This study examines a reservoir of ionized gas in the galactic halo that can sustain star formation in the Milky Way. The authors detect a substantial amount of warm-hot gas in the halo of a star-forming galaxy at z=0.2 through detection of Ne VIII absorption lines. This warm-hot gas reservoir contains as much mass as the galaxy's stars and can replenish its supply of cool gas to sustain star formation over billions of years.
Measurements of a_massive_galaxy_clusterSérgio Sacani
This document reports on observations of IDCS J1426.5+3508, a galaxy cluster located at a redshift of 1.75. A Sunyaev-Zeldovich decrement was detected towards this cluster, indicating a total mass of 4.3×1014 solar masses. This makes it the most distant cluster detected via the Sunyaev-Zeldovich effect to date and the most massive cluster found at a redshift greater than 1.4. Despite its rarity, the cluster is not unexpected given cosmological models and the large area surveyed. However, it remains one of the rarest and most extreme clusters discovered and provides insight into the early formation of the most massive clusters.
The first hyper_luminous_infrared_galaxy_discovered_by_wiseSérgio Sacani
This document summarizes the discovery of WISE J181417.29+341224.9 (WISE 1814+3412), the first hyper-luminous infrared galaxy (LIR > 1013 L⊙) discovered by the Wide-field Infrared Survey Explorer (WISE). Follow-up images of WISE 1814+3412 revealed four nearby sources - a QSO, two Lyman Break Galaxies at z=2.45, and an M dwarf star. The brighter LBG dominates the bolometric emission of WISE 1814+3412 and has a star formation rate of ~300M⊙ yr−1, accounting for <10% of the total luminosity. An obscured
1. Scientists used stellar occultation to measure the size of the dwarf planet Eris more accurately. They found it has a radius of 1,163 km, smaller than previous estimates, though not definitively smaller than Pluto due to uncertainties in Pluto's size.
2. Surprisingly, Eris' surface was found to be very bright, which could indicate a collapsed or localized atmosphere had recently condensed onto the surface from sublimated ices as Eris moves closer to the Sun in its orbit.
3. The discovery of Eris and other large Kuiper Belt objects has challenged definitions of planets and our understanding of the outer solar system, showing Pluto is not unique and sparking debate about what constitutes
Color and albedo_heterogeneity_on_vestaSérgio Sacani
The document summarizes findings from the Dawn spacecraft about the composition and geology of Vesta. It found that Vesta's surface has significant heterogeneity in color and albedo. Spectroscopic data revealed variations in the mineralogy and composition, with the Oppia region showing differences possibly related to mass movements. Craters exposed layers with different mineral and chemical compositions, providing insights into Vesta's complex, stratified crust formed from magmatic processes during planetary differentiation.
Detection of brown dwarf like objects in the core of ngc3603Sérgio Sacani
This document describes observations of the massive galactic cluster NGC 3603 using the Wide Field Camera 3 on the Hubble Space Telescope. Near-infrared data was obtained using narrow and medium band filters spanning the J and H bands, which are sensitive to the 1.3-1.5μm H2O molecular absorption band unique to brown dwarfs. Nine objects were identified having effective temperatures between 1700-2200K, typical of brown dwarfs, located strongly clustered towards the luminous core of NGC 3603. However, if located at the distance of the cluster, these objects would be too luminous to be normal brown dwarfs. The authors explore the possibility that these objects could represent a new class of stars having
A young protoplanet_candidate_embedded_in_the_circumstellar_disk_of_hd100546Sérgio Sacani
This document summarizes observations of HD100546 using high-contrast imaging techniques. A faint emission source was detected near the star at a projected separation of about 47 AU. The position of the source coincides with a deficit in polarization observed from the circumstellar disk. This suggests a physical link between the source and the disk. Considering various scenarios, the authors favor interpreting the source as a young protoplanet currently forming within the disk. Follow-up observations could distinguish between different possible explanations for the observed features. If confirmed, it would be a unique opportunity to study giant planet formation within an optically thick disk.
This document summarizes a study that identified 195 compact elliptical galaxies across different environments using data from optical and ultraviolet sky surveys. The researchers constructed the sample by selecting galaxies that were outliers from the universal color-magnitude relation and had small sizes and high stellar velocity dispersions based on spectral modeling. They found that 7 of the galaxies were isolated, not belonging to any known galaxy groups. For these isolated galaxies, the researchers identified possible host galaxies located up to 3.3 Mpc away. The stellar populations of the isolated compact elliptical galaxies were found to be similar to those in galaxy groups and clusters, suggesting a common formation mechanism.
This study examines a reservoir of ionized gas in the galactic halo that can sustain star formation in the Milky Way. The authors detect a substantial amount of warm-hot gas in the halo of a star-forming galaxy at z=0.2 through detection of Ne VIII absorption lines. This warm-hot gas reservoir contains as much mass as the galaxy's stars and can replenish its supply of cool gas to sustain star formation over billions of years.
Measurements of a_massive_galaxy_clusterSérgio Sacani
This document reports on observations of IDCS J1426.5+3508, a galaxy cluster located at a redshift of 1.75. A Sunyaev-Zeldovich decrement was detected towards this cluster, indicating a total mass of 4.3×1014 solar masses. This makes it the most distant cluster detected via the Sunyaev-Zeldovich effect to date and the most massive cluster found at a redshift greater than 1.4. Despite its rarity, the cluster is not unexpected given cosmological models and the large area surveyed. However, it remains one of the rarest and most extreme clusters discovered and provides insight into the early formation of the most massive clusters.
The first hyper_luminous_infrared_galaxy_discovered_by_wiseSérgio Sacani
This document summarizes the discovery of WISE J181417.29+341224.9 (WISE 1814+3412), the first hyper-luminous infrared galaxy (LIR > 1013 L⊙) discovered by the Wide-field Infrared Survey Explorer (WISE). Follow-up images of WISE 1814+3412 revealed four nearby sources - a QSO, two Lyman Break Galaxies at z=2.45, and an M dwarf star. The brighter LBG dominates the bolometric emission of WISE 1814+3412 and has a star formation rate of ~300M⊙ yr−1, accounting for <10% of the total luminosity. An obscured
1. Scientists used stellar occultation to measure the size of the dwarf planet Eris more accurately. They found it has a radius of 1,163 km, smaller than previous estimates, though not definitively smaller than Pluto due to uncertainties in Pluto's size.
2. Surprisingly, Eris' surface was found to be very bright, which could indicate a collapsed or localized atmosphere had recently condensed onto the surface from sublimated ices as Eris moves closer to the Sun in its orbit.
3. The discovery of Eris and other large Kuiper Belt objects has challenged definitions of planets and our understanding of the outer solar system, showing Pluto is not unique and sparking debate about what constitutes
Color and albedo_heterogeneity_on_vestaSérgio Sacani
The document summarizes findings from the Dawn spacecraft about the composition and geology of Vesta. It found that Vesta's surface has significant heterogeneity in color and albedo. Spectroscopic data revealed variations in the mineralogy and composition, with the Oppia region showing differences possibly related to mass movements. Craters exposed layers with different mineral and chemical compositions, providing insights into Vesta's complex, stratified crust formed from magmatic processes during planetary differentiation.
Detection of brown dwarf like objects in the core of ngc3603Sérgio Sacani
This document describes observations of the massive galactic cluster NGC 3603 using the Wide Field Camera 3 on the Hubble Space Telescope. Near-infrared data was obtained using narrow and medium band filters spanning the J and H bands, which are sensitive to the 1.3-1.5μm H2O molecular absorption band unique to brown dwarfs. Nine objects were identified having effective temperatures between 1700-2200K, typical of brown dwarfs, located strongly clustered towards the luminous core of NGC 3603. However, if located at the distance of the cluster, these objects would be too luminous to be normal brown dwarfs. The authors explore the possibility that these objects could represent a new class of stars having
A young protoplanet_candidate_embedded_in_the_circumstellar_disk_of_hd100546Sérgio Sacani
This document summarizes observations of HD100546 using high-contrast imaging techniques. A faint emission source was detected near the star at a projected separation of about 47 AU. The position of the source coincides with a deficit in polarization observed from the circumstellar disk. This suggests a physical link between the source and the disk. Considering various scenarios, the authors favor interpreting the source as a young protoplanet currently forming within the disk. Follow-up observations could distinguish between different possible explanations for the observed features. If confirmed, it would be a unique opportunity to study giant planet formation within an optically thick disk.
This document summarizes a study that identified 195 compact elliptical galaxies across different environments using data from optical and ultraviolet sky surveys. The researchers constructed the sample by selecting galaxies that were outliers from the universal color-magnitude relation and had small sizes and high stellar velocity dispersions based on spectral modeling. They found that 7 of the galaxies were isolated, not belonging to any known galaxy groups. For these isolated galaxies, the researchers identified possible host galaxies located up to 3.3 Mpc away. The stellar populations of the isolated compact elliptical galaxies were found to be similar to those in galaxy groups and clusters, suggesting a common formation mechanism.
The study examines a post-starburst galaxy outflow using ultraviolet spectroscopy of multiple ions including hydrogen. It finds the outflow extends at least 160,000 light-years from the galaxy and contains a hidden mass of at least 6x10^9 times the mass of our Sun. This challenges previous assumptions about the extent and mass of galaxy outflows, suggesting they may play a larger role in regulating galaxy evolution than thought.
The document summarizes findings from studying asteroid 4 Vesta using data from NASA's Dawn spacecraft. It finds that Vesta has experienced a violent collisional history, with large impacts creating steep slopes and resurfacing much of the surface. While no unambiguous volcanic deposits were found, some dark material in impact craters may be from excavated subsurface volcanic features. Smooth ponds found on Vesta are also seen on asteroid Eros and are thought to form from impact ejecta collecting in depressions.
This document summarizes the results of a deep near-infrared survey of the Carina Nebula complex using the HAWK-I instrument on the VLT. The survey imaged an area of 0.36 square degrees down to magnitudes of J=23, H=22, and Ks=21, detecting over 600,000 infrared sources. Color-magnitude diagrams of the sources were analyzed to determine properties of the low-mass stellar population such as ages and masses. The survey found that about 3200 sources have masses above 1 solar mass, consistent with expectations from the initial mass function. It also found that about half of the young stars in Carina are in a widely distributed, non-clustered configuration. Six
Star formation history_in_the_smc_the_case_of_ngc602Sérgio Sacani
This document summarizes a study of the star formation history in the NGC 602 region of the Small Magellanic Cloud based on Hubble Space Telescope observations. Deep photometry reveals numerous pre-main sequence stars as well as young stars on the main sequence, allowing the study of star formation into recent times. New pre-main sequence stellar evolutionary tracks are presented. A stellar population synthesis code is used to derive the best estimate of the star formation history by comparing observed and synthetic color-magnitude diagrams. The star formation rate in the region has increased over the past tens of Myr, reaching 0.3-0.7×10−3 M☉ yr−1 in the last 2.5 Myr, comparable to
We present spectroscopic observations of the nearby dwarf galaxy AGC 198691. This object is part
of the Survey of H I in Extremely Low-Mass Dwarfs (SHIELD) project, which is a multi-wavelength
study of galaxies with H I masses in the range of 106-107:2 M discovered by the ALFALFA survey.
We have obtained spectra of the lone H II region in AGC 198691 with the new high-throughput
KPNO Ohio State Multi-Object Spectrograph (KOSMOS) on the Mayall 4-m as well as with the Blue
Channel spectrograph on the MMT 6.5-m telescope. These observations enable the measurement of the
temperature-sensitive [O III]4363 line and hence the determination of a \direct" oxygen abundance
for AGC 198691. We nd this system to be an extremely metal-decient (XMD) system with an
oxygen abundance of 12+log(O/H) = 7.02 0.03, making AGC 198691 the lowest-abundance starforming
galaxy known in the local universe. Two of the ve lowest-abundance galaxies known have
been discovered by the ALFALFA blind H I survey; this high yield of XMD galaxies represents a
paradigm shift in the search for extremely metal-poor galaxies.
This document summarizes a survey of the massive star forming region RCW 57 (NGC 3576) using JHKs and L-band (3.5 μm) infrared data. Over 50% of the sources detected showed infrared excess emission, indicating the presence of circumstellar disks. Comparison to other regions supported a very high initial disk fraction (>80%) around massive stars, though disks may dissipate faster around high-mass stars. 33 sources only detected at L-band indicated heavily embedded, massive Class I protostars. Diffuse polycyclic aromatic hydrocarbon emission was also detected throughout the region.
This document summarizes a 1.3 mm continuum survey of protoplanetary disks in the 2-3 Myr old IC348 star cluster using the Submillimeter Array. 10 disks out of 85 young stars were detected with masses ranging from 2-6 Jupiter masses. This distribution is shifted to lower masses by a factor of 20 compared to younger regions like Taurus and Ophiuchus. The results reveal a rapid decline in the number of small dust grains in disks after 1 Myr, likely due to grain growth. The few detected disks may be the best candidates in IC348 to study planet formation.
This document summarizes a study that uses U-band photometry to determine photometric distances to young stars in the inner Galactic disk. The study focuses on the line of sight towards the Galactic longitude of 314 degrees. Photometric data is collected and calibrated using two open clusters in the field. Three groups of stars are detected at distances of 1.5, 2.5, and 5.1 kpc, which are consistent with the Carina-Sagittarius and Scutum-Crux spiral arms. The use of U-band photometry is shown to be an effective method for characterizing young star populations and making predictions about spiral structure in the Milky Way.
Science laser altimetry of small scale features on 433 eros from near-shoemakerFelipe Correa
This article summarizes findings from laser altimetry observations of asteroid 433 Eros made by the NEAR spacecraft during its close flyby. The laser observations revealed surface features on scales of meters to hundreds of meters, showing that the surface has a fractal structure dominated by blocks, structural features, and small crater walls. This fractal structure suggests a single process, likely impacts, dominates the surface morphology on these scales. Laser altimetry also measured local surface elevations and slopes, correlating elevations with morphological evidence of downslope movement of loose surface materials.
This document summarizes an X-ray study of the supernova remnant G352.7-0.1 using data from XMM-Newton and Chandra observations. Prior observations revealed G352.7-0.1 has a shell-like radio morphology but center-filled thermal X-ray morphology, classifying it as a mixed-morphology supernova remnant. The new observations confirm the X-ray emission comes from the interior and is dominated by ejecta. Spectra from XMM-Newton are fit by a single thermal component with enhanced silicon and sulfur. Some Chandra spectra require a second thermal component to fit, with solar abundances providing a better physical model. No evidence of overionization was found. A neutron
This document summarizes a study that used optical, infrared, and submillimeter data to examine star formation in the region surrounding the IC 348 star cluster and the nearby Flying Ghost Nebula. The study identified 13 protostars driving protostellar outflows in the region, including HH 211 which had not previously been detected at visible wavelengths. The region surrounding the Flying Ghost Nebula shows ongoing star formation with outflows similar to other areas of moderate star formation in Perseus. A candidate bent jet was also found, which may have been ejected from a multiple star system near IC 348.
This document summarizes evidence that a galaxy at a redshift of 1.35 contains three accreting black holes. Hubble Space Telescope observations reveal the galaxy has a clumpy morphology with four distinct components, labeled A, B, C, and D. Spectroscopy of the three brightest components (A, B, and C) shows high [O iii]/Hβ line ratios indicative of active galactic nuclei. This provides evidence that each of the three components contains a rapidly growing black hole of mass 106–107 solar masses. The black holes could have formed via early mergers or grown more recently within the galaxy.
Our deep, wide-field imaging of M101 and its surrounding environment reveals:
1) M101's disk extends to nearly 25 arcminutes (50 kpc), three times the measured optical radius, with an asymmetric plume of light to the northeast following the extended HI disk.
2) This outer plume has very blue colors, suggesting a somewhat evolved young stellar population, while another redder spur is detected to the east.
3) No evidence is found of very extended tidal tails around M101 or its companions despite signs of past interactions shaping M101's asymmetry.
4) The detection of starlight at such large radii allows studying the stellar populations and star formation histories in M101's outer disk
The document analyzes data from the open star cluster M11 to determine its fundamental properties. Photometry of stars in M11 was performed using images taken through two filters with a telescope. A color-magnitude diagram was created and fit with theoretical models, revealing M11 to be around 250 million years old, located 5930 light years away, and having a similar iron-to-hydrogen ratio as the sun. Analysis of independent star clusters provides insights into patterns of galaxy formation and evolution.
1) The VVV survey discovered a new globular cluster candidate, named VVV CL001, near the known globular cluster UKS 1 in the direction of the Galactic bulge.
2) Photometry of UKS 1 from the VVV survey was used to measure its reddening as E(B-V)=2.2 mag, distance modulus as (m-M)0=16.01 mag, and distance as 15.9 kpc.
3) Near-infrared color-magnitude diagrams of VVV CL001 suggest it has similar reddening as UKS 1 and is at least as metal-poor, though its distance remains uncertain. Further observations are needed to confirm if they are
Stellar-like objects with effective temperatures of 2700K and below are referred to as
20 "ultracool dwarfs"1. This heterogeneous group includes both extremely low-mass stars
21 and brown dwarfs (substellar objects not massive enough to sustain hydrogen fusion),
22 and represents about 15% of the stellar-like objects in the vicinity of the Sun2. Based on
23 the small masses and sizes of their protoplanetary disks3,4, core-accretion theory for
24 ultracool dwarfs predicts a large, but heretofore undetected, population of close-in
25 terrestrial planets5, ranging from metal-rich Mercury-sized planets6 to more hospitable
26 volatile-rich Earth-sized planets7. Here we report the discovery of three short-period
27 Earth-sized planets transiting an ultracool dwarf star 12 parsecs away. The inner two
28 planets receive four and two times the irradiation of Earth, respectively, placing them
29 close to the inner edge of the habitable zone of the star8. Eleven orbits remain possible
30 for the third planet based on our data, the most likely resulting in an irradiation
31 significantly smaller than Earth's. The infrared brightness of the host star combined
32 with its Jupiter-like size offer the possibility of constraining the composition and
33 thoroughly characterizing the atmospheric properties of the components of this nearby
34 planetary system, notably to detect potential biosignatures.
Characterizing interstellar filaments with herschel in ic5146Sérgio Sacani
This document summarizes early results from the Herschel Gould Belt survey of the IC5146 molecular cloud. It reveals a complex network of filaments identified in the cloud, which are shown to be the main sites of prestellar core formation. Analysis of 27 filaments finds that their radial column density profiles fall off with radii as r^-1.5 to r^-2.5. Remarkably, the filaments seem to have a narrow distribution of widths centered around 0.1 pc, in contrast to a broader distribution of central Jeans lengths. This characteristic width corresponds to the sonic scale below which turbulence becomes subsonic, supporting the argument that filaments may form from dissipating large-scale turbulence.
BETTII is an experimental infrared telescope and interferometer that will be launched via balloon to study star formation and active galactic nuclei. It aims to spatially resolve young stellar objects within dense star clusters using its high angular resolution in the far infrared spectrum. This will provide insight into the earliest stages of star formation and chemical evolution of protostars and their disks. BETTII will also observe active galactic nuclei to separate emissions from the supermassive black hole accretion disk and nearby starburst regions, improving understanding of their co-evolution.
A. Zakharov: Supermassive Black Hole at the Galactic CenterSEENET-MTP
The document summarizes research on the supermassive black hole at the center of the Milky Way galaxy. It discusses how Reinhard Genzel and Andrea Ghez received the 2012 Crafoord Prize in Astronomy for their observations of stars orbiting the galactic center, providing evidence of a supermassive black hole called Sagittarius A*. It also describes efforts to measure the shadow size of the black hole and constraints on its potential charge, finding that a significant negative charge is ruled out. Interferometric observations using radio telescopes aim to better understand properties of the black hole and test general relativity.
Discovery of a_probable_4_5_jupiter_mass_exoplanet_to_hd95086_by_direct_imagingSérgio Sacani
The document reports the discovery of a probable 4-5 Jupiter-mass exoplanet orbiting the young star HD 95086. Deep imaging observations using VLT/NaCo detected a faint source at a separation of 56 AU from the star. Follow-up observations over more than a year found the source to be co-moving with the star, suggesting it is bound. Its luminosity corresponds to a predicted mass of 4-5 Jupiter masses, making it the lowest mass exoplanet directly imaged around a star. If confirmed, this discovery could provide insights into giant planet formation and evolution.
1) The document outlines a photography experiment to take place on February 6th at The Stray Fields in Harrogate.
2) Three techniques will be used - out of focus images, movement images where the model dances and twirls, and double exposures created through editing in Photoshop.
3) For out of focus images, the camera will be manually focused while different apertures are tested. Movement images will use shutter priority to capture a model in motion against stationary backgrounds. Double exposures will composite photos of a model in different poses and facial expressions.
The document summarizes a photography shoot where the photographer experimented with different techniques, including multiple exposures and out of focus shots. Weather conditions made the shoot difficult and the photographer had to make adjustments on the fly. Edited photos applying different effects in Photoshop are included, such as overlaying shots and changing layers to black and white. The photographer aims to convey emotions like loneliness and discovery through surreal, overlapping images.
The study examines a post-starburst galaxy outflow using ultraviolet spectroscopy of multiple ions including hydrogen. It finds the outflow extends at least 160,000 light-years from the galaxy and contains a hidden mass of at least 6x10^9 times the mass of our Sun. This challenges previous assumptions about the extent and mass of galaxy outflows, suggesting they may play a larger role in regulating galaxy evolution than thought.
The document summarizes findings from studying asteroid 4 Vesta using data from NASA's Dawn spacecraft. It finds that Vesta has experienced a violent collisional history, with large impacts creating steep slopes and resurfacing much of the surface. While no unambiguous volcanic deposits were found, some dark material in impact craters may be from excavated subsurface volcanic features. Smooth ponds found on Vesta are also seen on asteroid Eros and are thought to form from impact ejecta collecting in depressions.
This document summarizes the results of a deep near-infrared survey of the Carina Nebula complex using the HAWK-I instrument on the VLT. The survey imaged an area of 0.36 square degrees down to magnitudes of J=23, H=22, and Ks=21, detecting over 600,000 infrared sources. Color-magnitude diagrams of the sources were analyzed to determine properties of the low-mass stellar population such as ages and masses. The survey found that about 3200 sources have masses above 1 solar mass, consistent with expectations from the initial mass function. It also found that about half of the young stars in Carina are in a widely distributed, non-clustered configuration. Six
Star formation history_in_the_smc_the_case_of_ngc602Sérgio Sacani
This document summarizes a study of the star formation history in the NGC 602 region of the Small Magellanic Cloud based on Hubble Space Telescope observations. Deep photometry reveals numerous pre-main sequence stars as well as young stars on the main sequence, allowing the study of star formation into recent times. New pre-main sequence stellar evolutionary tracks are presented. A stellar population synthesis code is used to derive the best estimate of the star formation history by comparing observed and synthetic color-magnitude diagrams. The star formation rate in the region has increased over the past tens of Myr, reaching 0.3-0.7×10−3 M☉ yr−1 in the last 2.5 Myr, comparable to
We present spectroscopic observations of the nearby dwarf galaxy AGC 198691. This object is part
of the Survey of H I in Extremely Low-Mass Dwarfs (SHIELD) project, which is a multi-wavelength
study of galaxies with H I masses in the range of 106-107:2 M discovered by the ALFALFA survey.
We have obtained spectra of the lone H II region in AGC 198691 with the new high-throughput
KPNO Ohio State Multi-Object Spectrograph (KOSMOS) on the Mayall 4-m as well as with the Blue
Channel spectrograph on the MMT 6.5-m telescope. These observations enable the measurement of the
temperature-sensitive [O III]4363 line and hence the determination of a \direct" oxygen abundance
for AGC 198691. We nd this system to be an extremely metal-decient (XMD) system with an
oxygen abundance of 12+log(O/H) = 7.02 0.03, making AGC 198691 the lowest-abundance starforming
galaxy known in the local universe. Two of the ve lowest-abundance galaxies known have
been discovered by the ALFALFA blind H I survey; this high yield of XMD galaxies represents a
paradigm shift in the search for extremely metal-poor galaxies.
This document summarizes a survey of the massive star forming region RCW 57 (NGC 3576) using JHKs and L-band (3.5 μm) infrared data. Over 50% of the sources detected showed infrared excess emission, indicating the presence of circumstellar disks. Comparison to other regions supported a very high initial disk fraction (>80%) around massive stars, though disks may dissipate faster around high-mass stars. 33 sources only detected at L-band indicated heavily embedded, massive Class I protostars. Diffuse polycyclic aromatic hydrocarbon emission was also detected throughout the region.
This document summarizes a 1.3 mm continuum survey of protoplanetary disks in the 2-3 Myr old IC348 star cluster using the Submillimeter Array. 10 disks out of 85 young stars were detected with masses ranging from 2-6 Jupiter masses. This distribution is shifted to lower masses by a factor of 20 compared to younger regions like Taurus and Ophiuchus. The results reveal a rapid decline in the number of small dust grains in disks after 1 Myr, likely due to grain growth. The few detected disks may be the best candidates in IC348 to study planet formation.
This document summarizes a study that uses U-band photometry to determine photometric distances to young stars in the inner Galactic disk. The study focuses on the line of sight towards the Galactic longitude of 314 degrees. Photometric data is collected and calibrated using two open clusters in the field. Three groups of stars are detected at distances of 1.5, 2.5, and 5.1 kpc, which are consistent with the Carina-Sagittarius and Scutum-Crux spiral arms. The use of U-band photometry is shown to be an effective method for characterizing young star populations and making predictions about spiral structure in the Milky Way.
Science laser altimetry of small scale features on 433 eros from near-shoemakerFelipe Correa
This article summarizes findings from laser altimetry observations of asteroid 433 Eros made by the NEAR spacecraft during its close flyby. The laser observations revealed surface features on scales of meters to hundreds of meters, showing that the surface has a fractal structure dominated by blocks, structural features, and small crater walls. This fractal structure suggests a single process, likely impacts, dominates the surface morphology on these scales. Laser altimetry also measured local surface elevations and slopes, correlating elevations with morphological evidence of downslope movement of loose surface materials.
This document summarizes an X-ray study of the supernova remnant G352.7-0.1 using data from XMM-Newton and Chandra observations. Prior observations revealed G352.7-0.1 has a shell-like radio morphology but center-filled thermal X-ray morphology, classifying it as a mixed-morphology supernova remnant. The new observations confirm the X-ray emission comes from the interior and is dominated by ejecta. Spectra from XMM-Newton are fit by a single thermal component with enhanced silicon and sulfur. Some Chandra spectra require a second thermal component to fit, with solar abundances providing a better physical model. No evidence of overionization was found. A neutron
This document summarizes a study that used optical, infrared, and submillimeter data to examine star formation in the region surrounding the IC 348 star cluster and the nearby Flying Ghost Nebula. The study identified 13 protostars driving protostellar outflows in the region, including HH 211 which had not previously been detected at visible wavelengths. The region surrounding the Flying Ghost Nebula shows ongoing star formation with outflows similar to other areas of moderate star formation in Perseus. A candidate bent jet was also found, which may have been ejected from a multiple star system near IC 348.
This document summarizes evidence that a galaxy at a redshift of 1.35 contains three accreting black holes. Hubble Space Telescope observations reveal the galaxy has a clumpy morphology with four distinct components, labeled A, B, C, and D. Spectroscopy of the three brightest components (A, B, and C) shows high [O iii]/Hβ line ratios indicative of active galactic nuclei. This provides evidence that each of the three components contains a rapidly growing black hole of mass 106–107 solar masses. The black holes could have formed via early mergers or grown more recently within the galaxy.
Our deep, wide-field imaging of M101 and its surrounding environment reveals:
1) M101's disk extends to nearly 25 arcminutes (50 kpc), three times the measured optical radius, with an asymmetric plume of light to the northeast following the extended HI disk.
2) This outer plume has very blue colors, suggesting a somewhat evolved young stellar population, while another redder spur is detected to the east.
3) No evidence is found of very extended tidal tails around M101 or its companions despite signs of past interactions shaping M101's asymmetry.
4) The detection of starlight at such large radii allows studying the stellar populations and star formation histories in M101's outer disk
The document analyzes data from the open star cluster M11 to determine its fundamental properties. Photometry of stars in M11 was performed using images taken through two filters with a telescope. A color-magnitude diagram was created and fit with theoretical models, revealing M11 to be around 250 million years old, located 5930 light years away, and having a similar iron-to-hydrogen ratio as the sun. Analysis of independent star clusters provides insights into patterns of galaxy formation and evolution.
1) The VVV survey discovered a new globular cluster candidate, named VVV CL001, near the known globular cluster UKS 1 in the direction of the Galactic bulge.
2) Photometry of UKS 1 from the VVV survey was used to measure its reddening as E(B-V)=2.2 mag, distance modulus as (m-M)0=16.01 mag, and distance as 15.9 kpc.
3) Near-infrared color-magnitude diagrams of VVV CL001 suggest it has similar reddening as UKS 1 and is at least as metal-poor, though its distance remains uncertain. Further observations are needed to confirm if they are
Stellar-like objects with effective temperatures of 2700K and below are referred to as
20 "ultracool dwarfs"1. This heterogeneous group includes both extremely low-mass stars
21 and brown dwarfs (substellar objects not massive enough to sustain hydrogen fusion),
22 and represents about 15% of the stellar-like objects in the vicinity of the Sun2. Based on
23 the small masses and sizes of their protoplanetary disks3,4, core-accretion theory for
24 ultracool dwarfs predicts a large, but heretofore undetected, population of close-in
25 terrestrial planets5, ranging from metal-rich Mercury-sized planets6 to more hospitable
26 volatile-rich Earth-sized planets7. Here we report the discovery of three short-period
27 Earth-sized planets transiting an ultracool dwarf star 12 parsecs away. The inner two
28 planets receive four and two times the irradiation of Earth, respectively, placing them
29 close to the inner edge of the habitable zone of the star8. Eleven orbits remain possible
30 for the third planet based on our data, the most likely resulting in an irradiation
31 significantly smaller than Earth's. The infrared brightness of the host star combined
32 with its Jupiter-like size offer the possibility of constraining the composition and
33 thoroughly characterizing the atmospheric properties of the components of this nearby
34 planetary system, notably to detect potential biosignatures.
Characterizing interstellar filaments with herschel in ic5146Sérgio Sacani
This document summarizes early results from the Herschel Gould Belt survey of the IC5146 molecular cloud. It reveals a complex network of filaments identified in the cloud, which are shown to be the main sites of prestellar core formation. Analysis of 27 filaments finds that their radial column density profiles fall off with radii as r^-1.5 to r^-2.5. Remarkably, the filaments seem to have a narrow distribution of widths centered around 0.1 pc, in contrast to a broader distribution of central Jeans lengths. This characteristic width corresponds to the sonic scale below which turbulence becomes subsonic, supporting the argument that filaments may form from dissipating large-scale turbulence.
BETTII is an experimental infrared telescope and interferometer that will be launched via balloon to study star formation and active galactic nuclei. It aims to spatially resolve young stellar objects within dense star clusters using its high angular resolution in the far infrared spectrum. This will provide insight into the earliest stages of star formation and chemical evolution of protostars and their disks. BETTII will also observe active galactic nuclei to separate emissions from the supermassive black hole accretion disk and nearby starburst regions, improving understanding of their co-evolution.
A. Zakharov: Supermassive Black Hole at the Galactic CenterSEENET-MTP
The document summarizes research on the supermassive black hole at the center of the Milky Way galaxy. It discusses how Reinhard Genzel and Andrea Ghez received the 2012 Crafoord Prize in Astronomy for their observations of stars orbiting the galactic center, providing evidence of a supermassive black hole called Sagittarius A*. It also describes efforts to measure the shadow size of the black hole and constraints on its potential charge, finding that a significant negative charge is ruled out. Interferometric observations using radio telescopes aim to better understand properties of the black hole and test general relativity.
Discovery of a_probable_4_5_jupiter_mass_exoplanet_to_hd95086_by_direct_imagingSérgio Sacani
The document reports the discovery of a probable 4-5 Jupiter-mass exoplanet orbiting the young star HD 95086. Deep imaging observations using VLT/NaCo detected a faint source at a separation of 56 AU from the star. Follow-up observations over more than a year found the source to be co-moving with the star, suggesting it is bound. Its luminosity corresponds to a predicted mass of 4-5 Jupiter masses, making it the lowest mass exoplanet directly imaged around a star. If confirmed, this discovery could provide insights into giant planet formation and evolution.
1) The document outlines a photography experiment to take place on February 6th at The Stray Fields in Harrogate.
2) Three techniques will be used - out of focus images, movement images where the model dances and twirls, and double exposures created through editing in Photoshop.
3) For out of focus images, the camera will be manually focused while different apertures are tested. Movement images will use shutter priority to capture a model in motion against stationary backgrounds. Double exposures will composite photos of a model in different poses and facial expressions.
The document summarizes a photography shoot where the photographer experimented with different techniques, including multiple exposures and out of focus shots. Weather conditions made the shoot difficult and the photographer had to make adjustments on the fly. Edited photos applying different effects in Photoshop are included, such as overlaying shots and changing layers to black and white. The photographer aims to convey emotions like loneliness and discovery through surreal, overlapping images.
The document describes experiments with the double exposure photography technique. The author used Photoshop to combine an image of a face with one of snowy scenery by dragging the images into the same box and adjusting the opacity. To make the face layer match the rectangular landscape shape, the author used the "Layer via copy" function after selecting both images while holding the control button. These experiments provided an understanding of how to professionally create double exposures for the author's upcoming photo shoot and editing project.
The document discusses the history and development of early photography processes prior to widespread adoption of the technology. It describes some of the key pioneers and their inventions, including Joseph Nicéphore Niépce creating the first permanent photograph in 1816. Early processes struggled with long exposure times and poor image quality but led to important innovations like Louis Daguerre's daguerreotype in 1839 and Fox Talbot's calotype process. Frederick Archer introduced the wet plate collodion process in 1851, improving image quality but limiting reproduction. These early experiments laid the foundation for modern photography.
This document provides instructions for converting an old camera body into a lamp. It notes that using an electrician is required for wiring and that safety should be the top priority. The steps include removing the lens, taking it apart while keeping the parts, removing the shutter curtain, and gluing the mirror open to create space for lighting. The body then needs to be taken to an electrician to add wiring safely.
This document covers a wide range of topics related to lenses, including lens terminology such as aperture, focal length, prime vs zoom lenses, resolution and contrast. It discusses the relationship between camera structure and lenses. Other topics include diffraction, focus scale, screen changes according to focal length, focal length and handheld photography, confusion when changing sensor formats, lens errors like flare and chromatic aberration. Macro lenses, tilt-shift lenses, lens filters like polarization are described. The document provides information on lens maintenance including cleaning dust from front and back elements. It provides additional resources for further information on lenses and optics.
This document discusses different types of lenses that can be used with digital single-lens reflex (DSLR) cameras. It explains that DSLR cameras use a mirror system to direct light from the lens to an optical viewfinder. It then provides details on wide-angle lenses, standard lenses, telephoto lenses, and zoom lenses. Specifically, it discusses lens mounts, apertures, focal lengths and specific lenses like Canon's L-series lenses.
The document discusses photographic principles, including the evolution of cameras from pinhole cameras to modern digital SLRs. It covers key camera components like lenses, shutters, and sensors. Exposure is controlled through the aperture, shutter speed, and ISO. Lenses use different focal lengths to capture different angles of view. Autofocus works by comparing the contrast between adjacent pixels to achieve focus. Image stabilization compensates for angular and shift camera shake. Intelligent recognition allows cameras to detect faces and scenes. A variety of equipment is needed for taking, processing, and developing photos.
This document discusses photojournalism and its use in telling stories through photographs. It examines the pioneering work of photographers like Henri Cartier-Bresson and Robert Capa. Students are tasked with exploring uses of photojournalism today like sports, wars, celebrity events and disasters. They are also asked to find local historical images and photographs from their area to compare how places have changed over time.
This document provides an overview of Optical Distortion Inc.'s plans to address cannibalism in the poultry industry by developing contact lenses for chickens. It discusses cannibalism issues in chickens and debeaking as a common solution. It then outlines ODI's lens technology, market analysis, pricing strategy, and break-even point analysis. ODI plans to enter key markets, target large farms, and initially price lenses at $0.28 per pair through a skimming strategy to maximize profits and fund R&D before competition emerges once their patent expires in 3 years.
This slide gives you the basic information about the types of photography lenses used worldwide.
Image source: Google Images
*the content provided here has been copied from various sources. no authentication proof is available.
The document discusses different lens materials used in ophthalmic lenses, including their properties and characteristics. It covers natural materials like quartz, glass materials like crown glass and flint glass, and plastic materials like CR-39, polycarbonate, high index plastics, and Trivex. For each material, it provides details on composition, refractive index, Abbe value, advantages and disadvantages. The document aims to educate about different lens materials and their properties for lens manufacturing.
The document discusses lens aberrations and ophthalmic lens design. It defines lens aberrations as optical defects where rays from a point object do not form a perfect point after passing through an optical system. It describes two main types of aberrations - chromatic aberration caused by the material properties of the lens, and monochromatic aberrations caused when incident light is not confined to paraxial rays. It further explains five specific monochromatic aberrations known as Seidel aberrations and how they are corrected in lens design.
The history of photography began in ancient times with the use of camera obscuras to project images. In the early 19th century, Nicéphore Niépce and Louis Daguerre developed early photographic processes allowing the creation of permanent images. William Henry Fox Talbot's invention of the calotype process in the 1840s allowed for the mass-production of photographs. In 1888, George Eastman introduced the Kodak camera, making photography widely popular. Throughout the 20th century, technological advances such as roll film, 35mm cameras, and digital cameras transformed photography.
The document discusses key parts and concepts related to cameras and photography. It describes the shutter speed dial and what shutter speed means, with higher shutter speeds avoiding blur from movement and lower shutter speeds allowing more light in low light conditions. It also discusses the aperture ring and how the f-number relates to the aperture diameter and exposure. Finally, it touches on depth of field and how factors like aperture, focal length, and distance to subject impact the zone of sharp focus.
The puzzling source_in_ngc6388_a_possible_planetary_tidal_disruption_eventSérgio Sacani
Artigo descreve a descoberta da destruição de um planeta ao passar próximo a uma estrela do tipo anã branca presente dentro do aglomerado globular de estrelas NGC 6388. Para isso os astrônomos utilizaram um arsenal de telescópios.
Creation of cosmic structure in the complex galaxy cluster merger abell 2744Sérgio Sacani
Abell 2744 is one of the most actively merging galaxy clusters known, appearing to have "dark", "ghost", "bullet", and "stripped" substructures of around 1014 solar masses each. The cluster shows a complex phenomenology that will challenge simulations to reproduce. The authors present a detailed strong lensing, weak lensing, and X-ray analysis of Abell 2744, identifying 34 strongly lensed images around the massive Southern core and producing the most detailed mass map to date. They find evidence that the Southern core and Northwestern substructure are post-merger systems similar to the Bullet Cluster viewed from an angle, and derive a new constraint on the self-interaction cross section of dark matter particles. They
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.
The Dawn spacecraft's VIR instrument obtained hyperspectral images of Vesta's surface. Analysis of the spectra showed considerable regional variations in mineralogy. The south polar region, including the Rheasilvia basin, displayed a higher diogenitic component with deeper pyroxene absorption bands. Equatorial regions showed a higher eucritic component with shallower bands. This lithological distribution indicates Vesta had a deeper diogenitic crust exposed by the Rheasilvia impact, overlain by an upper eucritic crust. Evidence for layering was observed on crater walls and in ejecta, broadly consistent with magma ocean differentiation models. However, spectral variability also highlighted local variations, suggesting a complex crustal
The massive relic galaxy NGC 1277 is dark matter deficient From dynamical mod...Sérgio Sacani
According to the Λ cold dark matter (ΛCDM) cosmology, present-day galaxies with stellar masses M? > 1011 M should contain
a sizable fraction of dark matter within their stellar body. Models indicate that in massive early-type galaxies (ETGs) with M? ≈
1.5 × 1011 M, dark matter should account for ∼15% of the dynamical mass within one effective radius (1 Re) and for ∼60% within
5 Re
. Most massive ETGs have been shaped through a two-phase process: the rapid growth of a compact core was followed by the
accretion of an extended envelope through mergers. The exceedingly rare galaxies that have avoided the second phase, the so-called
relic galaxies, are thought to be the frozen remains of the massive ETG population at z & 2. The best relic galaxy candidate discovered
to date is NGC 1277, in the Perseus cluster. We used deep integral field George and Cynthia Mitchel Spectrograph (GCMS) data to
revisit NGC 1277 out to an unprecedented radius of 6 kpc (corresponding to 5 Re). By using Jeans anisotropic modelling, we find
a negligible dark matter fraction within 5 Re (fDM(5 Re) < 0.05; two-sigma confidence level), which is in tension with the ΛCDM
expectation. Since the lack of an extended envelope would reduce dynamical friction and prevent the accretion of an envelope, we
propose that NGC 1277 lost its dark matter very early or that it was dark matter deficient ab initio. We discuss our discovery in the
framework of recent proposals, suggesting that some relic galaxies may result from dark matter stripping as they fell in and interacted
within galaxy clusters. Alternatively, NGC 1277 might have been born in a high-velocity collision of gas-rich proto-galactic fragments,
where dark matter left behind a disc of dissipative baryons. We speculate that the relative velocities of ≈2000 km s−1
required for the
latter process to happen were possible in the progenitors of the present-day rich galaxy clusters.
This summarizes a scientific study on long-distance quantum teleportation between two laboratories separated by 55 meters but connected by 2 kilometers of fiber optic cable. The key points are:
1) Researchers teleported quantum states (qubits) carried by photons at 1.3 micrometer wavelengths onto photons at 1.55 micrometer wavelengths between the two laboratories.
2) The qubits were encoded in time-bin superpositions and entanglement rather than polarization to make them more robust against decoherence in optical fibers.
3) A partial Bell state measurement was performed using linear optics at the receiving end to probabilistically teleport the quantum states over the long distance.
Visible spectra of (474640) 2004 VN112–2013 RF98 with OSIRIS at the 10.4 m GT...Sérgio Sacani
The existence of significant anisotropies in the distributions of the directions of perihelia and
orbital poles of the known extreme trans-Neptunian objects (ETNOs) has been used to claim
that trans-Plutonian planets may exist. Among the known ETNOs, the pair (474640) 2004
VN112–2013 RF98 stands out. Their orbital poles and the directions of their perihelia and their
velocities at perihelion/aphelion are separated by a few degrees, but orbital similarity does
not necessarily imply common physical origin. In an attempt to unravel their physical nature,
visible spectroscopy of both targets was obtained using the OSIRIS camera-spectrograph at the
10.4 m Gran Telescopio Canarias (GTC). From the spectral analysis, we find that 474640–2013
RF98 have similar spectral slopes (12 versus 15 per cent/0.1 µm), very different from Sedna’s
but compatible with those of (148209) 2000 CR105 and 2012 VP113. These five ETNOs belong
to the group of seven linked to the Planet Nine hypothesis. A dynamical pathway consistent
with these findings is dissociation of a binary asteroid during a close encounter with a planet
and we confirm its plausibility using N-body simulations. We thus conclude that both the
dynamical and spectroscopic properties of 474640–2013 RF98 favour a genetic link and their
current orbits suggest that the pair was kicked by a perturber near aphelion
This document describes a study searching for supermassive black holes (SMBHs) with masses below 107 solar masses by looking for signs of low-level nuclear activity in nearby galaxies that are not known to be active galactic nuclei (AGNs). The study uses Chandra X-ray Observatory data to select for X-ray emission, a signature of AGNs, focusing on late-type spiral and dwarf galaxies most likely to host low-mass SMBHs. Preliminary results applying this technique to six nearby spiral galaxies find nuclear X-ray sources in all six, with NGC 3169 and NGC 4102 likely confirmed as AGNs and NGC 3184 and NGC 5457 possibly hosting AGNs.
X rays and-protostars_in_the_trifid_nebulaSérgio Sacani
This document summarizes an astronomical study of the Trifid Nebula using X-ray and infrared observations. The ROSAT X-ray image revealed over a dozen X-ray sources in the nebula, including the bright O7 star that provides most of the ionization. Infrared observations identified 85 young star candidates. Ten X-ray sources had infrared counterparts. Spectroscopy of the brightest X-ray source with ASCA showed unusually hot plasma up to 10 keV, suggesting interaction between winds or flares from embedded young stars.
This research news article discusses two studies that propose different models to explain an unusual gamma-ray burst (GRB) called the "Christmas burst" that occurred on Christmas Day in 2010.
One study suggests the GRB originated from a tightly bound binary system of a neutron star and supergiant helium star that merged, producing a jet within a common gas envelope. The other study proposes that a minor body like an asteroid or comet was tidally disrupted after passing close to a neutron star, producing debris that formed a disk and caused multiple emission peaks.
While both models can explain aspects of the complex data from the unusual GRB, the article notes that at least one model must be incorrect as the definitive proof
This paper analyzes Spitzer observations of the Eagle Nebula to study the energetics and evolution of dust. The observations show a shell of emission within the nebula at mid-IR wavelengths that is distinct from the morphology at longer wavelengths. Spectral energy distributions are measured across the nebula and modeled to constrain dust properties and heating sources. Two possible interpretations are proposed for the nature of the mid-IR shell: 1) dust processing in shocks driven by stellar winds, or 2) emission from a hot plasma where dust is collisionally heated. The goal is to better understand dust evolution in massive star forming regions.
A giant thin stellar stream in the Coma Galaxy ClusterSérgio Sacani
The study of dynamically cold stellar streams reveals information about the gravitational potential where they reside and provides
important constraints on the properties of dark matter. However, the intrinsic faintness of these streams makes their detection beyond
Local environments highly challenging. Here, we report the detection of an extremely faint stellar stream (µg,max = 29.5 mag arcsec−2
)
with an extraordinarily coherent and thin morphology in the Coma Galaxy Cluster. This Giant Coma Stream spans ∼510 kpc in length
and appears as a free-floating structure located at a projected distance of 0.8 Mpc from the center of Coma. We do not identify any
potential galaxy remnant or core, and the stream structure appears featureless in our data. We interpret the Giant Coma Stream as
being a recently accreted, tidally disrupting passive dwarf. Using the Illustris-TNG50 simulation, we identify a case with similar
characteristics, showing that, although rare, these types of streams are predicted to exist in Λ-CDM. Our work unveils the presence
of free-floating, extremely faint and thin stellar streams in galaxy clusters, widening the environmental context in which these objects
are found ahead of their promising future application in the study of the properties of dark matter.
X ray emission-from_strongly_asymmetric_circumstellar_material_in_the_remnant...Sérgio Sacani
This document summarizes a study of X-ray emission from circumstellar material (CSM) in the remnant of Kepler's supernova. The researchers used a statistical technique to isolate X-ray emission from CSM versus ejecta based on spectral characteristics. They found that most CSM is distributed along the bright north rim, but substantial amounts are also projected against the center, indicating a disk-like distribution of CSM from the progenitor system before the supernova. Hydrodynamic simulations support an AGB star companion as the origin of the asymmetric CSM. Quantitative analysis of magnesium emission identifies CSM and requires Kepler to have originated from a close binary system.
A super earth transiting a naked-eye starSérgio Sacani
This document summarizes the detection of transits of an exoplanet orbiting the star 55 Cnc, using photometry from the MOST space telescope. The transits match the period, phase, duration, and depth predicted for the innermost planet of 55 Cnc, designated 55 Cnc e. Analysis of the transit data indicates the planet has a mass of 8.57 Earth masses, a radius of 1.63 Earth radii, and a dense composition of rock and iron. This makes 55 Cnc e similar to other dense super-Earth exoplanets in short orbits, unlike lower-density super-Earths further from their stars. The brightness of 55 Cnc will enable further study of this transiting exoplanet system.
The SPHERE view of three interacting twin disc systems in polarised lightSérgio Sacani
Dense stellar environments as hosts of ongoing star formation increase the probability of gravitational encounters among stellar
systems during the early stages of evolution. Stellar interaction may occur through non-recurring, hyperbolic or parabolic passages
(a so-called ‘fly-by’), through secular binary evolution, or through binary capture. In all three scenarios, the strong gravitational
perturbation is expected to manifest itself in the disc structures around the individual stars. Here, we present near-infrared
polarised light observations that were taken with the SPHERE/IRDIS instrument of three known interacting twin-disc systems:
AS 205, EM* SR 24, and FU Orionis. The scattered light exposes spirals likely caused by the gravitational interaction. On
a larger scale, we observe connecting filaments between the stars. We analyse their very complex polarised intensity and put
particular attention to the presence of multiple light sources in these systems. The local angle of linear polarisation indicates
the source whose light dominates the scattering process from the bridging region between the two stars. Further, we show
that the polarised intensity from scattering with multiple relevant light sources results from an incoherent summation of the
individuals’ contribution. This can produce nulls of polarised intensity in an image, as potentially observed in AS 205.We discuss
the geometry and content of the systems by comparing the polarised light observations with other data at similar resolution,
namely with ALMA continuum and gas emission. Collective observational data can constrain the systems’ geometry and stellar
trajectories, with the important potential to differentiate between dynamical scenarios of stellar interaction.
The first hyper_luminous_infrared_galaxy_discovered_by_wiseSérgio Sacani
This document summarizes the discovery of WISE J181417.29+341224.9 (WISE 1814+3412), the first hyper-luminous infrared galaxy (LIR > 1013 L⊙) discovered by the Wide-field Infrared Survey Explorer (WISE). Follow-up images of WISE 1814+3412 revealed four nearby sources - a QSO, two Lyman Break Galaxies at z = 2.45, and an M dwarf star. The brighter LBG dominates the bolometric emission and has a star formation rate of ~300M⊙ yr−1, accounting for <10% of the bolometric luminosity. An obscured AGN combined with starburst and
Young remmants of_type_ia_supernovae_and_their_progenitors_a_study_of_snr_g19_03Sérgio Sacani
Type Ia supernovae, with their remarkably homogeneous light curves and spectra, have been used as
standardizable candles to measure the accelerating expansion of the Universe. Yet, their progenitors
remain elusive. Common explanations invoke a degenerate star (white dwarf) which explodes upon
reaching close to the Chandrasekhar limit, by either steadily accreting mass from a companion star
or violently merging with another degenerate star. We show that circumstellar interaction in young
Galactic supernova remnants can be used to distinguish between these single and double degenerate
progenitor scenarios. Here we propose a new diagnostic, the Surface Brightness Index, which can
be computed from theory and compared with Chandra and VLA observations. We use this method
to demonstrate that a double degenerate progenitor can explain the decades-long
ux rise and size
increase of the youngest known Galactic SNR G1.9+0.3. We disfavor a single degenerate scenario.
We attribute the observed properties to the interaction between a steep ejecta prole and a constant
density environment. We suggest using the upgraded VLA to detect circumstellar interaction in
the remnants of historical Type Ia supernovae in the Local Group of galaxies. This may settle the
long-standing debate over their progenitors.
Subject headings: ISM: supernova remnants | radio continuum: general | X-rays: general | bi-
naries: general | circumstellar matter | supernovae: general | ISM: individual
objects(SNR G1.9+0.3)
The document summarizes the timeline of major discoveries in cosmology, including Einstein's theory of general relativity, Hubble's discovery of the expanding universe, and the discovery of the cosmic microwave background radiation by Penzias and Wilson which provided evidence for the Big Bang theory. It then discusses supernovae types and their use in determining the accelerating expansion of the universe, for which three scientists - Perlmutter, Riess, and Schmidt - were awarded the 2011 Nobel Prize in Physics for their findings which suggested the universe is dominated by dark energy.
This document summarizes an infrared survey of the massive star forming region RCW 57 (NGC 3576) using L-band (3.5 μm) data from SPIREX and JHKs data from 2MASS. Over 50% of the 209 sources detected showed infrared excess, indicating circumstellar disks. Comparison to other surveys supports a very high initial disk fraction (>80%) around massive stars, though disks may dissipate faster around high-mass stars. 33 sources only detected at L-band indicate heavily embedded, massive Class I protostars. Diffuse PAH emission was also detected throughout RCW 57.
This document summarizes follow-up observations of galaxies selected from WISE as being hyperluminous. The authors observed 14 galaxies at 350-850 μm with SHARC-II and 18 galaxies at 1.1 mm with Bolocam, detecting 9 and 5 galaxies respectively. They also observed 25 targets at 3.6 and 4.5 μm with Spitzer and obtained optical spectra for 12 targets. By combining these data with WISE observations, they constructed mid-IR to millimeter spectral energy distributions that showed hotter dust temperatures than galaxy templates, estimated to be 60-120 K. These galaxies have infrared luminosities over 10^13 solar luminosities and represent an extreme population of luminous, hot dust-ob
The document discusses exoplanet formation theory and detection methods. It reviews that planets likely form through core accretion, with cores forming more easily beyond the snow line. Migration may cause planets to move inward through the protoplanetary disk. Exoplanets are discovered using radial velocity, which detects planets via stellar wobble, transits, which finds planets as they pass in front of their star, and microlensing. Observations have revealed details about exoplanet compositions, atmospheres, and distributions around other stars.
From my class on nuclear physics for nuclear medicine technologists. This class covers alpha, beta, and gamma decay, plus conversion electrons, Auger electrons, and k-alpha and other X-rays
Einstein originally introduced the cosmological constant to allow for a static universe, but its discovery that the universe is expanding led him to call it his "biggest blunder". Observations of type Ia supernovae revealed that the expansion of the universe is accelerating, suggesting a form of dark energy is driving acceleration. The cause of the cosmological constant and dark energy remains poorly understood and a major focus of research, with future satellite missions like SNAP seeking more data from distant supernovae to help explain the mysterious force accelerating cosmic expansion.
A history of some of the topics of astronomy developed during the enlightenment, with emphasis on the nebular theory of the solar system as developed by Kant and Laplace.
Talk for a general audience.
This document discusses the search for life on other planets and what we have learned so far. It covers topics like the Drake equation, the Fermi paradox, discoveries of exoplanets, the conditions needed to support life, biosignatures in atmospheres, searches for life in our solar system and detection of life around other stars. Key points are that the basic ingredients for life are common, life emerged on Earth as soon as it was habitable, and complex life may be rare and take a long time to evolve.
Tomography involves measuring gamma ray attenuation along lines of sight at different angles in order to reconstruct the internal structure of an object. Filtered back projection enhances edges in the projection data through filtering and backprojects the filtered data to form an image. Iterative reconstruction accounts for physical factors like attenuation, scatter, and noise by comparing projections of a patient model to actual data and updating the model. Quality control ensures proper system operation through tests of the center of rotation, uniformity, and ability to detect small objects.
The sculpture "The Short, Rich Life of Positronium" commemorates fundamental research on antimatter conducted at the University of Michigan. Positron emission tomography (PET) uses positron-emitting radioactive isotopes as tracers and coincidence detection of the resulting back-to-back photons to construct tomographic images. PET enables visualization of functional processes in the body by tracking radioactive tracers like fluorodeoxyglucose, which is used to show glucose metabolism and thus tissue activity. While providing valuable medical information, PET also involves some radiation risks due to the penetrating nature of the emitted photons.
How to Setup Warehouse & Location in Odoo 17 InventoryCeline George
In this slide, we'll explore how to set up warehouses and locations in Odoo 17 Inventory. This will help us manage our stock effectively, track inventory levels, and streamline warehouse operations.
Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
हिंदी वर्णमाला पीपीटी, hindi alphabet PPT presentation, hindi varnamala PPT, Hindi Varnamala pdf, हिंदी स्वर, हिंदी व्यंजन, sikhiye hindi varnmala, dr. mulla adam ali, hindi language and literature, hindi alphabet with drawing, hindi alphabet pdf, hindi varnamala for childrens, hindi language, hindi varnamala practice for kids, https://www.drmullaadamali.com
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
Strategies for Effective Upskilling is a presentation by Chinwendu Peace in a Your Skill Boost Masterclass organisation by the Excellence Foundation for South Sudan on 08th and 09th June 2024 from 1 PM to 3 PM on each day.
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
Walmart Business+ and Spark Good for Nonprofits.pdfTechSoup
"Learn about all the ways Walmart supports nonprofit organizations.
You will hear from Liz Willett, the Head of Nonprofits, and hear about what Walmart is doing to help nonprofits, including Walmart Business and Spark Good. Walmart Business+ is a new offer for nonprofits that offers discounts and also streamlines nonprofits order and expense tracking, saving time and money.
The webinar may also give some examples on how nonprofits can best leverage Walmart Business+.
The event will cover the following::
Walmart Business + (https://business.walmart.com/plus) is a new shopping experience for nonprofits, schools, and local business customers that connects an exclusive online shopping experience to stores. Benefits include free delivery and shipping, a 'Spend Analytics” feature, special discounts, deals and tax-exempt shopping.
Special TechSoup offer for a free 180 days membership, and up to $150 in discounts on eligible orders.
Spark Good (walmart.com/sparkgood) is a charitable platform that enables nonprofits to receive donations directly from customers and associates.
Answers about how you can do more with Walmart!"
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
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Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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A workshop hosted by the South African Journal of Science aimed at postgraduate students and early career researchers with little or no experience in writing and publishing journal articles.
2. Gravitational
Microlensing
David S. Graff Ph.D.
University of Michigan
Ohio State University
CEN Saclay, France
American Museum of Natural History
Friday, February 13, 2009
4. 2 survey of the Magellanic Clouds halo white dwarfs Sources and Detection of Dark Matter in the Universe, Not enough stellar mass Macho
aboration: P. Tisserand, L. Le Guillou The EROS collaboration: B. Goldman et al. Marina del Rey, CA, February 2000 The EROS collaboration: T. Las
Astronomy & Astrophysics 389 69 (2002) http://arxiv.org/abs/astro-ph/0007444 Astronomy & Astrophysics Letters 3
rophysics 469 387 (2007)
Observation of periodic variable stars towards the Type Ia supernova rate at z ~ 0.1 Death of Stellar Baryonic Dark
icrolensing Blending-Parallax Galactic spiral arms by EROS II The EROS collaboration: D. Hardin et al. Katherine Freese, Brian D. Field
g source variability The EROS collaboration: F. Derue et al. Astronomy & Astrophysics 362 419 (2000) Proceedings of “The First Stars”, M
aboration: R.J. Assef, A. Gould et al. Astronomy & Astrophysics 389 149 (2002) Aug. 4-6, 1999
l Journal: 649 954 (2006) Eros variable stars: A catalog of Cepheids in the http://arxiv.org/abs/astro-ph/000
Blue irregular variable stars in the Small Magellanic Magellanic Clouds
microlensing optical depth from Cloud from EROS2: The EROS collaboration: C. Afonso et al. Observation of Microlensing to
Herbig Ae/Be or classical Be stars? Astronomy & Astrophysics submitted astro-ph/9907355 Spiral Arms. EROS II 2 year sur
aboration: C. Hamadache et al. The EROS collaboration: J. P. Beaulieu et al. The EROS collaboration: F. De
rophysics: 454 185 (2006) Astronomy & Astrophysics 380 168 (2001) The velocity dispersion of LMC Carbon stars: Astronomy & Astrophysics 351 87 (
possible detection of a kinematically distinct
event 2c 2859: a classic nova outburst? Disk Contamination in a Sample of Proper Motion population Limits on Stellar Objects as the
aboration: C. Afonso et al. Selected Halo Stars: David Graff, Andrew Gould, Nicholas Suntzeff, Halo:
rophysics: 450 233 (2006) A Comment on “Direct Detection of Galactic Halo Robert Schommer, and Eduardo Hardy Nonbaryonic Dark Matter Seem
Dark Matter” Astrophysical Journal 540 211 (2000) Katherine Freese, Brian Fields,
etry of probable R Coronae Borealis David S. Graff Proceedings of the 19th Texas Sympo
ll Magellanic Cloud Science 292 2211 (2001) Detection of light from Giant Planets in the Galactic Astrophysics and Cosmology
aboration: P. Tisserand et al. Bulge http://arxiv.org/abs/astro-ph/990
rophysics 424 245 (2004) Photometric constraints on microlens spectroscopy Amplified by caustic-crossing microlensing events
of EROS-BLG-2000-5 David S. Graff and B. Scott Gaudi EROS 2 proper motion survey:
va rate at a redshift of z~0.1 The EROS collaboration: C. Afonso et al. Astrophysical Journal Letters 538 133 (2000) and an L dwarf companion to L
aboration: G. Blanc et al. Astronomy & Astrophysics 378 1014 (2001) The EROS collaboration: B. Go
rophysics 423 881 (2004) What are MACHOs? Interpreting LMC Astronomy & Astrophysics 351 5 (1
Observation of Microlensing towards the Galactic microlensing
upermassive Black Holes in Galactic Spiral Arms. EROS II 3 year survey David S. Graff Constraining the Cosmic Abund
The EROS collaboration: F. Derue et al. Microlensing 2000: A New Era of Microlensing Astrophysics Remnants with Multi-TeV Gam
lapse Model Consistent with the MBH- Astronomy & Astrophysics 373 126 (2001) ASP conference proceedings, eds. J.W. Menzies and David S. Graff, Katherine Frees
P.D. Sackett Marc H. Pinsonneault
No Nearby Counterparts to the moving objects in http://arxiv.org/abs/astro-ph/0005521 Astrophysical Journal 523 77 (1999
David S. Graff, Mannase Mbonye &
the Hubble Deep Field
hstone
Chris Flynn, J. Sommer-Larsen, Burkhard Fuchs, Chemical Abundance Constraints on White Dwarfs Microlensing in the SMC: Lesso
l Journal 591 125 (2003)
David S. Graff and Samir Salim as Halo Dark Matter simulations
Monthly Notices of the Royal Astronomical Society 322 533 Brian D. Fields, Katherine Freese, and David S. Graff David S. Graff and Lance Gardi
sing optical depth from EROS 2
(2001) Astrophysical Journal 534 265 (2000) Monthly Notices of the Royal Astro
(1999)
aboration: C. Afonso et al.
Using the Supernova Acceleration Probe (SNAP) High Velocity Star Formation in the LMC
rophysics 404 145 (2003)
to Search for Microlensing Events Towards the LMC David S. Graff and Andrew Gould A Slope Variation in the Period-
David S. Graff and Alex Kim Astrophysical Journal Letters 534 51 (2000) for Short Period SMC Cepheids
f Stars via Microlensing
http://arxiv.org/abs/astro-ph/0101395 The EROS collaboration: F. Bau
Cheongho Han & David S. Graff
Combined Analysis of the Binary-Lens Caustic- Astronomy & Astrophysics 348 175
l Journal 586 451 (2003)
A Theoretical Model for the MBH- Relation for Crossing Event MACHO 98-SMC-1
Supermassive Black Holes in Galaxies The EROS, MACHO/GMAN, MPS, OGLE, and Microlensing towards the Small
tic dark matter with 5 years of EROS
Fred C. Adams, David S. Graff, and Douglas O. PLANET Collaborations EROS II two year analysis
Richstone C. Afonso et al., C. Alcock et al., S.H. Rhie et al., A. The EROS collaboration: C. Af
aboration: C. Afonso et al
Astrophysical Journal 551 31 (2001) Udalski et al., M. Albrow et al. Astronomy & Astrophysics 344 63
rophysics 400 951 (2002)
Astrophysical Journal 532 340 (2000)
The Kinematics Of The LMC From Its Carbon Stars What are Machos? Limits on St
llaxes of Binary Lenses Measured from
E. Hardy, D. Alves, D. Graff, N. Suntzeff, and R. Magnitude bias of microlensed sources towards the Dark Matter of our Halo
Schommer Large Magellanic Cloud Katherine Freese, Brian Fields,
Andrew P. Gould
Astrophysics and Space Science Supplement 277 271 (2001) HongSheng Zhao, David Graff, and Puragra Proceedings of the International Wo
l Journal 580 253 (2002)
Guhathakurta Dark Matter in Astro andParticle P
Death of Stellar Baryonic Dark Matter Candidates Astrophysical Journal 532 37 (2000) Germany, July 1998
Friday, February 13, 2009
5. Lensing Physics Dark Matter Microlensing & Microlensing
Dark Matter & Planets
Friday, February 13, 2009
6. Lensing Physics Dark Matter Microlensing & Microlensing
Dark Matter & Planets
Friday, February 13, 2009
7. Lensing Physics Dark Matter Microlensing & Microlensing
Dark Matter & Planets
Friday, February 13, 2009
8. Lensing Physics Dark Matter Microlensing & Microlensing
Dark Matter & Planets
Friday, February 13, 2009
9. AB will perceive, instead of a point-like star A, a to the expression
x2
luminius circle of the angular radius @ around the 1 -!-
I
center of B, where q=-.- 21
where
6
I t should be noted that this angular diameter does