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This study aims to search for ultra-compact dwarf galaxies (UCDs) around local galaxies using photometric and spectroscopic data from surveys like SDSS and Hubble Space Telescope. The researchers discovered a new UCD, VO-UCD1, around the galaxy M59. Spectroscopy of VO-UCD1 found a velocity dispersion of 64 km/s and dynamical mass of 1.0 x 108 solar masses. Further study of newly discovered UCDs could provide insights into their origins, which remain unknown. The researchers plan to use HST to study UCD sizes and shapes and pursue additional data to understand black hole contributions to UCD masses.
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A New Search for Ultra-compact Dwarfs
Richard Vo, Aaron J. Romanowsky, Jay Strader, Charlie Conroy, Mark A. Norris, Jean P. Brodie,
San José State University
Introduction:
Ultra-compact dwarfs (UCD) are a recently
discovered class of compact stellar system.
They have estimated diameters of up to 200
light years, with up to a hundred million
stars. It is believed that these may be the
cores of larger galaxies that have been
stripped of gas and outlying stars by tidal
interactions with other galaxies and galaxy
clusters. UCDs lie in the middle ground
between galaxies and star clusters and have
intermediate sizes and luminosities (UCDs;
Hilker et al. 1999; Drinkwater et al. 2000;
Jones et al 2006).
Methods
The primary starting point of our research
was the recently discovered object M60-
UCD1: the densest known galaxy in the
local universe (Strader et al 2013). Our
main focus was searching for more unusual
objects like M60-UCD1. We would then
further analyze them to gain a better
knowledge of where to look, and how to
look, and better understanding about the
origins of ultra-compact dwarfs.
Photometric search techniques:
We used a wide variety of open source
databases that have not been fully analyzed
which are accessible to the public. These
included Hubble Space Telescope (HST)
imaging and the Sloan Digital Sky Survey
(SDSS). First we would access the SDSS
and search for all objects located around any
particular large, central galaxy and obtain
their photometric properties. From the
parameters of M60-UCD1, we considered
the apparent magnitudes of (V~17) and (g-
i~1.2).
Analysis and Results
VO-UCD1
This object was noticed from a test search
for a known UCD, M59cO. A radial search
of 3 arc minutes around the host galaxy M59
was made with the SDSS database. The
color magnitude diagram of sources around
M59 showed two objects. One being M59cO
and the other we dubbed VO-UCD1 (or
M59-UCD3). Unfortunately, this object laid
just outside of the HST footprint, hence was
not studied by the AIMSS. VO-UCD1 has
color of (g-i) = 1.16 and an apparent
magnitude of V=16.4 and an absolute
magnitude of 𝑀 𝑉= -14.52.
Spectroscopy
We have obtain spectra from the following
sources: Southern Astrophysical Research
telescope/ Large Binocular Telescope/ Multi-
Object Double Spectrographs and Keck II.
The velocity dispersion is σ = 64
± 2 𝑘𝑚 𝑠−1
and dynamical mass is
𝑀 𝑑𝑦𝑛 ≅ 1.0 𝑥 108
𝑀⊙
The Mass to light ratio
𝑀 𝑑𝑦𝑛
𝐿 𝑟
≅ 2.1 𝑆𝑜𝑙𝑎𝑟 𝑢𝑛𝑖𝑡𝑠
Abstract
Ultra-compact dwarfs (UCDs) are a recently discovered class of object that consists of high stellar densities in a radius of around 10
to 40 pc. We are searching for UCDs around local galaxies using the SDSS database, with spectroscopic follow-up. We present initial
results of our survey including a discovery of a unique and interesting object.
Fig. 1 – M60-UCD1
(highlighted in red),
with neighboring
Galaxy M60
Fig. 2 – Color–
magnitude diagram of a
radial search around
M59 from SDSS.
This was the first
detection
Of M59-UCD3.
Fig. 2 – The
spectrum of
VO-UCD1 as shown
using the IRAF data
analysis tool. The
prominent dips are
absorption lines that
is used to measure
redshift and velocity
dispersion.
Next steps:
We have submitted a proposal for the use of
the Hubble Space Telescope to help further
analyze the sizes and shapes of these objects.
We will also pursue further X-ray data and
study the contributions of black holes to the
dynamical masses. All in all, we are still
actively searching for new candidates to
study. The origins of UCDs however, still
remains unknown.
M59-UCD3
M59cO
star
Fig. 1 – central image is M59 and its neighboring UCDs. Top left and
right panel is M59-UCD3 and M59cO with its i-band image beneath it
respectively. Bottom Left is a comparison star with equal image scaling.
Fig. 4 – Size-
luminosity diagram
of stellar systems in
the nearby universe
References:
[1] Hilker, M., Infante, L., Viera, G., Kissler-Patig, M., &
Richtler, T. 1999, A&AS, 134, 75
[2] Drinkwater, M. J., Jones, J. B., Gregg, M. D., &
Phillipps, S. 2000, PASA, 17, 227
[3] Jones, J. B., Drinkwater, M. J., Jurek, R., et al. 2006,
AJ, 131, 312
[4] Strader, J., Seth, A. C., Forbes, D. A., et al. 2013, ApJ,
775, L6](https://image.slidesharecdn.com/231e305e-cb6d-40a4-ae81-5aa06b0b5e07-150429145915-conversion-gate01/85/AAS_Richard_poster1_final-1-320.jpg)
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Os astrónomos usaram o ALMA e os telescópios do IRAM para fazer a primeira medição direta da temperatura dos grãos de poeira grandes situados nas regiões periféricas de um disco de formação planetária que se encontra em torno de uma estrela jovem. Ao observar de forma inovadora um objeto cujo nome informal é Disco Voador, os astrónomos descobriram que os grãos de poeira são muito mais frios do que o esperado: -266º Celsius. Este resultado surpreendente sugere que os modelos teóricos destes discos precisam de ser revistos.
Uma equipa internacional liderada por Stephane Guilloteau do Laboratoire d´Astrophysique de Bordeaux, França, mediu a temperatura de enormes grãos de poeira que se encontram em torno da jovem estrela 2MASS J16281370-2431391 na região de formação estelar Rho Ophiuchi, a cerca de 400 anos-luz de distância da Terra.
Esta estrela encontra-se rodeada por um disco de gás e poeira — chamado disco protoplanetário, uma vez que se encontra na fase inicial da formação de um sistema planetário. Este disco é visto de perfil quando observado a partir da Terra e a sua aparência em imagens no visível levou a que se lhe desse o nome informal de Disco Voador.
Os astrónomos utilizaram o ALMA para observar o brilho emitido pelas moléculas de monóxido de carbono no disco da 2MASS J16281370-2431391. As imagens revelaram-se extremamente nítidas e descobriu-se algo estranho — em alguns casos o sinal recebido era negativo. Normalmente um sinal negativo é fisicamente impossível, mas neste caso existe uma explicação, que leva a uma conclusão surpreendente.
Multiple images of_a_highly_magnified_supernova_formed_by_an_early_type_clust...
Artigo descreve a descoberta dos astrônomos de 4 imagens de uma supernova geradas pelo efeito de lente gravitacional e formando o raro padrão da Cruz de Einstein.
“A ring system detected around the Centaur (10199) Chariklo”
- The Centaur object (10199) Chariklo was observed to occult a star, revealing the presence of two narrow rings around the object.
- The rings have widths of about 7 km and 3 km, and orbital radii of 391 km and 405 km from the center of Chariklo.
- Evidence supports the rings being composed of water ice and their geometry explaining the dimming and changing spectrum of Chariklo observed between 1997 and 2008. The discovery of rings around a minor planet is a first for the Solar System.
Low surface brightness_imaging_of_the_magellanic_system_imprints_of_tidal_int...
We present deep optical images of the Large and Small Magellanic Clouds (LMC and SMC) using
a low cost telephoto lens with a wide field of view to explore stellar substructure in the outskirts
of the stellar disk of the LMC (r < 10 degrees from the center). These data have higher resolution
than existing star count maps, and highlight the existence of stellar arcs and multiple spiral arms in
the northern periphery, with no comparable counterparts in the South. We compare these data to
detailed simulations of the LMC disk outskirts, following interactions with its low mass companion,
the SMC. We consider interaction in isolation and with the inclusion of the Milky Way tidal field.
The simulations are used to assess the origin of the northern structures, including also the low density
stellar arc recently identified in the DES data by Mackey et al. (2015) at ∼ 15 degrees. We conclude
that repeated close interactions with the SMC are primarily responsible for the asymmetric stellar
structures seen in the periphery of the LMC. The orientation and density of these arcs can be used to
constrain the LMC’s interaction history with and impact parameter of the SMC. More generally, we
find that such asymmetric structures should be ubiquitous about pairs of dwarfs and can persist for
1-2 Gyr even after the secondary merges entirely with the primary. As such, the lack of a companion
around a Magellanic Irregular does not disprove the hypothesis that their asymmetric structures are
driven by dwarf-dwarf interactions.
Deep nearinfrared survey_carina_nebula
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
Major mergers host_the_most_luminous_red_quasars_at_z2_a_hubble_space_telesco...
Estudo do Hubble mostra os quasares na sua adolescência e ajuda a desvendar mais um capítulo da evolução galáctica.
BETTIIGoalsExploration
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.
An excess of massive stars in the local 30 Doradus starburst
The 30 Doradus star-forming region in the Large Magellanic Cloud is a nearby analog of large
star-formation events in the distant universe.We determined the recent formation history and
the initial mass function (IMF) of massive stars in 30 Doradus on the basis of spectroscopic
observations of 247 stars more massive than 15 solarmasses (M⊙).Themain episode of massive
star formation began about 8 million years (My) ago, and the star-formation rate seems to
have declined in the last 1 My.The IMF is densely sampled up to 200M⊙ and contains 32 ± 12%
more stars above 30 M⊙ than predicted by a standard Salpeter IMF. In the mass range of 15
to 200M⊙, the IMF power-law exponent is 1:90þ0:37
0:26, shallower than the Salpeter value of 2.35.
The ionized nebula_surrounding_the_w26_in_westerlund_1
The document summarizes observations of an ionized nebula surrounding the red supergiant star W26 in the massive star cluster Westerlund 1. H-alpha images reveal a circumstellar shell or ring 0.1 pc in diameter surrounding the star, as well as a triangular nebula 0.2 pc away with a complex filamentary structure. Spectroscopy confirms the nebula is ionized but the excitation mechanism is unclear given red supergiants do not produce ionizing photons. The nebula and star's high luminosity and spectral variability suggest W26 is a highly evolved red supergiant experiencing extreme mass loss, making it an important case study for understanding the late stages of massive star evolution.
A candidate redshift z < 10 galaxy and rapid changes in that population at...
The document summarizes the findings of a study searching for galaxies at redshift z > 10 using deep imaging data from the Hubble Ultra Deep Field. The key points are:
1) The study detects one possible galaxy candidate at z ~ 10.3, the earliest galaxy reported to date.
2) Regardless of detections, the star formation rate density is found to be much smaller (~10%) at z ~ 10 than just 200 million years later at z ~ 8, demonstrating rapid galaxy build-up in the first 500 million years.
3) The 100-200 million years before z ~ 10 appears to be a crucial phase in the early assembly of galaxies.
The nustar extragalactic_survey_a_first_sensitive_look
The document summarizes the first ten sources detected by the Nuclear Spectroscopic Telescope Array (NuSTAR) as part of its extragalactic survey. NuSTAR provides the first sensitive census of the cosmic X-ray background source population at energies above 10 keV. The ten sources have a broad range of redshifts and luminosities, with a median redshift of 0.7 and luminosity of 3×10^44 erg/s. Based on broad-band spectroscopy and SED analysis, the dominant population is quasars with luminosities above 10^44 erg/s, of which around 50% are obscured. However, none are Compton thick and the fraction of Compton thick quasars is constrained to
Prvision jeudi 30 avril 2015
الخميس 30 أفريل 2015: أحداث منتظرة
9.00 ندوة بعنوان:" إعادة تأسيس وتجديد الحركة النقابية التونسية"/ نزل الهناء الدولي بالعاصمة
9.00 اجتماع لجان مجلس نواب الشعب / مقر مجلس النواب بباردو
9.30 منتدى اقتصادي حول" تونس- لكسنبورغ: شراكة مستقبلية/ مقر اتحاد الصناعة والتجارة بحي الخضراء
10.00 ندوة صحفية لتقديم برنامج "مهرجان الألوان الدولي"/ نزل "الشيراتون" بالعاصمة
10.00 اتحاد عمال تونس يكرم عمال المتحف الوطني بباردو/ نزل الماجستيك بالعاصمة
10.30 التوقيع على اتفاقية بين الممثل جعفر القاسمي وقرى SOS في تونس/ قرية "اس او اس" بقمرت
10.30 ندوة حول "المقاربة القانونية لمشروع زجر الاعتداءات على القوات المسلحة" / مركز دراسة الإسلام والديمقراطيّة
12.00 توقيع اتفاقيات تمويل بين تونس والمفوضية الأوروبية / مقر وزارة التنمية والاستثمار والتعاون الدولي
14.00 مائدة مستديرة بعنوان: "أيّة حقوق لعاملات النظافة؟"/ فرع منتدى الحقوق الاقتصادية والاجتماعية بالقيروان
Trabalho karnal
Este documento resume la historia de Pedro Bohórquez, un aventurero español que logró hacerse coronar como Inca de los calchaquíes en 1656 engañando a los indígenas y españoles. Bohórquez ganó la confianza de los calchaquíes haciéndose pasar por el último descendiente de los incas. Convenció a los españoles de que podía someter a los indígenas y revelar la ubicación de yacimientos de metales preciosos. El gobernador del Tucumán lo reconoció
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This document summarizes observations of rapid dust formation in the luminous supernova SN 2010jl over multiple epochs from 26 to 868 days past peak brightness. Analysis of emission line profiles shows increasing extinction over time, indicating continuous dust formation. The extinction curve implies the presence of very large (>1 micron) dust grains. Thermal emission models suggest dust temperatures declining from 2300K to 1100K over time, requiring carbonaceous rather than silicate dust. Combined extinction and emission data indicate a dust mass of ~0.0025 solar masses at 868 days, growing rapidly and expected to reach ~0.5 solar masses by 8000 days if production continues. The results provide evidence for very efficient and rapid dust formation in the dense
Refsdal meets popper_comparing_predictions_of_the_reapperance_of_the_multiply...
O Telescópio Espacial Hubble das agências NASA e ESA registrou a imagem pela primeira vez da explosão prevista de uma supernova. O reaparecimento da supernova Refsdal foi calculado a partir de diferentes modelos de aglomerados de galáxias, cuja imensa gravidade está entortando a luz da supernova.
Muitas estrelas terminam a sua vida com uma explosão, mas somente poucas dessas explosões estelares têm sido registradas no ato que acontecem. Quando isso acontece, é pura sorte, pelo menos até agora. No dia 11 de Dezembro de 2015, os astrônomos não somente fizeram a imagem de uma supernova em ação, como também observaram quando e onde ela estava prevista para acontecer.
A supernova, apelidada de Refsdal, foi registrada no aglomerado de galáxias, conhecido como MACS J1149.5+2223. Enquanto que a luz do aglomerado gasta cerca de cinco bilhões de anos para chegar até nós, a supernova explodiu muito tempo antes, a aproximadamente 10 bilhões de anos atrás.
A história da Refsdal começou em Novembro de 2014, quando os cientistas registraram quatro imagens separadas da supernova num raro arranjo conhecido como Cruz de Einstein, ao redor de uma galáxia dentro do MACS J1149.5+2223. A ilusão de óptica cósmica ocorreu devido ao fato da massa de uma única galáxia dentro do aglomerado estar entortando e ampliando a luz da distante explosão estelar, num processo conhecido como lente gravitacional.
Deja vu all_over_again_the_reapperance_of_supernova_refsdal
O Telescópio Espacial Hubble das agências NASA e ESA registrou a imagem pela primeira vez da explosão prevista de uma supernova. O reaparecimento da supernova Refsdal foi calculado a partir de diferentes modelos de aglomerados de galáxias, cuja imensa gravidade está entortando a luz da supernova.
Muitas estrelas terminam a sua vida com uma explosão, mas somente poucas dessas explosões estelares têm sido registradas no ato que acontecem. Quando isso acontece, é pura sorte, pelo menos até agora. No dia 11 de Dezembro de 2015, os astrônomos não somente fizeram a imagem de uma supernova em ação, como também observaram quando e onde ela estava prevista para acontecer.
A supernova, apelidada de Refsdal, foi registrada no aglomerado de galáxias, conhecido como MACS J1149.5+2223. Enquanto que a luz do aglomerado gasta cerca de cinco bilhões de anos para chegar até nós, a supernova explodiu muito tempo antes, a aproximadamente 10 bilhões de anos atrás.
A história da Refsdal começou em Novembro de 2014, quando os cientistas registraram quatro imagens separadas da supernova num raro arranjo conhecido como Cruz de Einstein, ao redor de uma galáxia dentro do MACS J1149.5+2223. A ilusão de óptica cósmica ocorreu devido ao fato da massa de uma única galáxia dentro do aglomerado estar entortando e ampliando a luz da distante explosão estelar, num processo conhecido como lente gravitacional.
Protoplanetary disks masses_in_ic348_a_rapid_decline_in_the_population_of_sma...
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.
Temperate earth sized_planets_transiting_a_nearly_ultracool_dwarf_star
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.
Spitzer bright ultravista_faint_sources_in_cosmos_the_contribution_to_the_ove...
O telescópio de rastreio VISTA do ESO encontrou uma horda de galáxias massivas anteriormente ocultas por poeira, que existiram quando o Universo era ainda bebê. Ao descobrir e estudar uma grande quantidade deste tipo de galáxias, os astrônomos descobriram, exatamente e pela primeira vez, quando é que tais monstros apareceram pela primeira vez no Universo.
O simples fato de contar o número de galáxias que existem em determinada área do céu permite aos astrônomos testar teorias de formação e evolução galática. No entanto, uma tarefa aparentemente tão fácil torna-se mais difícil quando tentamos contar galáxias cada vez mais distantes e tênues e é mais complicada ainda devido ao fato das galáxias mais brilhantes e fáceis de observar — as mais massivas no Universo — se tornarem mais raras à medida que os astrônomos observam o passado do Universo, enquanto que as galáxias menos brilhantes, mas muito mais numerosas, são ainda mais difíceis de detectar.
Uma equipe de astrônomos liderada por Karina Caputi do Instituto Astronômico Kapteyn da Universidade de Groningen, descobriu muitas galáxias distantes que não tinham sido detectadas anteriormente. A equipe utilizou imagens do rastreioUltraVISTA, um dos seis projetos que usam o VISTA para mapear o céu no infravermelho próximo, e fez um censo das galáxias tênues quando a idade do Universo estava compreendida entre 0,75 e 2,1 bilhões de anos.
Deep chandra observations_of_pictor_a
Todo mundo sabe que os raios produzidos pela Estrela da Morte em Guerra nas Estrelas não pode existir na vida real, porém no universo existem fenômenos que as vezes conseguem superar até a mais surpreendente ficção.
A galáxia Pictor A, é um desses objetos que possuem fenômenos tão espetaculares quanto aqueles exibidos no cinema. Essa galáxia localiza-se a cerca de 500 milhões de anos-luz da Terra e possui um buraco negro supermassivo no seu centro. Uma grande quantidade de energia gravitacional é lançada, à medida que o material cai em direção ao horizonte de eventos, o ponto sem volta ao redor do buraco negro. Essa energia produz um enorme jato de partículas que viajam a uma velocidade próxima da velocidade da luz no espaço intergaláctico, chamado de jato relativístico.
Para obter imagens desse jato, os cientistas usaram o Observatório de Raios-X Chandra, da NASA várias vezes durante 15 anos. Os dados do Chandra, apresentados em azul nas imagens, foram combinados com os dados obtidos em ondas de rádio a partir do Australia Telescope Compact Array, e são aparesentados em vermelho nas imagens.
The ASTRODEEP Frontier Fields catalogues II. Photometric redshifts and rest f...
This document describes a public release of photometric redshifts and galaxy properties from multi-wavelength data in the Abell-2744 and MACS-J0416 galaxy cluster fields observed as part of the Frontier Fields program. Photometric redshifts were estimated using six different methods and have an accuracy of 3-5%. Accounting for gravitational lensing magnification, the H-band number counts agree with CANDELS at bright magnitudes but extend to intrinsically fainter galaxies of H=32-33. The Frontier Fields data allow probing galaxy stellar masses 0.5-1.5 dex lower than in wide fields, including sources with masses of 107-108 solar masses at z>5. Star formation rates can be detected 1
Eso1437a
This document describes observations of the galaxy ESO137-001 using the MUSE instrument on the VLT. The key points are:
1) MUSE observations reveal an extended gas tail stretching over 30 kpc from the galaxy, tracing ongoing ram pressure stripping as it falls into the Norma galaxy cluster.
2) Analysis of the gas kinematics and stellar velocity field show that ram pressure has removed the interstellar medium from the outer disk while the primary tail is still fed by gas from the galaxy center.
3) The stripped gas retains evidence of the disk's rotational velocity out to 20 kpc downstream, indicating the galaxy is moving radially through the cluster. Beyond this the gas shows greater turbulence,
The shadow _of_the_flying_saucer_a_very_low_temperature_for_large_dust_grains
Os astrónomos usaram o ALMA e os telescópios do IRAM para fazer a primeira medição direta da temperatura dos grãos de poeira grandes situados nas regiões periféricas de um disco de formação planetária que se encontra em torno de uma estrela jovem. Ao observar de forma inovadora um objeto cujo nome informal é Disco Voador, os astrónomos descobriram que os grãos de poeira são muito mais frios do que o esperado: -266º Celsius. Este resultado surpreendente sugere que os modelos teóricos destes discos precisam de ser revistos.
Uma equipa internacional liderada por Stephane Guilloteau do Laboratoire d´Astrophysique de Bordeaux, França, mediu a temperatura de enormes grãos de poeira que se encontram em torno da jovem estrela 2MASS J16281370-2431391 na região de formação estelar Rho Ophiuchi, a cerca de 400 anos-luz de distância da Terra.
Esta estrela encontra-se rodeada por um disco de gás e poeira — chamado disco protoplanetário, uma vez que se encontra na fase inicial da formação de um sistema planetário. Este disco é visto de perfil quando observado a partir da Terra e a sua aparência em imagens no visível levou a que se lhe desse o nome informal de Disco Voador.
Os astrónomos utilizaram o ALMA para observar o brilho emitido pelas moléculas de monóxido de carbono no disco da 2MASS J16281370-2431391. As imagens revelaram-se extremamente nítidas e descobriu-se algo estranho — em alguns casos o sinal recebido era negativo. Normalmente um sinal negativo é fisicamente impossível, mas neste caso existe uma explicação, que leva a uma conclusão surpreendente.
Multiple images of_a_highly_magnified_supernova_formed_by_an_early_type_clust...
Artigo descreve a descoberta dos astrônomos de 4 imagens de uma supernova geradas pelo efeito de lente gravitacional e formando o raro padrão da Cruz de Einstein.
“A ring system detected around the Centaur (10199) Chariklo”
- The Centaur object (10199) Chariklo was observed to occult a star, revealing the presence of two narrow rings around the object.
- The rings have widths of about 7 km and 3 km, and orbital radii of 391 km and 405 km from the center of Chariklo.
- Evidence supports the rings being composed of water ice and their geometry explaining the dimming and changing spectrum of Chariklo observed between 1997 and 2008. The discovery of rings around a minor planet is a first for the Solar System.
Low surface brightness_imaging_of_the_magellanic_system_imprints_of_tidal_int...
We present deep optical images of the Large and Small Magellanic Clouds (LMC and SMC) using
a low cost telephoto lens with a wide field of view to explore stellar substructure in the outskirts
of the stellar disk of the LMC (r < 10 degrees from the center). These data have higher resolution
than existing star count maps, and highlight the existence of stellar arcs and multiple spiral arms in
the northern periphery, with no comparable counterparts in the South. We compare these data to
detailed simulations of the LMC disk outskirts, following interactions with its low mass companion,
the SMC. We consider interaction in isolation and with the inclusion of the Milky Way tidal field.
The simulations are used to assess the origin of the northern structures, including also the low density
stellar arc recently identified in the DES data by Mackey et al. (2015) at ∼ 15 degrees. We conclude
that repeated close interactions with the SMC are primarily responsible for the asymmetric stellar
structures seen in the periphery of the LMC. The orientation and density of these arcs can be used to
constrain the LMC’s interaction history with and impact parameter of the SMC. More generally, we
find that such asymmetric structures should be ubiquitous about pairs of dwarfs and can persist for
1-2 Gyr even after the secondary merges entirely with the primary. As such, the lack of a companion
around a Magellanic Irregular does not disprove the hypothesis that their asymmetric structures are
driven by dwarf-dwarf interactions.
Deep nearinfrared survey_carina_nebula
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
Major mergers host_the_most_luminous_red_quasars_at_z2_a_hubble_space_telesco...
Estudo do Hubble mostra os quasares na sua adolescência e ajuda a desvendar mais um capítulo da evolução galáctica.
BETTIIGoalsExploration
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.
An excess of massive stars in the local 30 Doradus starburst
The 30 Doradus star-forming region in the Large Magellanic Cloud is a nearby analog of large
star-formation events in the distant universe.We determined the recent formation history and
the initial mass function (IMF) of massive stars in 30 Doradus on the basis of spectroscopic
observations of 247 stars more massive than 15 solarmasses (M⊙).Themain episode of massive
star formation began about 8 million years (My) ago, and the star-formation rate seems to
have declined in the last 1 My.The IMF is densely sampled up to 200M⊙ and contains 32 ± 12%
more stars above 30 M⊙ than predicted by a standard Salpeter IMF. In the mass range of 15
to 200M⊙, the IMF power-law exponent is 1:90þ0:37
0:26, shallower than the Salpeter value of 2.35.
The ionized nebula_surrounding_the_w26_in_westerlund_1
The document summarizes observations of an ionized nebula surrounding the red supergiant star W26 in the massive star cluster Westerlund 1. H-alpha images reveal a circumstellar shell or ring 0.1 pc in diameter surrounding the star, as well as a triangular nebula 0.2 pc away with a complex filamentary structure. Spectroscopy confirms the nebula is ionized but the excitation mechanism is unclear given red supergiants do not produce ionizing photons. The nebula and star's high luminosity and spectral variability suggest W26 is a highly evolved red supergiant experiencing extreme mass loss, making it an important case study for understanding the late stages of massive star evolution.
A candidate redshift z < 10 galaxy and rapid changes in that population at...
The document summarizes the findings of a study searching for galaxies at redshift z > 10 using deep imaging data from the Hubble Ultra Deep Field. The key points are:
1) The study detects one possible galaxy candidate at z ~ 10.3, the earliest galaxy reported to date.
2) Regardless of detections, the star formation rate density is found to be much smaller (~10%) at z ~ 10 than just 200 million years later at z ~ 8, demonstrating rapid galaxy build-up in the first 500 million years.
3) The 100-200 million years before z ~ 10 appears to be a crucial phase in the early assembly of galaxies.
The nustar extragalactic_survey_a_first_sensitive_look
The document summarizes the first ten sources detected by the Nuclear Spectroscopic Telescope Array (NuSTAR) as part of its extragalactic survey. NuSTAR provides the first sensitive census of the cosmic X-ray background source population at energies above 10 keV. The ten sources have a broad range of redshifts and luminosities, with a median redshift of 0.7 and luminosity of 3×10^44 erg/s. Based on broad-band spectroscopy and SED analysis, the dominant population is quasars with luminosities above 10^44 erg/s, of which around 50% are obscured. However, none are Compton thick and the fraction of Compton thick quasars is constrained to
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Deja vu all_over_again_the_reapperance_of_supernova_refsdal
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Protoplanetary disks masses_in_ic348_a_rapid_decline_in_the_population_of_sma...
Temperate earth sized_planets_transiting_a_nearly_ultracool_dwarf_star
Temperate earth sized_planets_transiting_a_nearly_ultracool_dwarf_star
Spitzer bright ultravista_faint_sources_in_cosmos_the_contribution_to_the_ove...
Spitzer bright ultravista_faint_sources_in_cosmos_the_contribution_to_the_ove...
The ASTRODEEP Frontier Fields catalogues II. Photometric redshifts and rest f...
The ASTRODEEP Frontier Fields catalogues II. Photometric redshifts and rest f...
The shadow _of_the_flying_saucer_a_very_low_temperature_for_large_dust_grains
The shadow _of_the_flying_saucer_a_very_low_temperature_for_large_dust_grains
Multiple images of_a_highly_magnified_supernova_formed_by_an_early_type_clust...
Multiple images of_a_highly_magnified_supernova_formed_by_an_early_type_clust...
“A ring system detected around the Centaur (10199) Chariklo”
“A ring system detected around the Centaur (10199) Chariklo”
Low surface brightness_imaging_of_the_magellanic_system_imprints_of_tidal_int...
Low surface brightness_imaging_of_the_magellanic_system_imprints_of_tidal_int...
Major mergers host_the_most_luminous_red_quasars_at_z2_a_hubble_space_telesco...
Major mergers host_the_most_luminous_red_quasars_at_z2_a_hubble_space_telesco...
An excess of massive stars in the local 30 Doradus starburst
An excess of massive stars in the local 30 Doradus starburst
The ionized nebula_surrounding_the_w26_in_westerlund_1
The ionized nebula_surrounding_the_w26_in_westerlund_1
A candidate redshift z < 10 galaxy and rapid changes in that population at...
A candidate redshift z < 10 galaxy and rapid changes in that population at...
The nustar extragalactic_survey_a_first_sensitive_look
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الخميس 30 أفريل 2015: أحداث منتظرة
9.00 ندوة بعنوان:" إعادة تأسيس وتجديد الحركة النقابية التونسية"/ نزل الهناء الدولي بالعاصمة
9.00 اجتماع لجان مجلس نواب الشعب / مقر مجلس النواب بباردو
9.30 منتدى اقتصادي حول" تونس- لكسنبورغ: شراكة مستقبلية/ مقر اتحاد الصناعة والتجارة بحي الخضراء
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10.00 اتحاد عمال تونس يكرم عمال المتحف الوطني بباردو/ نزل الماجستيك بالعاصمة
10.30 التوقيع على اتفاقية بين الممثل جعفر القاسمي وقرى SOS في تونس/ قرية "اس او اس" بقمرت
10.30 ندوة حول "المقاربة القانونية لمشروع زجر الاعتداءات على القوات المسلحة" / مركز دراسة الإسلام والديمقراطيّة
12.00 توقيع اتفاقيات تمويل بين تونس والمفوضية الأوروبية / مقر وزارة التنمية والاستثمار والتعاون الدولي
14.00 مائدة مستديرة بعنوان: "أيّة حقوق لعاملات النظافة؟"/ فرع منتدى الحقوق الاقتصادية والاجتماعية بالقيروان
Trabalho karnal
Este documento resume la historia de Pedro Bohórquez, un aventurero español que logró hacerse coronar como Inca de los calchaquíes en 1656 engañando a los indígenas y españoles. Bohórquez ganó la confianza de los calchaquíes haciéndose pasar por el último descendiente de los incas. Convenció a los españoles de que podía someter a los indígenas y revelar la ubicación de yacimientos de metales preciosos. El gobernador del Tucumán lo reconoció
Adventure by Revolution Hostels
Adventure by Revolution Hostels es una empresa de gestión de Hostels, Transportes y actividade nacida en el año 2014, cuyo principal objetivo es proveer de servicios únicos a clientes de Hostels en Latino América.
Concepto / Idea de Marca
Nuestra experiencia, nos lleva a conocer los nuevos conceptos del sector hotelero/hstelero, abarcando diferentes áreas de gestión, nos han aportado un gran conocimiento de este sector y de las principales necesidades y demandas del mismo.
Formada por un equipo de cualificados profesionales, cuya principal preocupación es la constante evolución y conocimiento de las últimas tendencias de este sector, Adventure by Revolution Hostels pretende proveer a su organización de toda una serie de ventajas competitivas respecto a sus competidores, bajo nuestras principales premisas de excelencia, rapidez en el servicio y una correcta relación calidad/precio.
Valores
En Adventure by Revolution Hostels tenemos una filosofía de transparencia total. Somos una organización totalmente horizontal, en la que los principales activo son nuestro equipo, nuestras empresas partners y nuestros asociados y accionistas.
Patients2People - Virgin Pitch to Rich Presentation
A presentation for Virgin pitch to rich campaign. Which encompasses how Patients2People can help to give back independance.
Please find our YouTube video to accompany our presentation: https://youtu.be/wcbrjiNcuUI
Thedaily
The document discusses the potential of mineral resources along the Bay of Bengal in Bangladesh. It notes that Bangladesh has deposits of minerals like rutile, zircon, magnetite, ilmenite, garnet, and monazite in beach sand that could be exploited. Pilot plants were set up in the 1970s with foreign assistance to study separating and processing these minerals, but commercial production has not materialized. The author argues that further studies are needed to accurately assess reserves and ensure minerals can be economically extracted and processed to market standards to develop this industry. Doing so could provide resources for industries like nuclear power and reduce foreign exchange expenditures.
Recargas Cigarro Eletrónico
Este documento descreve produtos anti-tabagismo, incluindo recargas para cigarros eletrônicos. As recargas permitem que fumantes continuem fumando, mas sem os agentes nocivos do cigarro comum. O cigarro eletrônico é promovido como uma opção mais saudável que permite manter o estilo de vida do fumante sem preocupações como mau cheiro e dentes amarelados.
Principal analyst
This role is for a Principal Analyst at a globally recognized broadcaster to oversee the analytics team and ensure delivery of insights on all client accounts. Key responsibilities include managing other analysts, determining analysis priorities with the Head of Analysis, delivering best-in-class analysis to clients, and challenging stakeholders on how analysis will create change. The ideal candidate has a degree in statistics/mathematics/computing, excellent client and team management skills, experience managing analytics projects, and the drive to succeed in a client-facing environment. This is a contract position requiring eligibility to work in the UK.
Skuby
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This study aims to measure the level of English proficiency among rural students, examine the causes of their limited English vocabulary, and suggest ways to enrich their vocabulary. A survey research design is used to collect data on students' proficiency levels, the causes of limitations, and ways to improve vocabulary, using tests, questionnaires, and interviews. Data will be analyzed using statistical methods like mean and standard deviation, as well as transcribing interviews.
Bus 620 week 1 dq 2 marketing strategies
This document provides marketing strategy questions for a homework assignment. Students are asked to select a consumer product they recently purchased and fill out a marketing management matrix analyzing the product's marketing mix from the customer's perspective. They then answer questions about how the marketing mix aligns with strategic objectives, whether all marketing mix elements contribute to each strategy, and if there is room for improvement in how different customer types would assess the product.
New microsoft word document
This very short document does not contain any discernible information to summarize in 3 sentences or less. It appears to be random characters without any meaning or context.
Grafico diario del s&p 500 para el 01 02 2013
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This risk assessment sheet is for a student film project called the "Armani Code Advert" to be filmed at the student's house. It identifies tripping on wires as a potential hazard and proposes taping the wires to the floor to minimize the risk. Emergency contact information is provided, including for the student's mother, site safety manager who is the house owner, and local emergency services numbers.
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Patients2People - Virgin Pitch to Rich Presentation
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Similar to AAS_Richard_poster1_final
A supermassive black_hole_in_a_ultra_compact_dwarf_galaxy
Hubble e Gemini observam a galáxia ultra compacta M60-UCD1 e por meio de imagens e medidas de espectrometria descobrem buraco negro que representa 15% da massa da galáxia. Um buraco negro gigante em uma galáxia anã.
Studies of ngc_6720_with_calibrated_hst_wfc3_emission_line_filter_images
This study uses calibrated Hubble Space Telescope images of the Ring Nebula (NGC 6720) taken 12.925 years apart to measure tangential motions within the nebula. Individual features were measured in nitrogen emission line images as well as dark knots seen against oxygen emission. The results indicate that the nebula is expanding homologously, but at a faster rate along its major axis. Dark knots were found to expand more slowly than the nebular gas. The tangential motion measurements allow estimates of the nebula's distance and dynamic age to be about 720 pc and 4000 years, respectively.
A three-dimensional map of the Milky Way using 66,000 Mira variable stars
We study the three-dimensional structure of the Milky Way using 65,981 Mira variable stars discovered
by the Optical Gravitational Lensing Experiment (OGLE) survey. The spatial distribution of the Mira
stars is analyzed with a model containing three barred components that include the X-shaped boxy
component in the Galactic center (GC), and an axisymmetric disk. We take into account the distance
uncertainties by implementing the Bayesian hierarchical inference method. The distance to the GC is
R0 = 7.66 ± 0.01(stat.) ± 0.39(sys.) kpc, while the inclination of the major axis of the bulge to the
Sun-GC line-of-sight is θ = 20.2
◦ ± 0.6
◦
(stat.) ± 0.7
◦
(sys.). We present, for the first time, a detailed
three-dimensional map of the Milky Way composed of young and intermediate-age stellar populations.
Our analysis provides independent evidence for both the X-shaped bulge component and the flaring
disk (being plausibly warped). We provide the complete dataset of properties of Miras that were used
for calculations in this work. The table includes: mean brightness and amplitudes in nine photometric
bands (covering a range of wavelength from 0.5 to 12 µm), photometric chemical type, estimated
extinction, and calculated distance with its uncertainty for each Mira variable. The median distance
accuracy to a Mira star is at the level of 6.6%.
The Sparkler: Evolved High-redshift Globular Cluster Candidates Captured by JWST
This document discusses compact red sources detected around a strongly lensed galaxy ("the Sparkler") at a redshift of 1.378 using JWST data. Photometry and morphological fits of the sources suggest they are spatially unresolved, very red, and consistent with old stellar populations. Spectroscopy shows emission from the galaxy but no signs of star formation in the red sources. The sources are most likely evolved globular clusters dating back to formation redshifts between 7-11, corresponding to ages of 3.9-4.1 billion years at the time of observation. If confirmed, these would be the first observed globular clusters at high redshift, opening a window into early globular cluster formation in the first billion years of
Eso1141a
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
Ngc3576
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.
Hubble Space Telescope Observations of NGC 253 Dwarf Satellites: Three Ultra-...
We present deep Hubble Space Telescope (HST) imaging of five faint dwarf galaxies associated with the nearby
spiral NGC 253 (D ≈ 3.5 Mpc). Three of these are newly discovered dwarf galaxies, while all five were found in
the Panoramic Imaging Survey of Centaurus and Sculptor, a Magellan+Megacam survey to identify faint dwarfs
and other substructures in resolved stellar light around massive galaxies outside of the Local Group. Our HST data
reach 3 magnitudes below the tip of the red giant branch for each dwarf, allowing us to derive their distances,
structural parameters, and luminosities. All five systems contain mostly old, metal-poor stellar populations
(age ∼12 Gyr, [M/H] −1.5) and have sizes (rh ∼ 110–3000 pc) and luminosities (MV ∼ −7 to −12 mag) largely
consistent with Local Group dwarfs. The three new NGC 253 satellites are among the faintest systems discovered
beyond the Local Group. We also use archival H I data to place limits on the gas content of our discoveries. Deep
imaging surveys such as our program around NGC 253 promise to elucidate the faint end of the satellite luminosity
function and its scatter across a range of galaxy masses, morphologies, and environments in the decade to come
Two super-Earths at the edge of the habitable zone of the nearby M dwarf TOI-...
The main scientific goal of TESS is to find planets smaller than Neptune around stars bright enough to allow further characterization studies. Given
our current instrumentation and detection biases, M dwarfs are prime targets to search for small planets that are in (or nearby) the habitable zone
of their host star. Here we use photometric observations and CARMENES radial velocity measurements to validate a pair of transiting planet
candidates found by TESS. The data was fitted simultaneously using a Bayesian MCMC procedure taking into account the stellar variability
present in the photometric and spectroscopic time series. We confirm the planetary origin of the two transiting candidates orbiting around TOI-
2095 (TIC 235678745). The star is a nearby M dwarf (d = 41:90 0:03 pc, Te = 3759 87 K, V = 12:6 mag) with a stellar mass and radius
of M? = 0:44 0:02 M and R? = 0:44 0:02 R , respectively. The planetary system is composed of two transiting planets: TOI-2095b with an
orbital period of Pb = 17:66484 (7 105) days and TOI-2095c with Pc = 28:17232 (14 105) days. Both planets have similar sizes with
Rb = 1:250:07 R and Rc = 1:330:08 R for planet b and c, respectively.We put upper limits on the masses of these objects with Mb < 4:1 M
for the inner and Mc < 7:4 M for the outer planet (95% confidence level). These two planets present equilibrium temperatures in the range of 300
- 350 K and are close to the inner edge of the habitable zone of their star.
Orbital Decay in M82 X-2
M82 X-2 is the first pulsating ultraluminous X-ray source discovered. The luminosity of these extreme pulsars, if
isotropic, implies an extreme mass transfer rate. An alternative is to assume a much lower mass transfer rate, but
with an apparent luminosity boosted by geometrical beaming. Only an independent measurement of the mass
transfer rate can help discriminate between these two scenarios. In this paper, we follow the orbit of the neutron star
for 7 yr, measure the decay of the orbit (P P orb orb 8 10 yr 6 1 · » - - - ), and argue that this orbital decay is driven by
extreme mass transfer of more than 150 times the mass transfer limit set by the Eddington luminosity. If this is true,
the mass available to the accretor is more than enough to justify its luminosity, with no need for beaming. This also
strongly favors models where the accretor is a highly magnetized neutron star.
Observational constraints on mergers creating magnetism in massive stars
Massive stars (those ≥8 solar masses at birth) have radiative envelopes that cannot sustain the dynamos that produce magnetic fields in lower mass stars. Despite this, ∼7% of massive stars have observed magnetic fields. We use multi-epoch interferometric and spectroscopic observations to characterise a magnetic binary system formed of two massive stars. We find that only one star of the binary is magnetic. Using the non-magnetic star as an independent reference clock to estimate the age of the system, we show that the magnetic star appears younger than its companion. The system properties, and a surrounding bipolar nebula, can be reproduced by a model in which this system was originally a triple within which two of the stars merged, producing the magnetic massive star. Thus, our results provide observational evidence that magnetic fields form in at least some massive stars through stellar mergers.
Discovery and properties of the earliest galaxies with confirmed distances
Surveys with James Webb Space Telescope (JWST) have discovered candidate galaxies in
the first 400 Myr of cosmic time1-5
. The properties of these distant galaxies provide initial
conditions for understanding early galaxy formation and cosmic reionisation6
. Preliminary
indications have suggested these candidate galaxies may be more massive and abundant
than previously thought1,7-9
. However, without spectroscopic confirmation of their
distances to constrain their intrinsic brightnesses, their inferred properties remain
uncertain. Here we report on four galaxies located in the JWST Advanced Deep
Extragalactic Survey (JADES) Near-Infrared Camera (NIRCam) imaging with
photometric redshifts � ∼ �� − �� subsequently confirmed by JADES JWST NearInfrared Spectrograph (NIRSpec) observations10. These galaxies include the first redshift
� > �� systems both discovered and spectroscopically confirmed by JWST. Using stellar
population modelling, we find the galaxies typically contain a hundred million solar masses
in stars, in stellar populations that are less than one hundred million years old. The
moderate star formation rates and compact sizes suggest elevated star formation rate
surface densities, a key indicator of their formation pathways. Taken together, these
measurements show that the first galaxies contributing to cosmic reionisation formed
rapidly and with intense internal radiation fields.
Siena Galaxy Atlas 2020
We present the 2020 version of the Siena Galaxy Atlas (SGA-2020), a multiwavelength optical and infrared
imaging atlas of 383,620 nearby galaxies. The SGA-2020 uses optical grz imaging over ≈20,000 deg2 from the
Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys Data Release 9 and infrared imaging in
four bands (spanning 3.4–22 μm) from the 6 year unWISE coadds; it is more than 95% complete for galaxies larger
than R(26) ≈ 25″ and r < 18 measured at the 26 mag arcsec−2 isophote in the r band. The atlas delivers precise
coordinates, multiwavelength mosaics, azimuthally averaged optical surface-brightness profiles, model images and
photometry, and additional ancillary metadata for the full sample. Coupled with existing and forthcoming optical
spectroscopy from the DESI, the SGA-2020 will facilitate new detailed studies of the star formation and mass
assembly histories of nearby galaxies; enable precise measurements of the local velocity field via the Tully–Fisher
and fundamental plane relations; serve as a reference sample of lasting legacy value for time-domain and
multimessenger astronomical events; and more.
The JWST Discovery of the Triply-imaged Type Ia “Supernova H0pe” and Observat...
A Type Ia supernova (SN) at z = 1.78 was discovered in James Webb Space Telescope Near Infrared
Camera imaging of the galaxy cluster PLCK G165.7+67.0 (G165; z = 0.35). The SN is situated 1.5–
2 kpc from its host galaxy Arc 2 and appears in three different locations as a result of gravitational
lensing by G165. These data can yield a value for Hubble’s constant using time delays from this
multiply-imaged SN Ia that we call “SN H0pe.” Over the entire field we identified 21 image multiplicities,
confirmed five of them using Near-Infrared Spectrograph (NIRspec), and constructed a new
lens model that gives a total mass within 600 kpc of (2.6 ± 0.3) × 1014M⊙. The photometry uncovered
a galaxy overdensity at Arc 2’s redshift. NIRSpec confirmed six member galaxies, four of which
surround Arc 2 with relative velocity ≲900 km s−1 and projected physical extent ≲33 kpc. Arc 2
dominates the stellar mass ((5.0±0.1)×1011M⊙), which is a factor of ten higher than other members
of this compact galaxy group. These other group members have specific star formation rates (sSFR)
arXiv:2309.07326v1 [astro-ph.GA] 13 Sep 2023
2 Frye, Pascale, Pierel et al.
of 2–260 Gyr−1 derived from the Hα-line flux corrected for stellar absorption, dust extinction, and slit
losses. Another group centered on the dusty star forming galaxy Arc 1 is at z = 2.24. The total SFR
for the Arc 1 group (≳400M⊙ yr−1) translates to a supernova rate of ∼1 SNe yr−1, suggesting that
regular monitoring of this cluster may yield additional SNe.
Xray and protostars_in_the_trifid_nebula
The document summarizes X-ray observations of the Trifid Nebula using ROSAT and ASCA. ROSAT images revealed around a dozen X-ray sources in the nebula, including the bright O7 star HD 164492 that provides much of the ionization. Ten X-ray sources were correlated with near-infrared sources identified as young stars or protostars. ASCA spectroscopy of the brightest source showed hard X-ray emission up to 10 keV including an iron K line, best fit with a two-temperature thermal model and absorption. The hotter component's temperature is unusually high and may originate from interaction with another object or protostellar flares.
Multiwavelength observations of_na_st1_(wr122)_equatorial_mass_loss_and_x_ray...
Artigo descreve estudo realizado por astrônomos com o Hubble para tentar entender o que se passa com a estrela Nasty 1.
Mission Critical Risk Taking: The Hubble Deep Field by Robert Williams
MivaCon 2014: Mission Critical Risk Taking: The Hubble Deep Field
Presented by Robert Williams, Space Telescope Inst., Johns Hopkins University
1701.06227
This document presents the target selection process for the first year of the Breakthrough Listen search for intelligent life using the Green Bank Telescope, Parkes Telescope, and Automated Planet Finder. The targets include: 1) The 60 nearest stars within 5.1 parsecs to search for faint signals; 2) 1649 stars spanning stellar types from the Hipparcos catalog; 3) 123 nearby galaxies representing different morphological types to search billions of stars simultaneously; and 4) several classes of exotic objects like white dwarfs and neutron stars. The telescopes will observe 1,000,000 stars and galaxies at radio and optical wavelengths between 350 MHz to 100 GHz and 374-950nm, respectively, to search for technological signals.
Muscle w49a data_and_mass_structure_of_the_giant_molecular_cloud
This document summarizes observations of the W49 giant molecular cloud (GMC) using the PMO 14m telescope and the Submillimeter Array (SMA). The PMO observations mapped the entire GMC in various molecular lines at scales up to 113 pc, while the SMA mosaic mapped the central star-forming region W49N at scales down to 0.5 pc. The observations are used to derive the mass structure of the GMC across all scales. The main findings are that the W49 GMC has a total gas mass of 1.1 million solar masses within 60 pc and 2x10^5 solar masses within 6 pc. The mass is distributed in a hierarchical network of filaments converging toward the central
A nearby yoiung_m_dwarf_with_wide_possibly_planetary_m_ass_companion
This document summarizes the identification of two young objects, TYC 9486-927-1 and 2MASS J21265040−8140293, as a likely very wide binary system. It presents revised astrometry showing they have common proper motion. Spectroscopy of the secondary yields a radial velocity consistent with the primary. Analysis of lithium absorption and kinematics suggests an age range of 10-45 Myr, with the secondary having an estimated mass in the planetary mass regime. If confirmed, this would be the widest known exoplanet system at over 4500 AU separation.
Kinematics and simulations_of_the_stellar_stream_in_the_halo_of_the_umbrella_...
This document summarizes a study of the stellar stream and substructures around the Umbrella Galaxy (NGC 4651). Deep imaging and spectroscopy were used to characterize the properties and kinematics of the stream. Tracer objects like globular clusters and planetary nebulae were identified and found to delineate a kinematically cold feature in position-velocity space. Dynamical modeling suggests the stream originated from the tidal disruption of a dwarf galaxy on a highly eccentric orbit about 6-10 billion years ago. This work demonstrates the feasibility of using discrete tracers to recover the kinematics and model the dynamics of low surface brightness stellar streams around distant galaxies.
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A supermassive black_hole_in_a_ultra_compact_dwarf_galaxy
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Studies of ngc_6720_with_calibrated_hst_wfc3_emission_line_filter_images
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A three-dimensional map of the Milky Way using 66,000 Mira variable stars
A three-dimensional map of the Milky Way using 66,000 Mira variable stars
The Sparkler: Evolved High-redshift Globular Cluster Candidates Captured by JWST
The Sparkler: Evolved High-redshift Globular Cluster Candidates Captured by JWST
Hubble Space Telescope Observations of NGC 253 Dwarf Satellites: Three Ultra-...
Hubble Space Telescope Observations of NGC 253 Dwarf Satellites: Three Ultra-...
Two super-Earths at the edge of the habitable zone of the nearby M dwarf TOI-...
Two super-Earths at the edge of the habitable zone of the nearby M dwarf TOI-...
Observational constraints on mergers creating magnetism in massive stars
Observational constraints on mergers creating magnetism in massive stars
Discovery and properties of the earliest galaxies with confirmed distances
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The JWST Discovery of the Triply-imaged Type Ia “Supernova H0pe” and Observat...
The JWST Discovery of the Triply-imaged Type Ia “Supernova H0pe” and Observat...
Multiwavelength observations of_na_st1_(wr122)_equatorial_mass_loss_and_x_ray...
Multiwavelength observations of_na_st1_(wr122)_equatorial_mass_loss_and_x_ray...
Mission Critical Risk Taking: The Hubble Deep Field by Robert Williams
Mission Critical Risk Taking: The Hubble Deep Field by Robert Williams
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Muscle w49a data_and_mass_structure_of_the_giant_molecular_cloud
A nearby yoiung_m_dwarf_with_wide_possibly_planetary_m_ass_companion
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Kinematics and simulations_of_the_stellar_stream_in_the_halo_of_the_umbrella_...
AAS_Richard_poster1_final
- 1. printed by www.postersession.com A New Search for Ultra-compact Dwarfs Richard Vo, Aaron J. Romanowsky, Jay Strader, Charlie Conroy, Mark A. Norris, Jean P. Brodie, San José State University Introduction: Ultra-compact dwarfs (UCD) are a recently discovered class of compact stellar system. They have estimated diameters of up to 200 light years, with up to a hundred million stars. It is believed that these may be the cores of larger galaxies that have been stripped of gas and outlying stars by tidal interactions with other galaxies and galaxy clusters. UCDs lie in the middle ground between galaxies and star clusters and have intermediate sizes and luminosities (UCDs; Hilker et al. 1999; Drinkwater et al. 2000; Jones et al 2006). Methods The primary starting point of our research was the recently discovered object M60- UCD1: the densest known galaxy in the local universe (Strader et al 2013). Our main focus was searching for more unusual objects like M60-UCD1. We would then further analyze them to gain a better knowledge of where to look, and how to look, and better understanding about the origins of ultra-compact dwarfs. Photometric search techniques: We used a wide variety of open source databases that have not been fully analyzed which are accessible to the public. These included Hubble Space Telescope (HST) imaging and the Sloan Digital Sky Survey (SDSS). First we would access the SDSS and search for all objects located around any particular large, central galaxy and obtain their photometric properties. From the parameters of M60-UCD1, we considered the apparent magnitudes of (V~17) and (g- i~1.2). Analysis and Results VO-UCD1 This object was noticed from a test search for a known UCD, M59cO. A radial search of 3 arc minutes around the host galaxy M59 was made with the SDSS database. The color magnitude diagram of sources around M59 showed two objects. One being M59cO and the other we dubbed VO-UCD1 (or M59-UCD3). Unfortunately, this object laid just outside of the HST footprint, hence was not studied by the AIMSS. VO-UCD1 has color of (g-i) = 1.16 and an apparent magnitude of V=16.4 and an absolute magnitude of 𝑀 𝑉= -14.52. Spectroscopy We have obtain spectra from the following sources: Southern Astrophysical Research telescope/ Large Binocular Telescope/ Multi- Object Double Spectrographs and Keck II. The velocity dispersion is σ = 64 ± 2 𝑘𝑚 𝑠−1 and dynamical mass is 𝑀 𝑑𝑦𝑛 ≅ 1.0 𝑥 108 𝑀⊙ The Mass to light ratio 𝑀 𝑑𝑦𝑛 𝐿 𝑟 ≅ 2.1 𝑆𝑜𝑙𝑎𝑟 𝑢𝑛𝑖𝑡𝑠 Abstract Ultra-compact dwarfs (UCDs) are a recently discovered class of object that consists of high stellar densities in a radius of around 10 to 40 pc. We are searching for UCDs around local galaxies using the SDSS database, with spectroscopic follow-up. We present initial results of our survey including a discovery of a unique and interesting object. Fig. 1 – M60-UCD1 (highlighted in red), with neighboring Galaxy M60 Fig. 2 – Color– magnitude diagram of a radial search around M59 from SDSS. This was the first detection Of M59-UCD3. Fig. 2 – The spectrum of VO-UCD1 as shown using the IRAF data analysis tool. The prominent dips are absorption lines that is used to measure redshift and velocity dispersion. Next steps: We have submitted a proposal for the use of the Hubble Space Telescope to help further analyze the sizes and shapes of these objects. We will also pursue further X-ray data and study the contributions of black holes to the dynamical masses. All in all, we are still actively searching for new candidates to study. The origins of UCDs however, still remains unknown. M59-UCD3 M59cO star Fig. 1 – central image is M59 and its neighboring UCDs. Top left and right panel is M59-UCD3 and M59cO with its i-band image beneath it respectively. Bottom Left is a comparison star with equal image scaling. Fig. 4 – Size- luminosity diagram of stellar systems in the nearby universe References: [1] Hilker, M., Infante, L., Viera, G., Kissler-Patig, M., & Richtler, T. 1999, A&AS, 134, 75 [2] Drinkwater, M. J., Jones, J. B., Gregg, M. D., & Phillipps, S. 2000, PASA, 17, 227 [3] Jones, J. B., Drinkwater, M. J., Jurek, R., et al. 2006, AJ, 131, 312 [4] Strader, J., Seth, A. C., Forbes, D. A., et al. 2013, ApJ, 775, L6