Caltech California Institute of Technology

Caltech Division of Physics, Mathematics and Astronomy

Physics 4 (Freshman Seminar) - Fall 2014
Astrophysics and Cosmology with Open Data

Astrophysics and cosmology are in the midst of a golden age of science-rich observations from incredibly powerful telescopes of various kinds. The data from these instruments are often freely available on the web. Anyone can do things like study x-rays from pulsars in our galaxy or gamma rays from distant galaxies using data from Swift and Fermi; discover planets eclipsing nearby stars using data from Kepler; measure the expansion of the universe using supernovae data; study the cosmic microwave background with data from Planck; find gravitational waves from binary black hole mergers using data from LIGO; and study the clustering of galaxies using Hubble data. We will explore some of these data sets and the science than can be extracted from them. A primary goal of this class is to develop skills in scientific computing and visualization - bring your laptop!

Hubble diagrams: then (Hubble 1929) and now (SCP)

The gamma-ray sky as seen by Fermi

The anisotropy of the microwave sky as seen by PLANCK

Gravitational waves from merging neutron stars (left), and merging black holes (right)

Left: are spinning neutron stars. Right: Catalog of pulsars from Australia Telescope National Facility (ATNF)

Galaxy catalog from the Cosmic Evolution Survey (COSMOS) project

Data from the Exoplanet Archive.

It goes without saying that this page is under construction.....

Announcements and links:

  • Check this space often for announcements, rescheduling, etc.
    Instructor: Prof. Alan J. Weinstein
    Office: 354A West Bridge, M/C 100-36, x2166
    E-mail: ajw AT
    I do not have regular office hours; email me!

    Meetings: Wednesday and Friday (TBD!) at 3pm, in 351 West Bridge

    I greatly appreciate student feedback; feedback prior to the end-of-term evaluations lets me modify the class to fit your needs. In person, by email to ajw AT, by campus mail, whatever you like. If you would like to preserve your anonymity, campus mail will usually work. My mailbox is on the 3rd floor of West Bridge.


    Note that this is way more than what we can get through in one term!


    Set up your computer for python (a nice, powerful interactive language, that they use in CS1 and that is heavily and increasingly used in scientific computing).
    • Install python, numpy, scipy, matplotlib, astropy, h5py.
    • Windows, Linux, Mac: Enthought offers some pre-compiled versions of Python that will run with a simple point and click. A free academic license is available to students, staff, and faculty at academic institutions, and this may provide an easy-to-install solution. Use your .edu e-mail address to request a free academic license; Download and install Canopy Express; Enter your license information to get the full version. Use the package manager to get all the above packages.
    • Browse the python tutorial, and the tutorials/FAQ/fast start for each of the other packages.
    • If you have a mac, you can install python with MacPorts following these instructions. You can probably install the latest version (python34); anything from v2.7 and up is ok, but make sure you get the proper version of numpy, scipy, matplotlib, astropy, h5py.
    • Linux: use whatever package system is native to your flavor of linux.
    • Python for Data Analysis

    Last Updated: Nov 26, 2014
    Alan Weinstein/ajw AT