| Abstract: |
I will describe two very different ways in which imaging and spectroscopic surveys can be combined to unlock information that is otherwise challenging to obtain. First, I will discuss the scope of spectroscopy needed both to optimize and to calibrate our understanding of measurements of photometric redshifts from large imaging surveys such as DES, HSC, and LSST. Both deep surveys from instruments such as PFS at Subaru and shallow, wide-area surveys such as DESI will have important roles to play. Next, I will describe how extragalactic surveys can make it possible to determine properties of the Milky Way that have historically been difficult to measure. Using hierarchical Bayesian meta-analysis methods, we have obtained improved measurements of the total stellar mass, star formation rate, and disk scale length of the Galaxy. We can then identify a set of Milky Way analog galaxies in SDSS with matching M* and SFR (including all uncertainties). Applying the Copernican assumption that the Milky Way should not be extraordinary amongst galaxies of similar properties, the range of colors and luminosities of these Galactic analogs then constrains these same characteristics of our own Galaxy. I will describe what we have learned about the Milky Way's global photometric properties and its location in major scaling relations from this sample. A subset of Milky Way analogs will be observed as ancillary targets as part of the SDSS-IV/MaNGA survey. |
