Jakob M. Helton — Astrophysicist

Research

Exploring the Universe's First Luminous Structures

Using data from the James Webb Space Telescope (JWST), I focus on identifying, characterizing, and understanding stars, galaxies, and galaxy clusters in the early Universe while connecting the physical properties of these structures with their large-scale environment.

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Redshift — Seeing the Past | Credit · NASA, ESA, L. Hustak (STScI)

Publications

Advancing and Improving Our Understanding of Cosmic Dawn

My contributions to extragalactic astronomy include the discovery of galaxies and galaxy clusters at the break of cosmic dawn, including one of the most distant galaxies currently known, JADES-GS-z14-0. I also study the detailed physical properties of galaxies and galaxy clusters at the redshift frontier, including their stellar populations, ionizing photon production, and chemical abundance patterns.

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Infographic: Unknown Era — The First Galaxies

Unknown Era — The First Galaxies | Credit · NASA, ESA, CSA, D. Player (STScI)

Outreach

Sharing Knowledge & Inspiring Wonder

I strongly believe that sharing knowledge with others is one of the most important things that I can do as a scientist. From mentoring students to giving public lectures to appearing in mainstream media, I work to make our beautiful Universe accessible to everyone.

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Pismis 24 | Credit · NASA, ESA, CSA, STScI; Image Processing: A. Pagan (STScI)

Art

A Visual Artist at Heart

Beyond research, I am a visual artist specializing in photography, painting, digital art, and film/videography. My long-term goals are to publish my photography books and exhibit my visual art in galleries.

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Featured First-Author Publication

Full rest-frame optical spectrum of JADES-GS-z14-0 from JWST/MIRI

Ionizing Photon Production Efficiencies and Chemical Abundances at Cosmic Dawn Revealed by Ultra-Deep Rest-Frame Optical Spectroscopy of JADES-GS-z14-0

Jakob M. Helton, Jane E. Morrison, Kevin N. Hainline, Francesco D’Eugenio, George H. Rieke et al. (2025)

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Publication: eprint arXiv:2512.19695

JWST has discovered an early period of galaxy formation that was more vigorous than expected, which has challenged our understanding of the early Universe. In this work, we present the longest spectroscopic integration ever acquired by JWST/MIRI. This spectrum covers the brightest rest-frame optical nebular emission lines for the luminous galaxy JADES-GS-z14-0 at $z > 14$. Most notably, we detect $[\mathrm{OIII}]\ \lambda\lambda4959,5007$ at $\approx 11\sigma$ and $\mathrm{H}\alpha$ at $\approx 4\sigma$ with these ultra-deep observations. These lines reveal that JADES-GS-z14-0 has low dust attenuation with a recent star-formation rate of $\mathrm{SFR} \approx 10 \pm 2\ M_{\odot}\ \mathrm{yr}^{-1}$, star-formation rate surface density of $\Sigma_{\mathrm{SFR}} \approx 23 \pm 5\ M_{\odot}\ \mathrm{yr}^{-1}\ \mathrm{kpc}^{-2}$, and ionizing photon production efficiency of $\xi_{\mathrm{ion}} \approx 10^{25.3 \pm 0.1}\ \mathrm{Hz\ erg}^{-1}$. Using standard strong-line diagnostics, we infer a gas-phase oxygen abundance of $[\mathrm{O/H}] \approx -1.1 \pm 0.4$ ($\approx 10\%\ Z_{\odot}$), carbon-to-oxygen ratio of $[\mathrm{C/O}] \approx -0.4 \pm 0.4$, ionization parameter of $\log_{10}(U) \gtrsim -2.4$, and density of $n_{\mathrm{H}} \approx 720 \pm 210\ \mathrm{cm}^{-3}$. Using detailed photoionization modeling, we instead derive $[\mathrm{O/H}] \approx -0.3_{-0.4}^{+0.4}$ ($\approx 50\%\ Z_{\odot}$) and $\log_{10}(U) \approx -1.5_{-0.4}^{+0.3}$. The inferred properties of JADES-GS-z14-0 are similar to those measured for similarly luminous galaxies at $z > 10$ with previous MIRI/Spectroscopy, such as GHZ2/GLASSz12, GN-z11, and MACS0647-JD1. Existing simulations are unable to reproduce the empirical and inferred properties of JADES-GS-z14-0. This work demonstrates an important step toward understanding the formation of the first stars and heavy elements in the Universe. [Abridged]