About

Rogier Windhorst is a Regents Professor at the School of Earth and Space Exploration at Arizona State University. His research is focused on astronomy, cosmology, galaxy formation and evolution, the cosmic dark ages, the epoch of First Light, and astronomical instrumentation. Since the early 1990s, his group at ASU has contributed significantly to understanding the formation and evolution of distant galaxies with the Hubble Space Telescope, and the role that supermassive black holes and Active Galactic Nuclei have played in galaxy assembly. He is one of the world's six Interdisciplinary Scientists for NASA's James Webb Space Telescope (JWST), which was launched in 2021, and his group plans to use JWST to map the epoch of First Light in detail. His educational background includes a Ph.D. in Astronomy from the University of Leiden, obtained in 1984, along with a master's and bachelor's degree in Astronomy, Physics, and Mathematics from the same university. His research interests encompass astronomy, astrophysics, cosmology, space sciences, telescope and instrument design, NASA space missions, the Hubble Space Telescope, and the James Webb Space Telescope.

Research topics

• Astronomy
• Physics
• Astrophysics
• Computer Science
• History

Selected publications

• The James Webb Space Telescope Mission

  Publications of the Astronomical Society of the Pacific · 2023 · 439 citations

  • Computer Science
  • Astronomy
  • Physics

  Abstract Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4 m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5 m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 yr, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.

  DOI

• JWST Reveals a Possible z ∼ 11 GalaxyMerger in Triply Lensed MACS0647–JD

  The Astrophysical Journal Letters · 2023 · 50 citations

  • Physics
  • Astrophysics
  • Astronomy

  Abstract MACS0647–JD is a triply lensed z ∼ 11 galaxy originally discovered with the Hubble Space Telescope. The three lensed images are magnified by factors of ∼8, 5, and 2 to AB mag 25.1, 25.6, and 26.6 at 3.5 μ m. The brightest is over a magnitude brighter than other galaxies recently discovered at similar redshifts z &gt; 10 with JWST. Here, we report new JWST imaging that clearly resolves MACS0647–JD as having two components that are either merging galaxies or stellar complexes within a single galaxy. The brighter larger component “A” is intrinsically very blue ( β ∼ −2.6 ± 0.1), likely due to very recent star formation and no dust, and is spatially extended with an effective radius ∼70 ± 24 pc. The smaller component “B” ( r ∼ 20 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow/> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>5</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>8</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace width="0.25em"/> </mml:math> pc) appears redder ( β ∼ −2 ± 0.2), likely because it is older (100–200 Myr) with mild dust extinction ( A V ∼ 0.1 mag). With an estimated stellar mass ratio of roughly 2:1 and physical projected separation ∼400 pc, we may be witnessing a galaxy merger 430 million years after the Big Bang. We identify galaxies with similar colors in a high-redshift simulation, finding their star formation histories to be dissimilar, which is also suggested by the spectral energy distribution fitting, suggesting they formed further apart. We also identify a candidate companion galaxy “C” ∼3 kpc away, likely destined to merge with A and B. Upcoming JWST Near Infrared Spectrograph observations planned for 2023 January will deliver spectroscopic redshifts and more physical properties for these tiny magnified distant galaxies observed in the early universe.

  PublisherOA PDFDOI

• JWST PEARLS. Prime Extragalactic Areas for Reionization and Lensing Science: Project Overview and First Results

  The Astronomical Journal · 2022 · 159 citations

  1st authorCorresponding
  • Physics
  • Astronomy
  • Astrophysics

  Abstract We give an overview and describe the rationale, methods, and first results from NIRCam images of the JWST “Prime Extragalactic Areas for Reionization and Lensing Science” (PEARLS) project. PEARLS uses up to eight NIRCam filters to survey several prime extragalactic survey areas: two fields at the North Ecliptic Pole (NEP); seven gravitationally lensing clusters; two high redshift protoclusters; and the iconic backlit VV 191 galaxy system to map its dust attenuation. PEARLS also includes NIRISS spectra for one of the NEP fields and NIRSpec spectra of two high-redshift quasars. The main goal of PEARLS is to study the epoch of galaxy assembly, active galactic nucleus (AGN) growth, and First Light. Five fields—the JWST NEP Time-Domain Field (TDF), IRAC Dark Field, and three lensing clusters—will be observed in up to four epochs over a year. The cadence and sensitivity of the imaging data are ideally suited to find faint variable objects such as weak AGN, high-redshift supernovae, and cluster caustic transits. Both NEP fields have sightlines through our Galaxy, providing significant numbers of very faint brown dwarfs whose proper motions can be studied. Observations from the first spoke in the NEP TDF are public. This paper presents our first PEARLS observations, their NIRCam data reduction and analysis, our first object catalogs, the 0.9–4.5 μ m galaxy counts and Integrated Galaxy Light. We assess the JWST sky brightness in 13 NIRCam filters, yielding our first constraints to diffuse light at 0.9–4.5 μ m. PEARLS is designed to be of lasting benefit to the community.

  DOI

• A highly magnified star at redshift 6.2

  Nature · 2022 · 126 citations

  • Physics
  • Astrophysics
  • Astronomy
  DOI

Frequent coauthors

• Seth H. Cohen

  Arizona State University

  256 shared

• Rolf A. Jansen

  225 shared

• Anton M. Koekemoer

  Space Telescope Science Institute

  224 shared

• Simon P. Driver

  University of Western Australia

  190 shared

• Nimish P. Hathi

  173 shared

• Norman A. Grogin

  Space Telescope Science Institute

  160 shared

• Christopher J. Conselice

  156 shared

• Russell E. Ryan

  143 shared

Education

• Ph.D., Astronomy

  University of Leiden

  1984

• M.S., Astronomy and Physics

  University of Leiden

  1979

• B.S., Astronomy, Physics and Mathematics

  University of Leiden

  1976

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• Jianguo Wuh-119
• Carolyn Comptonh-118
• Osvaldo Salah-114