Dr Joris Witstok FRAS
Curriculum Vitae
Research Interests
Research Experience
DAWN fellow
Cosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen
2024 - present
Postdoctoral research fellow (DAWN Fellow) at the Cosmic Dawn Center, Niels Bohr Institute, University of Copenhagen.
Postdoctoral Research Associate
Cavendish Laboratory, University of Cambridge
2022 - 2024
Multiple first-author publications including in Nature, Principal Investigator of multiple successful ALMA observing programs, Associate Member of the James Webb Space Telescope NIRSpec Instrument Team (allocated 800+ hours telescope time).
Doctor of Philosophy (PhD) in Astrophysics
Sidney Sussex College, University of Cambridge
2018 - 2022
Supervised by Dr Renske Smit and Prof Roberto Maiolino. Thesis title: Spectroscopic studies of star-forming galaxies and the intergalactic medium in the early Universe. Published four first-author papers, Principal Investigator of Hubble Space Telescope observations.
Education
Master of Advanced Study (MASt) in Astrophysics
Sidney Sussex College, University of Cambridge
2017 - 2018
Graduated with distinguished performance (Distinction, 85/100). Supervised by Dr Ewald Puchwein, Dr Girish Kulkarni, and Prof Martin Haehnelt.
Double Bachelor of Science in Physics and Astronomy
University of Leiden
2014 - 2017
Graduated cum laude both in Physics and Astronomy (8.9 out of 10 average), combined with Honours College.
Scholarships & Honours
Mike Phillips Award
Sidney Sussex College, University of Cambridge
2023
Awarded the Mike Phillips Award for the pursuit of excellence in sport (Full Blue in Road Cycling).
Distinction
Sidney Sussex College, University of Cambridge
2018
Awarded a Distinction in Master of Advanced Study (MASt) in Astrophysics.
Cum laude (2x)
University of Leiden
2017
Graduated cum laude in Bachelor of Science in Physics and Astronomy.
Honours College
University of Leiden
2017
Successfully completed Honours College: Beta and Life Sciences.
Summa cum laude
Gemeentelijk Gymnasium Hilversum
2014
Graduated summa cum laude in VWO Gymnasium.
Selected Publications
Publication metrics
See publication record for more details. Based on the SAO/NASA Astrophysics Data System (last updated: 8 November, 2026).
Successful Observing Proposals
Large Unified Modern Infrastructure (LUMI) project Deic-KU-L5-2026-036
Co-PI of Danish e-Infrastructure Cooperation (DeiC) project Deic-KU-L5-2026-036.
Benchmarking Luminous UV-Emitting Monsters Observed from Oxygen to Nitrogen: Ionizing Sources and ISM Conditions of z=8-15 Blue Monsters
Co-PI of JWST programme 12267.
Connecting the (Little Red) Dots: a unique z ~ 2.5 QSO as a blueprint for JWST's enigmas?
Co-PI of ESO programme 117.29UL.001.
Reionization revealed: ALMA anatomizes an enigmatic ionizing source within a galaxy at redshift 13
Principal Investigator of ALMA program 2025.1.00147.S, 2026.1.00390.S
A neutral stance: towards completing our view of the ISM in the earliest galaxies
Principal Investigator of ALMA program 2025.1.00418.S
Origins of Oxygen: ALMA probing chemical enrichment of the first stars
Principal Investigator of ALMA program 2023.1.00336.S
Cold Dust at Cosmic Dawn: uncovering a cool dust reservoir in the Epoch of Reionization
Principal Investigator of ALMA programs 2022.1.00925.S, 2023.1.00379.S, 2024.1.00675.S
Imaging the sites of star formation at sub-kiloparsec scales in the Epoch of Reionization
Principal Investigator of Hubble Space Telescope program ID 16506
Rest-frame UV diagnostics of star-forming galaxies in an extreme protocluster environment at z ~ 3
Co-Principal Investigator of ESO program 105.20RW
Various observing proposals
Co-Investigator on 40+ observing programs with James Webb Space Telescope, ALMA, and the Very Large Telescope
Selected Talks & Presentations
Miracles of the Early Universe II
Geneva, Switzerland
2026
Invited speaker at the Miracles of the Early Universe II meeting.
Star Forming Galaxies in the Reionization Epoch
Ishigaki, Japan
2026
Invited speaker at the Star Forming Galaxies in the Reionization Epoch workshop.
University of South Africa
Virtual
2026
Invited seminar at the University of South Africa.
European Space Agency
Virtual
2025
Invited seminar at the European Space Agency.
University of Southern Denmark
Odense, Denmark
2025
Invited seminar at the University of Southern Denmark.
Stockholm University
Stockholm, Sweden
2025
Invited seminar at the University of Stockholm.
12th International Asian Congress
Torun, Poland
2025
Invited speaker at the 12th International Asian Congress.
Saint Mary's University
Virtual
2025
Invited colloquium at Saint Mary's University.
Chalmers University
Gothenburg, Sweden
2025
Invited colloquium at Chalmers University.
University of Ljubljana
Ljubljana, Slovenia
2025
Invited seminar at the University of Ljubljana.
University of Groningen
Groningen, NL
2024
Invited seminar at the Kapteyn Astronomical Institute.
Harvard University
Virtual
2024
Invited seminar at the High Energy Astrophysics Division (HEAD) at the Center for Astrophysics (CfA).
European Astronomical Society Meeting 2024
Padova, Italy
2024
Invited speaker at the European Astronomical Society Meeting 2024.
Cardiff University
Virtual
2024
Invited seminar at Cardiff University.
California Institute of Technology
Pasadena, USA
2024
Invited seminar at the California Institute of Technology.
Royal Astronomical Society
London, UK
2024
Invited seminar at the RAS Astronomy and Geophysics Highlights Meeting and invited panellist at the RAS Specialist Discussion Meeting.
Cosmic Dawn Center
Copenhagen, Denmark
2024
Invited seminar talk at the Cosmic Dawn Center.
Complutense University
Virtual
2023
Invited seminar at Complutense University.
American Astronomical Society Bi-Annual Meeting
Albuquerque, USA
2023
Invited speaker at the 242nd meeting of the American Astronomical Society.
Scuola Normale Superiore
Pisa, Italy
2022
Invited seminar talk at the Scuola Normale Superiore.
In Situ View of Galaxy Formation 2
Ringberg, Germany
2022
Invited speaker at the In Situ View of Galaxy Formation 2 Conference.
Teaching & Supervision
Niels Bohr Institute, University of Copenhagen
2025 - 2026Teaching one-week project-based graduate course Gravitational Dynamics and Galaxy Formation.
Cavendish Laboratory, University of Cambridge
2019 - 2022Teaching assistant for (under)graduate courses in the Physics department at the University of Cambridge.
Physics and Astronomy, University of Leiden
2015 - 2017Teaching assistant for undergraduate courses in the Physics and Astronomy department at the University of Leiden.
Selected Media & Outreach
European Space Agency/NASA
2025
Co-led ESA/NASA press release covered by 100+ news outlets including The Guardian and New Scientist.
The Naked Scientists
2023
Podcast interview with The Naked Scientists (estimated 10 million yearly downloads).
European Space Agency/NASA
2023
Co-led ESA/NASA press release covered by 50+ news outlets including Sky & Telescope.
BNR Nieuwsradio
2023
Radio interview with BNR Dutch national radio (estimated 0.5 million weekly listeners).
Institute of Astronomy Open Evening
2020
Public Lecture at the Open Evening of Institute of Astronomy, University of Cambridge.
Skills & proficiencies
Written Communication
Proven track record in scientific literature (author on 150+ publications, 10 as first author, totalling 15,000+ citations; h-index of 68).
Leadership
(Co-)Principal Investigator of 11 JWST, ALMA, and HST observing programmes (150+ hours), Co-Chair of the Charting Cosmic Dawn (2026), From Dust till Dawn (Lorentz Center, 2026), and Richard Hills Memorial (2024) conference committees.
Network & Collaboration
Associate Member of the James Webb Space Telescope NIRSpec instrument team (allocated 800+ hours GTO time), member of the PHOENIX ALMA and BlackTHUNDER JWST Large Programme collaborations, Full Member of the Euclid Consortium.
Communication & Services
Presented scientific results at 14 invited seminars, colloquia as well as invited and contributed talks at 40 international conferences, helped organize several, served on multiple departmental committees, developed publicly available codes, acted as referee for major journals (Nature, Nature Astronomy, MNRAS, ApJ, A&A) and panellist on the JWST Cycle 6 Time Allocation Committee.
Mathematical and Statistical Modelling
Noise modelling and marginal signal retrieval, Bayesian inference with MCMC methods (development of publicly available parallelised codes).
Data Analysis & Visualisation
Extensive working experience with pipelines and statistical analysis of large data sets (cosmological hydrodynamical simulations and observational surveys).
Computing & Programming
Highly proficient at Python (NumPy, SciPy, JAX, NumPyro, mpi4py, Matplotlib), UNIX, bash, LaTeX, git (10+ years’ working experience); familiar with C++, SQL, HTML, machine-learning methods.
Training & Instructing
Extensive experience (10+ years) of tutoring, supervision (students of undergraduate through PhD level), teaching, and assessment (admission interviews at Cambridge); broad experience as a (professional) coach in baseball, rowing (10+ years).
Languages
Dutch (mother tongue), English (fluent).
Contact
For references or a more detailed version of my CV, please contact me directly: