Fought household illnesses all of the long weekend and today, but nonetheless managed to make a huge plot of everything vs. everything in the GALEX match to SDSS. That plot clearly shows the stellar locus, hot white dwarfs (I think), and AGN. Today I worked on understanding the clever NYU-VAGC description of the SDSS survey geometry so as to figure out which GALEX sources are inside the SDSS region. Once this (incredibly slow) process is complete, we will be able to discover sources that are bright in GALEX but not visible at all in SDSS. Should any such things exist? If there are any true non-detections in SDSS of true GALEX detections, they would be interesting, either as transients or sources with wacky spectra.


  1. Hi David,

    Do you think the GALEX-SDSS matches could be useful for helping distinguish between stars and redshift 2 to 3 quasars? - the latter of course crossing over the stellar locus in ugri/griz colour-space.

    I know a few ``BOSS'' people (including myself) that would be v. interested in this!!


  2. Yes, definitely; this is one of the reasons we are doing this. Unfortunately, we don't have GALEX over the whole SDSS footprint, so we can't use GALEX in a uniform way. But I still think we might be able to use the GALEX information to inform a better use of the SDSS information.

  3. David,

    MAST has been matching GALEX - SDSS for a while now. We are planning on meeting to discuss GALEX GR4 - SDSS DR6 matching next week.

    Perhaps we should talk :)