Planet Formation Imager (PFI): science vision and key requirements

The Planet Formation Imager (PFI) project aims to provide a strong scientific vision for ground-based optical astronomy beyond the upcoming generation of Extremely Large Telescopes. We make the case that a breakthrough in angular resolution imaging capabilities is required in order to unravel the processes involved in planet formation. PFI will be optimised to provide a complete census of the protoplanet population at all stellocentric radii and over the age range from 0.1 to ~100 Myr. Within this age period, planetary systems undergo dramatic changes and the final architecture of planetary systems is determined. Our goal is to study the planetary birth on the natural spatial scale where the material is assembled, which is the "Hill Sphere" of the forming planet, and to characterise the protoplanetary cores by measuring their masses and physical properties. Our science working group has investigated the observational characteristics of these young protoplanets as well as the migration mechanisms that might alter the system architecture. We simulated the imprints that the planets leave in the disk and study how PFI could revolutionise areas ranging from exoplanet to extragalactic science. In this contribution we outline the key science drivers of PFI and discuss the requirements that will guide the technology choices, the site selection, and potential science/technology tradeoffs.S.K. acknowledges support from an STFC Rutherford Fellowship (ST/J004030/1) and Philip Leverhulme Prize (PLP-2013-110). Part of this work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration

Planet migration in self-gravitating disks

We carry out two-dimensional hydrodynamical simulations to investigate the effects of the turbulence caused by gravitational instability on the migration of a 10 Jupiter-mass planet. We model three discs with different amounts of turbulence and model two scenarios: the first scenario allows the planet to migrate immediately and we find that the migration rates are similar in all three discs, regardless of the amount of turbulence. The second method involves keeping the planet fixed on a circular orbit such that it opens up a gap, before allowing it to migrate. We find that although the gap properties appear to be similar in all three cases, the migration rate is faster in a disc with a lower amount of turbulence

Planet migration in self-gravitating disks

We carry out two-dimensional hydrodynamical simulations to investigate the effects of the turbulence caused by gravitational instability on the migration of a 10 Jupiter-mass planet. We model three discs with different amounts of turbulence and model two scenarios: the first scenario allows the planet to migrate immediately and we find that the migration rates are similar in all three discs, regardless of the amount of turbulence. The second method involves keeping the planet fixed on a circular orbit such that it opens up a gap, before allowing it to migrate. We find that although the gap properties appear to be similar in all three cases, the migration rate is faster in a disc with a lower amount of turbulence

A cross-sectional study of COVID-19 impacts in culturally and linguistically diverse communities in greater Western Sydney, Australia

Abstracts Background This study explored the experiences of people from culturally and linguistically diverse (CALD) backgrounds in Greater Western Sydney, Australia, in selected livelihood items during COVID-19 and the perceived impacts of the pandemic on their lives. Methods A cross-sectional survey was used to collect data between 25 August and 30 September 2020 among CALD communities in Greater Western Sydney. Information was collected on respondents’ experiences in selected livelihood items, including housing, finances, safety, accessing social services and activities, finding work, food, clothing, and relationships during COVID-19 and the pandemic’s perceived impact on their lives. Descriptive and non-parametric statistics were used to analyze the data. Results One hundred and ninety-eight participants were included in the study, 45.5% male and 54.5% female. Many respondents reported their experience in the selected livelihood items as “worse” during COVID-19 at the time of the study. The feeling of safety was most disrupted, with 56% of respondents rating their experience as “worse”. This experience was followed by accessing social support group activities, with 50% of respondents stating their experience of using this service had worsened. The experience of accessing social services and financial situation was rated as “worse” by 41% of respondents. Experience in finding work, housing, and attending schools were all rated as “worse”. The median perceived impact of COVID-19 among respondents who rated their experience in the selected livelihood items as “worse” were statistically higher than those who rated their experience as the “same”. Respondents’ characteristics also predicted the perceived impact of COVID-19. Unemployed respondents were 3.53 (95% CI: 1.16–10.73, p = 0.026) times more likely to perceive the impact of COVID-19 on their lives as “high” compared to employed respondents. Conclusions The finding demonstrates that the “high” number of respondents had the same situation as before COVID-19 and highlights the level of resilience exhibited by CALD communities in the Australian context. It also suggests that services in Australia were good during the pandemic. However, enhanced policy and initiatives designed to meet the CALD population’s needs are required, particularly in the areas most reported to have been disrupted by changes associated with COVID-19. </jats:sec

A cross-sectional study of COVID-19 impacts in culturally and linguistically diverse communities in greater Western Sydney, Australia

Background: This study explored the experiences of people from culturally and linguistically diverse (CALD) backgrounds in Greater Western Sydney, Australia, in selected livelihood items during COVID-19 and the perceived impacts of the pandemic on their lives. Methods: A cross-sectional survey was used to collect data between 25 August and 30 September 2020 among CALD communities in Greater Western Sydney. Information was collected on respondents’ experiences in selected livelihood items, including housing, finances, safety, accessing social services and activities, finding work, food, clothing, and relationships during COVID-19 and the pandemic’s perceived impact on their lives. Descriptive and non-parametric statistics were used to analyze the data. Results: One hundred and ninety-eight participants were included in the study, 45.5% male and 54.5% female. Many respondents reported their experience in the selected livelihood items as “worse” during COVID-19 at the time of the study. The feeling of safety was most disrupted, with 56% of respondents rating their experience as “worse”. This experience was followed by accessing social support group activities, with 50% of respondents stating their experience of using this service had worsened. The experience of accessing social services and financial situation was rated as “worse” by 41% of respondents. Experience in finding work, housing, and attending schools were all rated as “worse”. The median perceived impact of COVID-19 among respondents who rated their experience in the selected livelihood items as “worse” were statistically higher than those who rated their experience as the “same”. Respondents’ characteristics also predicted the perceived impact of COVID-19. Unemployed respondents were 3.53 (95% CI: 1.16-10.73, p = 0.026) times more likely to perceive the impact of COVID-19 on their lives as “high” compared to employed respondents. Conclusions: The finding demonstrates that the “high” number of respondents had the same situation as before COVID-19 and highlights the level of resilience exhibited by CALD communities in the Australian context. It also suggests that services in Australia were good during the pandemic. However, enhanced policy and initiatives designed to meet the CALD population’s needs are required, particularly in the areas most reported to have been disrupted by changes associated with COVID-19

Additional file 1 of A cross-sectional study of COVID-19 impacts in culturally and linguistically diverse communities in greater Western Sydney, Australia

Additional file 1. Relevant items developed for the current study

A cross-sectional study of COVID-19 impacts in culturally and linguistically diverse communities in greater Western Sydney, Australia

Background: This study explored the experiences of people from culturally and linguistically diverse (CALD) backgrounds in Greater Western Sydney, Australia, in selected livelihood items during COVID-19 and the perceived impacts of the pandemic on their lives. Methods: A cross-sectional survey was used to collect data between 25 August and 30 September 2020 among CALD communities in Greater Western Sydney. Information was collected on respondents’ experiences in selected livelihood items, including housing, finances, safety, accessing social services and activities, finding work, food, clothing, and relationships during COVID-19 and the pandemic’s perceived impact on their lives. Descriptive and non-parametric statistics were used to analyze the data. Results: One hundred and ninety-eight participants were included in the study, 45.5% male and 54.5% female. Many respondents reported their experience in the selected livelihood items as “worse” during COVID-19 at the time of the study. The feeling of safety was most disrupted, with 56% of respondents rating their experience as “worse”. This experience was followed by accessing social support group activities, with 50% of respondents stating their experience of using this service had worsened. The experience of accessing social services and financial situation was rated as “worse” by 41% of respondents. Experience in finding work, housing, and attending schools were all rated as “worse”. The median perceived impact of COVID-19 among respondents who rated their experience in the selected livelihood items as “worse” were statistically higher than those who rated their experience as the “same”. Respondents’ characteristics also predicted the perceived impact of COVID-19. Unemployed respondents were 3.53 (95% CI: 1.16-10.73, p = 0.026) times more likely to perceive the impact of COVID-19 on their lives as “high” compared to employed respondents. Conclusions: The finding demonstrates that the “high” number of respondents had the same situation as before COVID-19 and highlights the level of resilience exhibited by CALD communities in the Australian context. It also suggests that services in Australia were good during the pandemic. However, enhanced policy and initiatives designed to meet the CALD population’s needs are required, particularly in the areas most reported to have been disrupted by changes associated with COVID-19

Planet Formation Imager (PFI): science vision and key requirements

International audienceThe Planet Formation Imager (PFI) project aims to provide a strong scientific vision for ground-based optical astronomy beyond the upcoming generation of Extremely Large Telescopes. We make the case that a breakthrough in angular resolution imaging capabilities is required in order to unravel the processes involved in planet formation. PFI will be optimised to provide a complete census of the protoplanet population at all stellocentric radii and over the age range from 0.1 to about 100 Myr. Within this age period, planetary systems undergo dramatic changes and the final architecture of planetary systems is determined. Our goal is to study the planetary birth on the natural spatial scale where the material is assembled, which is the "Hill Sphere" of the forming planet, and to characterise the protoplanetary cores by measuring their masses and physical properties. Our science working group has investigated the observational characteristics of these young protoplanets as well as the migration mechanisms that might alter the system architecture. We simulated the imprints that the planets leave in the disk and study how PFI could revolutionise areas ranging from exoplanet to extragalactic science. In this contribution we outline the key science drivers of PFI and discuss the requirements that will guide the technology choices, the site selection, and potential science/technology tradeoffs