Hello There!

I am a PhD student in the fundamental physics research group at the Max-Planck institute for Radio astronomy in Bonn, Germany. The main focus of my research is using MeerKAT data to test large scale cosmology.

In my current research I am working with the MeerKAT Absorption Line Survey (MALS). While the primary focus of the survey is to look at absorption lines in the spectra of the target sources, due to the sensitivity and large field of view of the telescope each observed field likely contains thousands of sources. As of writing more than 350 fields have been observed, presenting an enormous dataset that is neatly distributed across the sky. My work is largely focused on processing of continuum data in such a way as to create a data set that is as homogenous as possible. With the complete data I hope to measure the cosmic radio dipole in both continuum and polarisation.

On this page you can find more information about my research interests, a short CV and my contact information.

Research

Testing large scale cosmology with MeerKAT

PhD project, Max Planck institute for Radio Astronomy

Fundamental to our modern description of cosmology are the assumptions of homogeneity (no special place) and isotropy (no special direction) of the Universe at large scales. The largest anisotropy we can see on the sky is a dipole measured from the cosmic microwave background (CMB), mostly assumed to be caused by the motion of the Solar system through the Universe. Several studies show a discrepancy between the dipole measured from the CMB and the dipole measured from observations of radio sources, presenting an intriguing puzzle as to what causes this discrepancy. Thus far, surveys have struggled to be sensitive enough to convincingly measure this dipole, and many seen and unseen systematic effects might skew the results one way or the other. Through observations with the MeerKAT array I hope to measure this effect as well, and my efforts go towards preparing methods of efficiently processing the data and measuring the cosmic radio dipole from it.

Bayesian high redshift quasar selection

First master project, Leiden University

One of the most exciting frontiers in astronomy currently is in the era not long after the Big Bang where the first stars and galaxies are formed and the Universe lights up. Commonly referred to as the Epoch of Reionisation, the sources in this age are extremely difficult to observe due to their distance and faintness. One tried and true method is looking for quasars, which due to their extreme luminosities can be found in many large sky surveys. However for every quasar at these distances, there are thousands of sources to be sifted through, calling for effective methods of selecting them from large data sets. In my first master project, I worked on such a method, utilizing Bayesian statistics and machine learning techniques in order to effectively search for quasars at high redshifts.
Using this method we selected a handful of promising sources for spectroscopic observation. For this part of the project we used the Isaac Newton Telescope (INT) and Telescopio Nazionale Galileo (TNG). Results will come here very soon!

Weak lensing power spectrum inference with KiDS

Second master project, Leiden University

One of the most promising ways to unravel the structure and evolution of the Universe is through the study of weak gravitational lensing. Light coming from distant galaxies travels through the matter distribution which through its gravity distorts the images of these galaxies ever so slightly. Though the distortions are indistinguishable from the regular structure for individual galaxies, looking at enormous amounts of galaxies we are able to extract the underlying cosmological structure. This requires advanced statistical methods, and the research I did in my second master project involved testing one of these methods on data from the Kilo Degree Survey (KiDS), a survey containing millions of galaxies.

Analysis of the Sz91 transition disk

Bachelor project, Leiden University

With the current generation of telescopes observations can be so sensitive that planetary systems can be detected in the early stages of their life. Called protoplanetary disks, the objects contain gas and dust, and studying them can give great insight into the formation of planetary systems like our solar system. In my bachelor research, I worked together with a fellow student on calibrating and analysing observational data from the Atacama Large Millimeter Array (ALMA) of the protoplanetary disk Sz91.

Short CV

Below you can find a short version of my CV, a longer version can be found here

Education

PhD Astronomy and Astrophysics, Max Plank institute for radio astronomy, Germany, Nov 2019 -
MSc Astronomy & Research, Leiden University, The Netherlands, Sep. 2017 - Aug. 2019
BSc Astronomy, Leiden University, The Netherlands, Sep. 2014 - Aug. 2017

Publications

First author
  • The cosmic radio dipole: Bayesian estimators on new and old radio surveys, J.D. Wagenveld, et al., 2022, A&A
  • The MeerKAT Absorption Line Survey: Homogeneous continuum catalogues towards a measurement of the cosmic radio dipole, J.D. Wagenveld, et al., 2023, A&A
  • Revealing new high-redshift quasar populations through Gaussian mixture model selection, J.D. Wagenveld, et al., 2022, A&A

Successful observing proposals

  • Isaac Newton Telescope, PI, 10 nights visitor mode
  • Telescopio Nazionale Galileo, Co-I, 4 hours service mode

Contact Me

Here is where you can find me both physically and online.

Office Address

Max Planck Institut für Radioastronomie
Auf dem Hügel 69, 53129 Bonn
Germany

Email and phone

Email: wagenveld [at] mpifr-bonn [dot] mpg [dot] de
Phone: +49 (0)228-525-530

If you'd like to get in touch, either to find out more about my research or to complain about anything that you did not like on this website, why not send me an email on the address listed above?