In recent work, we have obtained improved measurements of the properties of the Milky Way and used the results to select a sample of Milky Way analog (MWA) galaxies from the Sloan Digital Sky Survey (SDSS) whose distributions of stellar mass and star formation rate match our Galaxy’s, incorporating all uncertainties. Relying on the Copernican assumption that the Milky Way should not be extraordinary, the colors and luminosities of the MWAs constrain the possible properties of our own Galaxy. This has enabled us to explore how our Galaxy fits in with the broader population; for instance, we can determine whether its properties are consistent with the power-law scaling relations exhibited by other spiral galaxies. The results have significant implications for the development of computational models of galaxy evolution in a cosmological context.  I will also describe follow-up work exploring the population of satellite galaxies in Milky Way-like dark matter halos.  It has been a long-standing puzzle why the Milky Way has considerably fewer satellite galaxies discovered to date than the typical number of satellite dark matter halos that would be found in a dark matter halo as massive as that which contains our Galaxy.  I will show that almost half of this ‘missing satellites’ problem can be explained by well-established ways in which our Galaxy’s dark matter halo is atypical.  Finally, if time allows I will also describe new work on the density profile of dark matter halos when mass within subhalos, which can often host individual galaxies, is not counted as part of the parent halo.  Widely-used profiles (such as Navarro Frenk and White) perform poorly at representing the smooth centrally-concentrated component of the halo, but there are simple functional forms which do better.

Zoom recording: https://uky.zoom.us/rec/play/58uXDQDw95A6o5P7owEDEwzb-X3PhCXv8WevwQSdhV…

The HI-MaNGA survey is an HI (21cm line) follow-up program for the SDSS-IV MaNGA survey.  I will describe the HI-MaNGA survey, its progress to date, and future plans.  I will then present new results where we combine HI-MaNGA and MaNGA data to investigate how the global HI content of star-forming galaxies relates to the mean properties of their ISM derived from optical emission lines, including integrated equivalent width, metallicity, ionization parameter, and the relative strength of low-ionization lines such as [SII] and [OI]. This analysis allows us to understand if and how the properties of the ISM vary between the most gas-rich galaxies to the most gas-poor, and how such variations may affect their evolution.  I will also discuss how gas content relates to the nuclear ionizing source (e.g., Seyfert, LINER, HII regions) and whether we find any evidence that AGN contribute to gas deficiency in the galaxy population.

Zoom Recording: https://uky.zoom.us/rec/share/xGrDewYs7rui5ao4A-_hr_N5r8_c6mkGkiksm--I61WP-hQ8VhJn9HM8fTadgDUG.M9oUhbMc-oa1r2Nr

The HI-MaNGA survey is an HI (21cm line) follow-up program for the SDSS-IV MaNGA survey.  I will describe the HI-MaNGA survey, its progress to date, and future plans.  I will then present new results where we combine HI-MaNGA and MaNGA data to investigate how the global HI content of star-forming galaxies relates to the mean properties of their ISM derived from optical emission lines, including integrated equivalent width, metallicity, ionization parameter, and the relative strength of low-ionization lines such as [SII] and [OI]. This analysis allows us to understand if and how the properties of the ISM vary between the most gas-rich galaxies to the most gas-poor, and how such variations may affect their evolution.  I will also discuss how gas content relates to the nuclear ionizing source (e.g., Seyfert, LINER, HII regions) and whether we find any evidence that AGN contribute to gas deficiency in the galaxy population.

Zoom Recording: https://uky.zoom.us/rec/share/xGrDewYs7rui5ao4A-_hr_N5r8_c6mkGkiksm--I61WP-hQ8VhJn9HM8fTadgDUG.M9oUhbMc-oa1r2Nr

The enormous amount of data collected by the Dark Energy Survey (DES) provide a great opportunity to explore low surface brightness science topics, such as faint diffuse light in galaxies and galaxy clusters. In this talk, I will describe how we study diffuse intra-cluster light through stacking the images of hundreds of galaxy clusters from DES, reaching a surface brightness limit of 30 mag/arcsec^2, out to a radial distance of 1 Mpc from the cluster center. Despite their low surface brightness, our studies show that intra-cluster light is a significant component of the galaxy cluster stellar content. The stacking method has also been applied to characterizing the light profiles of luminous red galaxies, as well as studying the aureole component of the DES point spread function. Weak lensing and precision photometry calibration  methods may wish to consider these effects in the future.