This document summarizes the analysis of spectra from 8 stars in the oldest globular cluster in the Galaxy, NGC 6522. The analysis reveals unusually high abundances of the heavy elements barium (Ba) and lanthanum (La), which are produced through the slow neutron capture process (s-process) in low-mass stars. However, the stars also show overabundances of the light elements yttrium (Y) and strontium (Sr) compared to iron, with a large scatter similar to that seen in extremely metal-poor stars. This pattern is best explained by enrichment from fast-rotating massive metal-poor stars, which models show can boost s-process yields through rotational mixing. The study suggests
Architecture and dynamics of kepler's candidate multiple transiting planet sy...Sérgio Sacani
This document summarizes the architecture and dynamics of Kepler's candidate multiple transiting planet systems. It finds:
1) Virtually all systems are dynamically stable based on numerical integration assuming a mass-radius relationship.
2) The distribution of observed period ratios is clustered just outside resonances, particularly the 2:1 resonance.
3) These characteristics suggest the majority of multi-candidate systems are true planetary systems, not false positives.
This document appears to be citing the same source multiple times without providing any additional context or information. It repeats "1987MNRAS.227..361M" over a dozen times but does not explain the content or significance of the source being cited.
The exceptional soft_x_ray_halo_of_the_galaxy_merger_ngc6240Sérgio Sacani
The document summarizes a recent 150-ks Chandra observation of the galaxy merger NGC 6240. Extended soft X-ray emission is detected over a 110x80 kpc region around NGC 6240. Spectral analysis finds the emission comes from hot gas with a temperature of around 7.5 million K and a total mass of about 10^10 solar masses. The gas properties suggest widespread star formation over the past 200 Myr rather than a recent nuclear starburst. The fate of the diffuse hot gas after the galaxy merger is uncertain but it may be retained and evolve into the halo of an elliptical galaxy.
Herschel galactic plane_survey_the_global_distribution_of_ism_gas_componnentSérgio Sacani
This document summarizes a study using Herschel observations of the [C ii] 158μm line to analyze the distribution of different gas components in the Milky Way galaxy. The observations provide high-resolution maps of [C ii] emission across the Galactic plane. By comparing these maps to observations of HI, CO, and other tracers, the study finds that [C ii] emission is associated with spiral arms between 4-10 kpc from the Galactic center. It estimates that [C ii] traces dense photon-dominated regions (47%), CO-dark H2 gas (28%), cold atomic gas (21%), and ionized gas (4%). The study also analyzes the distribution of cold neutral medium versus
This document summarizes the analysis of periodic variable stars in the open cluster NGC 3766 based on a 7-year monitoring campaign. The authors detected a new class of 36 variable stars located between the instability strips for slowly pulsating B stars and delta Scuti stars, where no variability was previously predicted. The majority of these new variables have periods between 0.1-0.7 days and amplitudes of 1-4 millimagnitudes. The properties of this new class are discussed and the authors argue they are likely pulsating variables sustained by stellar rotation. Additionally, the authors identify other periodic variables such as eclipsing binaries, slowly pulsating B stars, delta Scuti stars, and gamma Doradus candidates.
This document provides an overview of the STS-134 mission including objectives, crew, payloads, experiments, and timeline. The mission will deliver supplies and experiments to the International Space Station using the space shuttle Endeavour. Key objectives include delivering the Alpha Magnetic Spectrometer and Express Logistics Carrier to the ISS and conducting three spacewalks. The crew will return research samples and conduct several short-term experiments over a 16 day mission before landing back on Earth.
A giant planet around a metal poor star of extragalactic originSérgio Sacani
This document reports the detection of a giant planet orbiting the metal-poor star HIP 13044, which belongs to a group of stars accreted from a disrupted satellite galaxy. Radial velocity observations revealed periodic variations indicating a planetary companion with a minimum mass of 1.25 Jupiter masses and an orbital period of 16.2 days. Further analysis ruled out stellar activity as the cause, confirming the planetary origin of the radial velocity signal. As HIP 13044 likely originated from an extragalactic system, this planet may be the first discovered planet of extragalactic origin.
One armed spiral_waves_in_galaxy_simulations_with_computer_rotating_starsSérgio Sacani
This document summarizes simulations of disk galaxies with counter-rotating stars. The simulations found:
1) The formation of stationary one-armed spiral waves in galaxies with 25%, 37.5%, and 50% of stars counter-rotating.
2) These one-armed spirals persisted from a few to five rotation periods.
3) In some cases, the spiral wave changed direction over one rotation period, transforming from a leading to trailing arm.
The results support the theory that counter-rotating stars can drive a two-stream instability that forms one-armed spiral waves via gravitational interactions between the co- and counter-rotating populations.
Architecture and dynamics of kepler's candidate multiple transiting planet sy...Sérgio Sacani
This document summarizes the architecture and dynamics of Kepler's candidate multiple transiting planet systems. It finds:
1) Virtually all systems are dynamically stable based on numerical integration assuming a mass-radius relationship.
2) The distribution of observed period ratios is clustered just outside resonances, particularly the 2:1 resonance.
3) These characteristics suggest the majority of multi-candidate systems are true planetary systems, not false positives.
This document appears to be citing the same source multiple times without providing any additional context or information. It repeats "1987MNRAS.227..361M" over a dozen times but does not explain the content or significance of the source being cited.
The exceptional soft_x_ray_halo_of_the_galaxy_merger_ngc6240Sérgio Sacani
The document summarizes a recent 150-ks Chandra observation of the galaxy merger NGC 6240. Extended soft X-ray emission is detected over a 110x80 kpc region around NGC 6240. Spectral analysis finds the emission comes from hot gas with a temperature of around 7.5 million K and a total mass of about 10^10 solar masses. The gas properties suggest widespread star formation over the past 200 Myr rather than a recent nuclear starburst. The fate of the diffuse hot gas after the galaxy merger is uncertain but it may be retained and evolve into the halo of an elliptical galaxy.
Herschel galactic plane_survey_the_global_distribution_of_ism_gas_componnentSérgio Sacani
This document summarizes a study using Herschel observations of the [C ii] 158μm line to analyze the distribution of different gas components in the Milky Way galaxy. The observations provide high-resolution maps of [C ii] emission across the Galactic plane. By comparing these maps to observations of HI, CO, and other tracers, the study finds that [C ii] emission is associated with spiral arms between 4-10 kpc from the Galactic center. It estimates that [C ii] traces dense photon-dominated regions (47%), CO-dark H2 gas (28%), cold atomic gas (21%), and ionized gas (4%). The study also analyzes the distribution of cold neutral medium versus
This document summarizes the analysis of periodic variable stars in the open cluster NGC 3766 based on a 7-year monitoring campaign. The authors detected a new class of 36 variable stars located between the instability strips for slowly pulsating B stars and delta Scuti stars, where no variability was previously predicted. The majority of these new variables have periods between 0.1-0.7 days and amplitudes of 1-4 millimagnitudes. The properties of this new class are discussed and the authors argue they are likely pulsating variables sustained by stellar rotation. Additionally, the authors identify other periodic variables such as eclipsing binaries, slowly pulsating B stars, delta Scuti stars, and gamma Doradus candidates.
This document provides an overview of the STS-134 mission including objectives, crew, payloads, experiments, and timeline. The mission will deliver supplies and experiments to the International Space Station using the space shuttle Endeavour. Key objectives include delivering the Alpha Magnetic Spectrometer and Express Logistics Carrier to the ISS and conducting three spacewalks. The crew will return research samples and conduct several short-term experiments over a 16 day mission before landing back on Earth.
A giant planet around a metal poor star of extragalactic originSérgio Sacani
This document reports the detection of a giant planet orbiting the metal-poor star HIP 13044, which belongs to a group of stars accreted from a disrupted satellite galaxy. Radial velocity observations revealed periodic variations indicating a planetary companion with a minimum mass of 1.25 Jupiter masses and an orbital period of 16.2 days. Further analysis ruled out stellar activity as the cause, confirming the planetary origin of the radial velocity signal. As HIP 13044 likely originated from an extragalactic system, this planet may be the first discovered planet of extragalactic origin.
One armed spiral_waves_in_galaxy_simulations_with_computer_rotating_starsSérgio Sacani
This document summarizes simulations of disk galaxies with counter-rotating stars. The simulations found:
1) The formation of stationary one-armed spiral waves in galaxies with 25%, 37.5%, and 50% of stars counter-rotating.
2) These one-armed spirals persisted from a few to five rotation periods.
3) In some cases, the spiral wave changed direction over one rotation period, transforming from a leading to trailing arm.
The results support the theory that counter-rotating stars can drive a two-stream instability that forms one-armed spiral waves via gravitational interactions between the co- and counter-rotating populations.
High pre eruptive water contents preserved in lunar melt inclusionsSérgio Sacani
This study analyzed melt inclusions trapped in olivine crystals from lunar volcanic glass samples. The melt inclusions contained 615-1410 parts per million of water, much higher than previous measurements of lunar samples. They also contained high amounts of fluorine, sulfur, and chlorine similar to primitive terrestrial basalts. This indicates that some parts of the lunar interior contain as much water as Earth's upper mantle. The similarities to Earth and differences from previous models have implications for understanding the formation of the Earth-Moon system and the presence of water on the Moon.
A population of_fast_radio_bursts_ar_cosmological_distancesSérgio Sacani
1) Four fast radio bursts (FRBs) lasting only a few milliseconds were detected in a radio survey of the high Galactic latitude sky.
2) The bursts' properties indicate they are of celestial rather than terrestrial origin and likely originate from cosmological distances of 0.5 to 3 billion light years.
3) No coincident x-ray or gamma-ray signals were found associated with the bursts. Characterizing the population of FRBs could help determine the baryonic content of the universe.
This document summarizes observations of the debris disk around the subgiant star κ CrB using Herschel and Keck. Herschel spatially resolved images of the debris disk, the first such images of a disk around a subgiant star. Keck radial velocity monitoring provided evidence for a second planetary companion around κ CrB. Keck adaptive optics imaging placed an upper limit on the mass of this companion. Modeling of the Herschel images showed the dust is broadly distributed but could not distinguish between a single wide belt or two narrow belts. The observations are consistent with dynamical depletion or collisional erosion clearing the inner regions of the disk.
Herschel far infrared_spectroscopy_of_the_galactic_centerSérgio Sacani
The document summarizes observations from the Herschel Space Observatory of the Galactic Center region, focusing on a spectral scan toward Sagittarius A*. Key findings include:
1) Strong emission from atomic fine structure lines and rotationally excited lines of molecules like CO, H2O and HCO+ are detected.
2) The excitation of the CO ladder is consistent with either a hot isothermal gas component at 103.1 K and 104 cm-3, or a distribution of warmer gas at higher densities, with most CO at 300 K.
3) The detected molecular features suggest heating is from a combination of UV irradiation and shocks in the gas, rather than very enhanced X-ray or cosmic
3C 273 was one of the first quasars discovered in 1963. It remains one of the brightest and best studied quasars. It is located approximately 3 billion light years from Earth and radiates energy equivalent to 1014 times the luminosity of the Sun. 3C 273 plays a key role in understanding the nature of quasars as powered by accretion disks around supermassive black holes. It continues to be intensely observed across the electromagnetic spectrum to better understand the physics occurring in these energetic and distant cosmic objects.
Hd140283 a star_in_the_solar_neighborhood_that_formed_shortly_after_the_big_bangSérgio Sacani
This document summarizes a study that measured the parallax of the star HD 140283 using the Hubble Space Telescope's Fine Guidance Sensors. The study found a parallax of 17.15 ± 0.14 mas, improving on the previous measurement from Hipparcos. Using modern stellar evolution models, the authors estimate an age for HD 140283 of 14.46 ± 0.31 Gyr based on its precise distance, making it one of the oldest stars known. While its age is consistent with the age of the Universe, uncertainties in the star's composition increase the total age uncertainty to about ±0.8 Gyr. HD 140283 likely formed shortly after the Big Bang.
Titan obliquity as evidence for a subsurface oceanSérgio Sacani
This document summarizes a study investigating whether Titan's obliquity provides evidence for a subsurface ocean. The study finds that Titan's observed obliquity of 0.3° is inconsistent with its estimated moment of inertia if Titan is entirely solid. However, the study develops a new Cassini state model that assumes Titan has a liquid water ocean beneath an ice shell. This model considers gravitational and pressure torques between layers. With this model, the study finds better agreement between Titan's moment of inertia and rotation state than for the solid case, strengthening the possibility that Titan has a subsurface ocean.
Characteristics of planetary candidates observed by kepler, ii analysis of t...Sérgio Sacani
This document summarizes the analysis of the first four months of data from the Kepler Mission, which observed 156,453 stars between May and September 2009. A total of 1235 planetary candidates were detected orbiting 997 host stars. The candidates range in size from Earth-sized (68 candidates) to larger than Jupiter (19 candidates). 54 candidates were found in the habitable zone, with 5 being less than twice Earth's size. Over 74% of candidates are smaller than Neptune. The number of candidates peaks at 2-3 times Earth's size and then declines with increasing size. After correcting for biases, the estimated frequency of planets is 6% for Earth-sized, 7% for super-Earth sized, 17%
Dissecting x ray_emitting_gas_around_the_center_of_our_galaxySérgio Sacani
1) The Chandra X-ray Observatory was used to observe the supermassive black hole at the center of the Milky Way, Sgr A*, for a total of 3 megaseconds.
2) The observations revealed extended X-ray emission around Sgr A* that aligns spatially with a surrounding disk of massive stars.
3) Spectral analysis ruled out low-mass stars as the origin of the X-ray emission and instead found evidence that the emission is from a radiatively inefficient accretion flow onto the black hole, with an outflow present.
This document summarizes the discovery of two planetary companions orbiting the metal-poor star HIP 11952 based on radial velocity measurements. The star HIP 11952 was observed over a period of 16 months using the FEROS spectrograph. Analysis of the spectra revealed periodic radial velocity variations of 6.95 days and 290 days, indicating the presence of two planets with minimum masses of 0.78 MJup and 2.93 MJup orbiting at 0.07 AU and 0.81 AU, respectively. HIP 11952 is a metal-poor star with [Fe/H] of -1.95, making it one of the few known systems with planets orbiting a star with such low metallicity
Magnetic frustration effect in polycrystalline Ga2-xFexO3Nan Wang
This document discusses magnetic frustration effects in polycrystalline Ga2-xFexO3 materials. It finds that the disordered distribution of Fe ions across four crystallographic sites leads to some Fe ions having no strong antiferromagnetic superexchange coupling. These "non-effective" Fe ions are found to induce strong frequency dependent suppression of the ac susceptibility peak, demonstrating frustration effects in the normally ferrimagnetic material. The document also examines the dependence of properties like Curie temperature and magnetization on the Fe content x based on statistical models of the site occupations.
Sub-microscopicmagnetite andmetallic iron particles formed by eutectic reacti...Sérgio Sacani
Ferric iron as well as magnetite are rarely found in lunar samples, and their
distribution and formation mechanisms on the Moon have not been well
studied. Here, we discover sub-microscopic magnetite particles in Chang’E-5
lunar soil. Magnetite and puremetallic iron particles are embedded in oxygendissolved
iron-sulfide grains from the Chang’E-5 samples. This mineral
assemblage indicates a FeO eutectoid reaction (4FeO = Fe3O4+Fe) for formation
of magnetite. The iron-sulfide grains’ morphology features and the
oxygen’s distribution suggest that a gas–melt phase reaction occurred during
large-impact events. This could provide an effective method to form ubiquitous
sub-microscopic magnetite in fine lunar soils and be a contributor to the
presentation of ferric iron on the surface of the Moon. Additionally, the formation
of sub-microscopic magnetite and metallic iron by eutectoid reaction
may provide an alternative way for the formation of magnetic anomalies
observed on the Moon.
This document reports the discovery of the first natural hydride, vanadium hydride (VH2), found in xenolithic fragments from Cretaceous pyroclastic volcanoes on Mt. Carmel, Israel. Microprobe analysis and single-crystal X-ray diffraction were used to characterize the VH2 crystal. The VH2 has a cubic unit cell structure with the CaF2 structure type and space group Fm3m. Its discovery implies reducing conditions with hydrogen-dominated fluids were present in the upper mantle, with implications for transport of volatile species from the deep mantle to Earth's surface.
Triggered Star Formation inside the Shell of a Wolf–Rayet Bubble as the Origi...Sérgio Sacani
A critical constraint on solar system formation is the high Al 26 /27Al abundance ratio of ´ - 5 10 5 at the time of
formation, which was about 17 times higher than the average Galactic ratio, while the 60Fe/56Fe value was about
´ - 2 10 8, lower than the Galactic value. This challenges the assumption that a nearby supernova (SN) was
responsible for the injection of these short-lived radionuclides into the early solar system. We show that this
conundrum can be resolved if the solar system was formed by a triggered star formation at the edge of a Wolf–
Rayet (W–R) bubble. 26Al is produced during the evolution of the massive star, released in the wind during the
W–R phase, and condenses into dust grains that are seen around W–R stars. The dust grains survive passage
through the reverse shock and the low-density shocked wind, reach the dense shell swept-up by the bubble, detach
from the decelerated wind, and are injected into the shell. Some portions of this shell subsequently collapse to form
the dense cores that give rise to solar-type systems. The subsequent aspherical SN does not inject appreciable
amounts of Fe 60 into the proto–solar system, thus accounting for the observed low abundance of Fe 60 . We discuss
the details of various processes within the model and conclude that it is a viable model that can explain the initial
abundances of Al 26 and Fe 60 . We estimate that 1%–16% of all Sun-like stars could have formed in such a setting of
triggered star formation in the shell of a W–R bubble.
An extremely primitive star in the galactic haloSérgio Sacani
1. The document reports on the discovery of an extremely metal-poor star in the Galactic halo, named SDSS J1029151172927.
2. Spectroscopic analysis finds the star has a very low metallicity of Z=#6.9x10^-7, which is 4.5x10^-5 times the metallicity of the Sun.
3. The star's chemical pattern, including an absence of lithium, suggests it formed at a lower metallicity than current theories predict is necessary for low-mass star formation. This supports the idea that low-mass stars can form at even lower carbon and oxygen abundances.
This document provides information about important families of elements in the periodic table including halogens, noble gases, chalcogens, and alkali and alkaline earth metals. It also discusses the classes of elements, position and electronic configurations of transition metals, and trends in various properties like ionization energies, oxidation states, magnetic properties, and formation of colored ions and complex compounds. The document explains how transition metals exhibit a variety of properties due to their ability to adopt multiple oxidation states and form complexes through d-orbital involvement.
Carbon star formation as seen through the non-monotonic initial–final mass re...Sérgio Sacani
The initial–final mass relation (IFMR) links the birth mass of a star to the mass of the compact remnant left at its death. While
the relevance of the IFMR across astrophysics is universally acknowledged, not all of its fine details have yet been resolved.
A new analysis of a few carbon–oxygen white dwarfs in old open clusters of the Milky Way led us to identify a kink in the IFMR,
located over a range of initial masses, 1.65 ≲Mi
/M⊙ ≲ 2.10. The kink’s peak in white dwarf mass of about 0.70−0.75 M⊙ is
produced by stars with Mi≈ 1.8−1.9 M⊙, corresponding to ages of about 1.8−1.7 Gyr. Interestingly, this peak coincides with
the initial mass limit between low-mass stars that develop a degenerate helium core after central hydrogen exhaustion, and
intermediate-mass stars that avoid electron degeneracy. We interpret the IFMR kink as the signature of carbon star formation
in the Milky Way. This finding is critical to constraining the evolution and chemical enrichment of low-mass stars, and their
impact on the spectrophotometric properties of galaxies.
Shiva and Shakti: Presumed Proto-Galactic Fragments in the Inner Milky WaySérgio Sacani
Using Gaia Data Release 3 astrometry and spectroscopy, we study two new substructures in the orbit–metallicity space of the inner Milky Way: Shakti and Shiva. They were identified as two confined, high-contrast overdensities in the (Lz, E) distribution of bright (G < 16) and metal-poor (−2.5<[M/H]<−1.0) stars. Both have stellar masses of Må107Me, and are distributed on prograde orbits inside the solar circle in the Galaxy. Both structures have an orbit-space distribution that points toward an accreted origin; however, their abundance patterns—from APOGEE—are such that are conventionally attributed to an in situ population. These seemingly contradictory diagnostics could be reconciled if we interpret the abundances [Mg/Fe], [Al/Fe], [Mg/Mn] versus [Fe/H] distribution of their member stars merely as a sign of rapid enrichment. This would then suggest one of two scenarios. Either these prograde substructures were created by some form of resonant orbit trapping of the field stars by the rotating bar; a plausible scenario proposed by Dillamore et al. Or, Shakti and Shiva were protogalactic fragments that formed stars rapidly and coalesced early, akin to the constituents of the poor old heart of the Milky Way, just less deep in the Galactic potential and still discernible in orbit space.
This document discusses iron isotope measurements of lunar samples, including the oldest lunar rock dunite 72 415. The key points are:
1) Dunite 72 415 has a surprisingly light iron isotope composition, in contrast to other lunar samples which are enriched in heavy iron isotopes compared to Earth.
2) Additional measurements of dunite 72 415 confirm this light iron isotope signature.
3) The earliest olivine accumulation in the lunar magma ocean may have been enriched in light iron isotopes, allowing the overall iron isotope composition of the Moon to match that of Earth.
Characterising the true descendants of the first starsSérgio Sacani
This document discusses characterizing the true descendants of the first, or Population III (Pop III), stars through analysis of the chemical abundances of very metal-poor stars in the Galactic halo. It finds that stars with [C/Fe] > 2.5 likely formed in environments polluted solely by low-energy Pop III supernovae, while stars with lower [C/Fe] could be imprinted by Pop III stars or a combination of Pop III and normal Pop II stars. Very energetic Pop III supernovae only seem to have impacted a few rare metal-poor halo stars. The document aims to determine whether all metal-poor halo stars show solely a Pop III imprint or a mixture of Pop III and Pop II enrichment
This document contains figures that show patterns in geochemistry and mineral formation across parts of the periodic table. Arranging the periodic table with ions listed by ionic potential, as in the Earth Scientist's Periodic Table, causes many geochemical properties to follow predictable patterns. Speciation in solution, oxide mineral formation, and oxysalt mineral chemistry all vary systematically when viewed through this framework. Solubility, melting temperature, substitution behavior in igneous minerals, and compatibility in magmatic crystallization also correlate with ion properties along contours of equal ionic potential. This arrangement of the periodic table thus provides a useful perspective for understanding elemental behavior in earth materials and processes.
This document summarizes a study analyzing the chemical abundances of the exotic star PG0909+276 using spectroscopic data from the ultraviolet region. The star was previously found to have strong enhancements of iron-group elements compared to normal sdB stars. Modeling of the star's atmosphere and spectral fitting of UV data from 1400-2000 Angstroms confirmed higher abundances of heavy elements like calcium to nickel compared to both the Sun and normal sdB stars. While iron appeared close to solar levels, the results support that radiative acceleration in hot sdB stars enhances heavy element abundances at their surfaces. Further UV studies of peculiar stars are needed to better understand their compositions.
High pre eruptive water contents preserved in lunar melt inclusionsSérgio Sacani
This study analyzed melt inclusions trapped in olivine crystals from lunar volcanic glass samples. The melt inclusions contained 615-1410 parts per million of water, much higher than previous measurements of lunar samples. They also contained high amounts of fluorine, sulfur, and chlorine similar to primitive terrestrial basalts. This indicates that some parts of the lunar interior contain as much water as Earth's upper mantle. The similarities to Earth and differences from previous models have implications for understanding the formation of the Earth-Moon system and the presence of water on the Moon.
A population of_fast_radio_bursts_ar_cosmological_distancesSérgio Sacani
1) Four fast radio bursts (FRBs) lasting only a few milliseconds were detected in a radio survey of the high Galactic latitude sky.
2) The bursts' properties indicate they are of celestial rather than terrestrial origin and likely originate from cosmological distances of 0.5 to 3 billion light years.
3) No coincident x-ray or gamma-ray signals were found associated with the bursts. Characterizing the population of FRBs could help determine the baryonic content of the universe.
This document summarizes observations of the debris disk around the subgiant star κ CrB using Herschel and Keck. Herschel spatially resolved images of the debris disk, the first such images of a disk around a subgiant star. Keck radial velocity monitoring provided evidence for a second planetary companion around κ CrB. Keck adaptive optics imaging placed an upper limit on the mass of this companion. Modeling of the Herschel images showed the dust is broadly distributed but could not distinguish between a single wide belt or two narrow belts. The observations are consistent with dynamical depletion or collisional erosion clearing the inner regions of the disk.
Herschel far infrared_spectroscopy_of_the_galactic_centerSérgio Sacani
The document summarizes observations from the Herschel Space Observatory of the Galactic Center region, focusing on a spectral scan toward Sagittarius A*. Key findings include:
1) Strong emission from atomic fine structure lines and rotationally excited lines of molecules like CO, H2O and HCO+ are detected.
2) The excitation of the CO ladder is consistent with either a hot isothermal gas component at 103.1 K and 104 cm-3, or a distribution of warmer gas at higher densities, with most CO at 300 K.
3) The detected molecular features suggest heating is from a combination of UV irradiation and shocks in the gas, rather than very enhanced X-ray or cosmic
3C 273 was one of the first quasars discovered in 1963. It remains one of the brightest and best studied quasars. It is located approximately 3 billion light years from Earth and radiates energy equivalent to 1014 times the luminosity of the Sun. 3C 273 plays a key role in understanding the nature of quasars as powered by accretion disks around supermassive black holes. It continues to be intensely observed across the electromagnetic spectrum to better understand the physics occurring in these energetic and distant cosmic objects.
Hd140283 a star_in_the_solar_neighborhood_that_formed_shortly_after_the_big_bangSérgio Sacani
This document summarizes a study that measured the parallax of the star HD 140283 using the Hubble Space Telescope's Fine Guidance Sensors. The study found a parallax of 17.15 ± 0.14 mas, improving on the previous measurement from Hipparcos. Using modern stellar evolution models, the authors estimate an age for HD 140283 of 14.46 ± 0.31 Gyr based on its precise distance, making it one of the oldest stars known. While its age is consistent with the age of the Universe, uncertainties in the star's composition increase the total age uncertainty to about ±0.8 Gyr. HD 140283 likely formed shortly after the Big Bang.
Titan obliquity as evidence for a subsurface oceanSérgio Sacani
This document summarizes a study investigating whether Titan's obliquity provides evidence for a subsurface ocean. The study finds that Titan's observed obliquity of 0.3° is inconsistent with its estimated moment of inertia if Titan is entirely solid. However, the study develops a new Cassini state model that assumes Titan has a liquid water ocean beneath an ice shell. This model considers gravitational and pressure torques between layers. With this model, the study finds better agreement between Titan's moment of inertia and rotation state than for the solid case, strengthening the possibility that Titan has a subsurface ocean.
Characteristics of planetary candidates observed by kepler, ii analysis of t...Sérgio Sacani
This document summarizes the analysis of the first four months of data from the Kepler Mission, which observed 156,453 stars between May and September 2009. A total of 1235 planetary candidates were detected orbiting 997 host stars. The candidates range in size from Earth-sized (68 candidates) to larger than Jupiter (19 candidates). 54 candidates were found in the habitable zone, with 5 being less than twice Earth's size. Over 74% of candidates are smaller than Neptune. The number of candidates peaks at 2-3 times Earth's size and then declines with increasing size. After correcting for biases, the estimated frequency of planets is 6% for Earth-sized, 7% for super-Earth sized, 17%
Dissecting x ray_emitting_gas_around_the_center_of_our_galaxySérgio Sacani
1) The Chandra X-ray Observatory was used to observe the supermassive black hole at the center of the Milky Way, Sgr A*, for a total of 3 megaseconds.
2) The observations revealed extended X-ray emission around Sgr A* that aligns spatially with a surrounding disk of massive stars.
3) Spectral analysis ruled out low-mass stars as the origin of the X-ray emission and instead found evidence that the emission is from a radiatively inefficient accretion flow onto the black hole, with an outflow present.
This document summarizes the discovery of two planetary companions orbiting the metal-poor star HIP 11952 based on radial velocity measurements. The star HIP 11952 was observed over a period of 16 months using the FEROS spectrograph. Analysis of the spectra revealed periodic radial velocity variations of 6.95 days and 290 days, indicating the presence of two planets with minimum masses of 0.78 MJup and 2.93 MJup orbiting at 0.07 AU and 0.81 AU, respectively. HIP 11952 is a metal-poor star with [Fe/H] of -1.95, making it one of the few known systems with planets orbiting a star with such low metallicity
Magnetic frustration effect in polycrystalline Ga2-xFexO3Nan Wang
This document discusses magnetic frustration effects in polycrystalline Ga2-xFexO3 materials. It finds that the disordered distribution of Fe ions across four crystallographic sites leads to some Fe ions having no strong antiferromagnetic superexchange coupling. These "non-effective" Fe ions are found to induce strong frequency dependent suppression of the ac susceptibility peak, demonstrating frustration effects in the normally ferrimagnetic material. The document also examines the dependence of properties like Curie temperature and magnetization on the Fe content x based on statistical models of the site occupations.
Sub-microscopicmagnetite andmetallic iron particles formed by eutectic reacti...Sérgio Sacani
Ferric iron as well as magnetite are rarely found in lunar samples, and their
distribution and formation mechanisms on the Moon have not been well
studied. Here, we discover sub-microscopic magnetite particles in Chang’E-5
lunar soil. Magnetite and puremetallic iron particles are embedded in oxygendissolved
iron-sulfide grains from the Chang’E-5 samples. This mineral
assemblage indicates a FeO eutectoid reaction (4FeO = Fe3O4+Fe) for formation
of magnetite. The iron-sulfide grains’ morphology features and the
oxygen’s distribution suggest that a gas–melt phase reaction occurred during
large-impact events. This could provide an effective method to form ubiquitous
sub-microscopic magnetite in fine lunar soils and be a contributor to the
presentation of ferric iron on the surface of the Moon. Additionally, the formation
of sub-microscopic magnetite and metallic iron by eutectoid reaction
may provide an alternative way for the formation of magnetic anomalies
observed on the Moon.
This document reports the discovery of the first natural hydride, vanadium hydride (VH2), found in xenolithic fragments from Cretaceous pyroclastic volcanoes on Mt. Carmel, Israel. Microprobe analysis and single-crystal X-ray diffraction were used to characterize the VH2 crystal. The VH2 has a cubic unit cell structure with the CaF2 structure type and space group Fm3m. Its discovery implies reducing conditions with hydrogen-dominated fluids were present in the upper mantle, with implications for transport of volatile species from the deep mantle to Earth's surface.
Triggered Star Formation inside the Shell of a Wolf–Rayet Bubble as the Origi...Sérgio Sacani
A critical constraint on solar system formation is the high Al 26 /27Al abundance ratio of ´ - 5 10 5 at the time of
formation, which was about 17 times higher than the average Galactic ratio, while the 60Fe/56Fe value was about
´ - 2 10 8, lower than the Galactic value. This challenges the assumption that a nearby supernova (SN) was
responsible for the injection of these short-lived radionuclides into the early solar system. We show that this
conundrum can be resolved if the solar system was formed by a triggered star formation at the edge of a Wolf–
Rayet (W–R) bubble. 26Al is produced during the evolution of the massive star, released in the wind during the
W–R phase, and condenses into dust grains that are seen around W–R stars. The dust grains survive passage
through the reverse shock and the low-density shocked wind, reach the dense shell swept-up by the bubble, detach
from the decelerated wind, and are injected into the shell. Some portions of this shell subsequently collapse to form
the dense cores that give rise to solar-type systems. The subsequent aspherical SN does not inject appreciable
amounts of Fe 60 into the proto–solar system, thus accounting for the observed low abundance of Fe 60 . We discuss
the details of various processes within the model and conclude that it is a viable model that can explain the initial
abundances of Al 26 and Fe 60 . We estimate that 1%–16% of all Sun-like stars could have formed in such a setting of
triggered star formation in the shell of a W–R bubble.
An extremely primitive star in the galactic haloSérgio Sacani
1. The document reports on the discovery of an extremely metal-poor star in the Galactic halo, named SDSS J1029151172927.
2. Spectroscopic analysis finds the star has a very low metallicity of Z=#6.9x10^-7, which is 4.5x10^-5 times the metallicity of the Sun.
3. The star's chemical pattern, including an absence of lithium, suggests it formed at a lower metallicity than current theories predict is necessary for low-mass star formation. This supports the idea that low-mass stars can form at even lower carbon and oxygen abundances.
This document provides information about important families of elements in the periodic table including halogens, noble gases, chalcogens, and alkali and alkaline earth metals. It also discusses the classes of elements, position and electronic configurations of transition metals, and trends in various properties like ionization energies, oxidation states, magnetic properties, and formation of colored ions and complex compounds. The document explains how transition metals exhibit a variety of properties due to their ability to adopt multiple oxidation states and form complexes through d-orbital involvement.
Carbon star formation as seen through the non-monotonic initial–final mass re...Sérgio Sacani
The initial–final mass relation (IFMR) links the birth mass of a star to the mass of the compact remnant left at its death. While
the relevance of the IFMR across astrophysics is universally acknowledged, not all of its fine details have yet been resolved.
A new analysis of a few carbon–oxygen white dwarfs in old open clusters of the Milky Way led us to identify a kink in the IFMR,
located over a range of initial masses, 1.65 ≲Mi
/M⊙ ≲ 2.10. The kink’s peak in white dwarf mass of about 0.70−0.75 M⊙ is
produced by stars with Mi≈ 1.8−1.9 M⊙, corresponding to ages of about 1.8−1.7 Gyr. Interestingly, this peak coincides with
the initial mass limit between low-mass stars that develop a degenerate helium core after central hydrogen exhaustion, and
intermediate-mass stars that avoid electron degeneracy. We interpret the IFMR kink as the signature of carbon star formation
in the Milky Way. This finding is critical to constraining the evolution and chemical enrichment of low-mass stars, and their
impact on the spectrophotometric properties of galaxies.
Shiva and Shakti: Presumed Proto-Galactic Fragments in the Inner Milky WaySérgio Sacani
Using Gaia Data Release 3 astrometry and spectroscopy, we study two new substructures in the orbit–metallicity space of the inner Milky Way: Shakti and Shiva. They were identified as two confined, high-contrast overdensities in the (Lz, E) distribution of bright (G < 16) and metal-poor (−2.5<[M/H]<−1.0) stars. Both have stellar masses of Må107Me, and are distributed on prograde orbits inside the solar circle in the Galaxy. Both structures have an orbit-space distribution that points toward an accreted origin; however, their abundance patterns—from APOGEE—are such that are conventionally attributed to an in situ population. These seemingly contradictory diagnostics could be reconciled if we interpret the abundances [Mg/Fe], [Al/Fe], [Mg/Mn] versus [Fe/H] distribution of their member stars merely as a sign of rapid enrichment. This would then suggest one of two scenarios. Either these prograde substructures were created by some form of resonant orbit trapping of the field stars by the rotating bar; a plausible scenario proposed by Dillamore et al. Or, Shakti and Shiva were protogalactic fragments that formed stars rapidly and coalesced early, akin to the constituents of the poor old heart of the Milky Way, just less deep in the Galactic potential and still discernible in orbit space.
This document discusses iron isotope measurements of lunar samples, including the oldest lunar rock dunite 72 415. The key points are:
1) Dunite 72 415 has a surprisingly light iron isotope composition, in contrast to other lunar samples which are enriched in heavy iron isotopes compared to Earth.
2) Additional measurements of dunite 72 415 confirm this light iron isotope signature.
3) The earliest olivine accumulation in the lunar magma ocean may have been enriched in light iron isotopes, allowing the overall iron isotope composition of the Moon to match that of Earth.
Characterising the true descendants of the first starsSérgio Sacani
This document discusses characterizing the true descendants of the first, or Population III (Pop III), stars through analysis of the chemical abundances of very metal-poor stars in the Galactic halo. It finds that stars with [C/Fe] > 2.5 likely formed in environments polluted solely by low-energy Pop III supernovae, while stars with lower [C/Fe] could be imprinted by Pop III stars or a combination of Pop III and normal Pop II stars. Very energetic Pop III supernovae only seem to have impacted a few rare metal-poor halo stars. The document aims to determine whether all metal-poor halo stars show solely a Pop III imprint or a mixture of Pop III and Pop II enrichment
This document contains figures that show patterns in geochemistry and mineral formation across parts of the periodic table. Arranging the periodic table with ions listed by ionic potential, as in the Earth Scientist's Periodic Table, causes many geochemical properties to follow predictable patterns. Speciation in solution, oxide mineral formation, and oxysalt mineral chemistry all vary systematically when viewed through this framework. Solubility, melting temperature, substitution behavior in igneous minerals, and compatibility in magmatic crystallization also correlate with ion properties along contours of equal ionic potential. This arrangement of the periodic table thus provides a useful perspective for understanding elemental behavior in earth materials and processes.
This document summarizes a study analyzing the chemical abundances of the exotic star PG0909+276 using spectroscopic data from the ultraviolet region. The star was previously found to have strong enhancements of iron-group elements compared to normal sdB stars. Modeling of the star's atmosphere and spectral fitting of UV data from 1400-2000 Angstroms confirmed higher abundances of heavy elements like calcium to nickel compared to both the Sun and normal sdB stars. While iron appeared close to solar levels, the results support that radiative acceleration in hot sdB stars enhances heavy element abundances at their surfaces. Further UV studies of peculiar stars are needed to better understand their compositions.
Age of Jupiter inferred from the distinct genetics and formation times of met...Sérgio Sacani
The age of Jupiter, the largest planet in our Solar System, is still
unknown. Gas-giant planet formation likely involved the growth
of large solid cores, followed by the accumulation of gas onto
these cores. Thus, the gas-giant cores must have formed before
dissipation of the solar nebula, which likely occurred within less
than 10 My after Solar System formation. Although such rapid
accretion of the gas-giant cores has successfully been modeled,
until now it has not been possible to date their formation. Here,
using molybdenum and tungsten isotope measurements on iron
meteorites, we demonstrate that meteorites derive from two
genetically distinct nebular reservoirs that coexisted and remained
spatially separated between ∼1My and ∼3–4My after Solar System
formation. The most plausible mechanism for this efficient separation
is the formation of Jupiter, opening a gap in the disk and
preventing the exchange of material between the two reservoirs.
As such, our results indicate that Jupiter’s core grew to ∼20 Earth
masses within <1 My, followed by amore protracted growth to ∼50
Earth masses until at least ∼3–4 My after Solar System formation.
Thus, Jupiter is the oldest planet of the Solar System, and its solid
core formed well before the solar nebula gas dissipated, consistent
with the core accretion model for giant planet formation.
Modelling element abundances_in_semi_analytic_models_of_galaxy_formationSérgio Sacani
This document summarizes a new implementation of detailed chemical enrichment modeling in the Munich semi-analytic model of galaxy formation (L-Galaxies). The new implementation tracks the delayed enrichment of 11 heavy elements from stellar winds, supernovae type II, and supernovae type Ia. It considers different supernovae type II yield sets and three supernovae type Ia delay-time distributions. The results are compared to observational data on local star-forming galaxies, Milky Way disc G dwarfs, and local elliptical galaxies. Overall, the best model matches require a power-law supernovae type Ia delay-time distribution, supernovae type II yields accounting for prior mass loss, and some direct ejection
This document discusses evidence from WISE and GALEX imaging that nearby early type galaxies experienced multi-stage formation histories. Strong color gradients were found between inner and outer radii, with the outer radii being bluer by ~1 magnitude. This color difference suggests the outer regions formed ~1 Gyr after the inner regions through an inside-out formation process involving rapid early star formation within cores and later starburst events.
The d-block elements have d orbitals that are progressively filled in each period. They form three transition metal series (3d, 4d, 5d) and two inner transition metal series (4f, 5f). Transition metals are defined as having incompletely filled d orbitals. They have high melting and boiling points due to strong metallic bonding. They exhibit a variety of oxidation states and can form stable complexes and interstitial compounds.
1. VFTS 682 is a very massive star located 29 pc in projection from the young massive cluster R136 in the Tarantula Nebula of the LMC.
2. Spectral modeling finds it has an unusually high luminosity of log(L/L) = 6.5, corresponding to a present-day mass of ~150 solar masses.
3. Its isolation and mass pose the question of whether it formed in situ, which would profoundly impact theories of massive star formation, or if it was ejected from R136, making it the most massive runaway star known.
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.
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.
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.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Tr...Sérgio Sacani
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the
atmospheres of terrestrial planets via follow-up spectroscopic observations. However, the number of such planets
receiving low insolation is still small, limiting our ability to understand the diversity of the atmospheric
composition and climates of temperate terrestrial planets. We report the discovery of an Earth-sized planet
transiting the nearby (12 pc) inactive M3.0 dwarf Gliese 12 (TOI-6251) with an orbital period (Porb) of 12.76 days.
The planet, Gliese 12 b, was initially identified as a candidate with an ambiguous Porb from TESS data. We
confirmed the transit signal and Porb using ground-based photometry with MuSCAT2 and MuSCAT3, and
validated the planetary nature of the signal using high-resolution images from Gemini/NIRI and Keck/NIRC2 as
well as radial velocity (RV) measurements from the InfraRed Doppler instrument on the Subaru 8.2 m telescope
and from CARMENES on the CAHA 3.5 m telescope. X-ray observations with XMM-Newton showed the host
star is inactive, with an X-ray-to-bolometric luminosity ratio of log 5.7 L L X bol » - . Joint analysis of the light
curves and RV measurements revealed that Gliese 12 b has a radius of 0.96 ± 0.05 R⊕,a3σ mass upper limit of
3.9 M⊕, and an equilibrium temperature of 315 ± 6 K assuming zero albedo. The transmission spectroscopy metric
(TSM) value of Gliese 12 b is close to the TSM values of the TRAPPIST-1 planets, adding Gliese 12 b to the small
list of potentially terrestrial, temperate planets amenable to atmospheric characterization with JWST.
Gliese 12 b, a temperate Earth-sized planet at 12 parsecs discovered with TES...Sérgio Sacani
We report on the discovery of Gliese 12 b, the nearest transiting temperate, Earth-sized planet found to date. Gliese 12 is a
bright (V = 12.6 mag, K = 7.8 mag) metal-poor M4V star only 12.162 ± 0.005 pc away from the Solar system with one of the
lowest stellar activity levels known for M-dwarfs. A planet candidate was detected by TESS based on only 3 transits in sectors
42, 43, and 57, with an ambiguity in the orbital period due to observational gaps. We performed follow-up transit observations
with CHEOPS and ground-based photometry with MINERVA-Australis, SPECULOOS, and Purple Mountain Observatory,
as well as further TESS observations in sector 70. We statistically validate Gliese 12 b as a planet with an orbital period of
12.76144 ± 0.00006 d and a radius of 1.0 ± 0.1 R⊕, resulting in an equilibrium temperature of ∼315 K. Gliese 12 b has excellent
future prospects for precise mass measurement, which may inform how planetary internal structure is affected by the stellar
compositional environment. Gliese 12 b also represents one of the best targets to study whether Earth-like planets orbiting cool
stars can retain their atmospheres, a crucial step to advance our understanding of habitability on Earth and across the galaxy.
The importance of continents, oceans and plate tectonics for the evolution of...Sérgio Sacani
Within the uncertainties of involved astronomical and biological parameters, the Drake Equation
typically predicts that there should be many exoplanets in our galaxy hosting active, communicative
civilizations (ACCs). These optimistic calculations are however not supported by evidence, which is
often referred to as the Fermi Paradox. Here, we elaborate on this long-standing enigma by showing
the importance of planetary tectonic style for biological evolution. We summarize growing evidence
that a prolonged transition from Mesoproterozoic active single lid tectonics (1.6 to 1.0 Ga) to modern
plate tectonics occurred in the Neoproterozoic Era (1.0 to 0.541 Ga), which dramatically accelerated
emergence and evolution of complex species. We further suggest that both continents and oceans
are required for ACCs because early evolution of simple life must happen in water but late evolution
of advanced life capable of creating technology must happen on land. We resolve the Fermi Paradox
(1) by adding two additional terms to the Drake Equation: foc
(the fraction of habitable exoplanets
with significant continents and oceans) and fpt
(the fraction of habitable exoplanets with significant
continents and oceans that have had plate tectonics operating for at least 0.5 Ga); and (2) by
demonstrating that the product of foc
and fpt
is very small (< 0.00003–0.002). We propose that the lack
of evidence for ACCs reflects the scarcity of long-lived plate tectonics and/or continents and oceans on
exoplanets with primitive life.
A Giant Impact Origin for the First Subduction on EarthSérgio Sacani
Hadean zircons provide a potential record of Earth's earliest subduction 4.3 billion years ago. Itremains enigmatic how subduction could be initiated so soon after the presumably Moon‐forming giant impact(MGI). Earlier studies found an increase in Earth's core‐mantle boundary (CMB) temperature due to theaccumulation of the impactor's core, and our recent work shows Earth's lower mantle remains largely solid, withsome of the impactor's mantle potentially surviving as the large low‐shear velocity provinces (LLSVPs). Here,we show that a hot post‐impact CMB drives the initiation of strong mantle plumes that can induce subductioninitiation ∼200 Myr after the MGI. 2D and 3D thermomechanical computations show that a high CMBtemperature is the primary factor triggering early subduction, with enrichment of heat‐producing elements inLLSVPs as another potential factor. The models link the earliest subduction to the MGI with implications forunderstanding the diverse tectonic regimes of rocky planets.
Climate extremes likely to drive land mammal extinction during next supercont...Sérgio Sacani
Mammals have dominated Earth for approximately 55 Myr thanks to their
adaptations and resilience to warming and cooling during the Cenozoic. All
life will eventually perish in a runaway greenhouse once absorbed solar
radiation exceeds the emission of thermal radiation in several billions of
years. However, conditions rendering the Earth naturally inhospitable to
mammals may develop sooner because of long-term processes linked to
plate tectonics (short-term perturbations are not considered here). In
~250 Myr, all continents will converge to form Earth’s next supercontinent,
Pangea Ultima. A natural consequence of the creation and decay of Pangea
Ultima will be extremes in pCO2 due to changes in volcanic rifting and
outgassing. Here we show that increased pCO2, solar energy (F⨀;
approximately +2.5% W m−2 greater than today) and continentality (larger
range in temperatures away from the ocean) lead to increasing warming
hostile to mammalian life. We assess their impact on mammalian
physiological limits (dry bulb, wet bulb and Humidex heat stress indicators)
as well as a planetary habitability index. Given mammals’ continued survival,
predicted background pCO2 levels of 410–816 ppm combined with increased
F⨀ will probably lead to a climate tipping point and their mass extinction.
The results also highlight how global landmass configuration, pCO2 and F⨀
play a critical role in planetary habitability.
Constraints on Neutrino Natal Kicks from Black-Hole Binary VFTS 243Sérgio Sacani
The recently reported observation of VFTS 243 is the first example of a massive black-hole binary
system with negligible binary interaction following black-hole formation. The black-hole mass (≈10M⊙)
and near-circular orbit (e ≈ 0.02) of VFTS 243 suggest that the progenitor star experienced complete
collapse, with energy-momentum being lost predominantly through neutrinos. VFTS 243 enables us to
constrain the natal kick and neutrino-emission asymmetry during black-hole formation. At 68% confidence
level, the natal kick velocity (mass decrement) is ≲10 km=s (≲1.0M⊙), with a full probability distribution
that peaks when ≈0.3M⊙ were ejected, presumably in neutrinos, and the black hole experienced a natal
kick of 4 km=s. The neutrino-emission asymmetry is ≲4%, with best fit values of ∼0–0.2%. Such a small
neutrino natal kick accompanying black-hole formation is in agreement with theoretical predictions.
Detectability of Solar Panels as a TechnosignatureSérgio Sacani
In this work, we assess the potential detectability of solar panels made of silicon on an Earth-like
exoplanet as a potential technosignature. Silicon-based photovoltaic cells have high reflectance in the
UV-VIS and in the near-IR, within the wavelength range of a space-based flagship mission concept
like the Habitable Worlds Observatory (HWO). Assuming that only solar energy is used to provide
the 2022 human energy needs with a land cover of ∼ 2.4%, and projecting the future energy demand
assuming various growth-rate scenarios, we assess the detectability with an 8 m HWO-like telescope.
Assuming the most favorable viewing orientation, and focusing on the strong absorption edge in the
ultraviolet-to-visible (0.34 − 0.52 µm), we find that several 100s of hours of observation time is needed
to reach a SNR of 5 for an Earth-like planet around a Sun-like star at 10pc, even with a solar panel
coverage of ∼ 23% land coverage of a future Earth. We discuss the necessity of concepts like Kardeshev
Type I/II civilizations and Dyson spheres, which would aim to harness vast amounts of energy. Even
with much larger populations than today, the total energy use of human civilization would be orders of
magnitude below the threshold for causing direct thermal heating or reaching the scale of a Kardashev
Type I civilization. Any extraterrrestrial civilization that likewise achieves sustainable population
levels may also find a limit on its need to expand, which suggests that a galaxy-spanning civilization
as imagined in the Fermi paradox may not exist.
Jet reorientation in central galaxies of clusters and groups: insights from V...Sérgio Sacani
Recent observations of galaxy clusters and groups with misalignments between their central AGN jets
and X-ray cavities, or with multiple misaligned cavities, have raised concerns about the jet – bubble
connection in cooling cores, and the processes responsible for jet realignment. To investigate the
frequency and causes of such misalignments, we construct a sample of 16 cool core galaxy clusters and
groups. Using VLBA radio data we measure the parsec-scale position angle of the jets, and compare
it with the position angle of the X-ray cavities detected in Chandra data. Using the overall sample
and selected subsets, we consistently find that there is a 30% – 38% chance to find a misalignment
larger than ∆Ψ = 45◦ when observing a cluster/group with a detected jet and at least one cavity. We
determine that projection may account for an apparently large ∆Ψ only in a fraction of objects (∼35%),
and given that gas dynamical disturbances (as sloshing) are found in both aligned and misaligned
systems, we exclude environmental perturbation as the main driver of cavity – jet misalignment.
Moreover, we find that large misalignments (up to ∼ 90◦
) are favored over smaller ones (45◦ ≤ ∆Ψ ≤
70◦
), and that the change in jet direction can occur on timescales between one and a few tens of Myr.
We conclude that misalignments are more likely related to actual reorientation of the jet axis, and we
discuss several engine-based mechanisms that may cause these dramatic changes.
The solar dynamo begins near the surfaceSérgio Sacani
The magnetic dynamo cycle of the Sun features a distinct pattern: a propagating
region of sunspot emergence appears around 30° latitude and vanishes near the
equator every 11 years (ref. 1). Moreover, longitudinal flows called torsional oscillations
closely shadow sunspot migration, undoubtedly sharing a common cause2. Contrary
to theories suggesting deep origins of these phenomena, helioseismology pinpoints
low-latitude torsional oscillations to the outer 5–10% of the Sun, the near-surface
shear layer3,4. Within this zone, inwardly increasing differential rotation coupled with
a poloidal magnetic field strongly implicates the magneto-rotational instability5,6,
prominent in accretion-disk theory and observed in laboratory experiments7.
Together, these two facts prompt the general question: whether the solar dynamo is
possibly a near-surface instability. Here we report strong affirmative evidence in stark
contrast to traditional models8 focusing on the deeper tachocline. Simple analytic
estimates show that the near-surface magneto-rotational instability better explains
the spatiotemporal scales of the torsional oscillations and inferred subsurface
magnetic field amplitudes9. State-of-the-art numerical simulations corroborate these
estimates and reproduce hemispherical magnetic current helicity laws10. The dynamo
resulting from a well-understood near-surface phenomenon improves prospects
for accurate predictions of full magnetic cycles and space weather, affecting the
electromagnetic infrastructure of Earth.
Extensive Pollution of Uranus and Neptune’s Atmospheres by Upsweep of Icy Mat...Sérgio Sacani
In the Nice model of solar system formation, Uranus and Neptune undergo an orbital upheaval,
sweeping through a planetesimal disk. The region of the disk from which material is accreted by
the ice giants during this phase of their evolution has not previously been identified. We perform
direct N-body orbital simulations of the four giant planets to determine the amount and origin of solid
accretion during this orbital upheaval. We find that the ice giants undergo an extreme bombardment
event, with collision rates as much as ∼3 per hour assuming km-sized planetesimals, increasing the
total planet mass by up to ∼0.35%. In all cases, the initially outermost ice giant experiences the
largest total enhancement. We determine that for some plausible planetesimal properties, the resulting
atmospheric enrichment could potentially produce sufficient latent heat to alter the planetary cooling
timescale according to existing models. Our findings suggest that substantial accretion during this
phase of planetary evolution may have been sufficient to impact the atmospheric composition and
thermal evolution of the ice giants, motivating future work on the fate of deposited solid material.
Exomoons & Exorings with the Habitable Worlds Observatory I: On the Detection...Sérgio Sacani
The highest priority recommendation of the Astro2020 Decadal Survey for space-based astronomy
was the construction of an observatory capable of characterizing habitable worlds. In this paper series
we explore the detectability of and interference from exomoons and exorings serendipitously observed
with the proposed Habitable Worlds Observatory (HWO) as it seeks to characterize exoplanets, starting
in this manuscript with Earth-Moon analog mutual events. Unlike transits, which only occur in systems
viewed near edge-on, shadow (i.e., solar eclipse) and lunar eclipse mutual events occur in almost every
star-planet-moon system. The cadence of these events can vary widely from ∼yearly to multiple events
per day, as was the case in our younger Earth-Moon system. Leveraging previous space-based (EPOXI)
lightcurves of a Moon transit and performance predictions from the LUVOIR-B concept, we derive
the detectability of Moon analogs with HWO. We determine that Earth-Moon analogs are detectable
with observation of ∼2-20 mutual events for systems within 10 pc, and larger moons should remain
detectable out to 20 pc. We explore the extent to which exomoon mutual events can mimic planet
features and weather. We find that HWO wavelength coverage in the near-IR, specifically in the 1.4 µm
water band where large moons can outshine their host planet, will aid in differentiating exomoon signals
from exoplanet variability. Finally, we predict that exomoons formed through collision processes akin
to our Moon are more likely to be detected in younger systems, where shorter orbital periods and
favorable geometry enhance the probability and frequency of mutual events.
Emergent ribozyme behaviors in oxychlorine brines indicate a unique niche for...Sérgio Sacani
Mars is a particularly attractive candidate among known astronomical objects
to potentially host life. Results from space exploration missions have provided
insights into Martian geochemistry that indicate oxychlorine species, particularly perchlorate, are ubiquitous features of the Martian geochemical landscape. Perchlorate presents potential obstacles for known forms of life due to
its toxicity. However, it can also provide potential benefits, such as producing
brines by deliquescence, like those thought to exist on present-day Mars. Here
we show perchlorate brines support folding and catalysis of functional RNAs,
while inactivating representative protein enzymes. Additionally, we show
perchlorate and other oxychlorine species enable ribozyme functions,
including homeostasis-like regulatory behavior and ribozyme-catalyzed
chlorination of organic molecules. We suggest nucleic acids are uniquely wellsuited to hypersaline Martian environments. Furthermore, Martian near- or
subsurface oxychlorine brines, and brines found in potential lifeforms, could
provide a unique niche for biomolecular evolution.
Continuum emission from within the plunging region of black hole discsSérgio Sacani
The thermal continuum emission observed from accreting black holes across X-ray bands has the potential to be leveraged as a
powerful probe of the mass and spin of the central black hole. The vast majority of existing ‘continuum fitting’ models neglect
emission sourced at and within the innermost stable circular orbit (ISCO) of the black hole. Numerical simulations, however,
find non-zero emission sourced from these regions. In this work, we extend existing techniques by including the emission
sourced from within the plunging region, utilizing new analytical models that reproduce the properties of numerical accretion
simulations. We show that in general the neglected intra-ISCO emission produces a hot-and-small quasi-blackbody component,
but can also produce a weak power-law tail for more extreme parameter regions. A similar hot-and-small blackbody component
has been added in by hand in an ad hoc manner to previous analyses of X-ray binary spectra. We show that the X-ray spectrum
of MAXI J1820+070 in a soft-state outburst is extremely well described by a full Kerr black hole disc, while conventional
models that neglect intra-ISCO emission are unable to reproduce the data. We believe this represents the first robust detection of
intra-ISCO emission in the literature, and allows additional constraints to be placed on the MAXI J1820 + 070 black hole spin
which must be low a• < 0.5 to allow a detectable intra-ISCO region. Emission from within the ISCO is the dominant emission
component in the MAXI J1820 + 070 spectrum between 6 and 10 keV, highlighting the necessity of including this region. Our
continuum fitting model is made publicly available.
Ocean lotus Threat actors project by John Sitima 2024 (1).pptxSitimaJohn
Ocean Lotus cyber threat actors represent a sophisticated, persistent, and politically motivated group that poses a significant risk to organizations and individuals in the Southeast Asian region. Their continuous evolution and adaptability underscore the need for robust cybersecurity measures and international cooperation to identify and mitigate the threats posed by such advanced persistent threat groups.
Digital Marketing Trends in 2024 | Guide for Staying AheadWask
https://www.wask.co/ebooks/digital-marketing-trends-in-2024
Feeling lost in the digital marketing whirlwind of 2024? Technology is changing, consumer habits are evolving, and staying ahead of the curve feels like a never-ending pursuit. This e-book is your compass. Dive into actionable insights to handle the complexities of modern marketing. From hyper-personalization to the power of user-generated content, learn how to build long-term relationships with your audience and unlock the secrets to success in the ever-shifting digital landscape.
AI 101: An Introduction to the Basics and Impact of Artificial IntelligenceIndexBug
Imagine a world where machines not only perform tasks but also learn, adapt, and make decisions. This is the promise of Artificial Intelligence (AI), a technology that's not just enhancing our lives but revolutionizing entire industries.
Webinar: Designing a schema for a Data WarehouseFederico Razzoli
Are you new to data warehouses (DWH)? Do you need to check whether your data warehouse follows the best practices for a good design? In both cases, this webinar is for you.
A data warehouse is a central relational database that contains all measurements about a business or an organisation. This data comes from a variety of heterogeneous data sources, which includes databases of any type that back the applications used by the company, data files exported by some applications, or APIs provided by internal or external services.
But designing a data warehouse correctly is a hard task, which requires gathering information about the business processes that need to be analysed in the first place. These processes must be translated into so-called star schemas, which means, denormalised databases where each table represents a dimension or facts.
We will discuss these topics:
- How to gather information about a business;
- Understanding dictionaries and how to identify business entities;
- Dimensions and facts;
- Setting a table granularity;
- Types of facts;
- Types of dimensions;
- Snowflakes and how to avoid them;
- Expanding existing dimensions and facts.
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
Unlock the Future of Search with MongoDB Atlas_ Vector Search Unleashed.pdfMalak Abu Hammad
Discover how MongoDB Atlas and vector search technology can revolutionize your application's search capabilities. This comprehensive presentation covers:
* What is Vector Search?
* Importance and benefits of vector search
* Practical use cases across various industries
* Step-by-step implementation guide
* Live demos with code snippets
* Enhancing LLM capabilities with vector search
* Best practices and optimization strategies
Perfect for developers, AI enthusiasts, and tech leaders. Learn how to leverage MongoDB Atlas to deliver highly relevant, context-aware search results, transforming your data retrieval process. Stay ahead in tech innovation and maximize the potential of your applications.
#MongoDB #VectorSearch #AI #SemanticSearch #TechInnovation #DataScience #LLM #MachineLearning #SearchTechnology
In the rapidly evolving landscape of technologies, XML continues to play a vital role in structuring, storing, and transporting data across diverse systems. The recent advancements in artificial intelligence (AI) present new methodologies for enhancing XML development workflows, introducing efficiency, automation, and intelligent capabilities. This presentation will outline the scope and perspective of utilizing AI in XML development. The potential benefits and the possible pitfalls will be highlighted, providing a balanced view of the subject.
We will explore the capabilities of AI in understanding XML markup languages and autonomously creating structured XML content. Additionally, we will examine the capacity of AI to enrich plain text with appropriate XML markup. Practical examples and methodological guidelines will be provided to elucidate how AI can be effectively prompted to interpret and generate accurate XML markup.
Further emphasis will be placed on the role of AI in developing XSLT, or schemas such as XSD and Schematron. We will address the techniques and strategies adopted to create prompts for generating code, explaining code, or refactoring the code, and the results achieved.
The discussion will extend to how AI can be used to transform XML content. In particular, the focus will be on the use of AI XPath extension functions in XSLT, Schematron, Schematron Quick Fixes, or for XML content refactoring.
The presentation aims to deliver a comprehensive overview of AI usage in XML development, providing attendees with the necessary knowledge to make informed decisions. Whether you’re at the early stages of adopting AI or considering integrating it in advanced XML development, this presentation will cover all levels of expertise.
By highlighting the potential advantages and challenges of integrating AI with XML development tools and languages, the presentation seeks to inspire thoughtful conversation around the future of XML development. We’ll not only delve into the technical aspects of AI-powered XML development but also discuss practical implications and possible future directions.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
How to Interpret Trends in the Kalyan Rajdhani Mix Chart.pdfChart Kalyan
A Mix Chart displays historical data of numbers in a graphical or tabular form. The Kalyan Rajdhani Mix Chart specifically shows the results of a sequence of numbers over different periods.
Introduction of Cybersecurity with OSS at Code Europe 2024Hiroshi SHIBATA
I develop the Ruby programming language, RubyGems, and Bundler, which are package managers for Ruby. Today, I will introduce how to enhance the security of your application using open-source software (OSS) examples from Ruby and RubyGems.
The first topic is CVE (Common Vulnerabilities and Exposures). I have published CVEs many times. But what exactly is a CVE? I'll provide a basic understanding of CVEs and explain how to detect and handle vulnerabilities in OSS.
Next, let's discuss package managers. Package managers play a critical role in the OSS ecosystem. I'll explain how to manage library dependencies in your application.
I'll share insights into how the Ruby and RubyGems core team works to keep our ecosystem safe. By the end of this talk, you'll have a better understanding of how to safeguard your code.
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
Skybuffer SAM4U tool for SAP license adoptionTatiana Kojar
Manage and optimize your license adoption and consumption with SAM4U, an SAP free customer software asset management tool.
SAM4U, an SAP complimentary software asset management tool for customers, delivers a detailed and well-structured overview of license inventory and usage with a user-friendly interface. We offer a hosted, cost-effective, and performance-optimized SAM4U setup in the Skybuffer Cloud environment. You retain ownership of the system and data, while we manage the ABAP 7.58 infrastructure, ensuring fixed Total Cost of Ownership (TCO) and exceptional services through the SAP Fiori interface.
Best 20 SEO Techniques To Improve Website Visibility In SERPPixlogix Infotech
Boost your website's visibility with proven SEO techniques! Our latest blog dives into essential strategies to enhance your online presence, increase traffic, and rank higher on search engines. From keyword optimization to quality content creation, learn how to make your site stand out in the crowded digital landscape. Discover actionable tips and expert insights to elevate your SEO game.
Have you ever been confused by the myriad of choices offered by AWS for hosting a website or an API?
Lambda, Elastic Beanstalk, Lightsail, Amplify, S3 (and more!) can each host websites + APIs. But which one should we choose?
Which one is cheapest? Which one is fastest? Which one will scale to meet our needs?
Join me in this session as we dive into each AWS hosting service to determine which one is best for your scenario and explain why!
Building Production Ready Search Pipelines with Spark and MilvusZilliz
Spark is the widely used ETL tool for processing, indexing and ingesting data to serving stack for search. Milvus is the production-ready open-source vector database. In this talk we will show how to use Spark to process unstructured data to extract vector representations, and push the vectors to Milvus vector database for search serving.
Taking AI to the Next Level in Manufacturing.pdfssuserfac0301
Read Taking AI to the Next Level in Manufacturing to gain insights on AI adoption in the manufacturing industry, such as:
1. How quickly AI is being implemented in manufacturing.
2. Which barriers stand in the way of AI adoption.
3. How data quality and governance form the backbone of AI.
4. Organizational processes and structures that may inhibit effective AI adoption.
6. Ideas and approaches to help build your organization's AI strategy.
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
Main news related to the CCS TSI 2023 (2023/1695)Jakub Marek
An English 🇬🇧 translation of a presentation to the speech I gave about the main changes brought by CCS TSI 2023 at the biggest Czech conference on Communications and signalling systems on Railways, which was held in Clarion Hotel Olomouc from 7th to 9th November 2023 (konferenceszt.cz). Attended by around 500 participants and 200 on-line followers.
The original Czech 🇨🇿 version of the presentation can be found here: https://www.slideshare.net/slideshow/hlavni-novinky-souvisejici-s-ccs-tsi-2023-2023-1695/269688092 .
The videorecording (in Czech) from the presentation is available here: https://youtu.be/WzjJWm4IyPk?si=SImb06tuXGb30BEH .