Bachelor Onderzoek

Sterrenkundig Bacheloronderzoek - 2014/15


Het sterrenkundig onderzoek is een van de belangrijkste onderdelen van de bachelor studie, en neemt een groot gedeelte van het derde jaar in beslag. In de periode van september tot en met januari vindt de keuze van het onderzoeksonderwerp plaats. Tijdens de periode van februari tot juni sluiten de studenten (in groepjes van twee, en voor dubbele bachelorstudenten alleen) zich aan bij een van de onderzoeksgroepen, om zelf een echt onderzoek uitvoeren. Dit kan bijvoorbeeld bestaan uit het verwerken en analyseren van nieuwe waarnemingen, dan wel het berekenen of modeleren van bepaalde astrofysische processen. Tijdens deze periode krijgen de studenten zelf een werkplek op de sterrenwacht, met een bureau en PC, en wordt door middel van gezamenlijke sessies de voortgang van het onderzoek besproken. Het onderzoek wordt afgesloten met een scriptie en een eindpresentatie.

A more detailed overview of the Sterrekundig Bacheloronderzoek is given in these Introduction Slides.

Supervisor & assistants

The BO supervisor/coordinator is Dr. Bernhard Brandl, (office #535 in the Oort building, (071) 527-5830, email ).

The teaching assistants are Eva Bøgelund (office #532, email) and Mason Carney (office # 427, email ).


The schedule follows the 3rd year BSc Rooster -- watch out for updates!

Date Time Topic Room
4.9.2014 12:00-13:00 Introduction de Sitter
11.9.2014 09:00-17:00 Sterrewacht Science Day de Sitter
20.11.2014 11:15-13:00 Initial list of BO topics, how to choose HL 414
2.2.2015 09:00-09:45 BO topics and selection status HL 207
3.2.2015 11:15 - 13:00 Project management (Keller) HL 207
4.2.2015 10:30 - 13:00 LaTeX  
5.2.2015 11:15 - 13:00 Project management (Keller) HL 207
6.2.2015 11:15 - 13:00 Academic Integrity (Israel) HL 207
9.2.2015 no lecture Formal kick-off of the BO  
3.3.2015 13:45-16:30 First presentation (overview of projects) HL 207
17.3.2015 13:45-16:30 Progress Meeting HL 207
24.3.2015 13:45-16:00 TA Meeting (individual) HL 512
31.3.2015 13:45-16:30 Progress Meeting HL 207
07.4.2015 13:45-16:00 TA Meeting (individual) HL 512
14.4.2015 13:45-16:30 Progress Meeting HL 207
21.4.2015 13:45-16:00 TA Meeting (individual) HL 512
28.4.2015 13:45-16:30 Second presentation (progress review) HL 207
06.5.2015 13:45-16:00 TA Meeting (individual) HL 512
12.5.2015 13:45-16:30 Progress Meeting HL 207
19.5.2015 13:45-16:00 TA Meeting (individual) HL 512
26.5.2015 13:45-16:30 Progress Meeting HL 207
02.6.2015 13:45-16:00 TA Meeting (individual) HL 512
9.6.2015 13:45-16:30 Progress Meeting HL 207
15.6.2015 13:45-17:00 Final presentations I (rien ne va plus) HL 207
16.6.2015 13:45-17:00 Final presentations II (rien ne va plus) HL 207
23.6.2015 13:45-16:00 TA Meeting (individual) HL 512
30.6.2015   Deadline to hand in the final BO reports  


Students MUST have permission from the BSc study adviser to start with their BO! Usually that means that the practicals are finished and most courses (except for 1-2) have been completed before February 2015.

BO students must complete and hand in the registration form.

Working beyond the nominal office hours requires additional access rights for the building.

BO Research Projects

Check out the Introduction Slides for formal aspects and grading.

IMPORTANT NOTE: Unless agreed otherwise in individual cases, the deadline for the BO projects is Tuesday, 30 June 2015. One printed copy has to be given to the Onderwijscoördinator Sterrenkunde, Arianne Pen, Oort #564, and copies (printed or electronic) need to be provided to both readers/supervisors and the BO supervisor/coordinator B. Brandl. Both readers/supervisors have to complete and sign the grading form. The form has to be given to the Onderwijscoördinator Sterrenkunde within three weeks (i.e., before 21 July).

This is the list of currently assigned and available BO projects (as of 2 February 2015).

Supervisor(s) 2nd reader Title & short description
Bas Zoutendijk
Prof. Harold Linnartz Prof. Groenen

Broadband cavity enhanced absorption spectroscopy and the secret of the diffuse interstellar bands.

In the Sackler Laboratory for Astrophysics we have a BO project available for a student A, N or A/N to use a running setup ('BB-DIB') to search for carriers of the so called diffuse interstellar bands. The research involves the use of vacuum technology, plasma expansions, and broad band optical spectroscopy. The students job is to help in recording spectra and to compare results with the known DIB positions.

Hans Kleinwoud
Prof. Simon Portegies Zwart   Behaviour of a star during mass loss
Vincent Post
Dr. Frans Snik / Prof. Christoph Keller  

Polarimetric upgrade of a hyperspectral imaging instrument

Commercial remote-sensing instruments often only measure (part of) the spectral information for a given scene, while also the polarization of the collected light contains crucial information. You will work with us and a consortium of industrial partners to develop a polarimetric upgrade to a state-of-the-art hyperspectral imaging system. You will design and test the optomechanical system, perform calibrations, develop data reduction routines, and perform the first hyperspectropolarimetric imaging measurements ever of various scenes, particularly in the context of Crime Scene Investigation.

Lieke van Son

Robbie Brooijmans

Dr. Benne Holwerda/ Dr. Rychard Bouwens  

The size of z~8 Galaxies

z~8 is only a few hundred million years after the big bang, yet already galaxies have formed and may have the typical maximum luminosity of galaxies for the next few billion years. The project is to measure the sizes of z~8 galaxies (selected based on their colors) and determine their sizes. Only a brief cosmic time later (z~7), we see a distribution of sizes tailing off to large (>kpc) galaxies. The goal is to see if this is true at z~8.

Steven Bos
Dr. Frans Snik/ Prof. Christoph Keller  

Achromatic liquid crystal polarization modulation

Elger Vlieg P&A Prof. John van Noort Prof. Christoph Keller Implementation of acoustic tweezers (in magnetic tweezers setup) for in vitro force spectroscopy experiments.
Olivier Burggraaff

Dr. Frans Snik/ Prof. Christoph Keller


Quantitative spectroscopy with the iSPEX smartphone add-on.

The iSPEX add-on for smartphones has been developed to enable citizen science measurements of atmospheric aerosol properties through polarimetric observations of the blue sky. The unique implementation of the iSPEX optics makes that it is also a spectrograph. It will be your job to calibrate the iSPEX add-on and the smartphone to enable quantitative spectroscopy, much in the same way as the calibration of major spectroscopic instruments at large telescopes. The end goal is to show the applicabilty of spectroscopic iSPEX measurements for a multitude of interesting applications; e.g. color measurements of lamps, paint, water, etc.

Sander Schouws
Dr. Tim Shimwell / Prof. Huub Röttgering  

Low frequency radio observations of a galaxy cluster.

Radio emission from the intracluster medium was recently discovered in the galaxy cluster Abell 1550. This type of emission very rare and is thought to be caused by shocks and turbulence accelerating intracluster electrons to produce substantial synchrotron emission. In this project we will conduct the first study of the very low frequency radio emission from this cluster. Our aims will be to a) learn the aspects of radio astronomy that are required for challenging low frequency radio observations; b) refine the procedure used to produce high quality radio images; c) interpret the observed cluster radio emission.

Louis Cheung

Hiddo Algera

Dr. Michiel Hogerheijde  

ALMA observations of HL Tau

Newly formed stars are surrounded by disks of gas and dust. Inside these disks, planetyary systems are thought to form. The Atacama Large Millimeter / submillimeter Array (ALMA) is ideally suited to study the cold gas and dust for signatures of planet formation. In this project the students will calibrate an ALMA data set of one or more protoplanetary disks, 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.

Isabel van Vledder

Dieuwertje van der Vlugt

Dr. Benne Holwerda/ Dr. Matthew Kenworthy  

Measuring the Milky Way in Brown Dwarfs

Deep near-infrared surveys with the Hubble Space Telescope have found small brown dwarf stars far out into the outer reaches of our Milky Way. The project is to model the disk of the Milky Way using the MCMC fit program to determine the size and thickness of the brown dwarf disk of the Milky Way.

Mel Voet
Prof. Koen Kuijken  

Searching for minor Solar System bodies in KiDS

Study of the KiDS data set to characterize known and discover new asteroids and comets, and improve their orbital parameters.

Jos van der Spek
Prof. Ignas Snellen   Search for NEOs in MASCARA data
Paul Couzy M&A Dr. Elena Rossi Prof. Vivi Rottschafer

Accreting matter around black holes

Solve differential equations numerical and add drag force mimicking the presence of an ambient gas between BH and ring of matter around BH. Look at effects on the accretion rate.

Ewout Beukers
Prof. jan Aarts   physics project (superconductivity)
Queeny van der Spek
Prof. Tjerk Oosterkamp/Dr. Lucia Bossoni  

Magnetic Nanoparticles

A more realistic view of the feasibility of using magnetic particles for enhancing MRFM and studying Ferritin with MRFM.

Bert Visscher
Prof. Martin van Hecke,/Dr. Scott Waitukaitis   Water Origami
Jurien Huisman
Prof. John van Noort   Development of LNA toeholds for specific DNA pull down experiments
Prof. Frank Israel  

The variability of Centaurus A at radio frequencies

The aim of this project is to investigate the known variability of the supermassive black hole nucleus of the nearest radio galaxy Centaurus A at high radio frequencies (20 - 400 GHz), and its effect on the spectral index - an important clue to its nature. Practical work involves reduction and analysis of five sets of short observations with the Australia Telescope (ATCA) on five frequencies (20-100 GHz), using both the AIPS and MIRIAD reduction packages.

Prof. Walter Jaffe  

Design a dispersion corrector for a MATISSE Fringe Tracker

To remove atmospheric fluctuations from interferometric observations we to correct the chromatic effects in refraction.. The project will study the chromatic effects of different atmospheric components, and propose hardware solutions to remove them.

Prof. Ignas Snellen   Probing the varying sky with the Multi-site All-Sky CAmeRA MASCARA
Dr. Jarle Brinchmann  

The sizes and abundance of ultra-faint galaxies in MUSE datacubes

The MUSE instrument on the VLT has just entered operations and will be used in part to observe ultra-faint galaxies out to z~6.5. In particular the 30 hour exposure we have on the Hubble Deep Field South gives us an unprecedented view of the very faint and distant galaxy population and it allows us to see extended emission around galaxies - this is light coming from emission lines that extend further than the stellar light of the galaxies. The main goal of this project is to determine what fraction of galaxies show this extended emission and how this correlates with basic properties of the galaxies. Are these halos of extended emission associated with starburst galaxies, or maybe post-starburst galaxies? To do this it is necessary to find the objects so to test and possibly develop/improve methods to find objects in the MUSE data cubes and thereafter to measure the extent and estimate the basic physical parameters of the galaxies (if not available from other sources).

Dr. Henk Hoekstra  

Search for strong lensing by the BCG in low redshift galaxy clusters.

Strong gravitational lensing provides a direct measurement of the enclosed mass on the scales probed by the lensed images. For low redshift clusters these images probe small physical scales. As a consequence the brightest cluster galaxy (BCG) complicates finding the strong lensing cases, but with high-quality data the light from the BCG can be subtracted. We have collected data for a large sample of nearby clusters and the aim of this BO project is to model the BCG light and find strong lensing cases. These can then be used to select the best candidates for follow-up and detailed modelling.

Dr. Massimo Viola / Prof. Koen Kuijken  

Discovering galaxy groups and clusters in the KiDS data

In this project the student will look for galaxy groups and clusters using mainly optical images from the Kilo Degree Survey. The primary goals will be to confirm small groups candidates already identified using spectra from the GAMA survey and to find more systems at higher redshifts. Some preliminary cluster catalogues will be available at the time the project will start. If time will allow it, the student will also be to measure the luminosity and the stellar mass content of the groups/clusters and their masses using weak gravitational lensing.

Martin Børstad Eriksen / Prof. Koen Kuijken  

Photometric redshifts

The accelerated expansion of the universe is an open question, which potentially can be caused by dark energy, modified gravity or another form of unknown physics. To understand the expansion observers perform large galaxy surveys, probing the properties of dark energy and dark matter through galaxy clustering, redshift space distortions (RSD) and weak lensing (WL). The KiDS galaxy survey (Pi K. Kuijken, Leiden) is an ongoing lensing surveys with a large contribution from the Leiden cosmology group. To extract cosmological information, one need to determine the galaxy distance. Because the number of galaxies required for a lensing survey, spectroscopy is infeasible. Instead lensing surveys rely on measuring the galaxies in multiple broad band and estimate low resolution distances using algorithmic techniques (photo-z). The student is expected to work on photo-z, focusing on improving the performance and understanding of the distance determination on KiDS data.

Dr. Jorryt Matthee/ Prof. Huub Rottgering  

Searching for extended Lya haloes in KiDS

In this project, the student will search for Lyman alpha haloes at redshifts z~2-3 using broadband ugr data from the KiDS survey. Lyman alpha (Lya) haloes are among the largest individual structures in the Universe, the largest being ~100 kpc, and are also very luminous (~10^44 erg/s). The nature of these haloes is enigmatic and it is still uncertain what is the powering source, which could be either AGN, high star formation or even large gas inflows. Lya haloes are detected around high redshift radio galaxies, but are also blindly found using narrow-band surveys. A major limitation is the current sample size, which originates from the limited probed volume by narrow-band surveys. Because the Lya haloes are so bright, they are even visible as blue, extended sources in broadband data. By using the optimal combination of survey depth and area provided by KiDS, this project will be a major step forward in terms of probed volume and can lead to discoveries of new Lya haloes.

Dr. Bernhard Brandl/ Dr. Lars Venema  

Suitability of the material KBr as a instrument/cryostat window

Cryostats for astronomical instruments need windows to allow the signal to enter the instrument optics inside the vacuum vessel. However, the transmission of most materials is limited to a relatively small wavelength range. The instrument METIS for the E-ELT requires a window which transmits from 1 - 22 microns. One material with the proper transmission peroperties is KBr, which is, however, very hygroscopic. Manufacturers have claimed that the crystal can be protected against dissolution by coating layers but this has never been demonstrated. This project requires a test setup for a series of measurements of the transmission, reflection, and homogenity of the KBr and possible changes with time (humidity). The measurements have to be done within the NOVA O/IR group in Dwingeloo and should be done by a single student (not a team of two).

Dr. Bernhard Brandl/ Ramon Navarro  

The measured efficiency of the X-Shooter instrument on the VLT.

There appears to be a mismatch between the measured efficiency of the X-Shooter instrument on the VLT and the sum of the efficiencies of all of its optical components as given by the manufacturers. This discrepancy could be due to non optimal performance of the coatings at cryogenic temperature, but also due to polarization effects. A setup to measure polarisation (could be a simple polarizer or wire grid) has to be developed to derive the transmission properties of witness samples at low temperatureto measure. The measurements have to be done within the NOVA O/IR group in Dwingeloo and should be done by a single student (not a team of two).

*P = physics, A = Astronomy, M = mathematics

Last modification on Monday, 15-Jun-2015 9:39 by Bernhard Brandl