Taylor Hoyt

Postdoctoral Associate at Lawrence Berkeley National Lab (LBL)

My PhD research was on the extragalactic distance scale and the measurement of the universe's present day expansion rate. I used a class of stars called red giants to measure the distances to galaxies that hosted exploding supernovae, which we could then use to measure the expansion of the universe.

I have begun studying more closely our use of the supernovae to constrain the expansion rate as I continue my research at Berkeley as part of the Supernova Cosmology Project.

Recent Updates

Ongoing Postdoctoral Position

Continuing as postdoctoral scholar at Berkeley Lab through at least 2025.

JWST Cycle 1 Program

Collaborator on a JWST Cycle 1 program that aims to test the use of several astrophysical distance indicators with JWST's new and unprecedentedly sensitive instrumentation.

See the Research page for summaries of my previous work on these distance indicators as observed in the infrared, which provides some of the foundation for this JWST program.

HST Cycle 29 Program

Awarded time as PI of a Hubble Space Telescope program on calibrating the Tip of the Red Giant Branch method to use in constraining the present day expansion rate of the universe.

This will provide the most accurate calibration of the TRGB method as measured with the Hubble Space Telescope. Publication in prep and soon to be submitted.

Recent Publications

Coordinated JWST Imaging of Three Distance Indicators in a SN Host Galaxy and an Estimate of the TRGB Color Dependence. Hoyt, T. J., Jang, I. S., Freedman, W. L., et al. (In Review, 2024) (DOI: 10.48550/arXiv.2407.07309).

Sub-per-cent determination of the brightness at the tip of the red giant branch. Hoyt, T, (2023). Nature Astronomy. (DOI: s41550-023-01913-1)

Distances to Local Group Galaxies via Population II, Stellar Distance Indicators. I and II. Tran, Hoyt, et al., and Oakes, Hoyt et al., (2022) (ApJ...935...34T, ApJ...929..116O).

The Carnegie Chicago Hubble Program X: Tip of the Red Giant Branch Distances to NGC 5643 and NGC 1404. Hoyt, T. J., Beaton, R. L., Freedman, W. L., et al. (2021), ApJ, 915, 34 (ADS, arXiv).

The Tip of the Red Giant Branch

Stars about the mass of the Sun will reach an explosive end to their first ascent of the Red giant branch (RGB). These RGB stars provide us with an astronomical ruler with which we can measure distances to galaxies as far out as 60 million lightyears.

Observations with Space Telescopes

I reduce and analyze space telescope data, including those from the Hubble and James Webb Space Telescopes (HST and JWST, respectively). My technical work is on accurate Point Spread function photometry (PSF) of resolved point sources.

Type Ia Supernovae

I am investigating new ways to standardize Type Ia supernovae (SNe Ia) for use in measuring the expansion rate and how we can improve upon previous methods in terms of both experimental accuracy and observational efficiency.

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