Recruitment for the Particle Astrophysics Science and Technology Center

- see here.

 

 

Proposed subjects of PhD theses 2019/2020

(Recruitment closed)

 

Subject: Stellar-origin Black Holes across the Universe

Advisor: Prof. Krzysztof Belczynski (belczynski@camk.edu.pl)

 

Stellar-origin black holes are at the frontier of astrophysics and astronomy. They manifest their presence in X-ray binary systems, in LIGO/Virgo gravitational-wave data and are claimed to be responsible for several Gaia microlensing events. New surveys and instruments (e.g., LISA, LSST) are expected to hugely increase the number of known stellar-origin black holes. This project offers a synergy of stellar evolutionary predictions with various existing and future observations. In particular, Ph.D. candidate will have opportunity to learn about main evolutionary processes that lead to black hole formation. That knowledge will be applied in numerical (population synthesis) simulations that will deliver predictions about various black hole populations across the Universe. These simulations will be contrasted with observations to, in turn, improve our knowledge about stars that form black holes. Particular applications include projects that will deliver direct predictions for LIGO/Virgo, LISA and LAMOST and will involve a successful Ph.D. candidate in several international collaborations. Good programming skills, very good knowledge of English, and solid grade record from Master degree program are expected from candidates.

 

 

 

Subject: Measuring infrasound fields influence on GW detectors

Advisor: Prof. Tomasz Bulik (bulik@camk.edu.pl)

Co-advisor: Dr. Mariusz Suchenek

 

The project aims at the construction of an infra-sound sensor working in the frequency range below 10Hz. The sensor will be the basis for construction of a system to monitor the infra-sound field inside buildings in real time. The second part of the project is the construction of data acquisition system allowing to measure infra-sound from a network of 10-20 sensors and off-line analysis of infra-sound sources.

 

 

 

Subject: Design and testing of a new magnetic seismic sensor

Advisor: Prof. Tomasz Bulik (bulik@camk.edu.pl)

Co-advisor: Dr. Mariusz Suchenek

 

Construction and optimization of the seismic sensor working on the basis of magnetic compensation of a suspended test mass. The goal is to construct a sensor that will measure the mechanical vibration through the voltage required to maintain the suspended mass at rest.

 

 

 

Subject: Pulsar Astrophysics

Advisor: Dr hab. Jarosław Dyks (jinx@ncac.torun.pl)

 

The projects focus on the interpretation of radiative properties of pulsars, in particular: modelling of radio or optical polarisation, pulse profile morphology, the relation between radio and gamma-ray properties, analysis of temporal behaviour (subpulse drift or profile moding). Some of the projects are oriented mostly on high-level data analysis, others on numerical implementation of theoretical models.

 

 

 

Subject: Comparing Star Cluster Simulations with Observations

Advisor: Dr hab. Mirosław Giersz (mig@camk.edu.pl)


Stellar and dynamical evolution of extremely dense star clusters produces a myriad of interesting astrophysical objects. Observations of objects like globular clusters reveal that these systems not only contain stars at different stages of stellar evolution but also harbour exotic stars and binary systems like blue stragglers, cataclysmic variables and X-ray binaries. In recent years, numerical simulations of star clusters using N-body and Monte Carlo codes have become increasingly more realistic and can be used to evolve clusters with up to millions of stars. At the same time, technological developments in optics and instrumentation have lead to in-depth and detailed observations of numerous star clusters in our Galaxy and its neighbourhood. In upcoming years, systems like globular clusters will be observed in unprecedented detail with the advent of the James Webb Space Telescope and the European Extremely Large Telescope. 

Comparing these detailed observations with numerical simulations of theoretical star cluster models can provide useful insights that can significantly help to improve our knowledge of stellar systems like globular clusters by providing constraints on their initial conditions and properties. This project will focus mainly on transforming the data provided by state-of-the-art numerical simulations of star cluster models (provided by the MOCCA code for star cluster evolution) into synthetic observations. The main task of the student will be to further develop the COCOA (Cluster simulatiOn Comparison with ObservAtions) code which can create simulated observations from numerical snapshots provided by star cluster simulation codes. The student will work on analysing and reducing the synthetic observations in the same way as observers would do in order to obtain global cluster parameters and properties. This will include developing pipelines to determine the luminosity function, surface brightness profile, various scale radii, binary fraction, completeness and colour magnitude diagrams of hundreds of star cluster models. The student may also work on comparing observational properties of specific populations of stars and binary systems like variable stars, evolved giants, blue stragglers and eclipsing binaries from simulated models with real observations. This will be vital in understanding the formation and evolution of such interesting stars and binaries.
The student will work under the supervision of Mirek Giersz, who has been actively developing the MOCCA code for star cluster simulations at NCAC in Warsaw. Student will also closely collaborate with Abbas Askar, who has been developing the COCOA code for creating simulated observations. Prior knowledge of reducing observational data (specifically photometric data) will be extremely useful for this project.

 

 

 

Subject: Superfluid neutron stars: gravitational waves and pulsar glitches

Advisor: Dr Brynmor Haskell (bhaskell@camk.edu.pl)

 

Neutron stars are one of the most exotic and exciting nuclear physics laboratories in the Universe. With a mass comparable to that of the Sun squeezed into a 10 km radius they have interior densities that exceed nuclear saturation density. These are conditions that we cannot replicate with laboratory experiments on Earth and allow us to catch a glimpse of the behaviour of matter at high densities and low temperatures, with exotic phases, such as deconfined quark condensates, expected in the core of these stars.

Despite internal temperatures of tens of millions of degrees Kelvin, the thermal energy of these objects is in fact small compared to the huge Fermi energy of the constituents, and large scale superfluid components are expected in the interior. Superfluidity has a strong impact on the dynamics of the star, as the superfluid can flow with little or no viscosity with respect to the “normal” component. Quite strikingly these microscopic properties of matter can lead to large scale phenomena that are observable from Earth mainly with radio telescopes, X-ray and gamma-ray satellites, and now also with gravitational wave detectors.

PhD projects are available on the topic of modelling superfluids in the crust of the neutron star, considering the effects of general relativity and elasticity, to model pulsar glitches and gravitational wave emission mechanisms. 

 

 

 

Subject: Nucleosynthesis in black hole accretion flows

Advisor: Dr hab. Agnieszka Janiuk, prof. CFT PAN (agnes@cft.edu.pl)

Co-advisor: Dr hab. Michał Bejger, prof. CAMK PAN

 

In the accretion flows at the base of gamma ray burst jets, the physical conditions lead to a copious production of heavy elements. Light isotopes (helium, lithium, beryllium), as well as heavier elements with mass numbers in the range A ~ 60- 80, corresponding to the first maximum of nuclide production in the process of rapid neutron capture (r-process), are created in the accretion disks. The magnetically driven ejecta from these disks may be prone to a further synthesis of nuclides, namely the second, and third peak of r-process, until mass number A~200. The recent observational discoveries (e.g., electromagnetic counterpart of GW 170817) have proven that the subsequent radioactive decay of such isotopes is responsible for the emission at lower energies that follows the gamma-ray bursts, and the effect is called “kilonova”.

 

The proposed PhD topic involves numerical modeling of the general relativistic magneto-hydrodynamical evolution of the accretion flow in a GRB central engine, and the following nucleosynthesis. The latter task involves usage of the nuclear reaction network codes and libraries (code Skynet, see Lippuner & Roberts 2017). The MHD simulations are performed with our own version of the code HARM-COOL (see http://www.cft.edu.pl/astrofizyka/?page_id=345).

We expect that prospective candidates have a basic knowledge of programming techniques and numerical methods, and are strongly motivated for research in astrophysics.

 

 

 

Subject: Relativistic astrophysics

Advisor: Prof. Włodek Kluźniak (wlodek@camk.edu.pl)

 

PhD studies in a range of topics in theoretical astrophysics are offered including, but not limited to, the astrophysics of black holes and neutron stars. These include phenomena as diverse as TeV emission, gamma-ray bursts (GRBs), gravitational waves, the (magneto)hydrodynamics of accretion disks and jets, binary evolution. Work on these topics will be relevant to ongoing and future observations with several modern and planned instruments, including H.E.S.S., LIGO/VIRGO, CTA, ATHENA and a host of optical, radio and X-ray telescopes.

Among specific topics of current interest are studies of the variability and stability of accretion disks in the presence of strong radiation fields. Prospective graduate students would be welcome to perform radiative MHD simulations of accretion disks with existing codes, as well as to work on improving radiation routines.

Work on simulations of coalescence and tidal disruption is also possible.

 

 

 

Subject: Stellar astronomy and eclipse timing

Advisor: Prof. Maciej Konacki (maciej@ncac.torun.pl)

 

The aim of the project is to characterize with high precision eclipsing binary stars and search for circumbinary companions (stellar and planetary) thanks to the timing measurements of their eclipses. Determined parameters of the components of the binaries will be combined with the distances from the Gaia mission and used to test the models of stellar structure and evolution. Both parts of the project will be based on a vast database of photometric and spectroscopic measurements from the "Solaris" project. These database contains over 2 million frames (thousands of nights).

These tasks can be enhanced with new observing campaigns. The "Solaris" network consists of 4 robotic telescopes (0.5-m, 2 in South Africa, one in Argentina and one in Australia) with Johnson-Cousins (UBVRI) and Sloan (u'g'r'i'z') filter sets. Additionally, one of the telescopes in South Africa is equipped with a medium resolution (R = 20 000), high throughput echelle spectrograph suitable for stellar astronomy up to about 11 mag.

 

 

 

Subject: Stellar astrophysics - analysis of satellite-borne observations of detached eclipsing binaries

Advisor: Prof. Maciej Konacki (maciej@ncac.torun.pl)

Co-advisor: Dr Krzysztof Hełminiak (xysiek@ncac.torun.pl)

 

The aim of the work is to obtain high-precision (<1%) fundamental stellar parameters for components of selected detached eclipsing binaries. This will be done by producing models of these binaries on the basis of quality spectroscopic material and very high precision, satellite-based photometry from missions such as Kepler/K2, TESS, Gaia, and others. The models will be made for about 150-200 systems (depending on the availability of data). The results will be a base for further analysis, aimed for obtaining ages, chemical composition or distances to the systems. Results will be published in refereed journals (ApJ, MNRAS, A&A) and included in the newly created catalogue of eclipsing systems TSEBOOLA.

These tasks can be enhanced with new observing campaigns. The “Solaris” network consists of 4 robotic telescopes (0.5-m, 2 in South Africa, one in Argentina and one in Australia) with Johnson-Cousins (UBVRI) and Sloan (u’g’r’i’z’) filter sets. Additionally, one of the telescopes in South Africa is equipped with a medium resolution (R = 20 000), high throughput echelle spectrograph suitable for stellar astronomy up to about 11 mag.

 

 

 

Subject: Changing-State Active Galactic Nuclei with eROSITA

Advisor: Prof. Alex Schwarzenberg-Czerny

Co-advisor: Dr. Alex Markowitz (CAMK PAN; almarkowitz@camk.edu.pl)

Co-advisor: Prof. Dr. Joern Wilms (Karl Remeis Sternwarte/Erlangen Centre for Astroparticle Physics/Frederic-Alexander-Universitaet Erlangen-Nuernberg)

 

Our collaboration will use the German eROSITA telescope aboard the Spectrum X/Gamma spacecraft, to be launched in 2019.  eROSITA will perform all-sky X-ray surveys, and the new PhD student will join our collaboration in using eROSITA to identify new X-ray transients from compact objects (e.g., Neutron Star/Black Hole X-ray Binaries or flaring Active Galactic Nuclei [AGN]).

We seek a PhD student to support our focus on X-ray monitoring of large samples of AGN, as we will explore accretion ignition/depletion events to test AGN duty cycles, and changing-obscuration AGN to explore the characteristics of line-of-sight circumnuclear gas.  The PhD student will participate in follow-up X-ray/optical multi-wavelength campaigns e.g., X-ray observations with Chandra or NuSTAR. Having prior experience with working with X-ray data and/or AGN data is preferred.

Additional potential projects include observational studies of X-ray variability and/or spectroscopy of nearby Seyfert AGN, to be obtained with current X-ray telescopes, as well as preparation for future X-ray missions such as ATHENA.

 

Note: This will be a joint ("cotutelle") PhD between Poland and Germany; the successful candidate must satisfy the PhD  requirements of both CAMK-PAN and FAU-Erlangen-Nuernberg.  

 

 

 

Subject: Novae with evolved donors

Advisor: Prof. Joanna Mikołajewska (mikolaj@camk.edu.pl)

 

The proposed research is related to the OPUS grant "Life cycles of novae with evolved donors" led by prof. J. Mikołajewska and funded by the Polish National Science Centre. The following specific projects are possible:
(i) Extensive,  multi-approach follow up studies of the recently recovered by us progeny of Nova Sco 1437 which has been found to be the longest-period eclipsing intermediate polar (IP) known - an unique system to investigate, particularly as firm link between the CNe and CVs/IPs, and also to test their evolution.
(ii) Study of several recently discovered symbiotic novae (i.e. very slow novae with red giant donors) with the aims to provide observational constraints on their outburst behavior and physical parameters of the system based on ongoing photometric and spectroscopic observations.
For more details contact mikolaj@camk.edu.pl

 

 

 

Subject: Late-type variables in the Local Group of Galaxies

Advisor: Prof. Joanna Mikołajewska (mikolaj@camk.edu.pl)

 

The proposed PhD topic is built on recently completed spectroscopic survey of M33 and M31 for symbiotic stars led by prof. J. Mikołajewska. Among byproducts of this survey are spectra of over 1000 red stars among them are many red variables, cepheids, and other variables classified based on photometric characteristics (color-color and/or color-magnitude diagrams) and light curves, and that have never been spectroscopically confirmed.  Many of ~200 symbiotic stars discovered by our survey are misclassified cepheids, W Vir-type and other variables which are completely different objects from symbiotic binaries. The proposed research is to explore this spectroscopic database in combination with light curves, and other data to address the true physical nature of these variables.
For more details contact mikolaj@camk.edu.pl

 

 

 

Subject: Kinetic simulations of relativistic magnetic reconnection

Advisor: Dr hab. Krzysztof Nalewajko (knalew@camk.edu.pl  http://users.camk.edu.pl/knalew/)

 

Magnetic reconnection is one of the most promising dissipation mechanisms in relativistically magnetized plasma, that is thought to be present in most astrophysical sources of gamma-ray radiation: relativistic jets of active galaxies (blazars), gamma-ray bursts, pulsars, magnetars, etc.  In recent years, a significant progress was made in understanding the particle acceleration and production of gamma rays during relativistic reconnection, mainly due to kinetic numerical simulations ('particle-in-cell’ algorithm; PIC). Nevertheless, there are many outstanding problems regarding both numerical simulations as well as application of the numerical results to specific astrophysical situations. We seek PhD candidates with either numerical or theoretical skills.  We offer introduction to: basic plasma physics, theory of magnetic reconnection, gamma-ray astrophysics, high performance computing, as well as working with a PIC code (Zeltron).

 

 

 

 

Subject: Pulsar studies in Very-High-Energy domain of radiation

Advisors: Prof. Bronislaw Rudak (bronek@camk.edu.pl), dr hab. Jarosław Dyks

 

Pulsar astrophysics has gained new momentum after pulsed emission in the VHE domain (i.e. above 100 GeV)  of gamma-rays have been discovered from the Crab pulsar (MAGIC, VERITAS) and the Vela pulsar (HESS). The PhD project will consist of observations and data analysis of selected pulsars with subsequent numerical modeling of the inferred pulsar properties in the VHE domain. Observational part will be carried out within the HESS Collaboration ( www.mpi-hd.mpg.de/hfm/HESS/ ). Theoretical part will be to work out a physical model of the processes responsible for the origin of the VHE spectral componentt. The student will join the H.E.S.S. Collaboration and the Cherenkov Telescope Array Project during her/his PhD studies.

 

 

 

Subject: Light Element abundances (Li and Be) in nearby Galactic and extragalactic stars

Advisor: Dr hab. Rodolfo Smiljanic (rsmiljanic@camk.edu.pl, http://users.camk.edu.pl/rsmiljanic)

Co-advisor: Dr. Luca Pasquini (ESO/Germany - lpasquin@eso.org)

 

Evidences triggered by the GAIA DR2 release show that a large fraction of the stars of the nearby halo and thick disk originated in an accreted satellite, while others were born ‘in situ’. The accreted stars occupy defined regions in the dynamical and orbital spaces, and show element abundances characteristic of dwarf galaxies in the local group. The student is asked to identify a substantial sample of accreted stars and compare their abundances with an equivalent sample of stars formed in situ. For this s/he will use literature data, archive spectra and will propose new observations, if needed. The project is to concentrate mostly on the light elements Li and Be. In relatively metal poor, hot main sequence stars these elements are not expected to be destroyed in the stellar interior (but could suffer of diffusion), so their atmospheric abundances should principally follow the chemical enrichment of the galaxies where they were born. Li and Be are extremely interesting: Li is one of the few elements synthesized in the Big Bang, and it can be enriched in the life of a galaxy through several mechanism, that include Nova production and cosmic ray spallation. Beryllium can only be produced through cosmic ray spallation, and it has been proposed to be used as a cosmo-chronometer in the Galaxy. Li and Be have been extensively studied in halo and in thick disk stars, but the evidence that a major fraction of them is of extragalactic origin changes radically the perspective of the chemical evolution for these elements. The project involves a strong international collaboration and a research period spent at ESO/Germany is foreseen.

 

 

 

Subject: Cepheids in eclipsing binary systems as testbeds for stellar pulsation and evolution theories

Advisor: Dr hab. Radosław Smolec (smolec@camk.edu.pl)

 

Classical Cepheids are one of the most important tools of modern astrophysics and cosmology. As excellent standard candles and tracers of young stellar populations they allow to study the structure and evolution of the Milky Way and of the Magellanic Clouds. Still, there are many puzzles concerning evolution and pulsation of Cepheids. For example, masses of classical Cepheids predicted by stellar evolution theory are 10-20 per cent too high as compared to determinations resulting from pulsation theory, or resulting from dynamical mass determinations for Cepheids in eclipsing binary systems. The student will conduct detailed evolutionary and pulsation modeling of classical Cepheids, members of eclipsing binary systems, with emphasis on the role played by processes such as element mixing, mass loss and rotation, and their mutual interaction. The student will investigate current limitations of the stellar evolution and pulsation theories and will calibrate the parameters entering the model calculations. Modeling will be done with software instruments available in MESA: stellar evolution and stellar pulsation codes. Student will also take part in Cepheid observations in the Cerro Armazones Observatory in Chile. Good knowledge of programming languages will be an asset. This investigation is part of the SONATA BIS research project funded by the National Science Center.

 

 

 

Subject: Pulsation period changes in classical pulsating stars

Advisor: Dr hab. Radosław Smolec (smolec@camk.edu.pl)

 

Classical pulsators, Cepheids and RR Lyrae stars, are invaluable tools of modern astrophysics. They serve as distance indicators, excellent tools to study the structure and evolution of the Milky Way and of other stellar systems. They are also testbeds for the stellar evolution theory. As star evolves, its pulsation period changes. Evolution theory predicts these changes should be slow and monotonic. It turns out that in many stars the observed period changes are much more complex: they are irregular and occur on a much shorter time scale. The mechanism behind these non-evolutionary changes is unknown. The student will conduct a comprehensive investigation of pulsation period changes in classical pulsators using data of the OGLE project and archival data. The goal is to describe the fast changes quantitatively for the first time. This is a necessary step to disentangle  slow changes due to evolution from fast and irregular changes. This research will also help to understand the mechanism behind the non-evolutionary changes. Good knowledge of programming languages will be an asset. Student will also take part in Cepheid observations in the Cerro Armazones Observatory in Chile. Good knowledge of programming languages will be an asset. This investigation is part of the SONATA BIS research project funded by the National Science Center.

 

 

 

Subject: Simulations of molecular observations in evolved stars

Advisors: Prof. Ryszard Szczerba (szczerba@ncac.torun.pl)

Co-advisor: Dr Mirosław Schmidt

 

Interferometric observations in submilimeter range provide plenty of information on chemical composition, gas distribution and excitation of molecular species in circumstellar environment of evolved stars. The physical interpretation of acquired data demands yet heavy investment in theoretical modelling of observed results, especially in modelling of radiative transfer in gaseous envelope in three dimensions. The PhD student will work on the interpretation of archival (Herschel, ALMA) and current observational data of molecular species around evolved stars using radiative transfer codes both in one- (MOLEXCSE - Toruń) and three- (RATRAN, LIME, MC-3D, Shape) dimensions. We expect that in course of PhD study the student will acquire deep understanding of radiative transfer theory, molecular spectroscopy and of theory of molecular collisions, as well as broad knowledge on physical and chemical aspects of evolution of circumstellar envelopes in evolved stars. The prospective student should not be afraid of programming in different languages (e.g. python, fortran, c).

 

 

 

Subject: Neutron stars - observational constraints on dense matter theory

Advisor: Prof. Leszek Zdunik (jlz@camk.edu.pl)

 

Neutron stars, observed as radio pulsars, X-ray bursters, X-ray pulsars, and magnetars, are cosmic laboratories for studying properties of matter under extreme astrophysical conditions. The goal of the project is to confront recent observations of neutron stars properties (mass of the neutron star, fast rotation, cooling) with theories describing these processes. The project involves the study of the properties of the crust of neutron stars using methods of theoretical physics, and performing numerical simulations of the crust structure and dynamics. The crust plays very important role in neutron star evolution and dynamics and its properties are crucial for neutron star cooling and surface temperature. Another subject is the study of spin-up of a neutron star by accretion, including the impact of the properties of superdense matter on the rotational evolution. The problems listed above should be solved for a broad range of possible models of dense matter.

 

 

 

Subject: Measurement of nuclear recoils in liquid argon for dark matter searches

Advisor: Prof. Leszek Roszkowski (CAMK PAN)

Co-advisor: Dr Masayuki Wada (CAMK PAN, mwada@princeton.edu)

Co-advisor: Prof. Cristiano Galbiati (Princeton and GSSI, Italy, galbiati@Princeton.edu)

 

Today, dark matter represents the first evidence for new physics beyond the Standard Model, which is extremely successful to explain all observed phenomena in experimental particle physics, including the recent discovery of the Higgs boson. Currently, DarkSide, a liquid argon-based direct dark matter search experiment, has world-leading sensitivity for light dark matter candidates. The detailed characterization of liquid argon response to nuclear recoils (possible signals from dark matter particles) at low energy is essential to extend the sensitivity to lighter dark matter particles.

 

This project involves research on different aspects of the liquid-argon Time Projection Chamber (TPC) including designing and building of TPC, handling cryogenic system, simulating detector response using GEANT4, data acquisition, and analysis to draw physics results. Within this project, the obtained results will be used to re-analyze available data from DarkSide-50 experiment, which could lead to the world best results for light dark matter search.

 

The position is available for up to four years and funded by a studentship of 4700 PLN per month, plus medical and social insurance benefits. The position is available from Autumn 2019. The candidate is expected to have master degree in physics or astronomy at the starting date.

 

Note: This project is optionally available as a dual PhD program with Gran Sasso Science Institute (GSSI), leading to two PhD degrees (one in Poland and one in Italy); the successful candidate must satisfy PhD requirements of both CAMK PAN and GSSI. Long-term visits to GSSI will optionally be funded.

 

 

 

 Subject: Development of ultra-radiopure photodetector and light guides for Dark Matter direct search and neutrinoless double beta decay experiment

Advisor: Prof. Leszek Roszkowski (Astrocent, CAMK PAN)

Co-advisor: Dr Masayuki Wada (Astrocent, CAMK PAN, mwada@princeton.edu)

Co-advisor: Prof. Cristiano Galbiati (Princeton and GSSI, Italy, galbiati@Princeton.edu)

 

In rare event search experiments, such as dark matter searches and neutrinoless double beta decay searches, background event rates have to be suppressed below expected signal rates. In order to reach ultimate sensitivities for those searches, background contributions from detector components need to be suppressed. In this project, we focus on the photodetection part of detectors (silicon-based photodetector modules and light guides), which is a leading background contributor in both dark matter and neutrinoless double beta decay searches.

 

This project involves research on different aspects of the photodetector in cryogenic temperature including searching for radiopure components for the photo-detector and light guide, assaying materials, handling cryogenic system, and optimization of coupling between the photodetector and the light guide. This project also aims to design a photodetector module and to estimate sensitivities for future experiments.

 

The position is available for up to four years and funded by a studentship of 4700 PLN per month, plus medical and social insurance benefits. The position is available from Autumn 2019. The candidate is expected to have master degree in physics or astronomy at the starting date.

 

Note: This project is optionally available as a dual PhD program with Gran Sasso Science Institute (GSSI), leading to two PhD degrees (one in Poland and one in Italy); the successful candidate must satisfy PhD requirements of both CAMK PAN and GSSI. Long-term visits to GSSI will optionally be funded.

 

  

 

Subject: Optimization of pulse-shape discrimination for liquid argon based dark matter searches using silicon photomultipliers

Advisor: Prof. Leszek Roszkowski (CAMK PAN)

Co-advisor: Dr Marcin Kuźniak (CAMK PAN, mkuzniak@physics.carleton.ca)

Co-advisor: Dr Davide Franco (Astroparticle and Cosmology (APC) laboratory in Paris, France, dfranco@in2p3.fr)

 

Liquid argon based dark matter detectors currently taking data (DEAP-3600) or planned (DarkSide-20k, Argo) have a significant potential to discover Weakly Interacting Massive Particles (WIMPs) and will reach the ultimate sensitivity accessible to such searches. With silicon photomultipliers (SiPM), recently introduced novel light sensors to be used by the next round of experiments, pulse-shape discrimination (the key technique necessary to mitigate backgrounds in liquid argon), requires computational and experimental studies necessary to optimize it for better sensitivity to WIMPs.

 

This project includes testing of novel SiPM modules developed by the DarkSide collaboration, as well as the cutting-edge digital version of SiPMs, which is under development for future detectors at the Universite de Sherbrooke (Canada) and elsewhere.

 

Data from small and intermediate scale prototype detectors operated by the Global Argon Dark Matter Collaboration will be available for this analysis, with the goal of extracting important physics results with the optimized method.

 

The position is available for up to four years and funded by a studentship of 4700 PLN per month, plus medical and social insurance benefits. The position is available from Autumn 2019. The candidate is expected to have master degree in physics or astronomy at the starting date.

 

Note: This project is optionally available as a dual PhD program with the Astroparticle and Cosmology (APC) laboratory in Paris, leading to two PhD degrees (one in Poland and one in France); the successful candidate must satisfy PhD requirements of both CAMK PAN and APC. Long-term visits to APC and Sherbrooke will optionally be funded.

 

 

 

Subject: Development of novel wavelength shifters for future dark matter detectors

Advisor: Prof. Leszek Roszkowski (CAMK PAN)

Co-advisor: Dr Marcin Kuźniak (CAMK PAN, mkuzniak@physics.carleton.ca)

Co-advisor: Prof. Cristiano Galbiati (Princeton and GSSI, Italy, galbiati@Princeton.edu)

 

Liquid argon based dark matter detectors currently taking data (DEAP-3600) or planned (DarkSide-20k, Argo) have a significant potential to discover Weakly Interacting Massive Particles (WIMPs) and will reach the ultimate sensitivity accessible to such searches. In such detectors, wavelength shifter (WLS) materials are used to convert argon scintillation light (at 128 nm) to visible wavelengths, which can be efficiently detected by standard sensors.

 

This project involves comparative study of the most commonly used WLS and its novel alternatives, and selecting the best candidate tailored for specific application in the planned experiments, which would lead to extending their physics reach. Another aspect of this study is the compatibility of such new materials with silicon photomultipliers (SiPM) used by DarkSide-20k, quantifying their impact on the sensitivity of future experiments, and optimizing the light collection with Monte Carlo simulations.

 

The scope of this work includes R&D shared with collaborating institutions in Poland, Canada and Italy, and possible participation in development and installation of SiPM and WLS for the DarkSide-20k veto at Laboratori Nazionali del Gran Sasso (Italy).

 

The position is available for up to four years and funded by a studentship of 4700 PLN per month, plus medical and social insurance benefits. The position is available from Autumn 2019. The candidate is expected to have master degree in physics or astronomy at the starting date.

 

Note: This project is optionally available as a dual PhD program with Gran Sasso Science Institute (GSSI), leading to two PhD degrees (one in Poland and one in Italy); the successful candidate must satisfy PhD requirements of both CAMK PAN and GSSI. It will possibly involve extended visits to GSSI and Carleton University (Canada).

 

 

 

Subject: Search for dark matter with liquid argon detectors

Advisor: Prof. Leszek Roszkowski (CAMK PAN)

Co-advisor: Dr Marcin Kuźniak (CAMK PAN, mkuzniak@physics.carleton.ca)

Co-advisor: Dr Davide Franco (Astroparticle and Cosmology (APC) laboratory in Paris, France, dfranco@in2p3.fr)

 

The DEAP-3600 is a single-phase detector located 2 km underground at SNOLAB (Sudbury, Ontario), which searches for dark matter particle interactions with 3.3 tonnes total mass of liquid argon (LAr). DEAP-3600 has published the best limit on the WIMP-nucleon cross-section measured on Ar, and continues to take data as currently the only running LAr detector, with nearly 0.5 PB of data already collected and more coming in, bringing DEAP towards the design sensitivity competitive with xenon detectors.

 

The final analysis of the full 3-year dataset will require much more aggressive mitigation of backgrounds from natural sources of radioactivity as well as a multivariate, machine learning and/or profile likelihood ratio based analysis approach, which in a large part still needs to be developed.

 

The proposed topic involves analysis of data collected by the DEAP-3600 detector, with particular emphasis to exotic dark matter scenarios (Boosted Dark Matter, in particular) and background mitigation. Another aspect of this work is exploring the sensitivity of future detectors (DarkSide-20k, Argo) to this type of physics, and how it is impacted by instrumental backgrounds and non-linear response effects associated with the novel silicon photomultiplier-based detection and acquisition system.

 

The position is available for up to four years and funded by a studentship of 4700 PLN per month, plus medical and social insurance benefits. The position is available from Autumn 2019. The candidate is expected to have master degree in physics or astronomy at the starting date.

 

Note: This project is optionally available as a dual PhD program with the Astroparticle and Cosmology (APC) laboratory in Paris, leading to two PhD degrees (one in Poland and one in France); the successful candidate must satisfy PhD requirements of both CAMK PAN and APC. Long-term visits to APC and Carleton University (Canada) will optionally be funded.

 

 

 

Subject: Precision asteroseismology of massive stars with the TESS mission

Advisor: Prof. Gerald Handler (gerald@camk.edu.pl)

 

TESS is the acronym for Transiting Exoplanet Survey Satellite, a NASA space mission launched in April 2018. TESS performs an all-sky survey of bright stars for transiting exoplanets, but it also has an asteroseismology program to study the interiors of stars by using their oscillations as seismic waves. In this framework, high-precision measurements (of a quality compared to that of the Kepler mission, but for stars some five magnitudes brighter) with rapid time sampling will be available for millions of stars.

The purpose of the proposed PhD project concerns Beta Cephei stars, hot, massive main sequence pulsators that are tomorrow's supernovae. Preparatory work for TESS has almost tripled the number of known Beta Cephei stars to over 600, but TESS itself is permanently increasing this number. Therefore we now have the luxury of cherrypicking the best targets for in-depth asteroseismic studies.

These best targets can be separated in two groups, pulsators in eclipsing binary systems and pulsating runaway stars, which are stars that have been ejected from the Galactic plane by some catastrophic event such as a supernova explosion or binary star disruption. From the eclipsing binary stars, one obtains accurate constraints on the masses of the components, whereas the runaway stars provide upper limits to the ages of the pulsators.

The task of the PhD student working on this project is to select the best possible targets for this effort, to obtain and analyse additional observational data necessary for their further study, and to model the stellar interiors precisely in close collaboration with known specialists in this area. In this way, our knowledge of individual pulsators and hence on massive stars in general shall be considerably improved. This PhD work is expected to result in several high-impact publications and should firmly establish the candidate in the scientific community.