The document discusses the application of machine learning techniques to 21cm cosmology studies. It describes how artificial neural networks (ANNs) can be used as emulators to rapidly predict 21cm power spectra from cosmological parameters, bypassing the need for computationally expensive simulations. This allows ANNs to be combined with Markov chain Monte Carlo methods to efficiently estimate parameter posteriors. ANNs can also be applied to directly estimate parameters from 21cm power spectra or lightcones. The document outlines some open questions around fully characterizing uncertainties and obtaining rigorous posteriors when using ANN-based approaches in 21cm cosmology.
The document discusses using 21cm absorption lines, known as the 21cm forest, to probe properties of dark matter and the early universe. The 21cm forest signal is suppressed by both lower warm dark matter mass and higher X-ray heating. This is because both effects suppress the number of neutral hydrogen regions and masses of early halos. The document proposes using the 1D power spectrum of the 21cm forest to evaluate these effects and constrain dark matter scenarios. Future work could explore other dark matter models and primordial perturbations using this method.
Machine learning approaches are being applied in several ways to 21cm cosmology studies of the Epoch of Reionization (EoR):
1) Neural networks are used as emulators to rapidly predict 21cm power spectra from astrophysical parameters, speeding up Markov chain Monte Carlo parameter estimation.
2) Neural networks are trained on simulated 21cm power spectra to directly estimate astrophysical parameters, bypassing computationally expensive simulations.
3) Convolutional neural networks classify 21cm images to distinguish different sources driving reionization or compress image data into lower-dimensional summaries for likelihood-free inference of parameters.
Machine learning techniques are increasingly being used to tackle the statistical challenges of analyzing upcoming 21cm data and
1. Machine learning techniques can be applied to 21cm cosmology studies in various ways such as image reconstruction, signal detection, data analysis, simulation, and foreground subtraction.
2. Neural networks can be used to estimate cosmological parameters from 21cm power spectra or directly recover statistics like bubble size distributions from power spectra.
3. Studies have shown neural networks can accurately recover bubble size distributions from 21cm power spectra, even when including thermal noise at SKA sensitivity levels. This avoids information loss from incomplete image reconstruction.
4. Other work has used neural networks to reconstruct hydrogen distribution maps from galaxy surveys, demonstrating the potential of machine learning to connect 21cm signals to astrophysical sources and properties.
The document discusses the application of machine learning techniques to 21cm cosmology studies. It describes how artificial neural networks (ANNs) can be used as emulators to rapidly predict 21cm power spectra from cosmological parameters, bypassing the need for computationally expensive simulations. This allows ANNs to be combined with Markov chain Monte Carlo methods to efficiently estimate parameter posteriors. ANNs can also be applied to directly estimate parameters from 21cm power spectra or lightcones. The document outlines some open questions around fully characterizing uncertainties and obtaining rigorous posteriors when using ANN-based approaches in 21cm cosmology.
The document discusses using 21cm absorption lines, known as the 21cm forest, to probe properties of dark matter and the early universe. The 21cm forest signal is suppressed by both lower warm dark matter mass and higher X-ray heating. This is because both effects suppress the number of neutral hydrogen regions and masses of early halos. The document proposes using the 1D power spectrum of the 21cm forest to evaluate these effects and constrain dark matter scenarios. Future work could explore other dark matter models and primordial perturbations using this method.
Machine learning approaches are being applied in several ways to 21cm cosmology studies of the Epoch of Reionization (EoR):
1) Neural networks are used as emulators to rapidly predict 21cm power spectra from astrophysical parameters, speeding up Markov chain Monte Carlo parameter estimation.
2) Neural networks are trained on simulated 21cm power spectra to directly estimate astrophysical parameters, bypassing computationally expensive simulations.
3) Convolutional neural networks classify 21cm images to distinguish different sources driving reionization or compress image data into lower-dimensional summaries for likelihood-free inference of parameters.
Machine learning techniques are increasingly being used to tackle the statistical challenges of analyzing upcoming 21cm data and
1. Machine learning techniques can be applied to 21cm cosmology studies in various ways such as image reconstruction, signal detection, data analysis, simulation, and foreground subtraction.
2. Neural networks can be used to estimate cosmological parameters from 21cm power spectra or directly recover statistics like bubble size distributions from power spectra.
3. Studies have shown neural networks can accurately recover bubble size distributions from 21cm power spectra, even when including thermal noise at SKA sensitivity levels. This avoids information loss from incomplete image reconstruction.
4. Other work has used neural networks to reconstruct hydrogen distribution maps from galaxy surveys, demonstrating the potential of machine learning to connect 21cm signals to astrophysical sources and properties.
This document discusses the search for life in the universe. It begins by exploring definitions of life and the basic requirements for life as we understand it, such as the ability to grow, reproduce, and evolve. It then examines evidence that suggests life may have originated on Earth either from organic materials in space delivered by meteorites or around hydrothermal vents in the ocean. The document outlines NASA's roadmap for searching for life in our solar system and on exoplanets, including exploring moons of Jupiter and Saturn. It discusses using the Drake Equation to estimate the potential number of civilizations in our galaxy and the SETI Institute's plans to search for radio signals from extraterrestrial life using the upcoming SKA telescope.
1. In 1995, Michel Mayor and Didier Queloz directly discovered the first exoplanet orbiting the star 51 Pegasi b, for which they were later awarded the Nobel Prize in 2019.
2. There are now over 4000 known exoplanets that have been discovered, showing that our solar system is not unique in having planets.
3. The three main methods for detecting exoplanets are: measuring the Doppler effect of stars, detecting planetary transits that dim starlight, and directly imaging exoplanets.
- The document discusses the conditions needed for life to exist, namely liquid water, and the concept of the "habitable zone" where liquid water can exist on a planet based on its distance from its star.
- It notes that over 4,000 exoplanets have been discovered so far, and finding exoplanets within the habitable zones of their stars is key to searching for life in the universe. Approximately 50 exoplanets located in habitable zones have been discovered.
- The document also provides context on the timeline of life in the universe, noting that based on a "Cosmic Calendar" where the history of the universe is compressed into one year, life first emerged on September 21st, and human history only began in
1) The document discusses the early universe and the formation of light elements like hydrogen and helium in the first 3 minutes after the Big Bang through nuclear fusion processes.
2) It describes how the cosmic microwave background radiation provides evidence for the Big Bang theory, and how satellites like COBE and Planck have precisely measured tiny fluctuations in the CMB temperature that reveal information about the early universe.
3) Density fluctuations in the early universe seeded by cosmic inflation grew to form the large scale structures we observe today like dark matter halos, stars, and galaxies.
The document discusses the fate and evolution of the universe based on its density. It explains that if the density is greater than the critical density, the universe will collapse in a "Big Crunch", while if it is less it will expand forever. Observations find the density is approximately equal to the critical density, implying a flat universe. However, ordinary and dark matter only account for about 30% of the density, so some unknown "dark energy" is proposed to make up the remaining 70% and explain the observed accelerated expansion of the universe.
The document discusses key concepts in cosmology, including:
1) The universe appears homogeneous and isotropic at large scales, with only small fluctuations in density.
2) Olbers' paradox explains why the night sky is dark if the universe is assumed to be infinite and unchanging, which may be incorrect assumptions.
3) The expanding universe model provides a solution to Olbers' paradox, as the universe had a hot, dense beginning and a finite age, limiting the number of observable stars.
4) The fate of the universe depends on its total density - if density exceeds a critical threshold, the universe will eventually collapse, while a lower density means continued expansion.
1) Other galaxies, like the Milky Way, contain dark matter as evidenced by their rotation curves. Around 90% of the matter in the universe is dark matter.
2) While dark matter does not interact with electromagnetic waves, it can be observed through its gravitational effects such as gravitational lensing and its influence on galaxy cluster collisions.
3) Dark matter plays a key role in structure formation in the universe, starting with dark matter particles clumping together to form dark matter halos that then attract gas to form stars and galaxies.
1. The document discusses different types of galaxies including spiral, elliptical, irregular, and barred spiral galaxies.
2. It describes how Hubble classified galaxies into these categories and notes that galaxies do not evolve along Hubble's sequence.
3. Methods for measuring the distance to galaxies are explained, including using the Tully-Fisher relation to estimate the luminosity and distance of spiral galaxies based on measuring their circular velocity.
The document discusses key discoveries and concepts in astronomy:
1. Hubble discovered the expansion of the universe by measuring galaxies' receding velocities, which led to Hubble's law.
2. Some galaxies exhibit unusual activity and energy distributions, which is caused by violent events in their galactic nuclei, known as active galactic nuclei (AGN).
3. The central engine powering AGN is believed to be supermassive black holes that accrete material and produce powerful jets and radiation.
1. The document discusses the Milky Way Galaxy and other galaxies.
2. It describes how the existence of spiral galaxies was debated until Hubble observed variable stars in the Andromeda Nebula and measured its distance, finding it was outside the Milky Way Galaxy.
3. This supported Curtis's model that spiral nebulae exist outside the Milky Way and opened up the view that there are multiple galaxies in the universe beyond just the Milky Way.
The document discusses the Milky Way galaxy. It describes the Milky Way's structure, including the galactic disk, bulge, globular clusters, and halo. It explains how astronomers originally mapped the Milky Way by measuring the direction and distance to stars, using techniques like annual parallax and variable stars. The Milky Way is estimated to have formed around 13 billion years ago based on dating its oldest stars. The formation process likely involved the merging of smaller dwarf galaxies.
The document discusses neutron stars, pulsars, gamma-ray bursts, and black holes. It provides details on the properties of neutron stars, including their small size but large mass, extremely high density, rapid rotation, and strong magnetic fields. It also discusses the discovery of pulsars and how they provided evidence for rotating neutron stars. Gamma-ray bursts and fast radio bursts are also mentioned. The formation of black holes from objects with masses greater than the Schwarzschild radius is summarized.
1) Supernova explosions release energy equivalent to around 108-109 years of the sun's energy output.
2) There are two main types of supernovae - Type I with low hydrogen and Type II with lots of hydrogen. Their mechanisms differ but total energy output is similar.
3) Heavier elements up to iron form inside stars through fusion, while elements heavier than iron form via neutron capture processes during and after stellar evolution.
1) The document discusses the life cycles of stars and the different endings for low-mass and high-mass stars. Low-mass stars end as white dwarfs, while high-mass stars face more dramatic endings.
2) For high-mass stars, the core eventually collapses, triggering a supernova explosion that blows the outer layers away. This leaves behind a neutron star or black hole.
3) There are two main types of supernovae. Type I occur in binary systems and Type II result from core collapse, leaving behind a neutron star. Supernovae release tremendous amounts of energy visible across galaxies.
1) Stars spend most of their lives stably fusing hydrogen into helium on the main sequence.
2) After the main sequence, low mass stars evolve through red giant, asymptotic giant, and planetary nebula stages before becoming white dwarfs.
3) More massive stars evolve faster and burn carbon to produce oxygen in later stages.
- Stars form in the dense, cold clouds of gas and dust that make up the interstellar medium.
- Gravity causes the gas and dust to collapse into dense clumps. However, as the material compresses, pressure from heat increases, countering the gravitational collapse.
- When gravity and pressure reach an equilibrium, nuclear fusion begins in the core, forming a new star.
1) Stars form from dense fragments within interstellar clouds that collapse under gravity over millions of years.
2) Protostars form within the collapsing fragments and grow in mass through accretion until their cores reach temperatures high enough for nuclear fusion.
3) After 10 million years, the protostar becomes a true star on the main sequence, where nuclear fusion powers the star for its lifetime.
Cosmic Histories and human perspectives: A journey through time and spaceHayato Shimabukuro
The document discusses the evolution of human understanding of the universe through history. It begins with early astronomy among ancient civilizations like Babylonians, Greeks, Indians, Egyptians and Chinese. It then outlines major developments including Copernicus' heliocentric model, Kepler's laws, Galileo's observations supporting Copernicus, Newton's laws of motion and gravity, and Einstein's theory of general relativity. The document also summarizes modern cosmological concepts like the expansion of the universe observed by Hubble, the hot dense early universe, formation of light elements in Big Bang nucleosynthesis, cosmic microwave background radiation, and evolution of the universe from the dark ages to the present epoch.
The document discusses how astronomers classify and analyze stars using the Hertzsprung-Russell (HR) diagram. The HR diagram plots stars' luminosity versus temperature and reveals patterns like more luminous stars being hotter. Key properties of stars like their lifetimes and masses can be estimated from their position on the HR diagram. Understanding the HR diagram is important for learning about stellar interiors, evolution, and properties.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
This document discusses the search for life in the universe. It begins by exploring definitions of life and the basic requirements for life as we understand it, such as the ability to grow, reproduce, and evolve. It then examines evidence that suggests life may have originated on Earth either from organic materials in space delivered by meteorites or around hydrothermal vents in the ocean. The document outlines NASA's roadmap for searching for life in our solar system and on exoplanets, including exploring moons of Jupiter and Saturn. It discusses using the Drake Equation to estimate the potential number of civilizations in our galaxy and the SETI Institute's plans to search for radio signals from extraterrestrial life using the upcoming SKA telescope.
1. In 1995, Michel Mayor and Didier Queloz directly discovered the first exoplanet orbiting the star 51 Pegasi b, for which they were later awarded the Nobel Prize in 2019.
2. There are now over 4000 known exoplanets that have been discovered, showing that our solar system is not unique in having planets.
3. The three main methods for detecting exoplanets are: measuring the Doppler effect of stars, detecting planetary transits that dim starlight, and directly imaging exoplanets.
- The document discusses the conditions needed for life to exist, namely liquid water, and the concept of the "habitable zone" where liquid water can exist on a planet based on its distance from its star.
- It notes that over 4,000 exoplanets have been discovered so far, and finding exoplanets within the habitable zones of their stars is key to searching for life in the universe. Approximately 50 exoplanets located in habitable zones have been discovered.
- The document also provides context on the timeline of life in the universe, noting that based on a "Cosmic Calendar" where the history of the universe is compressed into one year, life first emerged on September 21st, and human history only began in
1) The document discusses the early universe and the formation of light elements like hydrogen and helium in the first 3 minutes after the Big Bang through nuclear fusion processes.
2) It describes how the cosmic microwave background radiation provides evidence for the Big Bang theory, and how satellites like COBE and Planck have precisely measured tiny fluctuations in the CMB temperature that reveal information about the early universe.
3) Density fluctuations in the early universe seeded by cosmic inflation grew to form the large scale structures we observe today like dark matter halos, stars, and galaxies.
The document discusses the fate and evolution of the universe based on its density. It explains that if the density is greater than the critical density, the universe will collapse in a "Big Crunch", while if it is less it will expand forever. Observations find the density is approximately equal to the critical density, implying a flat universe. However, ordinary and dark matter only account for about 30% of the density, so some unknown "dark energy" is proposed to make up the remaining 70% and explain the observed accelerated expansion of the universe.
The document discusses key concepts in cosmology, including:
1) The universe appears homogeneous and isotropic at large scales, with only small fluctuations in density.
2) Olbers' paradox explains why the night sky is dark if the universe is assumed to be infinite and unchanging, which may be incorrect assumptions.
3) The expanding universe model provides a solution to Olbers' paradox, as the universe had a hot, dense beginning and a finite age, limiting the number of observable stars.
4) The fate of the universe depends on its total density - if density exceeds a critical threshold, the universe will eventually collapse, while a lower density means continued expansion.
1) Other galaxies, like the Milky Way, contain dark matter as evidenced by their rotation curves. Around 90% of the matter in the universe is dark matter.
2) While dark matter does not interact with electromagnetic waves, it can be observed through its gravitational effects such as gravitational lensing and its influence on galaxy cluster collisions.
3) Dark matter plays a key role in structure formation in the universe, starting with dark matter particles clumping together to form dark matter halos that then attract gas to form stars and galaxies.
1. The document discusses different types of galaxies including spiral, elliptical, irregular, and barred spiral galaxies.
2. It describes how Hubble classified galaxies into these categories and notes that galaxies do not evolve along Hubble's sequence.
3. Methods for measuring the distance to galaxies are explained, including using the Tully-Fisher relation to estimate the luminosity and distance of spiral galaxies based on measuring their circular velocity.
The document discusses key discoveries and concepts in astronomy:
1. Hubble discovered the expansion of the universe by measuring galaxies' receding velocities, which led to Hubble's law.
2. Some galaxies exhibit unusual activity and energy distributions, which is caused by violent events in their galactic nuclei, known as active galactic nuclei (AGN).
3. The central engine powering AGN is believed to be supermassive black holes that accrete material and produce powerful jets and radiation.
1. The document discusses the Milky Way Galaxy and other galaxies.
2. It describes how the existence of spiral galaxies was debated until Hubble observed variable stars in the Andromeda Nebula and measured its distance, finding it was outside the Milky Way Galaxy.
3. This supported Curtis's model that spiral nebulae exist outside the Milky Way and opened up the view that there are multiple galaxies in the universe beyond just the Milky Way.
The document discusses the Milky Way galaxy. It describes the Milky Way's structure, including the galactic disk, bulge, globular clusters, and halo. It explains how astronomers originally mapped the Milky Way by measuring the direction and distance to stars, using techniques like annual parallax and variable stars. The Milky Way is estimated to have formed around 13 billion years ago based on dating its oldest stars. The formation process likely involved the merging of smaller dwarf galaxies.
The document discusses neutron stars, pulsars, gamma-ray bursts, and black holes. It provides details on the properties of neutron stars, including their small size but large mass, extremely high density, rapid rotation, and strong magnetic fields. It also discusses the discovery of pulsars and how they provided evidence for rotating neutron stars. Gamma-ray bursts and fast radio bursts are also mentioned. The formation of black holes from objects with masses greater than the Schwarzschild radius is summarized.
1) Supernova explosions release energy equivalent to around 108-109 years of the sun's energy output.
2) There are two main types of supernovae - Type I with low hydrogen and Type II with lots of hydrogen. Their mechanisms differ but total energy output is similar.
3) Heavier elements up to iron form inside stars through fusion, while elements heavier than iron form via neutron capture processes during and after stellar evolution.
1) The document discusses the life cycles of stars and the different endings for low-mass and high-mass stars. Low-mass stars end as white dwarfs, while high-mass stars face more dramatic endings.
2) For high-mass stars, the core eventually collapses, triggering a supernova explosion that blows the outer layers away. This leaves behind a neutron star or black hole.
3) There are two main types of supernovae. Type I occur in binary systems and Type II result from core collapse, leaving behind a neutron star. Supernovae release tremendous amounts of energy visible across galaxies.
1) Stars spend most of their lives stably fusing hydrogen into helium on the main sequence.
2) After the main sequence, low mass stars evolve through red giant, asymptotic giant, and planetary nebula stages before becoming white dwarfs.
3) More massive stars evolve faster and burn carbon to produce oxygen in later stages.
- Stars form in the dense, cold clouds of gas and dust that make up the interstellar medium.
- Gravity causes the gas and dust to collapse into dense clumps. However, as the material compresses, pressure from heat increases, countering the gravitational collapse.
- When gravity and pressure reach an equilibrium, nuclear fusion begins in the core, forming a new star.
1) Stars form from dense fragments within interstellar clouds that collapse under gravity over millions of years.
2) Protostars form within the collapsing fragments and grow in mass through accretion until their cores reach temperatures high enough for nuclear fusion.
3) After 10 million years, the protostar becomes a true star on the main sequence, where nuclear fusion powers the star for its lifetime.
Cosmic Histories and human perspectives: A journey through time and spaceHayato Shimabukuro
The document discusses the evolution of human understanding of the universe through history. It begins with early astronomy among ancient civilizations like Babylonians, Greeks, Indians, Egyptians and Chinese. It then outlines major developments including Copernicus' heliocentric model, Kepler's laws, Galileo's observations supporting Copernicus, Newton's laws of motion and gravity, and Einstein's theory of general relativity. The document also summarizes modern cosmological concepts like the expansion of the universe observed by Hubble, the hot dense early universe, formation of light elements in Big Bang nucleosynthesis, cosmic microwave background radiation, and evolution of the universe from the dark ages to the present epoch.
The document discusses how astronomers classify and analyze stars using the Hertzsprung-Russell (HR) diagram. The HR diagram plots stars' luminosity versus temperature and reveals patterns like more luminous stars being hotter. Key properties of stars like their lifetimes and masses can be estimated from their position on the HR diagram. Understanding the HR diagram is important for learning about stellar interiors, evolution, and properties.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
The technology uses reclaimed CO₂ as the dyeing medium in a closed loop process. When pressurized, CO₂ becomes supercritical (SC-CO₂). In this state CO₂ has a very high solvent power, allowing the dye to dissolve easily.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
2. Self-introduction
• 2019/12-present: Associate research professor, South-Western Institute for Astronomy Research, Yunnan University, China
• 2018/4-2019/11: Postdoc Fellow (Tsinghua international postdoc fellowship), Tsinghua University（清华大学）, China,
mentor: Prof. Yi Mao
• 2016/4-2018/3: Postdoc Fellow, Paris observatory（巴黎天文台）, France, mentor: Prof. Benoit Semelin
• 2013/4-2016/3: Ph.D. course, Department of physics, Nagoya University(名古屋⼤学), Japan, supervised by Prof. Takahiko
Matsubara
• 2014/4-2016/3: Visiting scholar, Graduate school of science and technology, Kumamoto University（熊本大学）, Japan,
supervised by Prof. Keitaro Takahashi.
• 2011/4-2013/3: Master course, Department of physics, Nagoya University(名古屋⼤学), Japan, supervised by Prof.
Takahiko Matsubara
• 2007/4-2011/3: Bachelor of Astronomy, Astronomy institute, Tohoku University（日本东北大学）, Japan
• Research interests: Cosmology, structure formation of the universe, Dark ages, Cosmic Dawn/Epoch of Reionization, 21cm
line, axion dark matter
Faculty, Postdoc, student
10. 21cm line emission
Proton Electron
21cm line emission(1.4GHz)
(Neutral) hydrogen atom is a good tracer for IGM through the dark ages to EoR.
singlet
Triplet
21cm radiation: neutral hydrogen atom emits 21cm line emission due to hyperfine structure.
Transition
Tb =
TS T
1 + z
(1 exp(⌧⌫))
⇠ 27xH(1 + m)
✓
H
dvr/dr + H
◆ ✓
1
T
TS
◆ ✓
1 + z
10
0.15
⌦mh2
◆1/2 ✓
⌦bh2
0.023
◆
[mK]
Brightness temperature
Red : cosmology Blue : astrophysics
11. 21cm line emission
Proton Electron
21cm line emission(1.4GHz)
(Neutral) hydrogen atom is a good tracer for IGM through the dark ages to EoR.
singlet
Triplet
21cm radiation: neutral hydrogen atom emits 21cm line emission due to hyperfine structure.
Transition
Tb =
TS T
1 + z
(1 exp(⌧⌫))
⇠ 27xH(1 + m)
✓
H
dvr/dr + H
◆ ✓
1
T
TS
◆ ✓
1 + z
10
0.15
⌦mh2
◆1/2 ✓
⌦bh2
0.023
◆
[mK]
Brightness temperature
Red : cosmology Blue : astrophysics
12. 21cm line emission
We can map the distribution of HI in the IGM with 21cm line.
Liu & Shaw (2020)
To describe 21cm signal statistically…
Redshift
13. 21cm line emission
We can map the distribution of HI in the IGM with 21cm line.
Liu & Shaw (2020)
21cm global signal: Sky-averaged 21cm line
signal
To describe 21cm signal statistically…
Redshift
14. We can map the distribution of HI in the IGM with 21cm line.
Redshift
To describe 21cm signal statistically…
Liu & Shaw (2020)
21cm line emission
15. We can map the distribution of HI in the IGM with 21cm line.
21cm line power spectrum
h Tb(k) Tb(k
0
)i = (2⇡)3
(k + k
0
)P21
Redshift
To describe 21cm signal statistically…
Liu & Shaw (2020)
21cm line emission
16. 21cm absorption lines
•We can use not only 21cm emission lines but also 21cm absorption lines called 21cm forest.
Wavelength
•The 21cm forest appeared in the radio continuum spectrum due to intervened HI gas in the IGM or
inside minihalos.
QSO,GRB etc
τ(ν, M, α) =
3hpc3
A10
32πkBν2
21
∫
Rmax(α)
−Rmax(α)
dR
nHI(r)
TS(r) πb
exp
(
−
v2
(ν)
b2 )
•The depth of 21cm absorption lines is characterized by optical depth τ
HI gas
18. 1.Exploring the nature of axion dark matter
with 21cm forest
Based on Shimabukuro et al (2020a,2020b)
19. Axion dark matter
•Axion particle was introduced in particle physics and it is generated as the result of PQ symmetry
breaking.
• Axion-like ultra-light particle(ULP) is one of the candidates of dark matter particles.
timeline
Inflation
•Whether PQ symmetry is broken before or after inflation changes the impact of axion dark matter
on the structure formation of the universe (matter power spectrum).
20. Axion dark matter
•Axion particle was introduced in particle physics and it is generated as the result of PQ symmetry
breaking.
• Axion-like ultra-light particle(ULP) is one of the candidates of dark matter particles.
timeline
Inflation
•Whether PQ symmetry is broken before or after inflation changes the impact of axion dark matter
on the structure formation of the universe (matter power spectrum).
PQ symmetry
breaking
•The matter power spectrum is suppressed.
21. Axion dark matter
•Axion particle was introduced in particle physics and it is generated as the result of PQ symmetry
breaking.
• Axion-like ultra-light particle(ULP) is one of the candidates of dark matter particles.
timeline
Inflation
•Whether PQ symmetry is broken before or after inflation changes the impact of axion dark matter
on the structure formation of the universe (matter power spectrum).
PQ symmetry
breaking
PQ symmetry
breaking
•The matter power spectrum is suppressed.
•The matter power spectrum is enhanced.
22. Impact on the 21cm forest
PQ symmetry breaks before inflation
•We explored the impact of axion-like ultra-light dark matter on the 21cm forest (the number of 21cm
absorption lines).
PQ symmetry breaks after inflation
•The abundance of the 21cm forest is suppressed.
•The abundance of the 21cm forest is enhanced.
•We can probe ULP mass up to . This is
3 orders of magnitude higher than the mass range where
Lyman-alpha forest can probe.
mu ∼ 10−19
eV
•We can probe ULP mass at
while Lyman alpha forest
observations exclude .
10−18
≲ mu ≲ 10−12
eV
mu ≲ 2 × 10−17
eV
23. 2. Application of machine learning
technique to analyze 21cm line signal
Based on Yoshiura et al (2021), Shimabukuro et al (2022a)
24. During EoR, ionized bubbles are generated.
Ionized bubble size distribution
We evaluate ionized bubbles by measuring
ionized bubble size distribution(BSD).
Giri et al (2017)
How do we obtain BSD by interferometer?
Fourier
transformation
Visibility Image
•In the radio interferometer, we first observe visibility and perform Fourier transformation to obtain
21cm image map.
25. Problem and our approach
•When we measure BSD starting from visibility, some information is lost in the process of Fourier
transformation(FT) due to the limited number of the antenna in the interferometer.
Problem
Our strategy
•Because the 21cm power spectrum(PS) is directly obtained from visibility without FT, we try to
recover BSD from the 21cm PS with the Artificial neural network (ANN).
21cm PS ANN BSD
26. Recovered BSD from 21cm PS with ANN
Black: Distribution obtained by 21cm 3D
image directly.
Red: Distribution obtained by ANN.
•We successfully recover ionized bubble size distribution from the 21cm PS with ANN.
Blue: Relative error between Red and black lines.
•Even if we assume SKA level instrumental noise, the
ANN can successfully recover BSD from the 21cm PS.
27. Reconstruction of HI distribution from LAE
Fig. 4. Sky distribution of the LAEs at z = 5.7. The red squares, magenta diamonds, and black circles represent positions of narrowband bright (< 23.5 mag),
medium-bright (23.5 − 24.0 mag), and faint (24.0 − 25.0 mag) LAEs, respectively. The large red open square indicates the LAEs with spatially extended Lyα
emission (Shibuya et al. 2017b). The gray shades denote either the areas with no HSC data or the masked regions with a bad data quality. The scale on the
map is marked in angles (degrees) and the projected distances (comoving megaparsecs).
Fig. 5. Same as Figure 4, but for the LAEs z = 6.6. The large red open squares indicate the LAEs with spatially extended Lyα emission including Himiko
(Ouchi et al. 2009a) and CR7 (Sobral et al. 2015). See Shibuya et al. (2017b) for more details.
Input :
Lyman-alpha emitter galaxies
Output :
HI distribution
Yoshiura,HS +2021
cGAN
•We reconstruct HI distribution from the distribution of Lyman-alpha emitter galaxies with GAN.
28. Shimabukuro et al 2022b, published in PASJ
Review paper about CD/EoR with 21cm line
30. Future research plans
1. Constructing the 21cm global signal from the 21cm line power spectrum with the ANN.
•As short-period research plans, I consider some theoretical studies.
2. Exploring the impact of the dark matter-baryon relative velocity on the 21cm forest.
3. Topological analysis for the 21cm image map.
•I am interested in not only theoretical studies but also observational studies as middle or long-period
plans. I am currently trained to deal with observational data by MWA.
SKA 鸿蒙计划
31. Teaching plans
•I am currently applying to Yunnan University to open the course “现代天⽂学入⻔” for students
who do not major science.
•I am interested in the lecture on “General Relativity”.
•I am also interested in the lecture on “Cosmology in the early universe”. Although the lecture on
cosmology is already open, I would like to open the course of cosmology whose subject is structure
formation in the early universe (Dark ages, the formation of the first stars and galaxies, and epoch of
reionization)
33. Publication list during Tenure-track
1. ``Exploring the cosmic dawn and epoch of Reionization with 21cm line’’, Hayato Shimabukuro,
Hidenobu Yajima, Kenji Hasegawa, Akira Kuchinomachi and Shintaro Yoshiura, Accepted in PASJ
(2022)
•First author paper(4 papers)
2. ``Estimation of HII bubble size distribution from 21cm power spectrum with artificial neural network’’,
Hayato Shimabukuro, Yi Mao, Jianrong Tan, RAA Vol 22 Number 3 (2022), selected as the highlight
paper
3.``21cm forest probes on the axion dark matter in the post-inflationary Peccei-Quinn symmetry breaking
scenario’’, Hayato Shimabukuro, Kiyotomo Ichiki and Kenji Kadota, PRD 102 Iss.2 023522(2020)
4. ``Constraints on the nature of ultra-light dark matter with 21cm forest’’, Hayato Shimabukuro,
Kiyotomo Ichiki and Kenji Kadota, PRD 102 Iss.4 043516 (2020)
•Co-author paper (1 paper)
1. ``Predicting 21cm line map from Lyman alpha emitter distribution with Generative Adversarial
Networks’’, Shintaro Yoshiura, Hayato Shimabukuro, Kenji Hasegawa, and Keitaro Takahashi,
MNRAS 506,357 (2021)
34. Teaching, Grants & Award
•Supervise 2 graduate students (Zhewu Song and Zhenfei Qin) at Yunnan university.
•National Natural Science Foundation of China (NSFC) for young researcher, 240,000RMB
•National SKA program of China (PI: Yi Mao, I am a core member of the grant.), 890,000RMB
Teaching
Grant
•Zhihui(智汇) Yunnan program, 120,000 RMB
Award
•President prize for educational excellence 2022 at Tohoku University (Co-prizewinner)
35. Research Activities & Services
•Organized SWIFAR weekly colloquium. I invited
73 domestic and international researchers to the
colloquium.
•Assigned to peer reviewer for international astronomy
professional journals (Nature Astronomy, PASJ,
JCAP, MNRAS)
•Assigned to proposal peer-reviewer for Subaru telescope.
•A chair of SKA-JAPAN EoR team. •A member of SKA-International CD/EoR team and
SKA-CHINA EoR team.
36. Invited talks at conferences & Invited colloquia
Invited talks at the conference (3 talks)
1. Japan Radio Astronomy Forum symposium (2022/3)
2. SKA Japan strategy workshop (2021/7)
3. SKA summer school at Shanghai astronomical observatory (2021/7)
1. SKA JAPAN webinar (2022/11)
Invited colloquia & seminars(9 talks)
3. Shanghai astronomical observatory (2022/9)
4. Tsinghua University (2022/6)
5. Osaka university (2022/6)
6. University of Tokyo(2022/6)
7. Shanghai Jiao-tong university, Tsung
Dao Lee Institute(2022/6)
8. Central China Normal university(2021/4)
9. SKA Japan webinar (2021/1)
2. 鸿蒙计划webinar (2022/10)
37. Invited outreach activities
1. `` The history of the universe’’, Asahi culture center, (2022/6)
2. `` Exploring the universe with radio telescope’’, Super Science Museum (2021/12)
3. ``My academic career and research introduction’’, Hikawa high school SSH program (2021/8)
4. ``Searching the universe by radio wave’’, Mitaka Astronomy pub (2021/3)
5. ``My experience in overseas and research introduction’’, KEK summer challenge career building
(2021/2)
6. ``Probing epoch of Reionization with 21cm line’’, science pub (2021/2)
7. ``Searching cosmic dawn with radio wave’’, 3 mins science club (2020/10)
7 invited outreach activities
38. (Further brief achievement….)
I passed HSK 4th grade (Intermediate Chinese level).
Thank you
for
your attendance!
*Lowest is 1st grade, Highest is 6th grade
谢谢你的参加！
