Project acronym 1st-principles-discs
Project A First Principles Approach to Accretion Discs
Researcher (PI) Martin Elias Pessah
Host Institution (HI) KOBENHAVNS UNIVERSITET
Call Details Starting Grant (StG), PE9, ERC-2012-StG_20111012
Summary Most celestial bodies, from planets, to stars, to black holes; gain mass during their lives by means of an accretion disc. Understanding the physical processes that determine the rate at which matter accretes and energy is radiated in these discs is vital for unraveling the formation, evolution, and fate of almost every type of object in the Universe. Despite the fact that magnetic fields have been known to be crucial in accretion discs since the early 90’s, the majority of astrophysical questions that depend on the details of how disc accretion proceeds are still being addressed using the “standard” accretion disc model (developed in the early 70’s), where magnetic fields do not play an explicit role. This has prevented us from fully exploring the astrophysical consequences and observational signatures of realistic accretion disc models, leading to a profound disconnect between observations (usually interpreted with the standard paradigm) and modern accretion disc theory and numerical simulations (where magnetic turbulence is crucial). The goal of this proposal is to use several complementary approaches in order to finally move beyond the standard paradigm. This program has two main objectives: 1) Develop the theoretical framework to incorporate magnetic fields, and the ensuing turbulence, into self-consistent accretion disc models, and investigate their observational implications. 2) Investigate transport and radiative processes in collision-less disc regions, where non-thermal radiation originates, by employing a kinetic particle description of the plasma. In order to achieve these goals, we will use, and build upon, state-of-the-art magnetohydrodynamic and particle-in-cell codes in conjunction with theoretical modeling. This framework will make it possible to address fundamental questions on stellar and planet formation, binary systems with a compact object, and supermassive black hole feedback in a way that has no counterpart within the standard paradigm.
Summary
Most celestial bodies, from planets, to stars, to black holes; gain mass during their lives by means of an accretion disc. Understanding the physical processes that determine the rate at which matter accretes and energy is radiated in these discs is vital for unraveling the formation, evolution, and fate of almost every type of object in the Universe. Despite the fact that magnetic fields have been known to be crucial in accretion discs since the early 90’s, the majority of astrophysical questions that depend on the details of how disc accretion proceeds are still being addressed using the “standard” accretion disc model (developed in the early 70’s), where magnetic fields do not play an explicit role. This has prevented us from fully exploring the astrophysical consequences and observational signatures of realistic accretion disc models, leading to a profound disconnect between observations (usually interpreted with the standard paradigm) and modern accretion disc theory and numerical simulations (where magnetic turbulence is crucial). The goal of this proposal is to use several complementary approaches in order to finally move beyond the standard paradigm. This program has two main objectives: 1) Develop the theoretical framework to incorporate magnetic fields, and the ensuing turbulence, into self-consistent accretion disc models, and investigate their observational implications. 2) Investigate transport and radiative processes in collision-less disc regions, where non-thermal radiation originates, by employing a kinetic particle description of the plasma. In order to achieve these goals, we will use, and build upon, state-of-the-art magnetohydrodynamic and particle-in-cell codes in conjunction with theoretical modeling. This framework will make it possible to address fundamental questions on stellar and planet formation, binary systems with a compact object, and supermassive black hole feedback in a way that has no counterpart within the standard paradigm.
Max ERC Funding
1 793 697 €
Duration
Start date: 2013-02-01, End date: 2018-01-31
Project acronym 3DICE
Project 3D Interstellar Chemo-physical Evolution
Researcher (PI) Valentine Wakelam
Host Institution (HI) CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
Call Details Starting Grant (StG), PE9, ERC-2013-StG
Summary At the end of their life, stars spread their inner material into the diffuse interstellar medium. This diffuse medium gets locally denser and form dark clouds (also called dense or molecular clouds) whose innermost part is shielded from the external UV field by the dust, allowing for molecules to grow and get more complex. Gravitational collapse occurs inside these dense clouds, forming protostars and their surrounding disks, and eventually planetary systems like (or unlike) our solar system. The formation and evolution of molecules, minerals, ices and organics from the diffuse medium to planetary bodies, their alteration or preservation throughout this cosmic chemical history set the initial conditions for building planets, atmospheres and possibly the first bricks of life. The current view of interstellar chemistry is based on fragmental works on key steps of the sequence that are observed. The objective of this proposal is to follow the fractionation of the elements between the gas-phase and the interstellar grains, from the most diffuse medium to protoplanetary disks, in order to constrain the chemical composition of the material in which planets are formed. The potential outcome of this project is to get a consistent and more accurate description of the chemical evolution of interstellar matter. To achieve this objective, I will improve our chemical model by adding new processes on grain surfaces relevant under the diffuse medium conditions. This upgraded gas-grain model will be coupled to 3D dynamical models of the formation of dense clouds from diffuse medium and of protoplanetary disks from dense clouds. The computed chemical composition will also be used with 3D radiative transfer codes to study the chemical tracers of the physics of protoplanetary disk formation. The robustness of the model predictions will be studied with sensitivity analyses. Finally, model results will be confronted to observations to address some of the current challenges.
Summary
At the end of their life, stars spread their inner material into the diffuse interstellar medium. This diffuse medium gets locally denser and form dark clouds (also called dense or molecular clouds) whose innermost part is shielded from the external UV field by the dust, allowing for molecules to grow and get more complex. Gravitational collapse occurs inside these dense clouds, forming protostars and their surrounding disks, and eventually planetary systems like (or unlike) our solar system. The formation and evolution of molecules, minerals, ices and organics from the diffuse medium to planetary bodies, their alteration or preservation throughout this cosmic chemical history set the initial conditions for building planets, atmospheres and possibly the first bricks of life. The current view of interstellar chemistry is based on fragmental works on key steps of the sequence that are observed. The objective of this proposal is to follow the fractionation of the elements between the gas-phase and the interstellar grains, from the most diffuse medium to protoplanetary disks, in order to constrain the chemical composition of the material in which planets are formed. The potential outcome of this project is to get a consistent and more accurate description of the chemical evolution of interstellar matter. To achieve this objective, I will improve our chemical model by adding new processes on grain surfaces relevant under the diffuse medium conditions. This upgraded gas-grain model will be coupled to 3D dynamical models of the formation of dense clouds from diffuse medium and of protoplanetary disks from dense clouds. The computed chemical composition will also be used with 3D radiative transfer codes to study the chemical tracers of the physics of protoplanetary disk formation. The robustness of the model predictions will be studied with sensitivity analyses. Finally, model results will be confronted to observations to address some of the current challenges.
Max ERC Funding
1 166 231 €
Duration
Start date: 2013-09-01, End date: 2018-08-31
Project acronym 4PI-SKY
Project 4 pi sky: Extreme Astrophysics with Revolutionary Radio Telescopes
Researcher (PI) Robert Philip Fender
Host Institution (HI) THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD
Call Details Advanced Grant (AdG), PE9, ERC-2010-AdG_20100224
Summary Extreme astrophysical events such as relativistic flows, cataclysmic explosions and black hole accretion are one of the key areas for astrophysics in the 21st century. The extremes of physics experienced in these environments are beyond anything achievable in any laboratory on Earth, and provide a unique glimpse at the laws of physics operating in extraordinary regimes. All of these events are associated with transient radio emission, a tracer both of the acceleration of particles to relativistic energies, and coherent emitting regions with huge effective temperatures. By studying radio bursts from these phenomena we can pinpoint the sources of explosive events, understand the budget of kinetic feedback by explosive events in the ambient medium, and probe the physical state of the universe back to the epoch of reionisation, less than a billion years after the big bang. In seeking to push back the frontiers of extreme astrophysics, I will use a trio of revolutionary new radio telescopes, LOFAR, ASKAP and MeerKAT, pathfinders for the Square Kilometre Array, and all facilities in which I have a major role in the search for transients. I will build an infrastructure which transforms their combined operations for the discovery, classification and reporting of transient astrophysical events, over the whole sky, making them much more than the sum of their parts. This will include development of environments for the coordinated handling of extreme astrophysical events, in real time, via automated systems, as well as novel techniques for the detection of these events in a sea of noise. I will furthermore augment this program by buying in as a major partner to a rapid-response robotic optical telescope, and by cementing my relationship with an orbiting X-ray facility. This multiwavelength dimension will secure the astrophysical interpretation of our observational results and help to revolutionise high-energy astrophysics via a strong scientific exploitation program.
Summary
Extreme astrophysical events such as relativistic flows, cataclysmic explosions and black hole accretion are one of the key areas for astrophysics in the 21st century. The extremes of physics experienced in these environments are beyond anything achievable in any laboratory on Earth, and provide a unique glimpse at the laws of physics operating in extraordinary regimes. All of these events are associated with transient radio emission, a tracer both of the acceleration of particles to relativistic energies, and coherent emitting regions with huge effective temperatures. By studying radio bursts from these phenomena we can pinpoint the sources of explosive events, understand the budget of kinetic feedback by explosive events in the ambient medium, and probe the physical state of the universe back to the epoch of reionisation, less than a billion years after the big bang. In seeking to push back the frontiers of extreme astrophysics, I will use a trio of revolutionary new radio telescopes, LOFAR, ASKAP and MeerKAT, pathfinders for the Square Kilometre Array, and all facilities in which I have a major role in the search for transients. I will build an infrastructure which transforms their combined operations for the discovery, classification and reporting of transient astrophysical events, over the whole sky, making them much more than the sum of their parts. This will include development of environments for the coordinated handling of extreme astrophysical events, in real time, via automated systems, as well as novel techniques for the detection of these events in a sea of noise. I will furthermore augment this program by buying in as a major partner to a rapid-response robotic optical telescope, and by cementing my relationship with an orbiting X-ray facility. This multiwavelength dimension will secure the astrophysical interpretation of our observational results and help to revolutionise high-energy astrophysics via a strong scientific exploitation program.
Max ERC Funding
2 999 847 €
Duration
Start date: 2011-07-01, End date: 2017-06-30
Project acronym A-BINGOS
Project Accreting binary populations in Nearby Galaxies: Observations and Simulations
Researcher (PI) Andreas Zezas
Host Institution (HI) IDRYMA TECHNOLOGIAS KAI EREVNAS
Call Details Consolidator Grant (CoG), PE9, ERC-2013-CoG
Summary "High-energy observations of our Galaxy offer a good, albeit not complete, picture of the X-ray source populations, in particular the accreting binary sources. Recent ability to study accreting binaries in nearby galaxies has shown that we would be short-sighted if we restricted ourselves to our Galaxy or to a few nearby ones. I propose an ambitious project that involves a comprehensive study of all the galaxies within 10 Mpc for which we can study in detail their X-ray sources and stellar populations. The study will combine data from a unique suite of observatories (Chandra, XMM-Newton, HST, Spitzer) with state-of-the-art theoretical modelling of binary systems. I propose a novel approach that links the accreting binary populations to their parent stellar populations and surpasses any current studies of X-ray binary populations, both in scale and in scope, by: (a) combining methods and results from several different areas of astrophysics (compact objects, binary systems, stellar populations, galaxy evolution); (b) using data from almost the whole electromagnetic spectrum (infrared to X-ray bands); (c) identifying and studying the different sub-populations of accreting binaries; and (d) performing direct comparison between observations and theoretical predictions, over a broad parameter space. The project: (a) will answer the long-standing question of the formation efficiency of accreting binaries in different environments; and (b) will constrain their evolutionary paths. As by-products the project will provide eagerly awaited input to the fields of gravitational-wave sources, γ-ray bursts, and X-ray emitting galaxies at cosmological distances and it will produce a heritage multi-wavelength dataset and library of models for future studies of galaxies and accreting binaries."
Summary
"High-energy observations of our Galaxy offer a good, albeit not complete, picture of the X-ray source populations, in particular the accreting binary sources. Recent ability to study accreting binaries in nearby galaxies has shown that we would be short-sighted if we restricted ourselves to our Galaxy or to a few nearby ones. I propose an ambitious project that involves a comprehensive study of all the galaxies within 10 Mpc for which we can study in detail their X-ray sources and stellar populations. The study will combine data from a unique suite of observatories (Chandra, XMM-Newton, HST, Spitzer) with state-of-the-art theoretical modelling of binary systems. I propose a novel approach that links the accreting binary populations to their parent stellar populations and surpasses any current studies of X-ray binary populations, both in scale and in scope, by: (a) combining methods and results from several different areas of astrophysics (compact objects, binary systems, stellar populations, galaxy evolution); (b) using data from almost the whole electromagnetic spectrum (infrared to X-ray bands); (c) identifying and studying the different sub-populations of accreting binaries; and (d) performing direct comparison between observations and theoretical predictions, over a broad parameter space. The project: (a) will answer the long-standing question of the formation efficiency of accreting binaries in different environments; and (b) will constrain their evolutionary paths. As by-products the project will provide eagerly awaited input to the fields of gravitational-wave sources, γ-ray bursts, and X-ray emitting galaxies at cosmological distances and it will produce a heritage multi-wavelength dataset and library of models for future studies of galaxies and accreting binaries."
Max ERC Funding
1 242 000 €
Duration
Start date: 2014-04-01, End date: 2019-03-31
Project acronym AARTFAAC
Project Amsterdam-ASTRON Radio Transient Facility And Analysis Centre: Probing the Extremes of Astrophysics
Researcher (PI) Ralph Antoine Marie Joseph Wijers
Host Institution (HI) UNIVERSITEIT VAN AMSTERDAM
Call Details Advanced Grant (AdG), PE9, ERC-2009-AdG
Summary Some of the most extreme tests of physical law come from its manifestations in the behaviour of black holes and neutron stars, and as such these objects should be used as fundamental physics labs. Due to advances in both theoretical work and observational techniques, I have a major opportunity now to significantly push this agenda forward and get better answers to questions like: How are black holes born? How can energy be extracted from black holes? What is the origin of magnetic fields and cosmic rays in jets and shocks? Is their primary energy stream hadronic or magnetic? I propose to do this by exploiting the advent of wide-field radio astronomy: extreme objects are very rare and usually transient, so not only must one survey large areas of sky, but also must one do this often. I propose to form and shape a group that will use the LOFAR wide-field radio telescope to hunt for these extreme transients and systematically collect enough well-documented examples of the behaviour of each type of transient. Furthermore, I propose to expand LOFAR with a true 24/7 all-sky monitor to catch and study even the rarest of events. Next, I will use my experience in gamma-ray burst followup to conduct a vigorous multi-wavelength programme of study of these objects, to constrain their physics from as many angles as possible. This will eventually include results from multi-messenger astrophysics, in which we use neutrinos, gravity waves, and other non-electromagnetic messengers as extra diagnostics of the physics of these sources. Finally, I will build on my experience in modelling accretion phenomena and relativistic explosions to develop a theoretical framework for these phenomena and constrain the resulting models with the rich data sets we obtain.
Summary
Some of the most extreme tests of physical law come from its manifestations in the behaviour of black holes and neutron stars, and as such these objects should be used as fundamental physics labs. Due to advances in both theoretical work and observational techniques, I have a major opportunity now to significantly push this agenda forward and get better answers to questions like: How are black holes born? How can energy be extracted from black holes? What is the origin of magnetic fields and cosmic rays in jets and shocks? Is their primary energy stream hadronic or magnetic? I propose to do this by exploiting the advent of wide-field radio astronomy: extreme objects are very rare and usually transient, so not only must one survey large areas of sky, but also must one do this often. I propose to form and shape a group that will use the LOFAR wide-field radio telescope to hunt for these extreme transients and systematically collect enough well-documented examples of the behaviour of each type of transient. Furthermore, I propose to expand LOFAR with a true 24/7 all-sky monitor to catch and study even the rarest of events. Next, I will use my experience in gamma-ray burst followup to conduct a vigorous multi-wavelength programme of study of these objects, to constrain their physics from as many angles as possible. This will eventually include results from multi-messenger astrophysics, in which we use neutrinos, gravity waves, and other non-electromagnetic messengers as extra diagnostics of the physics of these sources. Finally, I will build on my experience in modelling accretion phenomena and relativistic explosions to develop a theoretical framework for these phenomena and constrain the resulting models with the rich data sets we obtain.
Max ERC Funding
3 499 128 €
Duration
Start date: 2010-10-01, End date: 2016-09-30
Project acronym aCROBAT
Project Circadian Regulation Of Brown Adipose Thermogenesis
Researcher (PI) Zachary Philip Gerhart-Hines
Host Institution (HI) KOBENHAVNS UNIVERSITET
Call Details Starting Grant (StG), LS4, ERC-2014-STG
Summary Obesity and diabetes have reached pandemic proportions and new therapeutic strategies are critically needed. Brown adipose tissue (BAT), a major source of heat production, possesses significant energy-dissipating capacity and therefore represents a promising target to use in combating these diseases. Recently, I discovered a novel link between circadian rhythm and thermogenic stress in the control of the conserved, calorie-burning functions of BAT. Circadian and thermogenic signaling to BAT incorporates blood-borne hormonal and nutrient cues with direct neuronal input. Yet how these responses coordinately shape BAT energy-expending potential through the regulation of cell surface receptors, metabolic enzymes, and transcriptional effectors is still not understood. My primary goal is to investigate this previously unappreciated network of crosstalk that allows mammals to effectively orchestrate daily rhythms in BAT metabolism, while maintaining their ability to adapt to abrupt changes in energy demand. My group will address this question using gain and loss-of-function in vitro and in vivo studies, newly-generated mouse models, customized physiological phenotyping, and cutting-edge advances in next generation RNA sequencing and mass spectrometry. Preliminary, small-scale validations of our methodologies have already yielded a number of novel candidates that may drive key facets of BAT metabolism. Additionally, we will extend our circadian and thermogenic studies into humans to evaluate the translational potential. Our results will advance the fundamental understanding of how daily oscillations in bioenergetic networks establish a framework for the anticipation of and adaptation to environmental challenges. Importantly, we expect that these mechanistic insights will reveal pharmacological targets through which we can unlock evolutionary constraints and harness the energy-expending potential of BAT for the prevention and treatment of obesity and diabetes.
Summary
Obesity and diabetes have reached pandemic proportions and new therapeutic strategies are critically needed. Brown adipose tissue (BAT), a major source of heat production, possesses significant energy-dissipating capacity and therefore represents a promising target to use in combating these diseases. Recently, I discovered a novel link between circadian rhythm and thermogenic stress in the control of the conserved, calorie-burning functions of BAT. Circadian and thermogenic signaling to BAT incorporates blood-borne hormonal and nutrient cues with direct neuronal input. Yet how these responses coordinately shape BAT energy-expending potential through the regulation of cell surface receptors, metabolic enzymes, and transcriptional effectors is still not understood. My primary goal is to investigate this previously unappreciated network of crosstalk that allows mammals to effectively orchestrate daily rhythms in BAT metabolism, while maintaining their ability to adapt to abrupt changes in energy demand. My group will address this question using gain and loss-of-function in vitro and in vivo studies, newly-generated mouse models, customized physiological phenotyping, and cutting-edge advances in next generation RNA sequencing and mass spectrometry. Preliminary, small-scale validations of our methodologies have already yielded a number of novel candidates that may drive key facets of BAT metabolism. Additionally, we will extend our circadian and thermogenic studies into humans to evaluate the translational potential. Our results will advance the fundamental understanding of how daily oscillations in bioenergetic networks establish a framework for the anticipation of and adaptation to environmental challenges. Importantly, we expect that these mechanistic insights will reveal pharmacological targets through which we can unlock evolutionary constraints and harness the energy-expending potential of BAT for the prevention and treatment of obesity and diabetes.
Max ERC Funding
1 497 008 €
Duration
Start date: 2015-05-01, End date: 2020-04-30
Project acronym ADULT
Project Analysis of the Dark Universe through Lensing Tomography
Researcher (PI) Hendrik Hoekstra
Host Institution (HI) UNIVERSITEIT LEIDEN
Call Details Starting Grant (StG), PE9, ERC-2011-StG_20101014
Summary The discoveries that the expansion of the universe is accelerating due to an unknown “dark energy”
and that most of the matter is invisible, highlight our lack of understanding of the major constituents
of the universe. These surprising findings set the stage for research in cosmology at the start of the
21st century. The objective of this proposal is to advance observational constraints to a level where we can distinguish between physical mechanisms that aim to explain the properties of dark energy and the observed distribution of dark matter throughout the universe. We use a relatively new technique called weak gravitational lensing: the accurate measurement of correlations in the orientations of distant galaxies enables us to map the dark matter distribution directly and to extract the cosmological information that is encoded by the large-scale structure.
To study the dark universe we will analyse data from a new state-of-the-art imaging survey: the Kilo-
Degree Survey (KiDS) will cover 1500 square degrees in 9 filters. The combination of its large survey
area and the availability of exquisite photometric redshifts for the sources makes KiDS the first
project that can place interesting constraints on the dark energy equation-of-state using lensing data
alone. Combined with complementary results from Planck, our measurements will provide one of the
best views of the dark side of the universe before much larger space-based projects commence.
To reach the desired accuracy we need to carefully measure the shapes of distant background galaxies. We also need to account for any intrinsic alignments that arise due to tidal interactions, rather than through lensing. Reducing these observational and physical biases to negligible levels is a necessarystep to ensure the success of KiDS and an important part of our preparation for more challenging projects such as the European-led space mission Euclid.
Summary
The discoveries that the expansion of the universe is accelerating due to an unknown “dark energy”
and that most of the matter is invisible, highlight our lack of understanding of the major constituents
of the universe. These surprising findings set the stage for research in cosmology at the start of the
21st century. The objective of this proposal is to advance observational constraints to a level where we can distinguish between physical mechanisms that aim to explain the properties of dark energy and the observed distribution of dark matter throughout the universe. We use a relatively new technique called weak gravitational lensing: the accurate measurement of correlations in the orientations of distant galaxies enables us to map the dark matter distribution directly and to extract the cosmological information that is encoded by the large-scale structure.
To study the dark universe we will analyse data from a new state-of-the-art imaging survey: the Kilo-
Degree Survey (KiDS) will cover 1500 square degrees in 9 filters. The combination of its large survey
area and the availability of exquisite photometric redshifts for the sources makes KiDS the first
project that can place interesting constraints on the dark energy equation-of-state using lensing data
alone. Combined with complementary results from Planck, our measurements will provide one of the
best views of the dark side of the universe before much larger space-based projects commence.
To reach the desired accuracy we need to carefully measure the shapes of distant background galaxies. We also need to account for any intrinsic alignments that arise due to tidal interactions, rather than through lensing. Reducing these observational and physical biases to negligible levels is a necessarystep to ensure the success of KiDS and an important part of our preparation for more challenging projects such as the European-led space mission Euclid.
Max ERC Funding
1 316 880 €
Duration
Start date: 2012-01-01, End date: 2016-12-31
Project acronym AEONS
Project Advancing the Equation of state of Neutron Stars
Researcher (PI) Anna WATTS
Host Institution (HI) UNIVERSITEIT VAN AMSTERDAM
Call Details Consolidator Grant (CoG), PE9, ERC-2019-COG
Summary Densities in neutron star (NS) cores can reach up to ten times the density of a normal atomic nucleus, and the stabilising effect of gravitational confinement permits long-timescale weak interactions. This generates nucleonic matter that is extremely neutron-rich, and the exciting possibility of stable states of strange matter (hyperons or deconfined quarks). Our uncertainty about the nature of cold ultradense matter is encoded in the Equation of State (EOS), which can be mapped via the stellar structure equations to quantities like mass M and radius R that determine the exterior space-time.
One very promising technique for measuring the EOS exploits hotspots that form on the NS surface due to the pulsar mechanism, accretion streams, or during thermonuclear explosions in the stellar ocean. As the NS rotates, the hotspot gives rise to a pulsation and relativistic effects encode information about the EOS into the pulse profile. Pulse Profile Modelling (PPM), which employs relativistic ray-tracing and Bayesian inference codes to measure M-R and the EOS, is being pioneered by NASA’s NICER telescope, which is poised to deliver its first results in 2019.
Complexities, that have only become apparent with exposure to real data, mean that there is work to be done if we are to have confidence in the nominal 5-10% accuracy of NICER’s M-R results. AEONS will deliver this. The project will also look ahead to the next generation of large-area X-ray timing telescopes, since it is only then that PPM will place tight constraints on dense matter models. The sources these missions target, accreting neutron stars, pose challenges for PPM such as variability, surface pattern uncertainty, and polarimetric signatures. AEONS will develop a robust pipeline for accreting NS PPM and embed it in a multi-messenger EOS inference framework with radio and gravitational wave constraints. This will ensure that PPM delivers major advances in our understanding of the nature of matter.
Summary
Densities in neutron star (NS) cores can reach up to ten times the density of a normal atomic nucleus, and the stabilising effect of gravitational confinement permits long-timescale weak interactions. This generates nucleonic matter that is extremely neutron-rich, and the exciting possibility of stable states of strange matter (hyperons or deconfined quarks). Our uncertainty about the nature of cold ultradense matter is encoded in the Equation of State (EOS), which can be mapped via the stellar structure equations to quantities like mass M and radius R that determine the exterior space-time.
One very promising technique for measuring the EOS exploits hotspots that form on the NS surface due to the pulsar mechanism, accretion streams, or during thermonuclear explosions in the stellar ocean. As the NS rotates, the hotspot gives rise to a pulsation and relativistic effects encode information about the EOS into the pulse profile. Pulse Profile Modelling (PPM), which employs relativistic ray-tracing and Bayesian inference codes to measure M-R and the EOS, is being pioneered by NASA’s NICER telescope, which is poised to deliver its first results in 2019.
Complexities, that have only become apparent with exposure to real data, mean that there is work to be done if we are to have confidence in the nominal 5-10% accuracy of NICER’s M-R results. AEONS will deliver this. The project will also look ahead to the next generation of large-area X-ray timing telescopes, since it is only then that PPM will place tight constraints on dense matter models. The sources these missions target, accreting neutron stars, pose challenges for PPM such as variability, surface pattern uncertainty, and polarimetric signatures. AEONS will develop a robust pipeline for accreting NS PPM and embed it in a multi-messenger EOS inference framework with radio and gravitational wave constraints. This will ensure that PPM delivers major advances in our understanding of the nature of matter.
Max ERC Funding
2 425 000 €
Duration
Start date: 2020-06-01, End date: 2025-05-31
Project acronym AEROSOL
Project Astrochemistry of old stars: direct probing of unique chemical laboratories
Researcher (PI) Leen Katrien Els Decin
Host Institution (HI) KATHOLIEKE UNIVERSITEIT LEUVEN
Call Details Consolidator Grant (CoG), PE9, ERC-2014-CoG
Summary The gas and dust in the interstellar medium (ISM) drive the chemical evolution of galaxies, the formation of stars and planets, and the synthesis of complex prebiotic molecules. The prime birth places for this interstellar material are the winds of evolved (super)giant stars. These winds are unique chemical laboratories, in which a large variety of gas and dust species radially expand away from the star.
Recent progress on the observations of these winds has been impressive thanks to Herschel and ALMA. The next challenge is to unravel the wealth of chemical information contained in these data. This is an ambitious task since (1) a plethora of physical and chemical processes interact in a complex way, (2) laboratory data to interpret these interactions are lacking, and (3) theoretical tools to analyse the data do not meet current needs.
To boost the knowledge of the physics and chemistry characterizing these winds, I propose a world-leading multi-disciplinary project combining (1) high-quality data, (2) novel theoretical wind models, and (3) targeted laboratory experiments. The aim is to pinpoint the dominant chemical pathways, unravel the transition from gas-phase to dust species, elucidate the role of clumps on the overall wind structure, and study the reciprocal effect between various dynamical and chemical phenomena.
Now is the right time for this ambitious project thanks to the availability of (1) high-quality multi-wavelength data, including ALMA and Herschel data of the PI, (2) supercomputers enabling a homogeneous analysis of the data using sophisticated theoretical wind models, and (3) novel laboratory equipment to measure the gas-phase reaction rates of key species.
This project will have far-reaching impact on (1) the field of evolved stars, (2) the understanding of the chemical lifecycle of the ISM, (3) chemical studies of dynamically more complex systems, such as exoplanets, protostars, supernovae etc., and (4) it will guide new instrument development.
Summary
The gas and dust in the interstellar medium (ISM) drive the chemical evolution of galaxies, the formation of stars and planets, and the synthesis of complex prebiotic molecules. The prime birth places for this interstellar material are the winds of evolved (super)giant stars. These winds are unique chemical laboratories, in which a large variety of gas and dust species radially expand away from the star.
Recent progress on the observations of these winds has been impressive thanks to Herschel and ALMA. The next challenge is to unravel the wealth of chemical information contained in these data. This is an ambitious task since (1) a plethora of physical and chemical processes interact in a complex way, (2) laboratory data to interpret these interactions are lacking, and (3) theoretical tools to analyse the data do not meet current needs.
To boost the knowledge of the physics and chemistry characterizing these winds, I propose a world-leading multi-disciplinary project combining (1) high-quality data, (2) novel theoretical wind models, and (3) targeted laboratory experiments. The aim is to pinpoint the dominant chemical pathways, unravel the transition from gas-phase to dust species, elucidate the role of clumps on the overall wind structure, and study the reciprocal effect between various dynamical and chemical phenomena.
Now is the right time for this ambitious project thanks to the availability of (1) high-quality multi-wavelength data, including ALMA and Herschel data of the PI, (2) supercomputers enabling a homogeneous analysis of the data using sophisticated theoretical wind models, and (3) novel laboratory equipment to measure the gas-phase reaction rates of key species.
This project will have far-reaching impact on (1) the field of evolved stars, (2) the understanding of the chemical lifecycle of the ISM, (3) chemical studies of dynamically more complex systems, such as exoplanets, protostars, supernovae etc., and (4) it will guide new instrument development.
Max ERC Funding
2 605 897 €
Duration
Start date: 2016-01-01, End date: 2020-12-31
Project acronym AgeingStemCellFate
Project The Role of Ectopic Adipocyte Progenitors in Age-related Stem Cell Dysfunction, Systemic Inflammation, and Metabolic Disease
Researcher (PI) Tim Julius Schulz
Host Institution (HI) DEUTSCHES INSTITUT FUER ERNAEHRUNGSFORSCHUNG POTSDAM REHBRUECKE
Call Details Starting Grant (StG), LS4, ERC-2012-StG_20111109
Summary Ageing is accompanied by ectopic white adipose tissue depositions in skeletal muscle and other anatomical locations, such as brown adipose tissue and the bone marrow. Ectopic fat accrual contributes to organ dysfunction, systemic insulin resistance, and other perturbations that have been implicated in metabolic diseases.
This research proposal aims to identify the regulatory cues that control the development of ectopic progenitor cells that give rise to this type of fat. It is hypothesized that an age-related dysfunction of the stem cell niche leads to an imbalance between (1) tissue-specific stem cells and (2) fibroblast-like, primarily adipogenic progenitors that reside within many tissues. Novel methodologies that assess stem/progenitor cell characteristics on the single cell level will be combined with animal models of lineage tracing to determine the developmental origin of these adipogenic progenitors and processes that regulate their function.
Notch signalling is a key signalling pathway that relies on direct physical interaction to control stem cell fate. It is proposed that impaired Notch activity contributes to the phenotypical shift of precursor cell distribution in aged tissues.
Lastly, the role of the stem cell niche in ectopic adipocyte progenitor formation will be analyzed. External signals originating from the surrounding niche cells regulate the developmental fate of stem cells. Secreted factors and their role in the formation of ectopic adipocyte precursors during senescence will be identified using a combination of biochemical and systems biology approaches.
Accomplishment of these studies will help to understand the basic processes of stem cell ageing and identify mechanisms of age-related functional decline in tissue regeneration. By targeting the population of tissue-resident adipogenic progenitor cells, therapeutic strategies could be developed to counteract metabolic complications associated with the ageing process.
Summary
Ageing is accompanied by ectopic white adipose tissue depositions in skeletal muscle and other anatomical locations, such as brown adipose tissue and the bone marrow. Ectopic fat accrual contributes to organ dysfunction, systemic insulin resistance, and other perturbations that have been implicated in metabolic diseases.
This research proposal aims to identify the regulatory cues that control the development of ectopic progenitor cells that give rise to this type of fat. It is hypothesized that an age-related dysfunction of the stem cell niche leads to an imbalance between (1) tissue-specific stem cells and (2) fibroblast-like, primarily adipogenic progenitors that reside within many tissues. Novel methodologies that assess stem/progenitor cell characteristics on the single cell level will be combined with animal models of lineage tracing to determine the developmental origin of these adipogenic progenitors and processes that regulate their function.
Notch signalling is a key signalling pathway that relies on direct physical interaction to control stem cell fate. It is proposed that impaired Notch activity contributes to the phenotypical shift of precursor cell distribution in aged tissues.
Lastly, the role of the stem cell niche in ectopic adipocyte progenitor formation will be analyzed. External signals originating from the surrounding niche cells regulate the developmental fate of stem cells. Secreted factors and their role in the formation of ectopic adipocyte precursors during senescence will be identified using a combination of biochemical and systems biology approaches.
Accomplishment of these studies will help to understand the basic processes of stem cell ageing and identify mechanisms of age-related functional decline in tissue regeneration. By targeting the population of tissue-resident adipogenic progenitor cells, therapeutic strategies could be developed to counteract metabolic complications associated with the ageing process.
Max ERC Funding
1 496 444 €
Duration
Start date: 2013-03-01, End date: 2018-02-28
