Research

Dust in Galaxies

In overlapping galaxy pairs, the background galaxy acts as a lighttable highlighting the places in the foreground galaxy wehre light is absorbed. With careful mapping, one can measure the amount and optical properties of the dust in the foreground galaxy.

Edge-on Disk Galaxies

The edge-on perspective allows astronomers to characterize how stars, dust and gas are vertically distributed in galaxy disks. They are often remarkebly thin.

Rubin's Galaxy

This massive spiral is in all measurable ways a normal spiral. It rotates, it is very symmetric and forms stars at a steady rate in the outskirts. It was originally pointed out by Vera Rubin that it was the biggest spiral in the local Universe (nearest 100Mpc). This is the Hubble data of this galaxy and my team and I plan to study it in detail.

LADUMA

Looking At the Distant Universe with the MeerKAT Array (LADUMA, meaning "goal" in Zulu) is a key project with the new MeerKAT radio telescope in South Africa. Looking back to z=1.4 for hydrogen's 21cm signal. see also: http://www.laduma.uct.ac.za

High-redshift Galaxies

I am part of the CEERS and the GOLF science collaborations to sift through everything we can learn with Hubble and Spitzer (GOLF) and early science on the early Universe with JWST (CEERS). I have worked on the sizes and morphologies of these earliest galaxies.

Shape of the Milky Way

As part of my work on high-redshift galaxies, I got interested in their main contaminant: red and brown dwarf sub-stellar and low mass stars. The random sampling we end up with through Hubble proved to be good enough to constrain the shape of the Milky Way. Especially two Leiden University undergraduates made a first model of the whole galaxy (van Vledder+ 2016)

GAMA

The Galaxy and Mass Assembly survey is based on AAT spectroscopy and a wide range of multi-wavelength data. This survey has set the standard for data products, all of which are public. Exploring this data-set is an ideal starting point for an undergraduate project.

Dust And Supernovae

Ever since my PhD work on dust in galaxies, I have been fascinated by how the host galaxy's dusty ISM influences our view of distant supernovae. These supernovae are one of two probes of Cosmology and subtle dimming and reddening could throw our measurements off.