowed.

Exams are not collaborative, but your individually handwritten notes such as class notes may be permitted.

Grading will be based on the weekly assignments (50%), the mid-term assessment (5%), the term project (10%), the final exam (35%).

If you have either constructive feedback or complaints about this course, please come see me (or send an email).
I am always eager to know what is working vs not working for you.


Syllabus

Syllabus and reading assignments

Beyond your course reading/studying and class attendance, a quick (daily) visit to the Astronomy Picture of the Day might broaden your astronomical horizons.


Resources

Books

It is recommended to review the relevant material in Carroll & Ostlie (Ay20 text) for a refresher on the basics.
Specifically, I suggest you go over the sections on opacity and radiative transfer (Chapter 9) and on the interstellar medium and star formation (Chapter 12).

Texts that are appropriate for this course are the following.
Reading assignments are given on the syllabus page.

My baseline is

  • M.A. Dopita & R.S. Sutherland 2005, Astrophysics of the Diffuse Universe.
    Make sure you look at the 2005 "corrected third printing" or at minimum the 2003 "corrected second printing" and *not* the 2003 original, which has many deceptive errors.
    A suitable version is available from the publisher here and from Caltech IPs here or here.
    The notation used in lecture, as well as many of the slides shown, will come from this book.

    A standard text in ISM/IGM at the graduate level, which should be digestible by Caltech undergrads, is

  • B. Draine 2010, Physics of the Interstellar and Intergalactic Medium
    This is worth owning, at least for reference, even if you do much of your learning in this course from the other books with more words.
    It is also available from Caltech IPs here .
    I will draw on graphical/tabular material from this book in lecture, but the notation is different in some ways from what we will use.

    These next two books both start out well, but then both get a little heavy on the atomic, molecular, and dust spectroscopy/chemistry,
    which we will not cover in the full detail they are written about. They are good where they are good, though.

  • S. Kwok 2007, The Physics and Chemistry of the Interstellar Medium, available from the publisher here.
    OR
  • A.G.G.M. Tielens 2005, The Physics and Chemistry of the Interstellar Medium, available from the publisher here, and in an e-book version accessible from Caltech IPs here.

    The above are on reserve under the Ay102 listing.
    In the past, the reserve location has been the (Cahill) astrophysics library but if not the location would be SFL.

    Other good references can be found in the Cahill library. Listed in order of decreasing order of relevance, digestibility, and breadth, some resources are:

  • J.E. Dyson & D.A. Williams 1997, The Physics of the Interstellar Medium
  • Maciel 2013, Astrophysics of the Interstellar Medium
  • D.E. Osterbrock & G.J. Ferland 2005, Astrophysics of Gaseous Nebulae and Active Galactic Nuclei
  • L. Spitzer 1978, Physical Processes in the Interstellar Medium
  • S.W. Stahler & F. Palla 2004, The Formation of Stars
  • D.C.B. Whittet 2002, Dust in the Galactic Environment
  • F. Shu, The Physics of Astrophysics. Volume I (Radiation) and Volume II (Gas Dynamics)
  • J. Binney & M. Merrifield 1998, Galactic Astronomy
  • G.B. Rybicki & A.P. Lightman 1979, Radiative Processes in Astrophysics
  • C.H. Townes & A.L. Schawlow, Microwave Spectroscopy

    Supplemental tutorial readings

    On-Line (arranged semi-topically)

  • Origin of The Elements (be sure to continue on with "More Detailed" at the top, and mouse around)
  • Atomic and Molecular Orbitals visualization
  • Spectroscopic Notation tutorial (by S. Kulkarni) and historical development
  • NIST Atomic Spectral Data (all the official details, all in one place)
  • Atomic Data for nebular lines
  • Article on the 2018 census of Molecules in Space and current day list in order of discovery date
  • How to Calculate a Molecular Column Density
  • Catalog of the mysterious DIBS or diffuse interstellar bands
  • Scattering by Dust basics
  • Scattering lecture slides (same physics we discuss, but focussed on the terrestrial atmosphere, including rainbows!)
  • The gritty details of Optical Constants
  • Lorentz Force basics (relevant to Synchrotron radiation)
  • SNR expansion and evolution descriptions by Reynolds and by Vink

    Class slides



    Assignments

    The term project assignment is posted here.

    Problem sets are posted below. I will aim to post them on Tuesdays for the due date of the following Monday.
    Please please please get your sets in on time.
    It is easiest on everyone (the professor, the TA, and - especially - your fellow students) if all homeworks are turned in on time, so that they can be graded together, and turned back to you with solutions in a timely manner.

    Please write next to your name on submitted work how long it took *you* to do the set.

  • ps1 due 13 January -- see also the relevant figures from class on the ism:
    -- structure
    -- phases table


  • ps2 due 20 January ==> 21 January

  • ps3 due 27 January ==> 28 January

  • ps4 due 4 February

  • ps5 due 11 February (some requests for delay)

    -- the midterm assessment due 19 February in class

  • ps6 due 18 February

  • ps7 due 25 February

  • NO PROBLEM SET FOR 3 March -- you should work on your term project!
    and you can get started on the first 3 problems of ps8

  • ps8 due 10 March

    • Last Revised: 14 Feb 2020 by LAH