Photo in front of AMiBA on Mauna Loa

Hello!

I am a postdoctoral fellow at STScI (the Space Telescope Science Institute) in Baltimore, MD, where I work to understand the many roles that metals play in how galaxies formed and evolved. Originally from a small town in Arkansas’s River Valley, I earned my B.S. in physics from the University of Arkansas in 2016 and my Ph.D. in Astronomy from the University of Wisconsin-Madison in 2021.

Research Interests

Although elements heavier than helium – metals – make up only about 1% of the baryons in the Universe, they drive many of the most complicated processes and unsolved mysteries in astrophysics. As stellar generations come and go, the flow of metals between gas and stars fundamentally connects their physical properties. This means that understanding the birth and buildup of galaxies requires that we understand how these two components evolve and chemically influence each other. I use multi-wavelength observations (especially spectroscopy) of stars, atomic gas, and molecular gas to aid in this quest for metal.

Extragalactic Star Clusters

Measuring the metallicity of stars gives a different view on the past life of galaxies than looking at ionized gas. I wrote a Python code for Simultaneous Estimates of Star-cluster Age, Metallicity, Mass, and Extinction (SESAMME), which you can read more about by following the button below. I use SESAMME and other tools to understand how fast metals are recycled into new star clusters, based on spectroscopy in the optical and ultraviolet toward relatively nearby galaxies.

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CO-Dark Molecular Gas

Astronomers often use carbon monoxide (CO) as a proxy for molecular hydrogen (H2) – the fuel for imminent star formation, which is (historically) hard to observe. But CO often leaves out part of the story. Galaxies with low metallicity often have little dust and greater ultraviolet power from their stars, which destroys CO much more easily than H2. In such galaxies, CO may make up only a tiny fraction of the total amount of molecular gas they contain. I use data from JWST, ALMA, and other facilities to understand what makes some molecular gas "CO-dark."

Figure 1 from Jones et al. 2021, showing millimeter data from SCUBA-2 and NOEMA

Dusty Star-forming Galaxies

Some galaxies are like, really dusty. What's up with that?

The above image shows a protocluster of galaxies in the GOODS-North field at z ~ 3.14, first reported in Jones et al. 2021. The full SCUBA-2 map of the GOODS-North at 850 µm is in the upper left, a zoom-in on the overdensity of bright DSFGs in the upper right, and dust continuum and CO emission for three DSFGS at the bottom.

Figure 5 from Jones et al. 2018, showing a G280 spectrum from HST/WFC3 for a z = 2.5 AGN

Ionizing photon escape

Most galaxies disappear at rest-frame wavelengths below the Lyman limit (912 Å), but occasionally some don't. What's up with that?

The above image shows a G280 UV grism spectrum from HST/WFC3 (PI E. Hu) for an AGN at z ~ 2.5 in the GOODS-North field, including significant emission below the rest-frame Lyman limit (pink vertical line). Reproduced from Jones et al. 2018.

Teaching, Mentoring, and Public Engagement

As a graduate student and postdoc, I have worked with several undergraduate students across different institutions in a mentor-mentee relationship. I enjoy working with students to develop and carry out research projects that can give them experience in doing "real-world" science and which may lead to a senior thesis or even a published scientific paper. You can learn more about my mentoring style by looking at my mentoring agreement (and why I believe in mentoring agreements via the resources hosted by the National Research Mentoring Network).