Our research:

Using small galaxies to answer BIG questions

  • Most of the matter in the universe can be found in long, thin structures that make up the "cosmic web." But some galaxies live in the vast, low-density voids between these filaments—and some of these galaxies are low-mass “dwarf” galaxies! Our lab’s goal is to understand how the environments of these “void dwarf galaxies” have shaped their evolution.

    The Dwarfs In Void Environments (DIVE) survey targeted approximately 20 of these void dwarf galaxies (plus 10 relatively isolated but non-void “field” dwarf galaxies as a comparison sample) using the Keck Cosmic Web Imager. This instrument is an integral field spectrograph, which allows us to measure both spectral and spatial information simultaneously.

Related recent projects:

Searching for intermediate-mass black holes

Measuring the shapes of void dwarf galaxies

Measuring the motions of stars and gas in void galaxies

  • Dwarf galaxies are much fainter than more massive galaxies! As a result, for many years our understanding of dwarf galaxies has been limited to our immediate neighborhood, the Local Group—that is, the satellite galaxies of the Milky Way and our nearest neighbor M31.

    But we are now entering a new era of extragalactic surveys. Surveys like the Satellites Around Galactic Analogs (SAGA) survey, the Dark Energy Spectroscopic Instrument (DESI), and the Legacy Survey of Space and Time (LSST) are beginning to observe huge numbers of dwarf galaxies across a range of different environments. Characterizing the physical properties of these dwarf galaxies is an ongoing challenge.

Related recent projects:

Comparing the Local Group to analog galaxy systems

Measuring star formation in dwarf galaxies across different environments

Understanding how we measure dwarf galaxy properties

  • Here on Earth, archaeology involves finding what past generations of humans left behind, and using that to infer how past humans lived and died. Galactic archaeology is pretty much the same—but instead, inferring at how past stars lived and died by looking at the elements they left behind.

    Specific elements, like manganese, can tell us about the physics of certain types of stellar explosions. Tracking the evolution of many chemical elements at the same time can tell us about how galaxies evolved over time.

Related recent projects:

Using manganese to constrain Type Ia supernova physics

Developing chemical evolution models of dwarf galaxies