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The Leiden/ESA Astrophysics Program for Summer Students (LEAPS) 2017

Projects list 2017

Update: 31, January 2017

These are the proposed research projects for LEAPS 2017. Please note that not all projects will go ahead and some may still be added in the near future. Final funding decisions lie with the Faculty sponsors. And please make a note that if you are interested in an ESA project, to check if your state is an ESA member or affiliate state.

Project list (as of Jan 8 2017):

How the monsters were made: unlocking the formation of the most massive black holes in the Universe with LOFAR

Supervisor:

Type of project: Observational, galaxy

More info
Luminous high-redshift radio galaxies are spectacular objects and prime laboratories for studying the formation and evolution of massive galaxies and supermassive black-holes in the early Universe. These radio-loud active galactic nuclei (AGN) are known to reside in the most massive galaxies in the Universe and were likely some of the first galaxies and supermassive black holes to form.

In this project you will have the opportunity to combine brand new observations from the Low Frequency Array (LOFAR) radio survey with a wide range of multi-wavelength datasets to find and characterise this important population. As the deepest ever radio continuum survey, the unique dataset provided by LOFAR makes it possible to detect large numbers of these extreme sources and will allow us study the different modes of black hole accretion out to unprecedented distances, providing critical constraints on models of black-hole formation and AGN unification theories.

Shapes and sizes of Solar System small bodies

Supervisor: (ESA )

Type of project: Observational, asteroids, photometry

More info
Asteroid size is a very important physical parameter, since its accurate determination would give a better estimation of their densities. Additionally, the asteroid shape is an essential input to thermo-physical models in order to derive physical properties of the surface of these small bodies. How do asteroid surfaces look? How rocky are they? The determination of asteroid physical properties is crucial to construct a “map” of the distribution of material in the main asteroid belt and link the recovered meteorites with the asteroid parent bodies, which disrupted and sent material to Earth. Asteroids spin around their axes with periods of a few minutes up to tens of hours! The construction of asteroid shapes leads to the determination of their rotational axes. This, in combination with the orbit of the asteroid around the Sun can show whether the asteroid is slowly drifting towards the Sun or at larger heliocentric distances. This project will give access to observational data obtained from ESA-funded telescopes in Mediterranean. The student will be focused on the refinement/finalization of astronomical photometry software and/or its application on the analysis of the astronomical images to measure the light flux of the asteroid targets. In special cases it will be possible the co-observation of the asteroid targets, during the summer period. Experience in simple software development or use of telescopes would be appreciated.

How Astronomers View Public Engagement

Supervisor:

Type of project: Science Communication Research

More info
During this project, we will explore astronomers’ points of view on different aspects of their attitude towards public engagement (PE) initiatives, their level of confidence in taking part in PE activities, their perception of the public and their peers and the value of education and public outreach at their institution. We will also study some potential changes that are needed to be made in order to improve the astronomers' participation in EPO and how these changes can be implemented.

Understanding how the most massive stars in our Galaxy are formed

Supervisor:

Type of project: Observational, star forming regions using a radio-telescope

More info
The most massive stars in our Galaxy (with masses greater than 8 times the mass of our Sun) end their lives quite spectacularly when they become supernovae or black holes. Because of this, they are the main contributor to the chemical enrichment and energetic input in the Galaxy. However, despite their importance we still do not fully understand how these massive stars are formed and how they impact their immediate environment as they evolve. To understand this, we need to study the earliest stages of the formation of a massive star.

In this project we will use observations of a sample of 12 regions of massive star formation taken with the Atacama Large Millimeter/submillimeter Array (ALMA). ALMA is a revolutionary telescope compose of 66 antennas, located in the Chajnantor plateau in Chile. The 12 objects observed with ALMA have the perfect conditions to start forming massive stars but no evidence of active star formation has been found within them, suggesting we are witnessing the very earliest stages of massive star formation. The analysis of this unique dataset is going to be key to determine what is the physical, chemical and kinematical structure of the places where massive stars are born. The student working in this project will be required to analyse the density structure of the dust within these region using statistical tools. Experience in Python programming will be an asset.

Pulling Apart Eruptive Solar Filaments

Supervisor: Jack Carlyle (ESA )

Type of project: Observational, solar physics, data processing & analysis

More info
The solar atmosphere is a highly dynamic environment; the magnetic fields, which dominate the motion, are continuously reconfiguring, bringing the plasma along for the ride. This results in fascinating features and activity, such as filaments and coronal mass ejections (CMEs). In order to better understand these transient objects, a technique has been developed which allows us to peer into the internal structure of the plasma and uncover the density and mass distribution, as well as give estimates of total ejection masses. The aim of this project is to conduct analysis of the internal mass structure of a large number of filaments across their lifetimes. By comparing density maps with information about the underlying magnetic field evolution, a deeper insight into formation mechanisms may be gained, and typical eruption masses will be examined in order to begin to dissect the anatomy of CMEs. The student will observe the solar atmosphere over the past decade and search for suitable targets, and will be provided with several command-line tools with which to conduct the analysis itself. This is an exciting project for someone who wants to learn more about the stunning activity of the Sun, gain experience in data processing using interactive programming, and enjoy some freedom in choosing the specific focus of the project. The work will hopefully yield a publication in a peer-reviewed journal.

Planets-Disk Interaction in the Early Solar System: Formation of the Oort Cloud

Supervisor: and Santiago Torres

Type of project: planetary system dynamics, theory and simulations

More info
Jan Hendrik Oort proposed in 1950 the existence of the cometary cloud that surrounds the Solar System, but its formation remains unclear. In several studies it has been argued that the Oort cloud formed in the early stages of the Solar System, shortly after the giant planets formed. Jupiter, in particular, would have cleared the debris around its orbit and ejected the material into very elongated orbits. Approximately 8% of this material could have remained bound to the Solar System, the rest was ejected into the interstellar space. These studies are based on N-body simulations that only take Jupiter into account. The other giant planets are ignored, and the external perturbations by stars and the Galactic tidal field are ignored. The Galactic tidal field is important, however, in order to circularize the orbits of the ejected material.
We want to test the hypothesis that 8% of inter-planetary material formed the basis of the Oort cloud, and to what degree the orbits of the young Oort cloud objects can be circularized by the Galactic tidal field.
This study will be done by performing simulations of the early evolution of the Solar System including the giant planets and the Galactic tidal field.
Supervision will be done by postdoc dr. Maxwell Cai and PhD student Santiago Torres, under the supervision of prof. Portegies Zwart.

Aerosol characterization above California using the data of the test flight of the prototype SPEX instrument

Supervisor: Barend Ording (Airbus )

Type of project: Earth observation, Data analysis

More info
SPEX (Spectropolarimeter for Planetary EXploration) is an innovative, high precision, multi viewing angle spectropolarimeter for the characterization of planetary atmospheres. It can measure the flux and the degree and direction of linear polarization of sunlight that has been scattered within a planetary atmosphere from 400 to 800 nm.
In orbit around Earth, SPEX can perform multi-angle, multi-wavelength measurements of intensity and polarization, in order to characterize aerosol and cloud particles in the Earth atmosphere, with the overall goal to reduce the large uncertainty on the aerosol direct- and indirect effects on climate. The effect of aerosols on climate represents the largest reported uncertainty in the most recent assessment of the Intergovernmental Panel on Climate Change (IPCC). This uncertainty severely hampers future predictions of climate change [https://www.sron.nl/earth-instrument-development/spex].
In 2016, a test flight with a development model of the SPEX instrument was performed above California using the high altitude flying ER-2 airplane. The raw instrument data has been processed to extract the degree of polarization and depth of polarization across a range of wavelengths. This information can be used to determine the refractive index of the particulates in the atmosphere. In turn, the refractive index can be used to determine the particle type, e.g. sea salt or soot. The goal of the summer project is to develop a method to determine the refractive index per pixel and perform the aerosol classification using the real measurement data above California.

Characterising the largest interstellar molecules

Supervisor:

Type of project: astrochemistry, theoretical

More info
We live in a molecular universe! Nearly 200 molecules have been identified in interstellar or circumstellar clouds. The large part of these molecules containing carbon (C), which is one of the building blocks of the life as we know it. All the interstellar molecules are made of few (less than 15) atoms, the only exception being the buckminsterfullerene molecule, the most stable member of the fullerene family, which contains 60 carbon atoms.
The detection of this molecule prompt many questions: how does C60 form in the ejecta of dying stars? How does it interact with photons and cosmic rays? Why there is a big jump, from 15 to 60 atoms, in the mass distribution of interstellar molecules? Are other smaller or larger members of the fullerene family present in interstellar and circummstellar clouds? The project proposed here is to characterise the infrared vibrational spectrum of other type of fullerene molecules using theoretical methods and look for their signature in infrared spectrum of planetary nebulae and photodissociation regions.

The role of dust in star formation: A spatially resolved perspective

Supervisor:

Type of project: Observational/galaxies

More info
Dust is a fundamental constituent in galaxies, that is both a seed for, and a by-product of, massive star formation. While we have a better understanding of global properties of dust in galaxies in different galaxy environments across cosmic time, the distribution of dust within galaxies, or the spatial properties of dust, and its link to star formation remains largely a puzzle. This is key to understanding the connection between different modes of star formation within galaxies (e.g. compact or diffuse star formation, bursts of star formation etc.) and the production, destruction and distribution of dust, which will in-turn provide much needed insights into the role of dust in advancing star formation across a disk of a galaxy. There are now a number of on-going observational campaigns, such as SAMI and MaNGA surveys, aimed at obtaining spatially resolved information for large samples of galaxies. This project will make use of a unique sample of galaxies observed in the SAMI survey, for which we also have multi-wavelength (from far-UV to far-IR) global information, to investigate spatially the relationship between dust and star formation in galaxies in a range of different galaxy environments and types.

Water content of embedded planet forming disks

Supervisor:

Type of project: Observational, star formation

More info
Water makes up a large fraction of our own planet. Yet, the mechanism that initially delivered that water to Earth is still one of the major questions in astronomy and planetary sciences. One way to investigate the mechanism is to observe and quantify water toward objects that are on their way to form their planetary system.
This project will use the combination of interferometric observations and radiative transfer modelling of water lines to quantify the water content of young proto-planetary disks. The planetary system will eventually be formed in these disks. Thus, the quantification of the water content will provide constraints on how and when water is delivered to Earth size bodies.

Search for diffuse radio emission from galaxy clusters in LOFAR Tier-I survey data

Supervisor:

Type of project: simulation plus observational type project on galaxy clusters

More info
Clusters of galaxies are the largest gravitationally bound structures in the Universe. Galaxy clusters form through a sequence of mergers of sub-clusters. Observations with X-ray and radio telescopes reveal the co-existence of both thermal and non-thermal components of the intra-cluster medium. However, the number of clusters that are detected in radio band is far less than those reported by X-ray observations. A possibility is that the diffuse radio emission in most clusters is naturally faint and is below the detection limit of the current radio telescopes. Upcoming low-frequency radio surveys (e.g., LOFAR Tier-I, MWA) are expected to significantly increase the number of clusters detected in the radio. However, an optimal strategy to search for the faint diffuse emission is still unclear, especially for projects that aim to map a large area of the sky such as the LOFAR Tier-I and MWA GLEAM surveys. The aim of this LEAPS project is to develop a robust, efficient strategy to detect diffuse radio emission in the LOFAR Tier-I survey data. The work involves literature study (e.g., on radio interferometry), developing strategy (on either a group or individual), writing code (e.g., python, bash, C++), learning common radio packages (e.g., CASA, BBS, DPPP, PyBDSM), and testing the procedure on real LOFAR data.

The optical properties of far-IR selected galaxies

Supervisor: Janine Pforr (ESA )

Type of project: Observational, galaxies, spectroscopy

More info
A wide variety of multi-wavelength data (from the ultra-violet to the far- infrared) is available for the galaxies that lie in the CANDELS survey fields from both ground and space-based observatories. This allows us to study the properties of galaxies as well as galaxy evolution at a peak epoch in the formation of galaxies (z~2) in great detail. Particularly interesting are those dusty galaxies that actively form large amounts of stars or even undergo a strong burst of star formation. Such galaxies are easily identified through their emission in the far-infrared and consequential detection with the Herschel Space Telescope. We followed up our sample of Herschel detected galaxies with optical spectroscopy using the Multi-Object-Spectrograph on the Gemini- South telescope. The resulting spectra of ~300 galaxies now need to be reduced and analysed (redshifts measured and emission line properties analysed) and put into context with the existing photometric observations. Data reduction will be carried out with the Gemini IRAF package. This project will provide a good basis not only data reduction techniques for spectroscopy as well as the analysis of spectroscopic data. We are looking for a highly motivated student interested in galaxy evolution studies and willing to work in the framework of an international collaboration.

A giant LEAP: stepping through lookback times to directly calibrate the Lyman-alpha emission of young galaxies

Supervisor: Jorryt Matthee

Type of project: Extragalactic, Observational

More info
The Lyman-alpha (Lya) emission line is the strongest spectroscopic feature in star-forming galaxies in the early Universe (z>2). As such, Lya has been used to discover galaxies that are even fainter than those observed in the Hubble Deep Field. However, due to its sensitivty to neutral hydrogen and dust, the fraction of produced Lya photons that we observe is unknown. This severly limits the use of Lya as a tracer of galaxy properties like the star formation rate.
Observations now indicate that the majority of Lya photons escape at large distances from galaxies. However, the exact escape fraction or how this depends on galaxy properties is not well understood. This is because it has been challenging to measure escape fractions accurately, mostly due to the lack of well-understood spectroscopic features such as Halpha. The proposed LEAPS project will use new data from a specially designed experiment to measure the Lya escape fraction directly for a large sample of galaxies in well defined redshift-steps. With these measurements, it will be possible to determine how the Lyman-alpha escape fraction depends on galaxy properties and the distance from galaxies. The project involves the reduction and analysis of deep photometric data in the best extra-galactic fields.

Galaxy image modeling using Shapelets and sparse techniques

Supervisor: Arun Kannawadi (arunkannawadi@strw.leidenuniv.nl )

Type of project: Galaxies, simulations, modelling, gravitational lensing

More info
Galaxy images are sometimes decomposed in a special orthonormal basis called the Shapelets [1-2]. The Shapelet-decomposition describes the galaxies to a good extent and has remarkably good mathematical properties. Light from distant galaxies are lensed gravitationally by clusters of galaxies and by the large-scale structure of the Universe and this introduces a coherent shear in the observed images of the galaxies. The imprint of this shear can be found in every coefficient when expanded in the Shapelet basis [3-4], and hence the decomposition can be used to estimate the lensing shear and in turn map the invisible dark matter in the Universe! The Shapelet formalism also enables a simple way to deconvolve the point spread function (PSF) from the observed galaxy images [5]. While the infinite number of Shapelets serve as a complete basis, due to noise in the images, pixelisation and finite size of the images, only the low-order Shapelets are meaningful. The omission of the higher-order Shapelets can have artifacts and no longer accurately describe galaxies when they are highly elongated and/have have a complex morphology and substructures [6]. These artifacts can be minimized by employing a suite of Shapelets of different radii, also referred to as compound Shapelets [7]. Compound Shapelets form an overcomplete basis and thus the decomposition is not unique. The student will work on determining the "best" solution(s) given a set of shapelets and on the choice of the compound Shapelets themselves to optimise the performance. The student will have an opportunity to learn and apply some of the sparse optimisation tools and techniques. A basic background in astronomical imaging might be helpful but is not necessary.
References:
  1. https://arxiv.org/abs/astro-ph/0105178
  2. https://arxiv.org/abs/astro-ph/0202023
  3. https://arxiv.org/abs/astro-ph/0105179
  4. https://arxiv.org/abs/astro-ph/0601011
  5. https://arxiv.org/abs/0806.4042
  6. https://arxiv.org/abs/0906.5092
  7. https://arxiv.org/abs/1007.1681

Angular clustering with new wide-angle galaxy catalogues

Supervisor:

Type of project: Galaxies, radio astronomy, cosmological parameters

More info
The goal of the project will be to measure, and interpret in astrophysical and cosmological context, the angular clustering signal of galaxies in new wide-angle catalogues, such as the Kilo-Degree Survey (KiDS), as well as those based on SDSS or WISE. The measurement will be performed with publicly available tools, or software developed by the student, depending on student's interests. The interpretation will consist in estimating such cosmological parameters as the mean matter density of the Universe and large-scale galaxy bias, at various redshifts and for various galaxy types. The project could be further extended using other type of data such as from modern radio surveys, for instant LOFAR or SKA precursors.

Cosmic Ray Content of the Inter-Galactic Medium ? A multi-messenger approach

Supervisor: Meier Grootes (ESA )

Type of project: Extragalactic Astronomy/Astrophysics

More info
Cosmic rays (high energy particles) are a a hither-to poorly constrained element of the physics and the energy budget of galaxy groups. Although numerous production mechanisms for these particles exist (e.g star formation, acceleration at shocks, dark matter annihilation) it is unclear to what extent the inter-galactic medium(IGM) is permeated by these particles and what their importance to I) the energy budget of the IGM of galaxy groups is, respectively II) the (re-)ionization of the IGM may be.
The Galaxy And Mass Assembly survey in combination with the data from the Fermi-LAT instrument provides an ideal resource to begin constraining these questions empirically, by using information from across the electromagnetic spectrum. In particular GAMA provides the basis for a highly complete galaxy group catalog tracing the IGM of galaxy groups, while the gamma ray flux measured by Fermi traces the cosmic rays interacting with the IGM. Furthermore, GAMA's multi-wavelength coverage from the FUV-FIR/submm/radio provides information about possible sources of cosmic rays such as star formation. This project will initially focus on cross-correlating the available GAMA group and Fermi gamma ray data to constrain the incident cosmic ray flux. Follow-up characterization of potential sources may then be possible with the full GAMA survey data. Information on the GAMA survey is available here: www.gama-survey.org

Ultra-large scale observables in the EFT formalism of modified gravity

Supervisor: and Yashar Akrami

Type of project: Theory, Modified Gravity

More info
Upcoming cosmological experiments such as Euclid and the SKA will allow us to probe large cosmological scales, where modified gravity (MG) models possibly exhibit distinct signatures. The present project aims at expressing ultra-large scale effects in the Effective Field Theory (EFT) formalism and assessing the possibility to distinguish different MG models with future galaxy and/or 21 cm surveys.

Determine the sensitivity of an infrared earth observation instrument

Supervisor: (COSINE )

Type of project: Instrumentation/Remote sensing

More info
  • develop an experimental and theoretical method to determine the NETD of an infrared instrument
  • build and validate a test setup in the lab to measure the noise equivalent temperature difference of the detector
  • perform and validate measurements on a cooled infrared detector
  • understand the influence of thermal background radiation on the instrument performance
  • develop a model to assess the uncertainties and accuracy of the measurements
  • report your findings and collaborate with the other members of the design team

Perform spectral and radiometric characterization of the instrument

Supervisor: (COSINE )

Type of project: Instrumentation/Remote sensing

More info
  • develop an experimental and theoretical method to determine the spectral response of an infrared detector
  • improve the measurement setup when deemed necessary
  • perform and analyse measurements
  • assess the uncertainties of the setup and the performance of the instrument
  • report your findings and collaborate with the other members of the design team

Contribute to the development of a EO instrument simulator to validate in-orbit performance

Supervisor: (COSINE )

Type of project: Instrumentation/Remote sensing

More info
  • develop analitical methods to describe instrument subsystems performance
  • define typical use cases for the EO mission
  • develop the scene generator based on real and syntetic data
  • develop analitical methods for a instrument simulator
  • integrate existing retrieval algorithms into the simulator
  • report your findings and collaborate with the other members of the team

Investigate on the possible in-flight calibration strategies for EO instruments

Supervisor: (COSINE )

Type of project: Instrumentation/Remote sensing

More info
  • identify different in-flight calibration procedures for existing instruments
  • analyse the possible techniques and methods for the instruments under development
  • estimate the uncertainties and accuracies of the different methods
  • propose a detailed plan for an overall in-flight calibration plan
  • report your findings and collaborate with the other members of the team


Please note that the ESA projects are only available for students from ESA member or affiliate states The working language of the observatory is English, and students should be sufficiently proficient in English to perform a research project. (Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, The Netherlands, Norway, Poland, Portugal, Romania, Spain, Sweden, Switzerland, the United Kingdom and Canada). Students from Bulgaria, Cyprus, Malta, Latvia, Lithuania, Slovakia and Slovenia (affilliate members) can also apply for ESA projects.