Roelof's Research

Most of my work has concentrated on nearby galaxies; their structure, stellar and dust content, and the distribution of mass within them, and putting these measurements in the context hierarchical galaxy formation models.

I am currently leading the GHOSTS Survey, a large HST survey of the resolved stelllar populations of bulges, thick disks, and halos of nearby, massive disk galaxies. Hierarchical galaxy formation in a LambdaCDM cosmology has become the standard paradigm in recent years. However, our understanding of the galaxy formation process is incomplete. Which high redshift galaxy building blocks end up in what kind of local galaxies? How much of the stellar content of the different galaxy components (bulge, thin and thick disk, stellar halo) is created in situ and how much is accreted? How does the current accretion rate compare to LambdaCDM predictions? What regulates star formation in disk galaxies? To address these questions we have started the GHOSTS (Galaxy Halos, Outer disks, Substructure, Thick disks, and Star clusters) Survey, using HST to perform stellar archaeology in the outskirts of 14 nearby disk galaxies (8 of which are edge-on). I am also co-investigator of ANGST, a large HST survey using similar techniques as GHOSTS (resolved stellar populations) to study galaxies in the local volume to reconstruct their star formation history.

The precursor of GHOSTS was an HST survey of nearby edge-on galaxies to investigate their dust lane properties and stellar content. Anil Seth maintains a web site with pretty pictures from this survey.

My Thesis is fairly representative of the rest of my work. All data presented in the thesis is available; the images, the profiles, the bulge/disk ratios and other useful parameters and the file and data descriptions. To see the lineage that led to this thesis have a look at my Academic Genealogy (Ph.D. Family Tree).

Since my thesis I have written some more articles, so have a look at my Publications Page or at a PDF version of my CV and Publication List.

I am involved in a number of collaborative projects. Here are some web links

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Wed Dec 5 10:58:12 2007