Universiteit LeidenZegel Universiteit Leiden

The Leiden/ESA Astrophysics Program for Summer Students (LEAPS) 2024

Selection for LEAPS 2024 is over. Rejection emails have been sent.


LEAPS is an opportunity for students with an interest in astronomy and astrophysics to perform a 10 week summer research project in collaboration with a research scientist from Leiden Observatory or ESA/ESTEC. The program is open to all students not currently engaged in a Ph.D. program (please see the full eligibility criteria)

We would like to use LEAPS as an opportunity to increase the diversity of researchers in Astronomy as we understand that successful science is supported by this.

Students are selected for the program based on their academic achievements and research potential. Each applicant has the opportunity to choose up to two projects of interest, and they are selected by project advisors based on what they indicate their scientific interests and experience to be. Research at Leiden Observatory and ESA/ESTEC takes place on a diverse array of topics (see below for LEAPS 2024 projects), and student projects will likely consist of anything from the analysis of data from world-class telescopes, to large computer simulations, to hands-on work in the astrochemistry laboratories.

Leiden Observatory

Leiden Observatory (located in the Huygens and Oort buildings, Niels Bohrweg 2, 2333CA, Leiden) is a world-class institute for research in astronomy and astrophysics based in the Netherlands, approximately 35km from Amsterdam. The atmosphere at the observatory is dynamic, with approximately 100 faculty/research scientists and 70 graduate students engaged in astrophysical research on a wide range of topics. Major fields of interest include extrasolar planets, star formation, cosmology, galaxy formation, instrumentation, and astrochemistry. Multiple research projects will likely be available within these fields.

European Space Research and Technology Centre (ESTEC/ESA)

ESTEC is ESA’s largest establishment, and its technical and organisational hub. It is based at Keplerlaan 1, 2201AZ, Noordwijk, around 10 km from Leiden Central Station. ESA develops and manages many types of space missions, from exploration, telecommunications, to earth and space science. The Research and Scientific Support Department at ESTEC consists of approximately 40 staff scientists, with research interests ranging from the geology of planets in our solar system, to plasma physics in the magnetosphere of the Earth, space weather, to observational astronomy with ESA's space missions such as Planck, Herschel, GAIA and EUCLID.

Travel, Housing, and Stipend

Students accepted into the LEAPS program will be provided with travel costs to/from Leiden. We will also provide housing accommodations near the observatory, a modest stipend to help with living costs during the internship (approximately 197 EUR/week), and health insurance. Leiden is a small, picturesque university town located between the major cities of Amsterdam and The Hague. Summer is a beautiful time of year to be in Leiden, and we encourage LEAPS students to socialize and use their free time to enjoy the numerous summertime activities available in Holland. English is widely spoken throughout the Netherlands and international students should find it easy to live in the Leiden area. We are planning several field trips for LEAPS students including visits to the ESTEC complex where many ESA satellites are being built, and potentially to the LOFAR radio array, the world's largest low-frequency radio telescope.

How to Apply

Selection for LEAPS 2024 is over. Rejection emails have been sent.

Students should be sufficiently proficient in English to perform a research project. Please see FAQ for the full eligibility criteria.

For ESA projects (denoted by 'ESA' in the title), in case of equivalent qualifications, preference will be given to nationals of or applicants currently residing in one of the following ESA Member States, Associate Member States, or (European) Cooperating States: Austria, Belgium, Bulgaria, Canada, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, The Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, and the United Kingdom.

Applications for the LEAPS program require that you select two projects from the Research Project list that you are most interested in working on. The Research Project list for the LEAPS 2024 program is available below. You will also be required to submit the following documents (in PDF format):

  • Maximum one-page (A4, 12pt font, margins: top and bottom of 1 inch, and left and right of 1.25 inches) cover letter describing your motivation and research interests
  • Academic transcript or grades (with the grading scale)
  • Maximum two-page (A4, 12pt font, margins: top and bottom of 1 inch, and left and right of 1.25 inches) Curriculum Vitae
  • One letter of reference (to be directly submitted by your referee)

Please note: not following the above requirements will result in a rejection of your application!

Once you have submitted your application, or saved a draft version, an email will be sent to your reference letter writer requesting the letter. Students will be evaluated for participation in the program on the basis of their research potential and match to available projects in their area(s) of interest.

If you have any questions about the application process or the program, please consult the FAQ page. If you have any questions that are not answered on the FAQ page, please .

Research Projects and Supervisors

There are 9 projects on offer for LEAPS 2024.

Project list for LEAPS 2024:

Exploring the density-velocity interplay in circumnuclear discs of AGN-dominated galaxies

Supervisor(s): and

Keywords: hydrodynamic simulations, AGN feedback, molecular gas dynamics, circumnuclear disc, AGN-dominated galaxies

More info

This proposed research project aims to shed light on the density-velocity relation of circumnuclear discs of galaxies using HDGAS hydrodynamic simulations. By investigating the interplay between density and velocity, as influenced by various feedback parameters (i.e. wind/jet velocity and mass loading factor), we can gain valuable insights into the formation, evolution, and dynamics of galactic discs. While hydrodynamic simulations are essential for studying the underlying physical processes, comparing their results with observational data helps validate the simulations and provides a real-world context. There are some key observational results related to the density-velocity relation in the presence of AGN we can compare with HDGAS simulation: (a) Ionized Gas Dynamics: Observations have revealed that AGN activity can significantly influence the density-velocity relation of ionized gas in galaxies. AGN-driven outflows or jets can create regions of low-density, high-velocity gas, resulting in disturbed velocity fields and asymmetric density distributions. These disruptions can be observed as kinematic asymmetries, such as double-peaked or asymmetric line profiles. (b) Molecular Gas Kinematics: Studies of molecular gas, commonly traced by carbon monoxide (CO) emission, have provided insights into the density-velocity relation within AGN-hosting galaxies. Observations have shown that AGN can induce perturbations in molecular gas kinematics, leading to non-circular motions, velocity dispersions, and warps in the velocity field. These effects can be observed through CO line profiles and position-velocity diagrams.

The magnetic environment of the M dwarf AD Leonis

Supervisor(s): and

Keywords: stellar magnetic fields, stellar winds, spectropolarimetry, magnetohydrodynamical simulations

More info

AD Leonis is a bright M dwarf whose magnetic properties have been investigated extensively via spectropolarimetry. The latter is an observational technique that collects spectra in both unpolarised and polarised light, and is sensitive to the effects of magnetic fields on atoms present on the stellar surface. From a time series of circularly polarised spectra, we can reconstruct the shape of the large-scale magnetic field with a technique called Zeeman-Doppler imaging (ZDI), which can then be used as a boundary condition to simulate the environment and space weather around the star. Previous work revealed a strong large-scale magnetic field (1 kGauss) with a dipolar configuration that is symmetric relative to the stellar rotation axis. Recently, the magnetic field has weakened and tilted from the pole toward the equator, showing signs of an imminent polarity reversal and overall a solar-like cycle. The student will work on new near-infrared spectropolarimetric data to i) characterise the magnetic field of AD Leonis, ii) reconstruct a map of the large-scale magnetic field, and iii) simulate the stellar wind and environment surrounding the star. The project has both an observational/data analysis component, as well as a theoretical/simulation component. The output will feed back on the evolution of the large-scale magnetic field of AD Leonis and its environment, providing insights for both dynamo theories and star-planet interaction modelling.

(ESA) Mapping stellar remnants in the Magellanic clouds: a unique test of extragalactic transient progenitor models

Supervisor(s): and and

Keywords: extragalactic transients, neutron stars, black holes, X-ray binaries, magnetars, gamma-ray bursts, fast radio bursts, supernovae

More info

The locations of extragalactic transients, such as supernovae, tell us much about their origins. For example, long-duration gamma-ray bursts (GRBs) are strongly biassed towards the brightest regions of their star-forming host galaxies, implying an origin from the core-collapse of the shortest-lived, most luminous, and most massive stars. The distribution of transients on and around their host galaxies can be quantified in a variety of ways. Typical measurements include the offset (the projected distance from the centre of the galaxy to the transient), and the 'fraction of light' statistic, which quantifies how biassed transients are towards (or away) from bright areas in the galaxy. Many transients are linked with stellar remnants, such as neutron stars. For example, a leading hypothesis for fast radio bursts is that they are produced by magnetars (strongly magnetised neutron stars), and some long GRB models require binary star progenitor systems, which may be similar to X-ray binaries (XRBs). A way to test these ideas is to compare the spatial distribution of stellar remnants in the Milky Way - such as magnetars and XRBs - with the distribution of extragalactic transients in their host galaxies. However, since we are embedded in the Milky Way disc, creating an external image of our Galaxy - a necessary step to perform a comparison with transient locations in other galaxies - is challenging. A potential solution lies in the Magellanic clouds. These satellite galaxies are unique because they are external to the Milky Way, and therefore viewable in their entirety, but also close enough that large populations of stellar remnants within them can be detected. Previous works have studied the distribution of massive stars in the Magellanic clouds, comparing this with the locations of supernovae in distant galaxies. However, a comparison of the distribution of stellar remnants in the Magellanic clouds, versus the environments of extragalactic transients, has yet to be carried out. This is the aim of the project, which will make particular use of Gaia data for mapping the clouds. The project will therefore provide a unique test of progenitor models for various extragalactic transients. Some experience with a programming language (e.g. python) is desirable.

Modelling the delivery of ammonia to the inner regions of protoplanetary disks

Supervisor(s): and

Keywords: protoplanetary disks, dust transport, astrochemistry, planet formation

More info

The composition of planets is determined by that of the protoplanetary disks in which they form. The chemical composition of these disks is seen to be very diverse and is expected to evolve over time due to the radial motion of its constituent gas and dust components. In particular, dust grains undergo rapid inwards radial drift. As they do so they experience warmer ambient temperatures which can result in the sublimation of ice species from the grains. The temperature - and hence location - at which this desorption occurs can depend strongly on the interactions between different molecular ice species which can be parametrized through the “binding energy”. The goal of this project is to undertake simulations to explore the impact of different binding energies pertaining to pure ices, mixed (polar) ices or semi-refractory ammonium salts on the delivery of NH3 (which has so far eluded detection in JWST observations of protoplanetary disks) to the inner disk. For example, can NH3 become locked in solids and hidden from observations in the mid-IR? When in a disk's evolution are we most likely to see ammonia in the inner disk? The main simulations will be conducted using a python code following the evolution of disk gas & dust in 1D. The outputs could then be passed to a thermochemical code or slab models to make predictions for detectability of NH3 in mid-IR spectra or coupled with simple prescriptions for planet formation to understand how planetary nitrogen abundances would be affected.

Gravitational lensing analysis of dark matter haloes of dwarf galaxies using wide-field surveys

Supervisor(s): and

Keywords: galaxy-galaxy lensing, dwarf galaxies, halo-model, Kilo-Degree Survey, Hyper-Suprime Cam Survey

More info

The mechanism of galaxy evolution is tightly related to the growth of dark matter haloes. To investigate the invisible dark matter haloes that are hosting galaxies, we can use gravitational lensing analysis of wide-field surveys (e.g. Kilo-Degree Survey, Hyper-Suprime Cam Survey). As the surveys provide sharp galaxy images, it is possible to analyse shape distortion of distant background galaxies caused by the gravitational potential of target galaxies, which we call “gravitational lensing analysis.” By stacking the shape distortion signals from millions of galaxies, the profile of dark matter haloes of the target galaxies can be precisely measured. Among interesting galaxies, studies of dwarf galaxies provide ample knowledge about small scale properties of dark matter and galaxy-halo connection. Dwarf galaxies are tiny. Therefore, obtaining their gravitational lensing signal is a challenging task. We will apply a machine learning algorithm to select the dwarf galaxies. Eventually, we aim to constrain halo-model (profile) parameters from the measured gravitational lensing signal of dwarf galaxies.

(ESA) Multi-spectral characterisation of formation process of dynamic events in the solar atmosphere

Supervisor(s): and and

Keywords: solar physics, multispectral solar observations, chromospheric and coronal heating, interferometry, machine learning

More info

Understanding the physical processes taking place in the Sun and being able to predict violent events such as solar flares is imperative in order to sustain safe advancements in space exploration. The Solar Orbiter, developed by ESA, offers large advancements in measurements of the solar atmosphere. The spacecraft consists of several remote-sensing instruments operating at different wavelength regimes, each specialized to measure specific properties of the solar atmosphere. In addition, the close orbit around the Sun and the coming high latitude orbit of the Solar Orbiter enabling the study of the solar poles, facilitates novel scientific analysis. On the other hand, observations in the radio regime provide very powerful diagnostics to study the solar atmosphere as they provide more direct temperature measurements of the probed plasma. The Earth-based observatory Atacama Large Millimeter/sub-millimeter Array (ALMA), consisting of about 66 antennas, provides ground-breaking measurements in the radio regime in terms of high sensitivity and angular resolution, necessary to resolve small-scale features. This project would involve identifying small-scale features in the observations of the solar atmosphere and study the correlation between signatures at millimeter wavelengths to intensity measurements at other wavelength regimes and magnetic field measurements. The addition of the plasma temperature measurements with ALMA is important in understanding the formation processes of dynamic events detected in the Solar Orbiter data, that could potentially be small solar flares. The project could include machine learning techniques for the statistical analysis and feature detection algorithms. One of the main aims would be to efficiently distinguish potential different formation processes of small-scale brightening events, which would lead to meaningful scientific publication.

Estimating halo merging timescales through emulation-based models

Supervisor(s): and

Keywords: dynamics, haloes, machine learning, N-body simulations

More info

Cosmic structure formation proceeds in a bottom-up manner, whereby small structures form first and then coalesce together to form more massive ones. This process is largely driven by dynamical friction, which is the result of a lagging wake of mass behind the least massive object, inducing a dragging force that removes its orbital energy and angular momentum. The efficiency of this process, and hence the timescale on which mergers occur, depends on the orbital and structural properties of the objects that are involved. Previous models used to predict merging timescales are based on analytical arguments or formulas calibrated to cosmological simulations, which have resulted in varying degrees of success. In this project, we will leverage targeted simulations that sample a broad range of possible parameter combinations – e.g. orbital energy, eccentricity, relative masses – together with machine learning techniques to explore how well previous models do, what role does numerical resolution play, and whether emulation-based models fare better than traditional approaches. Programming skills are recommended.

Decoding chemistry within extragalactic star-forming regions

Supervisor(s): and

Keywords: astrochemistry, chemical modeling, star formation, interstellar medium, molecules

More info

Star-forming regions exhibit complex physical and chemical properties. Even a single region displays extremely different gas conditions, such as density and temperature, leading to local chemical variations. While it is possible to distinguish between the different environments within star-forming regions in our Galaxy, it may not always be feasible for external galaxies. In such cases, chemical modeling plays a crucial role in accurately constraining the origin of the observed emission. The goal of the project is to build a set of chemical templates of the most common environments within star-forming regions, like shocks and protostellar cores. The student will concentrate on species that are efficiently released through prevalent mechanisms in these environments, such as sputtering and heating. In particular, the focus will be on species, e.g., CH3OH, which can be equally abundant in shocks and protostellar cores. Using the in-house gas-grain chemical code, the student will model expected chemical properties and identify which physical conditions are critical for the chemical enhancement of the selected species. The model outputs will be validated against observational data from the literature.

(ESA) Uncovering solar flares through statistical analysis of over a decade of JAXA/ESA Hinode observations

Supervisor(s): and and

Keywords: solar flares, statistical analysis, spectroscopy, plasma physics, solar missions, solar dynamics

More info

Solar flares are the most energetic events in our solar system, capable of impacting technology and astronauts in space. As we enter the era of Solar Orbiter and new solar missions, understanding the processes behind flares takes on renewed significance. This project leverages over a decade of solar observations from the ESA/JAXA-led Hinode spacecraft to uncover and elucidate flare acceleration and heating mechanisms. Specifically, the student will compile a database correlating plasma properties with solar images, seeking relationships between flaring magnetic structures and energy release. Depending on the progress in the first part of the project, potential extensions include deriving key plasma parameters (densities, temperatures) over flare evolution from EIS spectra; alongside incorporating data from spacecraft observing different layers of the solar atmosphere, including the recently launched Solar Orbiter. The database created through this project will enable a series of novel statistical studies to fully understand solar flares and the spectroscopic signatures across events. As we enter an era of new missions like Solar Orbiter, this project provides an essential dataset to further the study of flare heating mechanisms and space weather origins. This project will be performed in collaboration with ESA scientists who are involved in a range of state-of-the-art solar missions, including the Solar Orbiter and Hinode emission.

End of list