Nikki Zabel, Bavo Croiset

Improved direct oxygen abundances

Jarle Brinchmann

Danielle van der Werff

Characterization of the atmosphere above Leiden

Remko Stuik

Kasper van Dam, Bart Verhaar

Discovering KINGFISH background galaxies

Bernhard Brandl

Stijn Debackere

Modelling the polarisation PSF of the E-ELT EPICS-EPOL instrument

Christoph Keller/Frans Snik

Alex Pietrow

CHGAPP (deadline: 15 July)

Christoph Keller

Leindert Boogaard, Leon Trapman

ALMA observations of a protoplanetary disk

Michiel Hogerheijde

Rene van der Smeede

Stability of planetary systems

Vincent Icke/Elena Rossi

Martijn Oei

New device for wavefront sensing

Matt Kenworthy/ Martin van Exter

Qian Qian Lin

Lowest energy of planets in the Solar System

Simon Portiegies Zwart /Lucie Jilkova

14:15 - 14:45

ALMA observations of a protoplanetary disk

In this project the students will calibrate an ALMA data set of a protoplanetary disk, reconstruct the image cube, and analyse the continuum emission from the dust and the line emission from the gas. We will look at the structure and kinematics of the disk, and compare this to theoretical expectations.

Rowin Meijerink

Paul van der Werf

The transient nature of the interstellar medium in black hole environments

Luminous Infrared Galaxies (LIRGs; L(8-1000mum) > 10^11 L_sun) belong to the brightest objects in the universe, since they are in a phase where many stars are born and/or the black hole is in an active accretion state. Although only a small fraction of the galaxy population in the local universe are LIRGs, and play a minor role in the present days, they are much more numerous in the early universe. The violent phase of star formation and accretion shape the galaxies to their current appearance, and understanding their properties is thus of major importance in the context of galaxy evolution. The Herschel Space Observatory, observing at far-infrared to sub-millimeter wavelengths, opened up a new spectral window. It allowed the study of the physical properties of the interstellar medium in an unprecedented way, and led to unexpected discoveries. Apart from molecules as CO and H2O, a major example is the observation of the OH+ transient molecular ion in Mrk 231. This species is extremely reactive and quickly destroyed after production, and yet we observe bright OH+ lines that hint to large abundances. In this project, we will study the OH+ molecule with a time-dependent chemistry program to see whether we are able to explain the observed quantities. This will learn us more about the transient nature of the interstellar medium that is exposed to the feedback of star-formation and/or the active galactic nucleus.

David Sobral

Huub Rottgering/Koen Kuijken

Lya halos in the KIDS survey

Lya halo's are very remarkable objects. They are enormous (100kpc) diffuse regions located in the early Universe emitting copious amounts of Lya emission. Most of them are likely to be situated at the center of forming clusters of galaxies, so called protoclusters. Studying them gives information on the physics of gas in forming clusters, directly relevant to how the first galaxies and galaxy clusters formed. So far CCD surveys have only covered limited areas of sky and hence only a handful of such objects are known. However the KIDS survey (led by Kuijken in Leiden) covers very large regions and has the prospects of increasing the number of luminous Lya halo's with orders of magnitudes. During this bachelor project we will use the KIDS data to search for these halos and study their properties. We will roughly follow the methods as described here:

http://iopscience.iop.org/0004-637X/762/1/38/pdf/apj_762_1_38.pdf

Calculate the lowest energy trajectories between planets in the solar system.

Remko Stuik

Bernhard Brandl

Characterization of the atmosphere over Leiden Observatory

The goal of the research project is to determine as accurately as possible the observing conditions at Leiden Observatory. A number of experiments will be designed, built, and executed to determine parameters like sky background, atmospheric transmission, turbulence strength and turbulence profile.

Discovering infrared galaxies

The KINGFISH proiject, one of the largest observing programs with the Herschel Space Telescope has obtained deep images of more than 60 nearby galaxies at far-infrared wavelengths. While the galaxies have been carefully studied, no one has yet search for interesting galaxies in the background around the targeted galaxies. This project will search for galaxies at intermediate redshifts and make a preliminary classification of the objects discovered.

Henk Hoekstra &

Michael Balogh

Improved direct oxygen abundances

There are a few different methods to measure the oxygen abundance of ionised gas. The most widely used is the technique called the strong line method which uses emission lines that very often are visible in the spectra of galaxies: [O II]3727, Hß, [O III]5007, Ha, [NII]6584. However this method relies on a number of assumptions that can be hard to justify. It is therefore generally thought that the so-called “direct” method for oxygen abundance measurements is better. This relies on the ability to measure the [O III]4363 line flux which when combined with other lines gives a good constraint on the temperature of the gas and thence to the metal abundance of the gas. When compared to the strong line method there is typically a significant offset in metallicity which has led to a significant uncertainty about the usefulness of the strong-line method. While very powerful, it has become clear that the metallicity measured using this method is very dependent on the atomic parameters used and the most widely used tools turn out to use outdated data. With this project the aim is to update the existing tools with the latest atomic parameters and use the improved calibration to derive oxygen abundances for a large number of low- redshift galaxies and see whether the metallicity still differs strongly from that inferred by strong-line method.