Project acronym BayeSN
Project Next-Generation Data-Driven Probabilistic Modelling of Type Ia Supernova SEDs in the Optical to Near-Infrared for Robust Cosmological Inference
Researcher (PI) Kaisey Mandel
Host Institution (HI) THE CHANCELLOR MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE
Country United Kingdom
Call Details Consolidator Grant (CoG), PE9, ERC-2020-COG
Summary Type Ia supernovae (SNe Ia) are used as “standardiseable candles”: their peak luminosities can be inferred from their optical light curve shapes and colours, so their distances can be estimated from their apparent brightnesses. SN Ia distances with high precision and small systematic error are essential to accurate constraints on the cosmic expansion history, local measurements of the Hubble constant, and the properties of the dark energy driving the acceleration, in particular, its equation-of-state parameter w. The current global sample used for cosmology has grown to over a thousand SNe Ia. Future surveys will boost that number by orders of magnitude. However, the constraints on dark energy with the current optical sample are already limited, not by statistical uncertainties from the numbers of SNe, but by systematic errors. Near-infrared (NIR) observations of SN Ia are a route to more precise and accurate distances and significantly enhance their cosmological utility. SNe Ia are excellent standard candles in the NIR, and are less vulnerable to absorption by dust in the host galaxies. These good NIR properties are not exploited by the conventional optical models currently used for cosmological SN Ia analysis. Furthermore, the present useful sample of SN Ia with NIR data is relatively small compared to the growing nearby or distant optical samples. In this Project, we will leverage our involvement in new SN surveys using the Hubble Space Telescope and ground-based observatories to build a ~10X larger sample of SNe Ia with high-quality optical and NIR data. We will develop the next-generation probabilistic model for SN Ia spectral energy distributions (SEDs) in the optical-to-NIR, accounting properly for the variabilities and uncertainties inherent in the data by fusing advanced hierarchical Bayesian modelling and functional data analysis techniques. We will apply our state-of-the-art model to our new SN datasets and LSST to obtain robust cosmological inferences.
Summary
Type Ia supernovae (SNe Ia) are used as “standardiseable candles”: their peak luminosities can be inferred from their optical light curve shapes and colours, so their distances can be estimated from their apparent brightnesses. SN Ia distances with high precision and small systematic error are essential to accurate constraints on the cosmic expansion history, local measurements of the Hubble constant, and the properties of the dark energy driving the acceleration, in particular, its equation-of-state parameter w. The current global sample used for cosmology has grown to over a thousand SNe Ia. Future surveys will boost that number by orders of magnitude. However, the constraints on dark energy with the current optical sample are already limited, not by statistical uncertainties from the numbers of SNe, but by systematic errors. Near-infrared (NIR) observations of SN Ia are a route to more precise and accurate distances and significantly enhance their cosmological utility. SNe Ia are excellent standard candles in the NIR, and are less vulnerable to absorption by dust in the host galaxies. These good NIR properties are not exploited by the conventional optical models currently used for cosmological SN Ia analysis. Furthermore, the present useful sample of SN Ia with NIR data is relatively small compared to the growing nearby or distant optical samples. In this Project, we will leverage our involvement in new SN surveys using the Hubble Space Telescope and ground-based observatories to build a ~10X larger sample of SNe Ia with high-quality optical and NIR data. We will develop the next-generation probabilistic model for SN Ia spectral energy distributions (SEDs) in the optical-to-NIR, accounting properly for the variabilities and uncertainties inherent in the data by fusing advanced hierarchical Bayesian modelling and functional data analysis techniques. We will apply our state-of-the-art model to our new SN datasets and LSST to obtain robust cosmological inferences.
Max ERC Funding
2 446 736 €
Duration
Start date: 2021-10-01, End date: 2026-09-30
Project acronym Chemtrip
Project The chemical trail in protostars: From the deeply embedded phase to the planet forming disk
Researcher (PI) Audrey COUTENS
Host Institution (HI) UNIVERSITE PAUL SABATIER TOULOUSE III
Country France
Call Details Starting Grant (StG), PE9, ERC-2020-STG
Summary The emergence of Life relied on the presence of key molecules like water and prebiotic molecules. The primitive objects of our Solar System (comets, asteroids), which formed in the disk of dust and gas surrounding the young Sun, are thought to have delivered them to Earth during heavy bombardments. Observations show that the deeply embedded Class 0 protostars also harbour a very rich chemistry in their inner regions. What occurs to the chemical composition between this early stage of the star formation process and the formation of planets, comets, and asteroids is unknown. Do the molecules detected in these young protostars survive or are they destroyed and reformed at a later stage before being incorporated into planets, comets, and asteroids?
This ERC project aims to reconstruct the physico-chemical evolution from the deeply embedded protostellar stage to the planet forming disk stage, through multi-source analyses of high angular resolution observations combined with chemical modeling studies.
I will investigate the evolution of complex organic chemistry and isotopic fractionation during the star formation process using interferometric observations (ALMA, NOEMA) of solar-type protostars. In addition, I will carry out numerical simulations with a state-of-the-art gas-grain chemistry code in order to interpret the observations as well as to characterize the impact of the physical conditions and their evolution (environment, grain growth and dust settling, episodic accretion) on the chemistry.
This ERC project will lead to a new understanding of the evolution of the chemical composition from the earliest protostellar stage to the formation of the disk that will give birth to the planets, comets, and asteroids, while identifying the processes affecting the final composition of the disk. The observational work will require the development of innovative tools of interest for the astrochemical community that I will release publicly.
Summary
The emergence of Life relied on the presence of key molecules like water and prebiotic molecules. The primitive objects of our Solar System (comets, asteroids), which formed in the disk of dust and gas surrounding the young Sun, are thought to have delivered them to Earth during heavy bombardments. Observations show that the deeply embedded Class 0 protostars also harbour a very rich chemistry in their inner regions. What occurs to the chemical composition between this early stage of the star formation process and the formation of planets, comets, and asteroids is unknown. Do the molecules detected in these young protostars survive or are they destroyed and reformed at a later stage before being incorporated into planets, comets, and asteroids?
This ERC project aims to reconstruct the physico-chemical evolution from the deeply embedded protostellar stage to the planet forming disk stage, through multi-source analyses of high angular resolution observations combined with chemical modeling studies.
I will investigate the evolution of complex organic chemistry and isotopic fractionation during the star formation process using interferometric observations (ALMA, NOEMA) of solar-type protostars. In addition, I will carry out numerical simulations with a state-of-the-art gas-grain chemistry code in order to interpret the observations as well as to characterize the impact of the physical conditions and their evolution (environment, grain growth and dust settling, episodic accretion) on the chemistry.
This ERC project will lead to a new understanding of the evolution of the chemical composition from the earliest protostellar stage to the formation of the disk that will give birth to the planets, comets, and asteroids, while identifying the processes affecting the final composition of the disk. The observational work will require the development of innovative tools of interest for the astrochemical community that I will release publicly.
Max ERC Funding
1 499 995 €
Duration
Start date: 2021-09-01, End date: 2026-08-31
Project acronym DarkQuest
Project Shedding Light on the Nature of Dark Matter and Dark Energy with Multi-Wavelength All-Sky Surveys
Researcher (PI) Esra Bulbul
Host Institution (HI) MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV
Country Germany
Call Details Consolidator Grant (CoG), PE9, ERC-2020-COG
Summary Despite two decades of intensive efforts after the discovery of the accelerating expansion of the Universe, the nature of dark energy that dominates 68 percent of the energy density remains unknown. The majority of the remainder is in dark matter. Similarly, the elementary particles which constitute its mass is unidentified. Galaxy clusters trace the highest peaks in the cosmic density field and offer an independent and powerful probe of the growth of structure. Their overall abundance on the sky is strongly dependent on underlying cosmology. With the new availability of all sky surveys of galaxy clusters in the X-ray band with eROSITA and the utility of weak lensing signal in accurate estimation of cluster masses, we are on the verge of constraining cosmology with percent level precision. We propose to measure the energy density of the total matter, the normalization of the power spectrum of dark energy, the dark energy equation-of-state, and neutrino masses with a percent level accuracy. All sky survey observation with eROSITA and complimentary weak lensing observations with HSC also offer new prospects to test general relativity at large scales, and constrain well-motivated dark matter models (e.g. warm dark matter and self-interacting dark matter). Europe will have an opportunity to be on the forefront of observational cosmology and set the stage for the upcoming experiments if this proposal is funded. Given my expertise in the field of galaxy clusters and my role as the chair of the clusters and cosmology working group of the eROSITA consortium, I am uniquely suited to lead this effort and accomplish the goals of this proposal.
Summary
Despite two decades of intensive efforts after the discovery of the accelerating expansion of the Universe, the nature of dark energy that dominates 68 percent of the energy density remains unknown. The majority of the remainder is in dark matter. Similarly, the elementary particles which constitute its mass is unidentified. Galaxy clusters trace the highest peaks in the cosmic density field and offer an independent and powerful probe of the growth of structure. Their overall abundance on the sky is strongly dependent on underlying cosmology. With the new availability of all sky surveys of galaxy clusters in the X-ray band with eROSITA and the utility of weak lensing signal in accurate estimation of cluster masses, we are on the verge of constraining cosmology with percent level precision. We propose to measure the energy density of the total matter, the normalization of the power spectrum of dark energy, the dark energy equation-of-state, and neutrino masses with a percent level accuracy. All sky survey observation with eROSITA and complimentary weak lensing observations with HSC also offer new prospects to test general relativity at large scales, and constrain well-motivated dark matter models (e.g. warm dark matter and self-interacting dark matter). Europe will have an opportunity to be on the forefront of observational cosmology and set the stage for the upcoming experiments if this proposal is funded. Given my expertise in the field of galaxy clusters and my role as the chair of the clusters and cosmology working group of the eROSITA consortium, I am uniquely suited to lead this effort and accomplish the goals of this proposal.
Max ERC Funding
2 000 000 €
Duration
Start date: 2021-04-01, End date: 2026-03-31
Project acronym DipolarSound
Project Internal structure of red-giant stars through the sound of dipole oscillation modes
Researcher (PI) Saskia HEKKER
Host Institution (HI) HITS GGMBH
Country Germany
Call Details Consolidator Grant (CoG), PE9, ERC-2020-COG
Summary What would a star look like below its opaque surface? What are the physical conditions in a star? What physical processes play an important role in stars? How do these physical conditions and processes interact? How do they change with time, when a star evolves? Answering these kinds of questions is of fundamental importance for astronomy and beyond. Stars are a dominant source of light in the universe as well as main building blocks of planetary systems and galaxies. Thus, understanding of stars has a major impact in these fields. Closer to home, understanding the past and future of the Sun has a potentially wide-ranging impact on other scientific fields. To pierce inside stars, we need observable features that are sensitive to the hidden layers in stars. Intrinsic global oscillations are observable, and are sensitive to the internal structures of stars. The application of these global modes to study internal stellar structures is the field of asteroseismology. Particularly interesting and opportune stars to apply asteroseismology to are red-giant stars. These evolved stars are abundant, relatively bright, exhibit different stellar structures, allow to trace back a long history, and possess probes that are sensitive to both their deep and their more shallow layers; the so-called mixed dipole oscillation modes. The observed characteristics of mixed dipole modes differ significantly between different red-giant stars, leading to the following questions: • ‘What are the physical differences in the structures of / conditions in red-giant stars which lead to different mixed dipole mode oscillation spectra?’ • ‘What is the cause of the different structures / conditions in these stars?’ The aim of the DipolarSound proposal is to unravel the physical conditions and physical processes at play in red-giant stars using mixed dipole oscillation modes and to understand the underlying physical origin of the different oscillation spectra observed in red-giant stars.
Summary
What would a star look like below its opaque surface? What are the physical conditions in a star? What physical processes play an important role in stars? How do these physical conditions and processes interact? How do they change with time, when a star evolves? Answering these kinds of questions is of fundamental importance for astronomy and beyond. Stars are a dominant source of light in the universe as well as main building blocks of planetary systems and galaxies. Thus, understanding of stars has a major impact in these fields. Closer to home, understanding the past and future of the Sun has a potentially wide-ranging impact on other scientific fields. To pierce inside stars, we need observable features that are sensitive to the hidden layers in stars. Intrinsic global oscillations are observable, and are sensitive to the internal structures of stars. The application of these global modes to study internal stellar structures is the field of asteroseismology. Particularly interesting and opportune stars to apply asteroseismology to are red-giant stars. These evolved stars are abundant, relatively bright, exhibit different stellar structures, allow to trace back a long history, and possess probes that are sensitive to both their deep and their more shallow layers; the so-called mixed dipole oscillation modes. The observed characteristics of mixed dipole modes differ significantly between different red-giant stars, leading to the following questions: • ‘What are the physical differences in the structures of / conditions in red-giant stars which lead to different mixed dipole mode oscillation spectra?’ • ‘What is the cause of the different structures / conditions in these stars?’ The aim of the DipolarSound proposal is to unravel the physical conditions and physical processes at play in red-giant stars using mixed dipole oscillation modes and to understand the underlying physical origin of the different oscillation spectra observed in red-giant stars.
Max ERC Funding
2 000 000 €
Duration
Start date: 2021-10-01, End date: 2026-09-30
Project acronym ELEMENTS
Project Role of extreme events in Galaxy evolution
Researcher (PI) Maria Bergemann
Host Institution (HI) MAX-PLANCK-GESELLSCHAFT ZUR FORDERUNG DER WISSENSCHAFTEN EV
Country Germany
Call Details Starting Grant (StG), PE9, ERC-2020-STG
Summary The primary goal of my proposal is to provide stringent observational constraints on the cosmic origins of elements heavier than iron and on the role of extreme objects in the evolution of the Milky Way. I will do this by employing abundances of different chemical elements for hundreds of thousands of stars from my high-resolution spectroscopic survey of the disk and bulge on the 4MOST instrument. These elements trace the production in a variety of extreme astrophysical sites: hydrostatic and explosive burning, s-process in asymptotic giant branch stars and in massive stars, r-process in compact binary mergers, neutrino-driven winds of core collapse supernovae, magnetars, and collapsars. I will use the novel Non-LTE models that I pioneered and successfully applied throughout my career to provide accurate and homogeneous chemical abundances of stars. I will quantify the trends of abundance ratios and their dispersions with metallicity, age, and location that will be directly compared with the predictions of Galactic chemical evolution models. My ERC project represents the first systematic investigation of s- and r-process nucleosynthesis in a large stellar sample. I will use the comprehensive maps of chemical enrichment to constrain the multimodality of the nuclear production sites, to confine the parameter space of stellar sources capable of hosting s- and r-process, and to test the role of these extreme events in the evolution of the Galaxy.
Summary
The primary goal of my proposal is to provide stringent observational constraints on the cosmic origins of elements heavier than iron and on the role of extreme objects in the evolution of the Milky Way. I will do this by employing abundances of different chemical elements for hundreds of thousands of stars from my high-resolution spectroscopic survey of the disk and bulge on the 4MOST instrument. These elements trace the production in a variety of extreme astrophysical sites: hydrostatic and explosive burning, s-process in asymptotic giant branch stars and in massive stars, r-process in compact binary mergers, neutrino-driven winds of core collapse supernovae, magnetars, and collapsars. I will use the novel Non-LTE models that I pioneered and successfully applied throughout my career to provide accurate and homogeneous chemical abundances of stars. I will quantify the trends of abundance ratios and their dispersions with metallicity, age, and location that will be directly compared with the predictions of Galactic chemical evolution models. My ERC project represents the first systematic investigation of s- and r-process nucleosynthesis in a large stellar sample. I will use the comprehensive maps of chemical enrichment to constrain the multimodality of the nuclear production sites, to confine the parameter space of stellar sources capable of hosting s- and r-process, and to test the role of these extreme events in the evolution of the Galaxy.
Max ERC Funding
1 367 500 €
Duration
Start date: 2021-06-01, End date: 2026-05-31
Project acronym ExSMBHs
Project The Missing Pieces of the SMBH Accretion Puzzle: Revealing Extreme Accretion Modes
Researcher (PI) Benny Trakhtenbrot
Host Institution (HI) TEL AVIV UNIVERSITY
Country Israel
Call Details Starting Grant (StG), PE9, ERC-2020-STG
Summary How do supermassive black holes (SMBHs) turn their accretion “on” and “off”? How fast can they grow? How is this related to their circumnuclear environments? What are the consequences for the emergence of the first SMBHs and their co-evolution with galaxies? The key to answering these and other questions is found in understanding SMBH accretion, in all possible modes and cosmic epochs. Recent progress in both theory and observations strongly support “extreme” modes of SMBH accretion, namely abrupt changes seen on timescales of weeks and the possibility of (also long-lived) super-Eddington accretion. Both of these sorts of extreme accretion are not yet well understood. Here I propose to change this, by leading a multi-faceted observational program that will reveal, survey, and characterize extreme modes of SMBH accretion. Some of the efforts I will lead include: (1) Responsive, multi-wavelength, and spectroscopic follow-up observations of hyper-variable and flaring accreting SMBHs, to provide new insights as to what starts or stops SMBH accretion, and a new way to study super-Eddington accretion; (2) Proprietary multi-epoch SDSS-V spectroscopy will allow me to determine how common these dramatic events are, and to look for trends with BH and host galaxy properties; (3) A complete, detailed survey of highly accreting SMBHs in the local universe; and (4) An exploratory survey of super-Eddington, advection-dominated SMBHs at significant redshifts. These and other new insights will be combined with newly established, highly complete distributions of the black hole masses and accretion rates at both low and high redshifts, to understand the role of extreme accretion modes in the general SMBH population and to help guide future surveys. This research has to be done now, as we try to complete our understanding of (cosmic) SMBH accretion and (co-)evolution; before we are flooded with millions transients; and before the next generation facilities and surveys are finalized.
Summary
How do supermassive black holes (SMBHs) turn their accretion “on” and “off”? How fast can they grow? How is this related to their circumnuclear environments? What are the consequences for the emergence of the first SMBHs and their co-evolution with galaxies? The key to answering these and other questions is found in understanding SMBH accretion, in all possible modes and cosmic epochs. Recent progress in both theory and observations strongly support “extreme” modes of SMBH accretion, namely abrupt changes seen on timescales of weeks and the possibility of (also long-lived) super-Eddington accretion. Both of these sorts of extreme accretion are not yet well understood. Here I propose to change this, by leading a multi-faceted observational program that will reveal, survey, and characterize extreme modes of SMBH accretion. Some of the efforts I will lead include: (1) Responsive, multi-wavelength, and spectroscopic follow-up observations of hyper-variable and flaring accreting SMBHs, to provide new insights as to what starts or stops SMBH accretion, and a new way to study super-Eddington accretion; (2) Proprietary multi-epoch SDSS-V spectroscopy will allow me to determine how common these dramatic events are, and to look for trends with BH and host galaxy properties; (3) A complete, detailed survey of highly accreting SMBHs in the local universe; and (4) An exploratory survey of super-Eddington, advection-dominated SMBHs at significant redshifts. These and other new insights will be combined with newly established, highly complete distributions of the black hole masses and accretion rates at both low and high redshifts, to understand the role of extreme accretion modes in the general SMBH population and to help guide future surveys. This research has to be done now, as we try to complete our understanding of (cosmic) SMBH accretion and (co-)evolution; before we are flooded with millions transients; and before the next generation facilities and surveys are finalized.
Max ERC Funding
1 684 750 €
Duration
Start date: 2021-10-01, End date: 2026-09-30
Project acronym GAIA-BIFROST
Project GAIA-BInaries: Formation and fundamental pRoperties Of Stars and planeTary systems
Researcher (PI) Stefan Kraus
Host Institution (HI) THE UNIVERSITY OF EXETER
Country United Kingdom
Call Details Consolidator Grant (CoG), PE9, ERC-2020-COG
Summary Systems with close stellar-mass or planetary-mass companions are ubiquities in the universe. However, the processes that shape the architecture of these systems are still not understood. By 2021 the GAIA mission will provide astrometric+radial velocity orbits for millions of multiple systems. For the vast majority, GAIA will measure only photocenter displacements and not be able to resolve the individual components, preventing masses and orbital statistics to be derived. The aim of the GAIA-BIFROST project is to exploit the GAIA sample in order to identify the processes that govern the formation and dynamical evolution of binaries and planetary systems. Using VLTI+CHARA interferometry we will resolve up to ∼6000 GAIA binaries in the continuum and in spectral lines, allowing us: (a) to derive precision dynamical masses, ages, and comprehensive orbital parameter statistics that is needed to discern between different binary formation scenarios; (b) to measure the spin-orbit and spin-spin alignment for hundreds of GAIA star-star and star-planet systems. This will constrain the origin of the orbit obliquity for stars and planets, providing unique information about their formation process and dynamical history; and (c) to image companion-disk interactions in young binary systems and use them as benchmark for studying the hydrodynamical processes that determine the system architecture at formation. Furthermore, our survey will provide a legacy data set of dynamical masses and precision ages for (literally!) thousands of stars, by far exceeding all earlier work in these areas. This will impact many areas of modern astrophysics, including studies on stellar evolution and Galactic Archaeology. To unlock these powerful new observational avenues, it is important to resolve GAIA binaries close to the GAIA wavebands and at high spectral resolution. We will achieve this by commissioning the BIFROST beam combiner at VLTI, building on our recent successful instrumentation work
Summary
Systems with close stellar-mass or planetary-mass companions are ubiquities in the universe. However, the processes that shape the architecture of these systems are still not understood. By 2021 the GAIA mission will provide astrometric+radial velocity orbits for millions of multiple systems. For the vast majority, GAIA will measure only photocenter displacements and not be able to resolve the individual components, preventing masses and orbital statistics to be derived. The aim of the GAIA-BIFROST project is to exploit the GAIA sample in order to identify the processes that govern the formation and dynamical evolution of binaries and planetary systems. Using VLTI+CHARA interferometry we will resolve up to ∼6000 GAIA binaries in the continuum and in spectral lines, allowing us: (a) to derive precision dynamical masses, ages, and comprehensive orbital parameter statistics that is needed to discern between different binary formation scenarios; (b) to measure the spin-orbit and spin-spin alignment for hundreds of GAIA star-star and star-planet systems. This will constrain the origin of the orbit obliquity for stars and planets, providing unique information about their formation process and dynamical history; and (c) to image companion-disk interactions in young binary systems and use them as benchmark for studying the hydrodynamical processes that determine the system architecture at formation. Furthermore, our survey will provide a legacy data set of dynamical masses and precision ages for (literally!) thousands of stars, by far exceeding all earlier work in these areas. This will impact many areas of modern astrophysics, including studies on stellar evolution and Galactic Archaeology. To unlock these powerful new observational avenues, it is important to resolve GAIA binaries close to the GAIA wavebands and at high spectral resolution. We will achieve this by commissioning the BIFROST beam combiner at VLTI, building on our recent successful instrumentation work
Max ERC Funding
2 998 750 €
Duration
Start date: 2021-12-01, End date: 2026-11-30
Project acronym GWmining
Project Gravitational-wave data mining
Researcher (PI) Davide Gerosa
Host Institution (HI) THE UNIVERSITY OF BIRMINGHAM
Country United Kingdom
Call Details Starting Grant (StG), PE9, ERC-2020-STG
Summary Gravitational-wave astronomy is entering its large-statistics regime. Catalogs with thousands of gravitational-wave events will soon be available, providing a wealth of information on the most compact objects in the Universe --black holes and neutron stars. These new datasets need new tools to be exploited effectively in order to maximize their scientific impact.
GWmining is an ambitious program to explore upcoming gravitational-wave catalogs with data-mining techniques. We will develop a complete framework to analyze gravitational-wave data in light of astrophysical predictions. Going beyond phenomenological models, we will train machine-learning algorithms directly on large banks of population-synthesis simulations and post-Newtonian integrations. The development of these astrophysical predictions requires new modeling strategies to accurately capture all the gravitational-wave observables, notably spins and eccentricities.
Combined with a hierarchical Bayesian analysis, our neural network will deliver the most stringent measurements to date on elusive phenomena influencing the lives of massive stars. We will constrain phenomena such as binary common envelope, supernova kicks, stellar winds, tidal interactions, etc.
Besides harnessing the catalog in its entirety, our complete framework will put us at the forefront to analyze outliers --golden events with favorable properties of one or more parameters. We will design a complete strategy to exploit the strongest signals to infer exquisite details of the relativistic dynamics of their sources.
GWmining is a unique project strategically placed at the intersection of astronomy, data analysis, and relativity. As the large-statistics revolution of gravitational-wave astronomy unfolds, GWmining will pioneer the application of data-mining techniques in gravitational-wave population studies, setting the foundations of this booming field for decades.
Summary
Gravitational-wave astronomy is entering its large-statistics regime. Catalogs with thousands of gravitational-wave events will soon be available, providing a wealth of information on the most compact objects in the Universe --black holes and neutron stars. These new datasets need new tools to be exploited effectively in order to maximize their scientific impact.
GWmining is an ambitious program to explore upcoming gravitational-wave catalogs with data-mining techniques. We will develop a complete framework to analyze gravitational-wave data in light of astrophysical predictions. Going beyond phenomenological models, we will train machine-learning algorithms directly on large banks of population-synthesis simulations and post-Newtonian integrations. The development of these astrophysical predictions requires new modeling strategies to accurately capture all the gravitational-wave observables, notably spins and eccentricities.
Combined with a hierarchical Bayesian analysis, our neural network will deliver the most stringent measurements to date on elusive phenomena influencing the lives of massive stars. We will constrain phenomena such as binary common envelope, supernova kicks, stellar winds, tidal interactions, etc.
Besides harnessing the catalog in its entirety, our complete framework will put us at the forefront to analyze outliers --golden events with favorable properties of one or more parameters. We will design a complete strategy to exploit the strongest signals to infer exquisite details of the relativistic dynamics of their sources.
GWmining is a unique project strategically placed at the intersection of astronomy, data analysis, and relativity. As the large-statistics revolution of gravitational-wave astronomy unfolds, GWmining will pioneer the application of data-mining techniques in gravitational-wave population studies, setting the foundations of this booming field for decades.
Max ERC Funding
1 499 917 €
Duration
Start date: 2021-10-01, End date: 2026-09-30
Project acronym H1PStars
Project Measuring Hubble's Constant to 1% with Pulsating Stars
Researcher (PI) Richard Anderson
Host Institution (HI) ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE
Country Switzerland
Call Details Starting Grant (StG), PE9, ERC-2020-STG
Summary What's up with Hubble's constant (H0)? Recent H0 measurements have shown that the Universe is expanding faster than cosmology predicts, indicating a possible cosmological crisis. To wit, H0 measured to 1.9% precision in today's Universe using a cosmic distance ladder composed of classical Cepheids and type-Ia supernovae differs by 8.9% (4.2 sigma) from H0 predicted by cosmology based on observations of the Cosmic Microwave Background emitted 13.8 billion years ago. However, it remains unclear whether new physics must be invoked to reconcile cosmology with today's H0, or whether today's H0 is subject to as yet unknown or underestimated systematic errors. An unbiased 1% measurement of H0 is required to understand whether physics is on the brink of a major breakthrough.
So, how solid is our distance ladder? To answer this, my research seeks to a) mitigate biases that can shift the center value of reported H0 measurements, b) quantify relevant systematic uncertainties, and c) reinforce the foundation of the distance ladder through a solid astrophysical understanding of pulsating stars, in particular, classical Cepheids. These steps must be taken now to achieve an unbiased 1% H0 measurement and to ensure the legacy of today's distance ladder for future space-borne facilities and ground-based extremely large telescopes. Imminent data releases of the ESA mission Gaia and precise time series spectroscopy will provide unprecedented opportunity to calibrate the distance ladder and unravel the structure and evolution of Cepheids through their variability.
The H1PStars project will leverage my expertise in the astrophysics of classical Cepheids and the calibration of the distance ladder to support precision cosmology via accurate stellar physics, and vice versa. Thanks to this fresh perspective, my team and I will either reconcile the tension in H0 or confidently establish a need to revise cosmology.
Summary
What's up with Hubble's constant (H0)? Recent H0 measurements have shown that the Universe is expanding faster than cosmology predicts, indicating a possible cosmological crisis. To wit, H0 measured to 1.9% precision in today's Universe using a cosmic distance ladder composed of classical Cepheids and type-Ia supernovae differs by 8.9% (4.2 sigma) from H0 predicted by cosmology based on observations of the Cosmic Microwave Background emitted 13.8 billion years ago. However, it remains unclear whether new physics must be invoked to reconcile cosmology with today's H0, or whether today's H0 is subject to as yet unknown or underestimated systematic errors. An unbiased 1% measurement of H0 is required to understand whether physics is on the brink of a major breakthrough.
So, how solid is our distance ladder? To answer this, my research seeks to a) mitigate biases that can shift the center value of reported H0 measurements, b) quantify relevant systematic uncertainties, and c) reinforce the foundation of the distance ladder through a solid astrophysical understanding of pulsating stars, in particular, classical Cepheids. These steps must be taken now to achieve an unbiased 1% H0 measurement and to ensure the legacy of today's distance ladder for future space-borne facilities and ground-based extremely large telescopes. Imminent data releases of the ESA mission Gaia and precise time series spectroscopy will provide unprecedented opportunity to calibrate the distance ladder and unravel the structure and evolution of Cepheids through their variability.
The H1PStars project will leverage my expertise in the astrophysics of classical Cepheids and the calibration of the distance ladder to support precision cosmology via accurate stellar physics, and vice versa. Thanks to this fresh perspective, my team and I will either reconcile the tension in H0 or confidently establish a need to revise cosmology.
Max ERC Funding
1 836 000 €
Duration
Start date: 2021-04-01, End date: 2026-03-31
Project acronym IMAGINE
Project Imprints of Magnetic fields in Exoplanets
Researcher (PI) Daniele VIGANO
Host Institution (HI) AGENCIA ESTATAL CONSEJO SUPERIOR DEINVESTIGACIONES CIENTIFICAS
Country Spain
Call Details Starting Grant (StG), PE9, ERC-2020-STG
Summary The fast-growing sample of thousands of extrasolar planets is unveiling an amazing variety of properties. It represents an opportunity to shed light on long-standing physics and astrobiology issues from a much wider sample than our Solar neighbours, especially for what concerns the still unclear internal structure, only grossly constrained by observable values of mass and/or radii. Planetary magnetism and its long-term evolution is currently understood only partially for the Earth, at a lesser extent for Jupiter and other Solar planets, and is still elusive in exoplanets. The project focuses on magnetic fields as a key factor in shaping habitability and as a messenger of the internal composition and dynamics.
For terrestrial planets, long-lasting, strong enough magnetic fields are arguably a key factor to guarantee habitability, but we are not even sure about how the Earth’s magnetic field has survived for so long. Magnetism leaves other detectable imprints in giant planets. A quest for the first exoplanetary Jupiter-like magnetospheric emission in radio is on-going, but the search needs to be driven by a reliable prediction of the most likely emitters. Magnetic fields can delay the cooling via Ohmic dissipation and could explain the often observed inflated radii in hot Jupiters, but models are still incomplete.
IMAGINE will simulate the long-term (Gyr) evolution of the exoplanetary magnetic fields, coupled with a cooling model, and will assess the relevant imprints on their observables for a broad range of distinctive features mass, composition, irradiation, rotation.
Combining a novel formulation, emission models and advanced numerical techniques partially imported and adapted from the scenario of magnetized neutron stars, on which the PI is expert, IMAGINE will predict values of magnetic fields for different exoplanets, comparing the associated observable properties of gas giants and contributing to identify the best rocky worlds candidates to habitability.
Summary
The fast-growing sample of thousands of extrasolar planets is unveiling an amazing variety of properties. It represents an opportunity to shed light on long-standing physics and astrobiology issues from a much wider sample than our Solar neighbours, especially for what concerns the still unclear internal structure, only grossly constrained by observable values of mass and/or radii. Planetary magnetism and its long-term evolution is currently understood only partially for the Earth, at a lesser extent for Jupiter and other Solar planets, and is still elusive in exoplanets. The project focuses on magnetic fields as a key factor in shaping habitability and as a messenger of the internal composition and dynamics.
For terrestrial planets, long-lasting, strong enough magnetic fields are arguably a key factor to guarantee habitability, but we are not even sure about how the Earth’s magnetic field has survived for so long. Magnetism leaves other detectable imprints in giant planets. A quest for the first exoplanetary Jupiter-like magnetospheric emission in radio is on-going, but the search needs to be driven by a reliable prediction of the most likely emitters. Magnetic fields can delay the cooling via Ohmic dissipation and could explain the often observed inflated radii in hot Jupiters, but models are still incomplete.
IMAGINE will simulate the long-term (Gyr) evolution of the exoplanetary magnetic fields, coupled with a cooling model, and will assess the relevant imprints on their observables for a broad range of distinctive features mass, composition, irradiation, rotation.
Combining a novel formulation, emission models and advanced numerical techniques partially imported and adapted from the scenario of magnetized neutron stars, on which the PI is expert, IMAGINE will predict values of magnetic fields for different exoplanets, comparing the associated observable properties of gas giants and contributing to identify the best rocky worlds candidates to habitability.
Max ERC Funding
1 495 046 €
Duration
Start date: 2021-05-01, End date: 2026-04-30
