About Me and My Research

Since fall 2022 I lead the new research group for Cosmology and Machine Learning at the Institute of Theoretical Physics (ITP), Heidelberg University. My group's research is mainly funded by the Freigeist Fellowship 'Changing the way we look at the sky - Computer Vision Astrophysics' (by the Volkswagen Foundation with ca. 1.1 million Euro).

Interested in a thesis?
We offer a range of thesis topics, from development of ML and network-based methods for cosmology and astrophysics, over large-scale structure simulations for intensity mapping, to analysis of large astronomical survey data. You are interested in these topics, or have questions? Feel free to contact me!

How did our Universe look like more than 12 billion years ago when the very first galaxies formed? How to map out the Universe and its structure from current time up to the early epoch of reionization and beyond? To tackle these early cosmic epochs, my group's research connects modern machine learning methods and artificial intelligence with large-scale intensity mapping measurements at multiple wavelengths. We use simulations tailored for intensity mapping, model analysis, forecasting, parameter estimation and advanced deep learning techniques to learn how the Universe. Primary goal is an integrated understanding of astrophysical processes and cosmology at play during these early epochs of our Universe, thus ‘computer vision astrophysics’ as a novel way to look at the (astronomical) sky.

Until recently, I had worked at the Hamburg Observatory to continue advancing the intensity mapping technique, supplemented by the application of advanced machine learning to a variety of astrophysical problems within the Platform for Challenges in Data Science of the Cluster of Excellence Quantum Universe. Before I worked as a researcher at the Scuola Superiore Normale in Pisa, Italy, on synergies of hydrogen 21cm intensity mapping with the Square Kilometre Array (SKA) and galaxy surveys as well as other line mappings to probe the late stages of reionization. Earlier, as a research fellow at the University of Heidelberg, I had kicked off my research on intensity mapping in general scenarios of gravity beyond LCDM. During my Ph.D. at Copenhagen University and as a visiting scientist at the University of California, Irvine, I laid the foundation for my multi-line modelling expertise with simulations of 21cm, Lyman-alpha and H-alpha cosmological volumes and their cross-sginals, as well as sensitivity forecasts for missions like SPHEREx and the Cosmic Dawn Intensity Mapper (CDIM).

Besides my work on multi-line intensity mapping, I also worked to design a convolutional neural network that revolutionizes galaxy deblending as part of the COIN collaboration, developed new Bayesian statistical techniques for bias detection, and demonstrated the detectability of dark energy fluctuations with galaxy clusters. As a research employee at the German Aerospace Center (DLR) in Cologne, Germany, working for the program strategy space, I developed mission concepts and strategies for the space research and technology program. I currently lead the development of a classification machine learning layer for ESO's 4MOST spectroscopic telescope and am engaged in constraining cosmology with the clustering signal of radio galaxies as measured by LOFAR.

The research group

Our new research group 'Computer Vision Astrophysics and Cosmology' for Cosmology and Machine Learning at the Institute of Theoretical Physics focuses on: Modern Machine Learning for cosmological inference and simulation; Computational astrophysics and cosmology; Intensity mapping; and Large (radio) surveys, in particular the Square Kilometre Array (SKA) and LOFAR.
Our goal is to learn about our Universe's cosmology, the epoch of reionization and high-redshift galaxy formation.

We are looking for a student assistant to join us! For more information see: HiWi-ad

The Team

Lara Alegre (Postdoc)

Yannic Pietschke (PhD student)

Abdulmalik Kara (Master student)

Tom Schlenker (Master student)

Former students:

Tim Ullrich (Master student, UHH 2022-23)

Jörn Bach (Master student, UHH 2021-22)

Steffen Neutsch (Master student, UHH 2020-21)

Research Projects

  • Line Intensity Mapping
    as a probe of Astrophysics and the Epoch of Reionization

    I work on simulations tailored for multi-line intensity mapping, to then employ them for parameter, calibration and cross-correlation studies, as well as the creation of realistic mock observations.
    [For a first release of simulations see arXiv:1611.09682; update: 2004.10097, 2104.12739]

  • Probing Cosmology
    with Line Intensity Mapping

    Besides multi-line simulations for astrophysics, I also simulate intensity mapping, especially the 21cm line during reionization and cosmic dawn, in general gravity scenarios to explore this novel observable and forecast the feasibility to detect deviations from LCDM.
    [See e.g. arXiv:1805.03629, 1910.02763]

  • Future Missions

    With my simulation-derived realistic mock observations for intensity mapping of multiple lines (Lyman-alpha, H-alpha, 21cm, CII, CO, ..), I provide detectabilty studies and forecasting for upcoming probes like SPHEREx and the Cosmic Dawn Intensity Mapper (CDIM).
    [See arXiv:1903.03144, 1903.03629, 1903.11744, 2104.12739]

  • Development of new Methods

    I am also interested in advanced statistical and machine learning tools for astronomy and cosmology. I so far worked on machine learning for cosmological inference, classification of spectra, galaxy deblending, as well as statistical tests of bias with Bayasian methods and genetic algorithms.
    [See arXiv:1310.8435, 1407.2531, 1905.01324, 2201.07587, 2201.02202]


  • The RENOIR project
    Reionization in multi-colour

    The RENOIR-code models hydrogen 21cm, Lyman-alpha and H-alpha emission and surface brightness during the epoch of reionization (redshift z>6) for intensity mapping studies. It is calibrated with obervations of high-redshift galaxies, and is based on the semi-numerical 21cmFAST code (Mesinger et al. '10). Updated calibration and additional emission lines (z.B. CO, CII, OIII) are in progress.
    [language: mostly C, python]

  • Intensity mapping in generalized gravity

    This code simulates both the global signal and intensity maps of 21cm hydrogen emission during reionization and cosmic dawn in generalized gravity scenarios (for an effective gravitational constant, general initial conditions, and/or interacting quintessence).
    [language: C, python]

  • Lyman-alpha emitter (LAE) calibration

    Add-on modules that calculate galaxy LAE maps, with their angular correlation and luminosity function calibrated against observations, and derive cross-statistics with 21cm intensity maps like the real-space and fourier-space cross-correlation coefficients.
    [language: mostly C, python]

  • Mission sensitivity predictions

    A fast code in C that enables the prediction of the sensitivity on intensity mapping power spectra, depending on mission design (e.g. mirror size, instrument temperature) and planning (e.g. integration time).
    [language: C]

  • MapMock

    Takes simulated surface brightness fields and together with instrument sensitivity predictions creates realistic mock observational maps.
    [language: C]

  • Blend2Flux CNN

    Convolutional neural network designed to deblend large samples of galaxy-pairs in photometric images, outputting the flux of the individual galaxies. To be made public within the COIN Cosmostatistics network.
    [language: python with Keras library]

  • Bayesian Robustness for bias detection

    Code that calculates the Bayesian robustness (ratio of evidences) of data sub-samples and compares these to unbiased mock data, to detect possibly biased sub-samples.
    [language: Mathematica]

  • Generalized spherical collapse

    Code that follows the spherical collapse of overdensities while including dark energy perturbations, to calculate characteristic quantities like the density threshold of collapse.
    [available in: Mathematica, Fortran95]

For more information and collaboration, feel free to contact me.

Short CV

Research Experience

2022 - Heidelberg University, Institute of Theoretical Physics (ITP), Germany.
Junior Group Leader.
2020 - 2022 Hamburg University, Observatory of Hamburg, Germany.
Senior Post-doctoral Researcher, Excellence Cluster Quantum Universe.
2019 - 2020 German Aerospace Center (DLR), Germany.
Research Employee.
2018 - 2019 Scuola Normale Superiore, Italy.
Research Associate, mentor: Andrei Mesinger
2017 Institute for Theoretical Physics, Heidelberg University.
Transregio TRR33 Post-doctoral Fellow, mentor: Luca Amendola
2015 - 2016 University of California, Irvine, USA.
Visiting scientist, mentor: Asantha Cooray

Degrees and Programmes

2017 Ph.D. in Physics, Copenhagen University, Denmark.
Thesis Advisors: Steen H. Hansen, David A. Rapetti.
2013 Master of Science Physics, Heidelberg University.
Thesis Advisors: Luca Amendola, Valerio Marra.
2011/12 NPAC, Institut d’astrophysique spatiale, Université Paris-Sud, France.
Thesis Advisor: Nicole Nesvadba.
2010 Bachelor of Science Physics, Heidelberg University.
Thesis Advisor: Matthias Bartelmann.

Awards and Memberships

2019 Marie Sklodowska-Curie Actions Seal of Excellence, call H2020-MSCF-IF-2018.
2019 Member International Astrostatistics Association (IAA).
2018 Top three in Ph.D. prize for best Astronomy Ph.D. thesis in Denmark.
2018 Square Kilometre Array (SKA): Science team member, member synergy focus group.
2018 Member of COIN (Cosmostatistics Initiative).
2017 Transregio33 (The Dark Universe) Post-doctoral Fellowship.
2017 Science working group member: CDIM satellite (Cosmic Dawn Intensity Mapper), NASA.
2015 Member American Astronomical Society (AAS).
2011 Erasmus scholarship for Master studies at Université Paris-Sud 11, France.
2007 e-fellows.net price for online-scholarship programme.
2007 Excellence Award of the German Physical Society (DPG).


You can find my scientific publications on ADS and arXiv.

Contact Me

Caroline Heneka
Heidelberg University
Institute for Theoretical Physics
Philosophenweg 16
69120 Heidelberg
+49 6221-54-5059
heneka[at] thphys.uni-heidelberg.de