For most galaxies with known redshift, the properties we can measure best are their color and luminosity, making these quantities vital for classifying galaxies from the local universe to high z. However, it is difficult to determine these same properties for the Milky Way, the galaxy we can study in the most detail, due to our location within it. Here, we employ a new approach which is immune to the effects of interstellar reddening. Using new infrared measurements of the Milky Way's star-formation rate and dynamical measurements of its stellar mass (along with their attendant uncertainties), we identify samples of galaxies in Sloan Digital Sky Survey data with matching properties, and evaluate the distribution of colors and luminosities of these analogs. Essentially, we make the Copernican assumption that the Milky Way is not unusual for a galaxy of its mass and star formation rate. This procedure tightly constrains the possible photometric properties of the Milky Way; we present results for both ugriz colors and absolute magnitudes, and explore the impact of potential systematic errors. We also present a gallery of images of galaxies whose properties should be similar to those of the Milky Way. Our results show that the Milky Way must be amongst the brightest, reddest star-forming spiral galaxies, with an overall color which is likely only slightly bluer than the bluest red sequence galaxies.
American Astronomical Society Meeting Abstracts #219
- Pub Date:
- January 2012