Another assignment for Paola

• Here is a file containing many parameters from the SDSS database for galaxies which lie in the region of the Pisces-Perseus supercluster.
  • Start by learning what all the columns are; their names should be self-explanatory but maybe they aren't. If not, ask.

  • Access the file using TOPCAT and make some plots... what should you plot? Do you need to add new columns (using the arithmetic functions built into TOPCAT? Do you need to make corrections to any of the values? Once you think about this a little, we can discuss how to proceed.
    To figure out what to do, go to the SDSS-3 site (known as SDSS-DR12), find the "Schema Browser" (under Help on the main page) and look at the Table called PhotoObjAll. Try to figure out what the columns in the file you have download are.
  • Think about what you need to do to make a color-magnitude diagram.

  • Think about what you need to do to calculate the stellar mass of each galaxy.

• Here is another file; it contains the HI properties of galaxies in the 70% ALFALFA catalog. Start by learning what all the columns are.

• We want to match the two tables using the "JOIN" function in TOPCAT. What's the best way to do that? Let's discuss how to do it.

• And, let's discuss what you want to do next...

• Here is another file; it contains the SDSS photometric values for the galaxies in the 70% ALFALFA catalog. Start by learning what all the columns are.