validation

After lunch, Alice Shapley (UCLA) gave a great Astro Seminar about what we can learn about high-redshift galaxies with multi-band photometry and infrared spectroscopy and, soon (or we hope soon!), JWST. There are hopes of seeing a consistent story in the star-formation rates, the build-up of mass, and the metallicity evolution in the stars and the interstellar medium.

At the end of the day, Andy Casey (Monash), Soledad Villar (NYU), and I met to discuss Villar's generation of APOGEE spectra of stars with a GAN, and how we might validate that. We discussed various options, but we are more-or-less converging on the idea that the spectra have to tell consistent or sensible stories about temperature and logg. I have ways to operationalize that. But one of the funny things is that real spectra of stars don't tell consistent stories! Because the physical models aren't awesome. So we can only require that the generated spectra do no worse than the real spectra.