PhD Projects 2018
The PhD application process is closed.
The interviews for the positions were scheduled for 15 & 16 February in Amsterdam.
We will be offering multiple positions across all areas of research carried out at the Anton Pannekoek Institute. Topics and project descriptions (where available) are given below. New projects may be added over the next few months, so please check back here in case of any updates.
If you are interested in working in a particular research area (or project, if listed), please indicate this in your cover letter, but note also that we will consider applicants for a variety of the positions being offered, so it is not obligatory to list specific projects. Also please note: all application materials should be submitted via the general application process. API staff may be contacted with questions about projects, but please do not email unsolicited application materials to API staff.
Computational Stellar Astrophysics and Gravitational Wave Progenitors
Supervisor: Selma de Mink
The detection of gravitational waves has marked the opening of a completely new field of gravitational wave astrophysics. As a PhD student in the BinCosmos group led by Dr. de Mink you will investigate the origin of these events. Why were the black holes detected by LIGO so heavy? What binary star systems end their lives as double neutron stars? What are all these detections teaching us about the physical processes that govern the lives and deaths of the most massive stars? These are the questions you will investigate, primarily using state-of-the-art computer simulations. This project is mainly theoretical/computational, but you will be collaborating directly with experts in observations of stellar populations and gravitational wave detections. More information can be found at www.selmademink.com.
Massive stars in low-metallicity environments
Supervisors: Alex de Koter and Lex Kaper
The detection of gravitational waves has opened a new decisive phase for the study of massive stars, providing the first observational evidence for the existence and merging of binary black hole systems. With inferred masses of tens of solar mass, the masses of the black holes prior to merging are surprisingly high in comparison to the black holes known in our galaxy so far. The origin of these massive black holes points to very massive stars (in binary systems) that feature only weak stellar winds, such that relatively little mass is lost during the life of the star. Weak winds strongly point to the events having taken place in low-metallicity environments, as stellar outflows are predicted and found to be weaker for lower metallicity stars. The project focusses on the study of massive stars in extreme metal-poor Local Group dwarf galaxies, featuring metal contents down to an unprecedented 1/15th of the solar metallicity. We will establish their properties and constrain the dependence of mass-loss on metallicity in this uncharted territory. This dependence is found to be the main uncertainty in predictions of the merging rate of binary black holes.
The Netherlands Research School for Astronomy (http://nova-astronomy.nl/), a collaboration of world-leading Dutch astronomy institutes, has been funded for a new 5-year phase (NOVA5). A key goal of NOVA is to develop cutting-edge research via collaborative research networks, which link together researchers at all the Dutch research institutes. The API is a leading institute in two of the three NOVA research networks which focus respectively on stars and planets, and high-energy astrophysics. The final detailed research programme for NOVA5 is still being worked out, but a substantial number of NOVA-funded PhD positions will be available in the following general subject areas. More project information will be added to the list of abstracts below as the details are finalised, although in some cases this may be after the application deadline has passed (in which case, you may still state your interest in the general PhD topic given in the list below).
Network 2 ("Origins": stars and planets and their formation and evolution):
1 PhD position on protoplanetary disks (supervisor: Dominik)
1 PhD position on observations of exoplanet atmospheres (supervisor: Birkby)
1 PhD position on simulations of exoplanet atmospheres (supervisor: Desert & Min)
Network 3 (High energy astrophysics):
1-2 PhD positions on detection/characterisation of multi-messenger transients (supervisors TBC from Wijnands, Wijers, Rowlinson, van Leeuwen)
1-2 PhD positions on X-ray studies of black holes using advanced analysis methods (supervisors TBC from Costantini (SRON), Uttley, Watts)
NOVA projects: detailed descriptions (as they become available)
Modeling and observing exoplanet atmospheres in the JWST era
Supervisors: Jean-Michel Désert (API) and Michiel Min (SRON)
The aim of the proposed PhD project is to leverage exoplanet detections, and innovative theoretical frameworks to model exoplanet atmospheres, in order to better understand exoplanetary physics. This project will focus on developing atmospheric modeling tools, in particular by including clouds formation and properties, and to test such models with observations. The model will be original since it will have the capability to explore large parameter spaces in terms of atmospheric structure, chemistry, photo-chemistry and cloud microphysics, and will do so in a fast manner. Given that observations and simulations of exoplanet atmospheres are intrinsically connected, this model will be particularly useful to harvest JWST observations.
Variability of Exoplanet Atmospheres
Supervisor: Jayne Birkby
We seek a highly motivated and ambitious student who is interested in working at the cutting-edge of direct imaging techniques, instrumentation and simulations to establish our best methods for exploring the variability of exoplanet atmospheres. Changes in an exoplanet’s brightness over time can reveal its rotation and how long a day lasts on the planet, the presence of giant storms like those seen in the Solar system planets, and potentially even the passage of its moons as they cross its disk along our line-of-sight. These properties link to the formation and evolution of the planet, and will help us to understand the incredible diversity of the exoplanet population.
The role of PAH & dust aggregation in protoplanetary disk physics
Supervisor: Carsten Dominik
The vertical structure of protoplanetary disks plays a key role in a number of physical processes, such as dust aggregation, that are crucial to understanding planet formation and the organic inventory of regions of planet formation. Resolved imaging of protoplanetary disks at multiple wavelengths allows us to image disk midplane and surface both in dust grain tracers and polycyclic aromatic hydrocarbons (PAHs), showing that in some disks, PAHs and small grains are abundant and present in the disk surface, while not visible in others, with consequences for disk structure, chemistry and dynamics. Observations with ALMA, SPHERE and soon with JWST are providing crucial new insights, so it is time to develop new models for dust aggregation in dusty protoplanetary disks and study the astrophysical consequences. The successful candidate will develop such models, apply them to protoplanetary disks under a variety of conditions and use them to help interpret the wealth of new data becoming available.
Within network 3, the exact project topics are still being decided, but they will fall within two themes listed below. Specific project descriptions follow underneath the theme descriptions, as and when the projects have been defined.
PhD positions in the NOVA NW3 MMT theme
The Netherlands Research School for Astronomy (NOVA) is creating a new national research group whose aim is to promote multi-messenger transient astronomy in the Netherlands. The focus of this newly formed group will be on highly variable and transient systems and will consist out of several postdocs and PhD students under the guidance of several scientific staff members associated with the NOVA institutes. Most investigations will be performed using electromagnetic radiation, but cosmic ray and gravitational wave studies will be performed as well. This year up to two PhD positions based at the API are available within this newly formed NOVA research group. It is expected that the PhDs will spend up to 20% of their time facilitating multi-messenger astronomy for the Dutch astronomy community.
PhD positions in the NOVA NW3 Accretion theme
The Netherlands Research School for Astronomy (NOVA) is creating a new national research group (a ‘virtual institute’) whose aim is to exploit a combination of new observational techniques and GRMHD simulations to explore the innermost regions of accreting compact objects and the powerful feedback (in the form of winds and jets) which these systems produce). The group will consist out of several postdocs and PhD students under the guidance of several scientific staff members associated with the NOVA institutes. This year up to two PhD positions based at the API are available within this newly formed NOVA research group. These positions will likely focus on modelling of novel X-ray ‘spectral-timing’ data analysis methods, to 1. understand the innermost regions of accreting black holes and compare with expectations based on GRMHD simulations, and 2. constrain the properties of powerful AGN winds via their variability signatures.
A radio and multi-messenger quest to establish the nature of Fast Radio Bursts (MMT theme)
Supervisor: Joeri van Leeuwen
The fast, millisecond transients that appear all over the radio sky point to extreme energies, magnetic field strengths, gravitational fields, and densities. The physical conditions on display in these sources must far exceed any terrestrial laboratory. Some of these short-lived radio bursts can be traced to one-off pulses from intermittent neutron stars, but a few dozen of other fast radio bursts (FRBs) clearly originate far outside our Galaxy, and defy any explanation. In our ALERT survey with the renewed Westerbork Radio Telescope (www.alert.eu), we will explore a 10x larger volume of the Universe for FRBs than before.
In this PhD project, you will be using real-time FRB detections to study these bursts at other wavelengths, also potentially correlating with gravitational wave sources. Using such a cross-messenger data exploration will help us better understand the extreme conditions under which these enigmatic, bright bursts emerge.
Mapping the innermost environment of accreting black holes with spectral-timing and simulations (Accretion theme)
Supervisor: Phil Uttley
Advanced X-ray spectral-timing methods are revealing the behaviour of the innermost regions of accretion flows on to stellar mass black holes, including noise-like variability produced in a turbulent accretion disk and an inner precessing geometry, likely driven by general relativistic frame dragging, which produces quasi-periodic oscillations. None of these behaviours can be explained with classical accretion theory and ‘standard’ thin accretion disks, so we must turn to the latest GRMHD simulations to guide our understanding. This project combines new observational data, simulations and theory to explore the spectral-timing signatures predicted by the simulations and confront them with the latest results from spectral-timing data obtained by XMM-Newton and NICER, to infer the physical parameters of the emitting regions and the GR effects contained within.
Timing and spectroscopy of outflows from supermassive black holes
Supervisor: Elisa Costantini (SRON), co-supervised at API by Phil Uttley
Active Galactic Nuclei (AGN) are powered by supermassive black holes. The self-sustenance of such galaxies is regulated by accretion on to the black hole and by ejection of matter, either in the form of relativistic jets or gas outflows, rich in metals. The impact of such matter in the AGN surrounding environments, the so-called feedback, has been invoked by theoretical models of black hole evolution and their impact on galaxy formation across cosmic time. However the real contribution of AGN to feedback has not been quantified yet. This PhD project is focused on the study of the characteristics of the outflowing gas and its impact on the environment outside the black hole system, using a novel combination of high-resolution X-ray spectroscopy and timing. We will use the data from the archives of the X-ray observatories XMM-Newton and Chandra as well as from the Hubble Space Telescope and new observations as they become available. This approach allows us to study the multi-phase AGN outflows from the far-UV to high X-ray energies.