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The Leiden/ESA Astrophysics Program for Summer Students (LEAPS) 2022

Applications for LEAPS 2022 will be open in late January 2022 and project details will be listed by then. We plan to run an in person summer school in 2022 but this may change depending on how the COVID-19 pandemic continunes to develop.

Overview


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. The program is open to all students not currently engaged in a Ph.D. program, although most past participants have been senior-undergraduate or masters' students who are enthusiastic about research in astrophysics.

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 takes place on a diverse array of topics (see below for LEAPS 2021 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.

The LEAPS 2021 program will run from mid June for 10 weeks (exact dates to be confirmed) although start dates for specific projects may vary.


Leiden Observatory


Leiden Observatory (located in the Huygens and Oort buildings, Niels Bohrweg 2, 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. 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, as well as a modest stipend to help with living costs during the internship. 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


The application process for LEAPS 2021 is now complete. We encourage interested and eligible candidates to apply next year.


The program is open to all international students provided they are not currently enrolled in a Ph.D. program. For ESA projects (Type of project: ESA), in case of equivalent qualifications, preference will be given to nationals of one of the following ESA member states and cooperating states: Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland, the United Kingdom plus Canada, Latvia, and Slovenia. The working language of the observatory is English, and students should be sufficiently proficient in English to perform a research project.

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


Research Projects, Categories and Supervisors


For reference listed below are the proposed research projects from LEAPS 2021.

Please note that for ESA projects (Type of project: ESA), in case of equivalent qualifications preference will be given to nationals of the following ESA member states: Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland, the United Kingdom plus Canada, Latvia, and Slovenia.



Project list for LEAPS 2021 (Last updated January 21):

The radio properties of high-redshift emission line galaxies

Supervisor:

Keywords: Observational, Galaxies, star-formation, high redshift

More info
The most intense period of star formation in the Universe is known to have occurred ~10 Gyr ago (redshift z~2). To understand the build-up of massive galaxies such as the Milky Way, it is therefore crucial to obtain accurate measurements of the star-formation rates of high-redshift galaxies. Among the best tracers of star-formation activity in the local Universe are the Balmer emission lines, which are produced in massive star-forming regions in the galaxy. At higher redshifts, these emission lines are often unattainable - at least until the launch of JWST - or strongly affected by dust attenuation. Radio emission provides a tracer of star-formation activity that is largely unaffected by obscuration from dust, and therefore has been widely used to measure galaxy star-formation rates throughout cosmic time. This technique, however, requires a thorough understanding of the connection between the radio emission and star-formation activity. In this project, the student will combine rest-frame optical and radio tracers of star formation, and compare the emission line and radio fluxes for a large sample of high-redshift galaxies. The student will subsequently 1) calibrate the relation between the radio emission and star-formation rate, and 2) determine empirical corrections for the effects of dust at rest-frame optical wavelengths. The student will use Python to analyze and visualize the data, and will further learn how to deal with large volumes of multi-wavelength data (near-infrared & radio).

Beyond the face value of HCN emission in the nearest major merger

Supervisor:

Keywords: Galaxy Mergers, Dense Gas, Molecular Emission, Excitation, Data Analysis

More info
The Antennae is the nearest (22 Mpc) merger between two, gas-rich spiral galaxies. This system is rich in dense gas and is home to an ongoing, vigorous starburst in its famous Overlap region. The extreme conditions in the Antennae, along with its proximity, make it an important testing ground for our understanding of star formation. For this LEAPS project, we will study the dense, molecular gas that stars form from, and we will assess how efficiently stars are born from this material in such an extreme system. Previous studies have used HCN emission to study the dense gas across the Antennae and have found that stars form less efficiently in the two nuclei of this system. The nuclei also appear to have the highest fractions of dense gas, which poses a challenge to current theoretical models of star formation. The results of these studies require that HCN is tracing dense, star-forming gas in a consistent manner across all regions of the Antennae. We will use observational data of multiple HCN and HCO+ molecular transitions to assess if this is the case. These data will be combined with the radio continuum (as a star formation rate tracer) to confirm if there are true variations in the star formation efficiency of dense gas across this system. These results will put important constraints on our understanding of star formation as whole. The student will gain experience working with interferometric data from the Sub-Millimeter Array and the Atacama Large Millimeter and submillimeter Array. If there is time, the student will be able to compare these observational results with the expectations of theoretical models of star formation. Analysis will be done using Python and will require some programming experience.

Studying the brightest galaxies in the early Universe (ESA)

Supervisor:

Keywords: Galaxies, High redshift, Reionisation, Galaxy formation, Galaxy evolution

More info
When and how did the first galaxies form? This is one of the major unanswered questions in extragalactic astronomy. The birth of the first luminous sources transformed the Universe from a neutral state to an ionised state. This is an important phase change in the history of our Universe termed as the “epoch of reionisation”. Using the power of gravitational lensing of massive clusters in the Hubble Frontier Fields (HFF) program, we were able to detect a large number of faint galaxies and identified among these the lowest mass galaxies ever observed at a distance corresponding to when the Universe was just 500 million years old. However, a complete understanding of the first galaxies requires an extended sample, which requires observing the exceptionally rare brightest and most massive galaxies, in addition to the faintest, lowest mass galaxies. To this end, the student will focus on finding and studying the brightest galaxies in the first billion years after the Big Bang, essentially in the ‘epoch of reionisation’ era, using the HFF parallel fields imaging data. This will involve the student deriving galaxy properties such as photometric redshifts, luminosities, stellar masses and star-formation rates. The estimation of these properties for the brightest objects will allow us to sample the entire range of galaxy luminosities that are required for the observed level of reionisation and will also provide us with a great opportunity to understand how galaxies evolve in the first billion years after the Big Bang. The results of the project could potentially lay the foundation of a paper. The student should be familiar with Python or have experience with other scientific programming languages.

A search for radio relics at the location of bow shocks

Supervisor:

Keywords: Clusters of galaxies, non-thermal radiation mechanisms, shock waves, radio relics

More info
Galaxy clusters are the largest gravitationally bound structures in the Universe. They grow by the merging of smaller clusters/groups of galaxies along the cosmic web filaments. During their formation, giant shock waves are generated in the intra-cluster medium (ICM). Studying the merger shocks provides insights into the physics of the ICM, the dynamics of cluster formation, and even the nature of dark matter. Shock fronts are detected with discontinuities in the surface brightness of X-ray emission that relates to the particle densities and gas temperature in the pre- and post-shock regions. In addition, the shock fronts are thought to (re-)accelerate cosmic rays to the relativistic speeds required for them to emit synchrotron radio emission in the present of magnetic fields. These synchrotron sources, so called radio relics, are observed in the outskirts of many merging galaxy clusters. However, it remains fuzzling why radio relics are not detected at the location of some of the most prominant and strong X-ray bow shocks. This challenges the current theoretical model. The aim of the project is to search for the presence of radio relics in the shock regions of these systems by studying the spectropolarimetric properties of extended radio emission at these shocks using sensitive data from telescopes such as LOFAR and uGMRT.

Cooking with the stars: Investigating the chemical ingredients in star-forming regions

Supervisor:

Keywords: Astrochemistry, Star formation, spectroscopy, ALMA

More info
Simple and complex molecules, such as water and ethanol, are formed in the gas and dust clouds from which stars are born. When these young stars start heating their surroundings and ice starts to evaporate, the gas becomes enriched in molecules that can be observed with Earth-based telescopes. Such observations shed light on physical conditions and chemical processes during star formation, provide information about the composition of the material from which planets are formed, and give insight into the molecules that can be delivered to planets by comets and potentially kick-start life. In this project, Atacama Large Millimiter/submillimeter Array (ALMA) observations of the Serpens SMM1 star-forming region are used to study the chemical complexity of its main source, SMM1-a, and to compare it with its companion SMM1-b. In the spectra of the two sources, rotational lines will be identified and used to determine, for example, abundances and excitation temperatures of molecules. The comparison between SMM1-a and SMM1-b will help us understand if and how the evolution of these two objects differs, while the comparison with literature values will provide insight into the general trends of interstellar chemistry.

The inner regions of planet-forming disks revealed by VLTI/MATISSE

Supervisor:

Keywords: star formation, planet-forming disks, infrared interferometry

More info
Young stars are surrounded by dust- and gas-rich disks. These planet-forming disks are being shaped by several processes, including accretion of material onto the star, dissipation of the disk material, and planet formation. All of these processes leave their imprints on the disk structure which can be studied by high angular resolution observations. While mm-interferometry (ALMA), and extreme adaptive optics imaging on 8-10 m class telescopes (SPHERE) probe the disks at tens of au spatial scales, infrared interferometry has the potential to resolve the inner one astronomical unit. The Very Large Telescope Interferometer (VLTI) is equipped with three such instruments, of which MATISSE is the latest one. MATISSE can probe the regions of circumstellar disks where terrestrial planets form. The aim of this project is to analyze the inner-disk structure and the dust content for a sample of planet-forming disks from MATISSE and other VLTI data. Scientific questions include the relation of the disk size with the stellar luminosity, distribution of inner-disk gaps, and the silicate mineralogy of the dust.

Characterisation of Oxia Planum, Mars: Preparing ESA ExoMars 2022 rover science by Pancam & other instruments (ESA)

Supervisor:

Keywords: planetary science, image processing, astrophysics, geoscience

More info
In June 2023 the Exomars Rosalind rover (to be launched sept 2022) is to land at Oxia Planum, a site that has hosted fluvial and lacustrine activity, and show sediments related to the geological and climatic history of Mars. Mars has also seen frequent episodes of periglacial activity. The student will use open data from MRO CTX & HIRISE, CRISM spectrometer, topography and MEX HRSC. The objectives are to trace the depositional history in Oxia Planum based on images, topography and compositional data. The diversity of textures and morphologies will be linked to the exposure of sedimentary layers. The analysis will help to prepare for the science and operations of ExoMars rover PanCam instrument (with Co-I B.Foing), and of other Exomars instruments. PREREQUISITES: Knowledge of planetary science, image processing, astrophysics, geoscience

The fundamental plane of simulated elliptical galaxies

Supervisor:

Keywords: galaxies, simulations

More info
Elliptical galaxies show a correlation between their stellar mass, half-light radius and central velocity dispersion, known as the “Fundamental plane” relation. The existence of the Fundamental plane follows from the virial theorem. The values of the coefficients describing the plane, however, depend on the details of the inner structure of elliptical galaxies, such as the stellar mass-to-light ratio, the orbital anisotropy and the dark matter density profile. Cosmological hydrodynamical simulations are able to reproduce the basic properties of elliptical galaxies, but it is not clear whether simulated galaxies lie on the same fundamental plane as real ones. The goal of this project is to measure the fundamental plane of simulated elliptical galaxies from the EAGLE simulation and compare it to that of observed galaxies. The outcome of the comparison will be used as a guide for improving the accuracy of simulations and for a better understanding of the structure of galaxies. The student will learn how to handle data from cosmological simulations and the basics of Bayesian inference.

The infrared and radio emission of distant galaxies in COSMOS-XS

Supervisor:

Keywords: galaxies, star formation, multiwavelength surveys

More info
The infrared and radio continuum luminosities are observed to be closely related in star-forming galaxies despite the fact that infrared radiation comes from the thermal radiation of dust heated by stars and radio synchrotron emission comes from non-thermal processes (cosmic rays accelerated by supernovae remnants). Even after decades of effort, this tight correlation is still not well understood, but it is used as evidence that radio continuum emission can be related to the star formation rate of galaxies. Recent progress has been made by careful analysis of large galaxy surveys, and there is now evidence that the infrared--radio correlation is not the same for all galaxies, but varies with mass. Theories also predict a change in the infrared--radio correlation with redshift, but observations do not support this. This LEAPS project aims to quantify how the infrared--radio correlation varies with galaxy stellar mass and redshift by using the deepest radio and infrared data available in the COSMOS field. Professor Hodge’s group at Leiden has led the COSMOS-XS survey, providing deep 3GHz radio data that, when combined with the latest multiwavelength data from the COSMOS collaboration, will allow us to detect faint low-mass galaxies at higher redshift than previously possible. A better understanding of the processes responsible for the radio emission in star-forming galaxies will be critical for interpreting data from future surveys, such as those with the international Square Kilometer Array.

Mirror Mode Waves in the Plasma at Comet 67P/Churyumov-Gerasimenko (ESA)

Supervisor:

Keywords: space plasma, comets, data analysis

More info
The plasma environment of a comet provides a unique laboratory to study plasma phenomena in the interplanetary medium. There, magnetic field waves are responsible for distributing energy and momentum any time the plasma is not in equilibrium. Mirror mode waves are generated when a plasma becomes unstable. They are commonly found in the magnetosheath plasma, between a planet's (or comet's) bow shock and magnetopause (cometopause). There, mirror modes are the result of the complex interaction of the solar wind plasma with the object's magnetic field or ionosphere. Mirror modes are also thought to be the starting point of magnetic holes, i.e. small scale depressions in the solar wind magnetic field that can propagate far into the cometary environment. The ESA Rosetta mission explored comet 67P/Churyumov-Gerasimenko from 2014 to 2016 and discovered many new phenomena as well as observed well-known processes under unusual conditions. Mirror modes were detected on a couple of days in 2015 (Volwerk et al. 2016) where their profile was studied and attributed to a change in the solar wind. Magnetic holes were detected in the spring of 2015 (Plaschke et al. 2018). The aim of this project is to find and characterise other intervals with mirror mode waves. We will then investigate if these waves and previously detected magnetic holes can be related. Optionally, as preparation for the new mission Comet Interceptor, the conditions under which the mirror modes occur and the conditions expected during the Comet Interceptor flyby can be compared. With this information, the mission team can better plan for design and operation of the spacecraft. The student will gain experience in common data analysis techniques as well as space plasma physics. Knowledge of a programming language is required. Knowledge of python or Matlab is beneficial but can also be acquired during the project.

Chemical enrichment in the hot halo of the galaxy M49 (ESA)

Supervisor:

Keywords: Galaxies, metals, X-ray astronomy

More info
As building blocks of matter and even life, metals are an essential ingredient of our present Universe. Completing the inspiring Carl Sagan's quote "We are made of star-stuff", these heavy elements (C, N, O, Fe,...) are all created from H and He in the burning core of stars and in supernovae explosions, before being ejected and enriching their surroundings. But metals are not only found in stars and their immediate vicinity. Instead, a substantial fraction of them actually ends up outside their host galaxies: i.e. in a hot, ionised, X-ray emitting halo pervading galaxies and galaxy clusters. Taking advantage of X-ray space telescopes to measure the chemical abundances of these elements (via their spectral emission lines) provides us with invaluable information on (i) the chemical history of the Universe at its largest scales and (ii) how galaxies produce and recycle metals. It also helps to determine what kind of stars and supernovae have mostly contributed to enriching (clusters of) galaxies from the cosmic dawn till now. Whereas the enrichment has been well studied at the scales of galaxy clusters, very little is known about metals in the hot haloes of isolated galaxies. In this project, the student will make use of exceptionally deep observations of the elliptical galaxy M49 with the X-ray satellite XMM-Newton. The primary goal will be to derive key abundance ratios (e.g. O/Fe, Mg/Fe, Si/Fe) in its hot halo for the first time, and to compare it with the chemical composition of galaxy clusters and nucleosynthesis models. If time allows it, deriving the spatial distribution of metals through the whole galaxy's extent will help understand the chemical history of this galaxy.

Molecular line emission from planet-forming disks

Supervisor:

Keywords: Planet formation, interferometric data, astrochemistry

More info
Planets form in the disks of gas and dust around young stars. With modern telescopes like ALMA we can observe the material in these protoplanetary disks with unprecedented detail. Recent observations have shown that there are many rings and gaps in the dust distribution in disks that may be carved by forming planets. By studying the properties of the gas - the distribution, molecular abundances and velocity patterns - and comparing this to the dust we can learn more about the potential formation of giant planets in these young star systems. The student will work with data of different gas tracers in a source that exhibits interesting properties in the dust and that has planet candidates.

Unveiling nascent stars with sulfur-bearing molecules

Supervisor:

Keywords: Observational, Astrochemistry, Protostars, ALMA

More info
Stars like our Sun form in interstellar clouds of gas, ice, and dust. By observing the emission from molecules around infant stars we can better understand how they are made, what the physical conditions around them are, and what the composition of star and planet-forming material is. In this project, you will get first-hand experience with ALMA ACA data that contain emission of H2S and OCS towards several low-mass protostars that are still young and embedded in their natal cloud. By looking at the emission lines of these two molecules and their isotopologues, you will analyze the spatial distribution of these two molecules and derive their abundances. The goal is to derive the H2S/OCS ratio in the envelopes of several low-mass protostars, which can be used as a tracer of the temperature of the birth cloud of these protostars. Such a chemical thermometer will show if the cloud is initially cold or warm. However, the ultraviolet radiation field also plays a role. H2S ice can be converted into OCS ice upon ultraviolet irradiation, thereby decreasing the H2S/OCS ratio. By probing the temperature and radiation around those young systems you will provide crucial information about the early years of Solar-like stars. This project will be carried out in close collaboration with ESO (Germany) and the University of Bern (Switzerland). Experience with Python is a plus.

Using Gaussian Processes to study exoplanet transits and stellar variability simultaneously (ESA)

Supervisor:

Keywords: Exoplanets, transits, stellar variability, Gaussian processes

More info
The study of exoplanet transits, asteroseismology, or stellar rotation from photometric light curves frequently involves filtering out data from the other two sources of variations. Modelling all three of these effects at once is expected to improve our ability to detect very faint transits (Barros et al. 2020). Simultaneously measuring stellar rotation rate will avoid signals being contaminated by transits, and including asteroseismic oscillations can constrain fundamental stellar parameters for short observations (Farr et al. 2018). One way of modelling these effects is by using Gaussian Processes (GPs). This modern technique is very effective at describing quasi-periodic or dampened signals such as stellar rotation and asteroseismic oscillations, but comes at a high computational cost. With this project, the student will improve an existing GP model to account for stellar variability as well as planetary transits. The student will then generate synthetic data, use them to test the precision of this model, and apply it to several stars with transiting planets observed by TESS, K2 and/or Kepler. Understanding how – and when – GPs can improve the search for planetary transits and the characterization of their host stars will tell us how to get the most out of current photometry missions, and future ones such as PLATO. Experience with a programming language is required, and a knowledge of Python in particular is strongly advised.
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Past LEAPS Successes


The LEAPS 2019 cohort had a great summer in Leiden and are already starting to share their research results with the world.
  • Danielle Rowland (supervised by B. Ribeiro and A. Paulino-Afonso) presented her research with a poster at the 2020 American Astronomical Society meeting. See here.
  • Lorena Acuña presented exoplanet atmospheric transmission spectra she obtained following her research on "Exploring the clearness/cloudiness of the atmosphere of gas giant exoplanets" in a poster at the ARIEL Science, Mission & Community 2020 conference held at ESA/ESTEC in January 2020.
  • and more publications are on the way!

LEAPS 2015 was a great success! Twenty-two students from four continents spent their summer in Leiden doing astrophysics research.

  • Joshua Borrow (with supervisor Pedro Russo) published a paper on astro-ph entitled "A Blueprint for Public Engagement Appraisal: Supporting Research Careers."
  • Lukasz Tychoniec (supervised by John Tobin) presented his research at the Polish Astronomical Society Summit, and his research already contributed to one published paper and he is preparing a paper on the full results.
  • Tessa Wilkinson (supervised by Anna-Lea Lesage) presented her research at the 2016 American Astronomical Society meeting.
  • Jeremy Dietrich (supervised by Christian Ginksi) submitted a paper to MNRAS "Archival VLT/NaCo multiplicity investigation of exoplanet host stars".
  • Maria Vincenzi (supervised by Carlo Manara) presented a poster at the workshop: "The accretion/outflow connection in YSOs" at ESTEC in October and a paper is in preparation.
  • Hope Boyce (supervised by Nora Lutzgendorf) presented a poster at the Canadian Conference for Undergraduate Women in Physics and a paper is in preparation.

The 2013, and 2014 groups of LEAPS students also performed very well and the first scientific publications are out!

  • Ryosuke Goto and his advisor Sean McGee published a paper on galaxy formation in the Monthly Notices of the Royal Astronomical Society on his LEAPS project; "The stellar mass function and efficiency of galaxy formation with a varying initial mass function". See here.
  • Steffi Yen and her advisor, Adam Muzzin, presented a poster at the American Astronomical Society (AAS) winter meeting in Washington DC, "Searching for the Most Distant Galaxy Clusters". See here.
  • Fiona Thiessen and her advisor Sebastien Besse submitted a paper on Lunar surface composition and lava flows (figure below).
  • Conny Weber worked with Agnes Kospal on infrared variability of young stars in Chamaeleon which featured on a poster at the "The Universe Explored by Herschel" conference in Noordwijk (conference website). See the poster here.
  • Hannah Harris, a 2014 LEAPS student, and her advisor Pedro Russo published a paper in the Space Policy Journal, "The Influence of Social Movements on Space Astronomy Policy." See here.
  • Saul Kohn (now a PhD student at UPenn) and his advisor David Sobral published a paper in Monthly Notices of the Royal Astronomical Society on his LEAPS project: "The most luminous Halpha emitters at z~0.8-2.23 from HiZELS". See here (link here).
  • LEAPS student Michael Hammer (from Cornell University) and his adviser Lucie Jilkova studied close stellar flybys that lead some stars to lose parts of their circumstellar discs. Using simulations in the AMUSE framework (www.amusecode.org), they showed that if the two stars approach each other close enough, part of the disc lost from one star can be transferred to the other one. These close encounters can happen shortly after stars form when many stars are clustered together. They further showed that even our Solar System might have experienced such an interaction and stolen some material, which is now orbiting in its outer parts, from another star. Michael presented a poster on the results of his LEAPS project on the 225th AAS meeting. The project eventually resulted to publication in an international refereed journal, which led to several press releases, for example: New Scientist, Scientific American, Universe Today.

Figure of the submitted paper by Fiona Thiessen, students of the LEAPS 2013 class. (a) M3 color composite image of the Imbrium basin (red: IBD1000, green: IBD2000, blue: R750 nm). Numbers indicate the basalt units mapped in this work. Large and spectrally bright craters are mapped separately in grey and were excluded from the basalt units. The surrounding highlands and kipuckas inside the Imbrium basin are also shown in grey. Dark strips correspond to portion of the lunar surface not observed with M3 using OP1B. (b) Eratosthenian basalt flows from Schaber [1973] with flow phases I-III. leaps2015 @ ESTEC

ESTEC group picture (joint tour with ASTRON summer school).

leaps2015 @ LOFAR

The rain could chase us away from LOFAR! (not quite drenched yet in this picture).

The 2013 LEAPS students (and some supervisors) on their visit to the Westerbork Radio telescope in Dwingeloo, the Netherlands.