Joshiwa van Marrewijk

PhD Student at ESO

About Me

I feel privileged that I enjoy what I study. Astronomy is my passion. My studies enable me to combine my hobbies, like programming, with abstract complex concepts such as the origins and evolution of the Universe. In my free time, I enjoy listening to music and reading books. Some of my favorite authors are Arjen van Veelen, Harry Mulisch, and Hermann Hesse.

Furthermore, I like to play baseball and football or go surfing when the weather permits it. I enjoy delivering qualitative work using my metrics. In life, I consider myself enthusiastic and driven, yet full of doubt. Strong opinions held loosely; I love that.

Research Interest

Astronomy's pursuit of understanding the Universe's content and growth is a fundamental research domain. Addressing this often involves extensive hydrodynamical simulations that can track the cosmic web's evolution over time. However, observationally, capturing a snapshot of the formation of large-scale structures has proven challenging, making a direct comparison between simulations and reality difficult. In my research, I push observations on the most massive objects to higher redshifts to better constrain their evolutionary pathways. During my Ph.D., I specialized in using ALMA to retrieve the characteristics of early-formed structures like the first galaxies and proto-clusters.

For me, every paper is a new opportunity to code something up. Hence, over the years, I have developed new techniques that help me retrieve relevant scientific information from complex data sets. For instance, I have experimented with utilizing a Bayesian-forward modeling routine to deconvolve interferometric data from the Atacama Large Millimeter/submillimeter Array (ALMA) of the Sunyaev-Zel'dovich effect to better recover extended scales.   

To study the first galaxies and proto-clusters, I typically use telescopes such as ALMA, the Green Bank Telescope (GBT), and the Atacama Cosmology Telescope (ACT). For the latter (as well as Simon's Observatory), I am an official junior member of the corresponding large collaboration. I am grateful to be supervised by T. Mroczkowski and G. Popping.

Before I joined ESO, I studied in Leiden for six years. I obtained my two bachelors in Astronomy and Physics, and I specialized in Astronomical Research during my master's. While in Leiden, I worked with J. Hodge, M. Rybak, S. Debackere, and H. Hoekstra.

For a more detailed overview of my current and previous work, please go to My Work and my CV.