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freckles-like-stars-n-shit · 5 months ago

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SUPERSOLES

Las primeras estrellas del universo

Autor: Lic. Mariano Ribas, Planetario de la Ciudad de Buenos Aires Galileo Galilei. Revista Si Muove n°26 - Primavera 2023

01: Ilustración de una de las extraordinarias estrellas de la antiquísima Población III.

Se encendieron cuando el cosmos aún gateaba, cuando todo era oscuridad. Eran enormes, supermasivas y extremadamente calientes y luminosas. Esas primeras estrellas vivieron pocos millones de años y luego explotaron como ninguna otra cosa haya vuelto a explotar. Gracias a su metamorfosis físico-química, cambiaron para siempre la historia del universo. Hoy, unos 13.600 millones de años más tarde, la astronomía, en una suerte de arqueología cósmica, arriesga modelos, juega con complejas simulaciones por computadora y busca pistas y radiaciones "fósiles" que puedan ayudarnos a delinear su perfil. Estamos comenzando a escribir la historia de aquellos arcaicos supersoles.

Al principio, todo era oscuridad. Luego del Big Bang, el universo en expansión era un pequeño, denso y muy caliente mar de espacio, energía y partículas elementales. No había estrellas, ni galaxias, ni planetas. Los primeros 200 millones de años del cosmos corresponden a lo que los astrónomos llaman las Eras Oscuras. En aquel cosmos primitivo, la gravedad fue organizando y agrupando la materia en estructuras cada vez más grandes, tanto la materia normal (o bariónica) como la materia oscura, que era y es abrumadoramente mayoritaria.

Poco a poco, a la par del progresivo crecimiento y enfriamiento generalizados, colosales nubes de hidrógeno, salpicadas de helio e ínfimas piscas de litio (y ningún otro elemento, porque no los había), fueron colapsando y ganando densidad y temperatura. Según los modelos actuales, se gestaron “mini-halos” de gas y materia oscura de alrededor de 1 millón de masas solares, en cuyo interior se formaron nódulos más densos. Eran los “embriones” de las primeras estrellas, soles primitivos que se encendieron gracias a la fusión termonuclear (de hidrógeno en helio) en sus núcleos; y que, a su vez y de a millones, darían cuerpo y luz a las primeras galaxias.

Universo diferente, estrellas diferentes

Tras ese necesario vistazo, breve y simplificado, al muy temprano y primitivo escenario cósmico, vamos directamente al punto de este artículo: según todos los modelos científicos vigentes, las primeras estrellas del universo eran muy diferentes a las actuales, tanto en escala como en composición química. Y eso fue así, justamente, porque las condiciones generales del cosmos eran bien distintas.

Tanto en el universo contemporáneo como en el de los últimos miles de millones de años, las nebulosas (que siempre fueron las “fábricas” de estrellas) están salpicadas de elementos pesados, como carbono, oxígeno, nitrógeno, calcio, hierro, y hasta granos de polvo. Elementos que las enfrían y facilitan la múltiple fragmentación de sus nódulos internos, sus partes más densas. Por el contrario, en los primeros cientos de millones de años, las nebulosas carecían de elementos pesados. Eran puro hidrógeno y helio. Y fue justamente esa pobreza química la que permitió que los nódulos protoestelares alcanzaran temperaturas relativamente altas (unos 500°C). Eso, a su vez, los hacía más resistentes a la fragmentación. De ese modo, los nódulos podían colapsar completos y dar origen a estrellas mucho más grandes y masivas que las modernas. ¿Cuán masivas?

La respuesta es sorprendente.

Estudios previos y actuales: ¿quién da más?

02: El Telescopio Espacial James Webb es un instrumento fundamental para la búsqueda y el estudio de las primeras estrellas y galaxias del universo. Está equipado con un espejo primario segmentado, bañado en oro, de 6,5 metros de diámetro, y observa el cosmos en el rango del infrarrojo cercano y medio.

Durante los últimos veinte años, el escenario teórico que acabamos de plantear se consolidó gracias a una multiplicidad de estudios, observaciones y modelos. Los astrónomos han ido afinando, pacientemente, el perfil de aquellos primeros y monumentales soles.

Si hacemos un rápido repaso cronológico, no podemos dejar de mencionar los aportes que, en 2005 y de modo independiente hicieron dos equipos de científicos: uno, de las Universidades de Yale y Harvard, en Estados Unidos; y el otro, del Instituto Max Planck de Astrofísica, en Alemania. Mediante sofisticadas simulaciones por computadora, estos detectives del pasado cosmológico recrearon las condiciones de gestación estelar en el universo primitivo. En ambos casos, llegaron a conclusiones similares: los nódulos primigenios habrían formado estrellas de cientos de masas solares; incluso, de más de 1000. Tengamos en cuenta que las estrellas más masivas de nuestra galaxia (como Eta Carinae A, WR42e, WR93, Arches-F9 o la llamada Pistol Star) tienen entre 100 y 150 masas solares.

Investigaciones posteriores, realizadas durante la pasada década (como el programa EDGES, encabezado por científicos del Instituto de Tecnología de Massachusetts, EE.UU., que utilizó un radiotelescopio en Australia en 2018) ajustaron algunas tuercas. Pero coincidieron en lo esencial: esas primitivas criaturas estelares habrían sido mucho más grandes y masivas que las actuales.

Mil masas solares no es poco. Pero un flamante estudio sugiere que, al menos en ciertos casos, las primeras estrellas pudieron haber ido mucho más allá. El trabajo en cuestión fue publicado a fines de enero, y sus autores principales son los astrofísicos japoneses Masaki Kiyuna, Takashi Hosokawa y Sunmyon Chon, del Departamento de Física de la Universidad de Kyoto. Mediante simulaciones con supercomputadoras de una resolución sin precedentes, estos investigadores no solo demostraron que para “construir” estrellas supermasivas se requiere un medio denso, relativamente caliente y carente de elementos pesados; sino que también el proceso de colapso gravitatorio debe afectar a masas muy elevadas, en volúmenes pequeños y en tiempos muy breves. Las simulaciones de Kiyuna, Hosokawa y Chon se basan en el fenómeno astrofísico de “acreción fría”, en el que también intervienen colisiones de flujos de materia sobre los discos protoestelares, ondas de choque y mecanismos que remueven el calor del material durante el abrupto colapso gravitatorio¹.

Y ahora sí, la asombrosa y prometida conclusión: según este minucioso trabajo científico, es probable que, bajo las condiciones imperantes en aquellos primerísimos tiempos del cosmos, el repentino e imparable colapso de inmensos nódulos de gas haya encendido estrellas de decenas de miles de masas solares; incluso, hasta 100 mil.

03: Gráfico a escala que muestra la relación de tamaño entre diferentes tipos de estrellas, incluido el Sol, y una de las colosales estrellas de la Población III que existieron en los primeros cientos de millones de años del universo.

Poblaciones I, II y III

Partiendo de la clasificación inicial realizada por el gran astrónomo alemán Walter Baade (1893-1960) durante la Segunda Guerra Mundial, los astrónomos de hoy en día hablan de tres tipos de poblaciones estelares a lo largo de la historia del universo. En su momento, Baade observó y analizó espectroscópicamente estrellas individuales de la vecina galaxia de Andrómeda (dicho sea de paso, fue el primero en resolverlas visualmente, con el auxilio del telescopio reflector de 2,5 m de diámetro del Observatorio de Monte Wilson, California, EE.UU.). Y así notó que podía dividirlas en dos grandes grupos: las azules, más jóvenes, calientes y luminosas; y las rojizas, más viejas y frías. La Población I y II, respectivamente. Mas tarde, los astrónomos se dieron cuenta de que esta clasificación tenía mucho que ver con la construcción de elementos químicos más pesados a lo largo de la historia de la Vía Láctea. Las estrellas de Población II, mucho más antiguas, estaban menos enriquecidas con elementos más pesados que el helio (carbono, oxígeno, hierro, por ejemplo). Las de Población I, en cambio, se habían gestado en nubes de gas mucho más “contaminadas” de elementos pesados, provenientes de estrellas ya extintas. Sin embargo, había algo que no terminaba de cerrar: a pesar de contener cantidades exiguas de oxígeno, calcio o hierro, las estrellas de Población II sí los tenían. Y esos elementos no podían haber nacido luego del Big Bang. Por lo tanto, debió existir una generación de estrellas aún más antiguas y primitivas, formadas solo a partir del hidrógeno y helio iniciales. Ya en la década de 1980, los astrónomos (entre ellos, el británico Bernard Carr), bautizaron a esas estrellas, arcaicas y fundacionales, como la Población III, y las modelaron teóricamente como colosales bolas de hidrógeno y helio crudos, esculpidas por la gravedad en los primeros cientos de millones de años del universo. Objetos de miles de millones de km de diámetro y cientos o miles de masas solares. Ni más ni menos que los supersoles de los que habla este artículo.

Monstruos luminosos y explosivos

Debido a sus descomunales masas, justamente, aquellos primitivos soles gigantes habrían sido decenas o cientos de millones de veces más luminosos que cualquier estrella común del universo actual (como el Sol, por ejemplo). Y qué decir de sus temperaturas superficiales, que según estos mismos modelos teóricos ardían a más de 100.000°C (contra los 5500°C del Sol; o los 20.000°C o 30.000°C de estrellas modernas fuera de serie, como las espléndidas y azuladas Spica, en la constelación de Virgo; Regulus, en Leo; o Rigel, en Orión). A punto tal, que su pico de emisión no estaba en el rango visible, sino en lo profundo de la luz ultravioleta (de menor longitud de onda, mayor frecuencia y mucha mayor energía). Con semejante perfil, esas superestrellas debieron haber calentado y ionizado todo el gas de sus alrededores, esa misma materia prima que les diera origen.

Semejante furia astrofísica iba de la mano de una brutal y muy veloz fusión termonuclear en sus núcleos todopoderosos. Y aquí se abre otra cuestión tan apasionante como decisiva para la posterior evolución del cosmos. Gracias a la fusión termonuclear en sus corazones, las primeras estrellas del universo reciclaron su hidrógeno y helio originales; y en etapas sucesivas, cada vez más calientes, breves y violentas, forjaron elementos más y más complejos: carbono, oxígeno, magnesio, nitrógeno, silicio e, incluso, hierro. Finalmente, tras brillar durante unos pocos millones de años, explotaron como hipernovas, estallidos cientos de veces más energéticos y luminosos que cualquier supernova contemporánea.

04: Esta imagen infrarroja, obtenida por el Telescopio Espacial Spitzer en 2005, muestra un suave resplandor de fondo, posiblemente asociado a radiación emitida, en tiempos muy remotos, por las primeras estrellas.

Población III: revolución y legado cósmico

Ya es hora de etiquetarlas: técnicamente hablando, los astrónomos dicen que las primeras estrellas formaron la Población III, y que sus descendientes, aquellas que vivieron en los siguientes miles de millones de años, corresponden a la Población II y a la Población I. Estas últimas, por ejemplo, incluyen al Sol y todas las estrellas que vemos en el cielo nocturno (ver apartado).

La aparición y desarrollo de las primeras estrellas no solo dio por finalizadas las Eras Oscuras, sino que dio inicio a una nueva y revolucionaria etapa en la historia del universo. Por un lado, la intensa luz ultravioleta derramada por estos monstruos calentó y ionizó las masas de gas interestelar, que en las Eras Oscuras habían permanecido esencialmente en estado calmo y neutro. Es decir: en lugar de dejar los átomos de hidrógeno intactos, con sus electrones ligados a sus núcleos, la radiación ultravioleta les arrancó los electrones a los núcleos de hidrógeno. Por un lado, desde aquel lejano momento, el gas que flota en el universo está mayormente ionizado. Pero lo más jugoso es algo que dejamos picando en el párrafo anterior: a fuerza de la fusión termonuclear del hidrógeno y del helio, las estrellas de Población III forjaron elementos químicos más complejos, que no existían en el amanecer del cosmos. Y cuando explotaron como hipernovas, desparramaron esos nuevos elementos a cientos de años luz a la redonda, nutriendo y enriqueciendo el medio interestelar y las, hasta entonces, nebulosas vírgenes, de puro hidrógeno y helio.

De esa manera, las posteriores generaciones de estrellas, si bien ya no tan masivas, calientes ni luminosas (por las mismas limitaciones cósmicas que imponían las nuevas condiciones físico-químicas), se hicieron cada vez más ricas químicamente. Las nuevas recetas estelares ya incluían también carbono, oxígeno, hierro y tantos otros preciosos elementos que permitirían la gestación de planetas. Y en épocas mucho más recientes, al menos en este pequeño rincón del universo, la vida. Ni más ni menos. Un tema que, desde luego, merece todo un artículo aparte. El legado de los supersoles fue verdaderamente trascendental.

05: Imagen artística que representa las primeras estrellas supermasivas aparecidas en el universo tan solo 200 millones de años después del Big Bang.

Huellas en el cosmos: antecedentes

Desde hace décadas, los astrónomos barren el cielo con toda clase de instrumentos para encontrar las posibles huellas de aquellas estrellas prodigiosas. No solo desde la superficie, sino también con sofisticados observatorios espaciales. Durante los años ’90, por ejemplo, el satélite COBE (Cosmic Backgroud Explorer), de la NASA, destinado principalmente a estudiar la famosa radiación de fondo cósmico de microondas (una suerte de “fósil” de los primeros tiempos del universo), detectó un muy débil “fondo infrarrojo”, tentativamente atribuido a la emisión de estrellas extremadamente lejanas/antiguas.

Ya a comienzos de este siglo, el observatorio espacial WMAP (Wilkinson Microwave Anisotropy Probe), sucesor del COBE, detectó curiosos patrones de polarización en la radiación de fondo cósmico de microondas, que fueron asociados a la ionización a gran escala generada por las primeras estrellas. También por entonces, el observatorio espacial Swift (también de la NASA) detectó un tremendo estallido de rayos gamma, aparentemente originado hace unos 12.800 millones de años. El brutal fogonazo cósmico bien pudo ser la señal de una hipernova de Población III.

Otra pista particularmente interesante surgió en 2005, cuando un equipo encabezado por Alexander Kashlinsky apuntó durante 10 horas el Telescopio Espacial Spitzer (NASA) hacia un rincón de la constelación boreal de Draco. El resultado fue una recordada imagen infrarroja, cargada de estrellas de la Vía Láctea y montones de galaxias de fondo (imagen 04). Pero lo verdaderamente interesante no eran las estrellas, ni las galaxias, sino el suave resplandor de fondo que bañaba la imagen. Mediante técnicas digitales de procesado, Kashlinsky y sus colegas le quitaron a la imagen original todas las estrellas y galaxias, y dejaron solo los manchones infrarrojos de fondo. Y fue entonces cuando arriesgaron una asombrosa explicación: “Creemos que esa es la luz colectiva de millones de los primeros objetos que se formaron en el universo (…), astros que desaparecieron hace eones, pero cuya luz sigue viajando por el cosmos”, decía el científico en la revista Nature. Si así fuera, es verdaderamente impresionante: luz estelar que viajó desde la infancia del universo, durante más de 13.000 millones de años, acompañando su expansión y “estirándose” y debilitándose a la par, pasando de ser furiosa luz ultravioleta, a ese actual y etéreo resplandor infrarrojo. Una suerte de fósiles electromagnéticos que permean el cosmos y hablan en nombre de incontables soles extintos.

En clara sintonía con aquel “fogonazo” detectado por el Swift, en 2009, y con la ayuda de un enorme globo que se elevó hasta la alta atmósfera, el programa ARCADE (Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission) de la NASA registró breves y débiles pulsos de ondas de radio, cuyo posterior análisis sugirió que podían ser los “ecos” de una o más hipernovas extremadamente lejanas/antiguas. La lista de sugerentes indicios podría extenderse mucho más. De hecho, durante la pasada década los astrónomos sumaron pistas muy similares que, tomadas en su conjunto, apuntan en la misma dirección: todas serían posibles evidencias de la presencia de estrellas extremadamente masivas y luminosas que vivieron y murieron en los primeros cientos de millones de años del cosmos.

06: El observatorio espacial de microondas WMAP (Wilkinson Microwave Anisotropy Probe) ha sido otra herramienta fundamental para detectar pistas sobre la existencia de las inmensas y extremadamente calientes y luminosas estrellas de la Población III.

Búsquedas con el Telescopio Espacial James Webb

Más allá de perfiles teóricos, sólidas simulaciones por computadoras y una muy buena cantidad de sugerentes indicios, ¿tenemos evidencias directas de aquellos arcaicos prodigios estelares? Oficialmente, aún no. Pero estamos cerca de lograrlo, fundamentalmente, gracias al flamante y prometedor Telescopio Espacial James Webb (JWST) de la NASA. A la luz de sus primeros e impresionantes imágenes y datos (que diferentes especialistas han abordado, incluso, en charlas especiales en la sala del Planetario), hay muy buenas razones para hacernos ilusiones. Gracias a su espejo primario de 6,5 metros de diámetro, sus múltiples sensores y espectroscopios, y su altísima sensibilidad en el rango del infrarrojo cercano y medio, el JWST es una máquina perfecta para escudriñar el universo más distante/primitivo. Eso incluye, por supuesto, las galaxias de hace más de 13 mil millones de años, donde anidaban las estrellas de Población III.

El JWST podría observar sin problemas las hipernovas en los límites del universo observable. Y mediante el análisis espectral de ese cataclismos, se podría perfilar mucho mejor los supersoles que los precedieron.

Otras pistas podrían surgir de la búsqueda y detección de helio ionizado (o helio II) en galaxias extremadamente antiguas. Los astrónomos sospechan que la brutal radiación de las estrellas de Población III debería haber “arrancado” electrones a sus átomos de helio, un fenómeno que emitiría patrones de luz específicos. Sobre este punto también tenemos novedades, y tienen que ver con el JWST. En febrero pasado se conocieron resultados muy preliminares de un estudio espectroscópico de más de 2 mil galaxias, realizado por el astrónomo Xin Wang (Academia China de Ciencias, en Pekín) y sus colegas. Entre los datos filtrados, aparece una galaxia que ya existía apenas 620 millones de años después del Big Bang, con claras señales de helio II. Es muy probable que pronto tengamos novedades.

¿Supersoles en los arrabales galácticos?

Dicho todo lo anterior, parecería completamente absurdo buscar aquellos supersoles en el universo actual. Sin embargo, hay quienes piensan que, no tan lejos, podríamos dar con criaturas bastante similares. ¿Dónde? La respuesta, una vez más, proviene de las simulaciones por computadora. Un estudio publicado en enero de este año por un grupo internacional de científicos², sugiere que en las zonas más externas de las más grandes galaxias modernas podrían existir reservorios de hidrógeno y helio esencialmente vírgenes. Regiones muy aisladas del resto del cuerpo galáctico, donde inmensas nubes de gas no “contaminado” de elementos pesados podrían gestar estrellas colosales, de características muy similares a las de la Población III original. Nuevamente, el JWST tendría la capacidad necesaria para encontrarlas, al menos, en galaxias situadas a decenas o cientos de millones de años luz.

Una asombrosa posibilidad

Para el final dejamos lo más extremo: bajo circunstancias tan extremas como fortuitas, el JWST podría lograr una imagen directa y puntual de alguna de las estrellas de la Población III. En principio, esto parece imposible dado que, incluso bajo la penetrante mirada infrarroja de este telescopio, galaxias enteras en los confines del espacio (y del tiempo) apenas lucen como vagas manchitas de unos pocos píxeles. ¿Cómo pretender, entonces, resolver una estrella, por más monumental que haya sido? La respuesta tiene que ver con el conocido fenómeno astrofísico de lentes gravitacionales.

En 2018, el astrónomo Rogier Windhorst (Universidad de Arizona, EE.UU.) y sus colegas, propusieron que la brutal fuerza de gravedad de los más grandes cúmulos de galaxias, podría torcer, concentrar y amplificas la luz estrellas individuales en galaxias ubicadas mucho más “atrás”, pero exactamente en la misma línea visual. Con esa ayudita de la naturaleza, la luz alguna vez emitida por los supersoles “podría sufrir una casi infinita magnificación, y así saltar a la vista (una imagen individual)”, dice Windhorst. No es casual que, sobre esa base y ahora mismo, este científico lidere un plan de búsqueda con el JWST: “Estoy muy confiado de que en uno o dos años veremos una… Ya tenemos algunos objetos candidatos”.

Sencillamente, fascinante. Quizás muy pronto, y desde la otra punta del espacio y del tiempo, aquellos super- soles que vivieron y brillaron durante el amanecer del universo, nos revelen el secreto último de su gloria, su tragedia y su revolucionario legado.

Notas ¹ Todo ha sido dicho de modo simplificado. Quienes quieran profundizar, pueden buscar el trabajo original en internet: First emergence of cold accretion and supermassive star formation in the early universe / Kiyuna, Hosokawa, Chon ² A needle in a haystack? Catching Pop III stars in the Epoch of Reionization: I. Pop III star forming environments / Venditti, Graziani, Schneider, Pentericci, Di Cesare, Maio, Omukai.

#space #astronomy #astronomía #scientific article #artículo científico #astrophysics #astrofísica #tani's log #divulgación científica #ciencia #si muove #si muove revista

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jameswebb-discoveries · 9 months ago

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Discovery Alert! In a discovery released on March 4, 2024 - Webb Telescope Just Found the Most Distant Black Hole EVER and Hints at the First Stars!

🪐 The James Webb Space Telescope (JWST) just dropped some mind-blowing discoveries and it's got the whole astronomy community buzzing.

Here's the lowdown:

Supermassive Black Hole from the Early Universe: JWST spotted the farthest black hole ever observed, chilling in the heart of a galaxy called GN-z11. This monster is 2 million times the mass of our sun and existed a mere 430 million years after the Big Bang!

Pristine Gas Hints at First Stars: Another JWST team found a clump of mostly helium gas surrounding GN-z11. This gas is super clean, almost untouched by heavier elements, suggesting it could be leftover material from the Big Bang itself! This discovery hints at the possible presence of the legendary Population III stars, the first generation of stars in the universe, composed mainly of hydrogen and helium.

These findings are HUGE! They offer a glimpse into the infancy of the universe, revealing how black holes formed and hinting at the birth of the very first stars. JWST is truly revolutionizing our understanding of the cosmos! ✨

What do you think? Did these discoveries blow your mind? Share your thoughts in the comments! #JWST #Space #BlackHole #FirstStars #Cosmology #MindBlown

Read more here - Webb Discovers Most Distant Black Hole, Hints of Primordial Gas in GN-z11

#JWST #Space #BlackHole #FirstStars #Cosmology #MindBlown

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spacetimewithstuartgary · 2 months ago

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Webb finds potential missing link to first stars

Looking deep into the early universe with NASA’s James Webb Space Telescope, astronomers have found something unprecedented: a galaxy with an odd light signature, which they attribute to its gas outshining its stars. Found approximately one billion years after the big bang, galaxy GS-NDG-9422 (9422) may be a missing-link phase of galactic evolution between the universe’s first stars and familiar, well-established galaxies.

“My first thought in looking at the galaxy’s spectrum was, ‘that’s weird,’ which is exactly what the Webb telescope was designed to reveal: totally new phenomena in the early universe that will help us understand how the cosmic story began,” said lead researcher Alex Cameron of the University of Oxford.

Cameron reached out to colleague Harley Katz, a theorist, to discuss the strange data. Working together, their team found that computer models of cosmic gas clouds heated by very hot, massive stars, to an extent that the gas shone brighter than the stars, was nearly a perfect match to Webb’s observations.

“It looks like these stars must be much hotter and more massive than what we see in the local universe, which makes sense because the early universe was a very different environment,” said Katz, of Oxford and the University of Chicago.

In the local universe, typical hot, massive stars have a temperature ranging between 70,000 to 90,000 degrees Fahrenheit (40,000 to 50,000 degrees Celsius). According to the team, galaxy 9422 has stars hotter than 140,000 degrees Fahrenheit (80,000 degrees Celsius).

The research team suspects that the galaxy is in the midst of a brief phase of intense star formation inside a cloud of dense gas that is producing a large number of massive, hot stars. The gas cloud is being hit with so many photons of light from the stars that it is shining extremely brightly.

In addition to its novelty, nebular gas outshining stars is intriguing because it is something predicted in the environments of the universe’s first generation of stars, which astronomers classify as Population III stars.

“We know that this galaxy does not have Population III stars, because the Webb data shows too much chemical complexity. However, its stars are different than what we are familiar with – the exotic stars in this galaxy could be a guide for understanding how galaxies transitioned from primordial stars to the types of galaxies we already know,” said Katz.

At this point, galaxy 9422 is one example of this phase of galaxy development, so there are still many questions to be answered. Are these conditions common in galaxies at this time period, or a rare occurrence? What more can they tell us about even earlier phases of galaxy evolution? Cameron, Katz, and their research colleagues are actively identifying more galaxies to add to this population to better understand what was happening in the universe within the first billion years after the big bang.

“It’s a very exciting time, to be able to use the Webb telescope to explore this time in the universe that was once inaccessible,” Cameron said. “We are just at the beginning of new discoveries and understanding.”

TOP IMAGE: What appears as a faint dot in this James Webb Space Telescope image may actually be a groundbreaking discovery. Detailed information on galaxy GS-NDG-9422, captured by Webb’s NIRSpec (Near-Infrared Spectrograph) instrument, indicates that the light we see in this image is coming from the galaxy’s hot gas, rather than its stars. Astronomers think that the galaxy’s stars are so extremely hot (more than 140,000 degrees Fahrenheit, or 80,000 degrees Celsius) that they are heating up the nebular gas, allowing it to shine even brighter than the stars themselves. Credit NASA, ESA, CSA, STScI, Alex Cameron (Oxford)

LOWER IMAGE: This comparison of the data collected by the James Webb Space Telescope with a computer model prediction highlights the same sloping feature that first caught the eye of astronomer Alex Cameron, lead researcher of a new study published in Monthly Notices of the Royal Astronomical Society. The bottom graphic compares what astronomers would expect to see in a "typical" galaxy, with its light coming predominantly from stars (white line), with a theoretical model of light coming from hot nebular gas, outshining stars (yellow line). The model comes from Cameron’s collaborator, theoretical astronomer Harley Katz, and together they realized the similarities between the model and Cameron's Webb observations of galaxy GS-NDG-9422 (top). The unusual downturn of the galaxy's spectrum, leading to an exaggerated spike in neutral hydrogen, is nearly a perfect match to Katz’s model of a spectrum dominated by super-heated gas. While this is still only one example, Cameron, Katz, and their fellow researchers think the conclusion that galaxy GS-NDG-9422 is dominated by nebular light, rather than starlight, is their strongest jumping-off point for future investigation. They are looking for more galaxies around the same one-billion-year mark in the universe’s history, hoping to find more examples of a new type of galaxy, a missing link in the history of galactic evolution. Credit NASA, ESA, CSA, Leah Hustak (STScI)

#science #space #astronomy #physics #news #nasa #astrophysics #esa

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covenawhite66 · 2 months ago

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A super massive black hole Galaxy GN-z11. The area has condensed gases and ionization in association with chemicals which are common in black holes. It is the farthest away black hole detected to date.

Halo surrounding Galaxy GN-z11 may have been caused by Population III star cluster collapses which created the pristine gas

#astrophysics #astronomy #outer space #black holes #james webb space telescope #nasa #science article

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mybeautifulchristianjourney · 6 months ago

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Doctrines of Grace - Collection of Essays

What the Bible Says About the Doctrines of Grace God's Part and Man's Part in Salvation - John Reisinger The Five Points of Calvinism – R.L. Dabney The Five Points of Calvinism – John Piper The Five Points of Calvinism - WJ Seaton The Reformaed Doctrine of Predestination by Boettner The Reformed Faith – Loraine Boettner The Reformed Faith – B.B. Warfield More Than A Calvinist – John Newton Why Can’t They See This – Tom Nettles A Defense of Calvinism – C.H. Spurgeon Calvinism Fact Sheet - Joel Barnes The Five Points of Calvinism @Monergism More articles like this....

Total Depravity Free Will – A Slave – C.H. Spurgeon Human Inability - Charles Spurgeon Man's Utter Inability to Rescue Himself - Thomas Boston The Doctrine of Total Depravity – Part I – John G Reisinger The Doctrine of Total Depravity – Part II – John G Reisinger Total Depravity – Loraine Boettner Man in His Fallen State – John Newton Decisional Regeneration - James E. Adams The Myth of Free Will - Walter Chantry Captive Hearts, Captive Church - R. C. Sproul More articles like this...

Unconditional Election Chain of Grace – John G. Reisinger The Doctrine of Election – Parts I, II & III – John G. Reisinger Election - B. B. Warfield Election - J. C. Ryle The Argument of Romans 9 – John Piper Who Chose Whom – John F. MacArthur Jr. Who Saves Whom – Michael Horton Unconditional Election - C. H. Spurgeon Election - C. H. Spurgeon Unconditional Election - Loraine Boettner Electing Love - Robert Murray McCheyne More resources like this...

Particular Redemption The Atonement – Arthur Pink Sufficient for All? - Jim Ellis Death of Death - John Owen Was Anyone Saved at the Cross – James White For Whom Did Christ Die? - C. H. Spurgeon Particular Redemption – C.H. Spurgeon Intro to The Death of Death – J.I. Packer Llimited Atonement - Loraine Boettner Partticular Redemption - Wayne Mack The Love of God and the Intent of the Atonement - D. A. Carson More Resources on Particular Redemption...

Effectual Grace Effectual Calling and Regeneration - Martyn Lloyd-Jones Justification & Regeneration - Charles Leiter The Internal and External Call - Wilhelmus a Brakel Effectual Calling – C.H. Spurgeon The Sovereignty of God the Holy Spirit in Salvation – Arthur Pink Irresistible Grace – Jacob Moseley Preaching the Grace of the Spirit’s Calling – S. Lewis Johnson Who Can Come – Mark Webb More Resources like this...

Preservation of the Saints Can a Christian Lose His or Her Salvation? - Greg Johnson Perseverance of the Saints – Loraine Boettner Sanctification and Perseverance - Herman Bavinck Perseverance of the Saints - Wilhelmus à Brakel Perseverance of the Saints by Brian Schwertley How to Know you are a Real Christian - Jonathan Edwards More Essays like this...

Related to the Doctrines of Grace

Augustine and Pelagius – R.C. Sproul From Whitefield to Wesley – George Whitefield (Includes Wesley’s Sermon Free Grace) Ian Murray on Whitefield and Wesley The Legacy of Charles Finney – Michael Horton The Carnal Christian Doctrine – John G. Reisinger The Pelagian Captivity of the Church – R.C. Sproul The Moral Basis of Faith – Tom Wells A Simple Explanation of Monergism

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sciencespies · 2 years ago

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2023 Space and Astronomy News: What to Expect

https://sciencespies.com/space/2023-space-and-astronomy-news-what-to-expect/

2023 Space and Astronomy News: What to Expect

As years in space and astronomy go, 2022 is going to be a tough act to follow.

NASA wowed us with cosmic scenes captured by the James Webb Space Telescope. The DART mission slammed an asteroid into a new orbit. Artemis I set humanity on a course back to the moon. China finished building a new space station in orbit. SpaceX launched 61 rockets in 12 months. And the invasion of Ukraine imperiled Russia’s status as a space power.

It’s a lot to measure up to, but 2023 is bound to have some excitement on the launchpad, the lunar surface and in the sky. Once again, you can get updates on your personal digital calendar by signing up for The New York Times’s Space and Astronomy Calendar. Here are some of the major events you can expect. Not all of them have certain dates yet, but Times journalists will provide additional information as it emerges. Learn more at nytimes.com/spacecalendar

New Rockets

NASA got its giant Space Launch System off the ground for the first time in 2022, lighting up the night in Florida with an incredible stream of flame as it carried the Artemis I mission toward the moon. That shifted attention to SpaceX, which is building a next generation rocket, Starship, that is also central to NASA’s crewed Artemis III moon landing attempt.

SpaceX cleared a key environmental review that would allow it to launch an uncrewed orbital test flight from South Texas if it met certain conditions. But the rocket wasn’t ready for flight in 2022. The company has not announced a date for a test this year, but regular ground tests of Starship equipment indicate it is working toward one.

The pathfinder first stage of the Vulcan Centaur, a new rocket by United Launch Alliance that will eventually replace that company’s Atlas V.United Launch Alliance

Numerous other rockets may take flight for the first time in 2023. The most important, Vulcan Centaur by United Launch Alliance, will eventually replace that company’s Atlas V, a vehicle that has been central to American spaceflight for two decades. The Vulcan relies on the BE-4 engine built by Blue Origin, the rocket company founded by Jeff Bezos. The same engine will in turn be used in Blue Origin’s New Glenn rocket, which may have a test flight late this year.

A number of American private companies are expected to test new rockets in 2023, including Relativity and ABL. They could be joined by foreign rocket makers, including Mitsubishi Heavy Industries which could test Japan’s H3 rocket in February, and Arianespace, which is working toward a test flight of Europe’s Ariane 6 rocket.

New Lunar Landings

We’re guaranteed at least one lunar landing attempt in 2023. A Japanese company, Ispace, launched its M1 mission on a SpaceX rocket in December. It’s taking a slow, fuel-efficient route to the moon and is set to arrive in April, when it will try to deploy a rover built by the United Arab Emirates, a robot built by Japan’s space agency, JAXA, as well as other payloads.

There could be as many as five more lunar landing attempts this year.

NASA has hired a pair of private companies to carry payloads to the lunar surface. Both of them, Intuitive Machines of Houston and Astrobotic Technology of Pittsburgh, faced delays in 2022, but may make the trip in the coming months.

They could be joined by three government space programs’ lunar missions. India’s Chandrayaan-3 mission was delayed last year but could be ready in 2023. A Japanese mission, Smart Lander for Investigating Moon, or SLIM, aims to test the country’s lunar landing technologies. Finally, Russia’s Luna-25 mission was postponed from last September, but Roscosmos, the Russian space agency, may try this year.

New Space Telescopes

Scientists in 2019 at work with the European Space Agency’s Euclid spacecraft, which will study energy and dark matter. Its 2022 launch was postponed by the Russian invasion of Ukraine.S. Corvaja/European Space Agency

The Webb telescope wowed space enthusiasts and scientists with its views of the cosmos, but we may get new vantages from a variety of orbital observatories.

The most significant may be Xuntian, a Chinese mission setting off later in the year that will be like a more sophisticated version of the Hubble Space Telescope. The spacecraft will survey the universe at optical and ultraviolet wavelengths in an orbit around Earth close to the country’s Tiangong space station.

A Japanese-led mission, XRISM, pronounced chrism, could launch earlier in the year as well. The mission will use X-ray spectroscopy to study clouds of plasma, which could help to explain the universe’s composition. A European space telescope, Euclid, may also launch on a SpaceX rocket after the Russian invasion of Ukraine resulted in the spacecraft losing its seat on a Russian Soyuz rocket. It will study the universe’s dark energy and dark matter.

New Planetary Missions

A new spacecraft will head toward Jupiter this year, aiming to become the first to ever orbit another planet’s moon. The European Space Agency’s Jupiter Icy Moon Explorer, or JUICE, will launch from an Ariane 5 rocket as early as April 5 to set off to the Jovian system, arriving in 2031. Once it reaches the gas giant, it will move to conduct 35 flybys of three of the giant world’s moons: Callisto, Europa and Ganymede, all of which are believed to have subsurface oceans. In 2034, JUICE will begin orbiting Ganymede, the largest moon in the solar system.

Heading closer to the sun will be Rocket Lab, a small launch company that was founded in New Zealand. It aims to use its Electron rocket to send a mission to Venus. The company’s Photon satellite will try to deploy a small probe, built with Massachusetts Institute of Technology researchers, that will briefly study the planet’s toxic atmosphere. The mission was planned for May, but it is expected to face delays while the company prioritizes missions for its other customers.

A Total Eclipse and a Not-So-Total One

There will be two solar eclipses in 2023.

A total eclipse on April 20 will be more of a Southern Hemisphere event, and the moon will only blot out the sun in remote parts of Australia and Indonesia. (Perhaps not a bad time to be on a boat in parts of the Indian and Pacific Oceans, too.)

But Americans may get a good show on Oct. 14, when North America will be visited by an annular eclipse. Eclipses of this type are sometimes called “ring of fire” eclipses because the moon is too far from Earth to fully block the sun but creates a ring-like effect when it reaches totality. The eclipse’s path runs through parts of Oregon, California, Nevada, Utah, Arizona, New Mexico and Texas before dipping into Central and South America. Where the weather cooperates, it should be a great solar show and a nice lead up for the April 8, 2024 total eclipse that will cross the United States from southwest to northeast.

#Space

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musispoedmacarsiv · 2 months ago

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2 Ekim 2024 Karşıyaka La Laguna Tenerife Maçı

*Mustafa Kemal Atatürk Karşıyaka Spor Salonu'nda saat 19:30'da başlayacak olan Basketbol Şampiyonlar Ligi Normal Sezon C Grubu birinci maçı. Temsilcimiz yeni sezona alıştığı arenada merhaba diyor. Adıyla adeta özdeşleşen 26 yıllık sponsoru ile olan birlikteliği bu yaz son bulan Kaf-Kaf'ta yeni bir süreç ve yapılanma işliyor artık. Tabi koç Ufuk Sarıca yine tecrübesiyle önderlik etmeyi sürdürüyor. Giriş mücadelemizde bu turnuvanın gediklilerinden ve zaferler yaşamış ekiplerinden birisi ile karşı karşıya geleceğiz. İspanya temsilcisine karşı zorlu bir akşam önümüzde ama tribün atmosferi ile dişe diş oynayabiliriz. İlk haftayı eksiksiz kapatalım ve bir zafere de İzmir'de imza atalım. Yürek dolusu başarı dileklerimizi ekibimizle paylaşıyoruz.

*Tivibu Spor 1'den naklen yayınlanacak olan maç.

*İlk çeyreği 23-23 eşitlikle tamamlandı. Maça iyi giren taraf bizdik. Bir ara 11-5'te 6 sayılık fark da yaptık. 14-10 üstünlüğümüzden sonra Tenerife'nin refleksi geldi ve 6 sayılık seriyle tabelayı çevirdiler. Kontrol onlara geçse de yakın takipteyiz ve dengede tutuyoruz.

*İlk devre sonunda 46-39 gerideyiz. Tenerife'den 23-16'lık oyun geldi bu dilimde. Aslında çeyreğe çok iyi başlamıştık. 38-31'de 7 sayılık fark yapmıştık. O noktadan sonra Tenerife'nin 13 sayılık serisi gelince işler darmadağın oldu. Toparlama çabasında olacağız ikinci yarıda.

*Üçüncü periyot sonunda Tenerife 65-57 ile önde olan taraf. Dilimin büyük bölümünde geride oynadık. 57-49'ken Karşıyaka'dan 8 sayılık seri geldi ve yakalamayı başardık. Ancak ne olduysa yine oradan sonra oldu. Bu kez de biz 8 sayılık seri yedik ve aynı yere döndük. Son periyotta üstün bir çaba gerek.

*Tenerife'nin 87-76 kazandığı maç olmuştur. İspanyol ekibi hiç düşmedi. Haliyle arayı eritemedik ve tamamen rahat bir son bölüm oyunu ile galibiyeti aldılar. Temsilcimiz yenilgiyle başlıyor serüvenine. Artık diğer rakiplere odaklanacağız. Karşıyaka'da Errick McCollum 16, James Webb III 15 sayı üretti. La Laguna Tenerife'de ise Fran Guerra 20, Payton Willis 19 sayı yolladı.

#spor arşivi #maç arşivi #basketbol şampiyonlar ligi #karşıyaka #la laguna tenerife #cb canarias #basketbol #basketball #spor #sport

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astroimages · 2 months ago

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JAMES WEBB ENCONTRA PISTAS DAS PRIMEIRAS ESTRELAS DO UNIVERSO

CONSIDERE APOIAR O TRABALHO DO SPACE TODAY, ASSINANDO A PLATAFORMA SPACE TODAY PLUS PREMIUM, POR APENAS R$29,00 POR MÊS, MENOS DE 1 REAL POR DIA!!! https://spacetodayplus.com.br/premium/ APRESENTAÇÃO "SERÁ QUE ESTAMOS SOZINHOS?" INGRESSOS PARA O RIO DE JANEIRO, DIA 29 DE SETEMBRO, 19 HORAS, NO TEATRO CLARA NUNES NO SHOPPING DA GÁVEA: https://bileto.sympla.com.br/event/96832 O telescópio espacial James Webb fez uma descoberta importante ao identificar uma galáxia distante que pode conter evidências das primeiras estrelas formadas no universo, chamadas de estrelas da População III. Essas estrelas, compostas apenas de hidrogênio e hélio, são consideradas cruciais para a evolução cósmica, já que deram origem aos primeiros elementos pesados. A galáxia, localizada a cerca de 13 bilhões de anos-luz, oferece um vislumbre do universo primordial e pode ajudar a preencher lacunas na compreensão da formação estelar. As estrelas da População III são teóricas, pois nunca foram diretamente observadas, mas suas assinaturas químicas foram detectadas na galáxia estudada pelo Webb. Essas estrelas representam o primeiro ciclo de criação de elementos no universo, fundamentais para a formação de galáxias e futuras gerações de estrelas. O Webb, com sua capacidade infravermelha avançada, está permitindo que os cientistas estudem essas estruturas distantes e antigas com um nível de detalhe sem precedentes. A detecção de estrelas da População III pode revolucionar a compreensão da evolução do universo. A observação dessas estrelas em estágios iniciais da galáxia proporciona novas pistas sobre a formação e evolução das primeiras estruturas cósmicas. Além disso, ajuda a explicar a origem dos elementos pesados, que são essenciais para a formação de planetas e da vida. Essas descobertas são apenas o começo do potencial do James Webb. Com suas capacidades únicas, o telescópio está trazendo à luz detalhes cruciais sobre o universo primordial, abrindo caminho para futuras investigações e ajudando a desvendar os mistérios da evolução cósmica. O estudo dessas primeiras estrelas e galáxias continuará a expandir os limites do conhecimento astronômico. FONTES: https://science.nasa.gov/missions/webb/in-odd-galaxy-nasas-webb-finds-potential-missing-link-to-first-stars/ #JAMESWEBB #UNIVERSE #STARS

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gonzalo-obes · 5 months ago

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IMAGENES Y DATOS INTERESANTES DEL DIA 12 DE JULIO DE 2024

Día Internacional de la Lucha contra las Tormentas de Arena y Polvo, Año Internacional de los Camélidos.

Santa Epifana, San Juan Gualberto, San Jasón y Santa Marciana.

Tal día como hoy en el año 2022

La NASA publica las primeras fotografías del telescopio espacial James Webb, cuatro fotografías y un análisis de atmósfera de un exoplaneta. En las que destacan la imagen de campo más profunda del universo tomada hasta la fecha, con galaxias formadas hace más de 13.000 millones de años.

1975

Tras un periodo de gobierno de transición, Santo Tomé y Príncipe, país africano formado por varias islas situadas en el golfo de Guinea, a unos 250 km de las costas de Gabón, se independiza de Portugal. Se elige como primer presidente al secretario general del MLSTP (Movimiento para la Liberación de Santo Tomé y Príncipe), Manuel Pinto da Costa. (Hace 49 años)

1962

En el Club Marquee de Londres (Reino Unido), los Rolling Stones ofrecen su primer concierto con Jagger, Richards, Jones, Stewart, Chapman y Taylor. (Hace 62 años)

1957

En Pakistán se proclama al príncipe Karim Al-hussain como Aga Kan IV, al suceder a su abuelo, Aga Kan III. Aga Kan es el título que la secta ismaelita Nizarí perteneciente al Chiísmo, da a los imanes. Durante su mandato se mostrará especialmente interesado en la eliminación de la pobreza mundial, por mejorar la condición de la mujer, promover la cultura islámica, el arte y la arquitectura, todo ello dentro de una sociedad pluralista. (Hace 67 años)

1920

En Bolivia, la crisis política acaba en revolución y se constituye una Junta de Gobierno que a los pocos días caerá por falta de entendimiento entre sus líderes, convocando al pueblo para elegir nuevo presidente. (Hace 104 años)

1920

Tras repeler la invasión de tropas soviéticas, la república independiente de Lituania, firma un tratado de paz con Rusia en Moscú en este día, mediante el cual los rusos reconocen la soberanía y la independencia de la nación lituana con todos los derechos asociados. (Hace 104 años)

1906

En Francia es rehabilitado el capitán Alfred Dreyfus que había sido injustamente condenado a cadena perpetua en la Isla del Diablo por supuesto espionaje a favor de Alemania. (Hace 118 años)

1776

James Cook, explorador y navegante inglés, con el fin de devolver a Tahití al nativo Omai, llevado a Inglaterra en el transcurso una exploración anterior, inicia un largo viaje que le conducirá al encuentro con la muerte el 14 de febrero de 1779, al ser atacada su expedición por los nativos de las islas Hawái, por haber apresado al rey de la isla como rehén hasta que apareciera una embarcación que había sido robada. (Hace 248 años)

1679

Inglaterra se pone a la cabeza de la protección de las libertades individuales al aprobar el Parlamento el "Habeas Corpus Act", mediante el cual, cualquier persona privada de libertad, podrá dirigirse a un juez para que, o bien sea puesta en libertad, o bien para que los acusadores prueben que hay razones suficientes para el arresto. (Hace 345 años)

1543

En el Palacio de Hampton Court, a 20 km de Londres, se celebra el matrimonio entre Catalina Parr y Enrique VIII. Como reina, Catalina será en parte responsable de la reconciliación de Enrique con sus hijas, María e Isabel y mantendrá, asimismo, una buena relación con el príncipe Eduardo, futuro rey Eduardo VI. Será la última de las seis esposas de Enrique VIII y la única que sobreviva a los caprichos de su marido. (Hace 481 años)

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jcmarchi · 9 months ago

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Webb Unlocks Secrets of One of the Most Distant Galaxies Ever Seen - Technology Org

New Post has been published on https://thedigitalinsider.com/webb-unlocks-secrets-of-one-of-the-most-distant-galaxies-ever-seen-technology-org/

Webb Unlocks Secrets of One of the Most Distant Galaxies Ever Seen - Technology Org

Looking deeply into space and time, two teams using NASA’s James Webb Space Telescope have studied the exceptionally luminous galaxy GN-z11, which existed when our 13.8 billion-year-old universe was only about 430 million years old.

Initially detected with NASA’s Hubble Space Telescope, this galaxy — one of the youngest and most distant ever observed — is so bright that it is challenging scientists to understand why. Now, GN-z11 is giving up some of its secrets.

Vigorous Black Hole Is Most Distant Ever Found

A team studying GN-z11 with Webb found the first clear evidence that the galaxy is hosting a central, supermassive black hole rapidly accreting matter. Their finding makes this the farthest active supermassive black hole spotted to date.

“We found extremely dense gas that is common in the vicinity of supermassive black holes accreting gas,” explained principal investigator Roberto Maiolino of the Cavendish Laboratory and the Kavli Institute of Cosmology at the University of Cambridge in the United Kingdom. “These were the first clear signatures that GN-z11 is hosting a black hole that is gobbling matter.”

Image: GOODS-North field of galaxies

This image from NASA’s James Webb Space Telescope NIRCam (Near-Infrared Camera) instrument shows a portion of the GOODS-North field of galaxies. At lower right, a pullout highlights the galaxy GN-z11, which is seen at a time just 430 million years after the big bang. The image reveals an extended component, tracing the GN-z11 host galaxy, and a central compact source whose colors are consistent with those of an accretion disk surrounding a black hole. Image credit: NASA, ESA, CSA, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Marcia Rieke (University of Arizona), Daniel Eisenstein (CfA)

Using Webb, the team also found indications of ionized chemical elements typically observed near accreting supermassive black holes. Additionally, they discovered a very powerful wind being expelled by the galaxy. Such high-velocity winds are typically driven by processes associated with vigorously accreting supermassive black holes.

“Webb’s NIRCam (Near-Infrared Camera) has revealed an extended component, tracing the host galaxy, and a central, compact source whose colors are consistent with those of an accretion disk surrounding a black hole,” said investigator Hannah Übler, also of the Cavendish Laboratory and the Kavli Institute.

Together, this evidence shows that GN-z11 hosts a 2-million-solar-mass, supermassive black hole in a very active phase of consuming matter, which is why it’s so luminous.

Pristine Gas Clump in GN-z11’s Halo Intrigues Researchers

A second team, also led by Maiolino, used Webb’s NIRSpec (Near-Infrared Spectrograph) to find a gaseous clump of helium in the halo surrounding GN-z11.

“The fact that we don’t see anything else beyond helium suggests that this clump must be fairly pristine,” said Maiolino. “This is something that was expected by theory and simulations in the vicinity of particularly massive galaxies from these epochs — that there should be pockets of pristine gas surviving in the halo, and these may collapse and form Population III star clusters.”

Finding the never-before-seen Population III stars — the first generation of stars formed almost entirely from hydrogen and helium — is one of the most important goals of modern astrophysics. These stars are anticipated to be massive, luminous, and hot. Their expected signature is the presence of ionized helium and the absence of chemical elements heavier than helium.

The formation of the first stars and galaxies marks a fundamental shift in cosmic history, during which the universe evolved from a dark and relatively simple state into the highly structured and complex environment we see today.

Image: Pristine Gas Clump Near GN-z11

This two-part graphic shows evidence of a gaseous clump of helium in the halo surrounding galaxy GN-z11. In the top portion, at the far right, a small box identifies GN-z11 in a field of galaxies. The middle box shows a zoomed-in image of the galaxy. The box at the far left displays a map of the helium gas in the halo of GN-z11, including a clump that does not appear in the infrared colors shown in the middle panel. In the lower half of the graphic, a spectrum shows the distinct “fingerprint” of helium in the halo. The full spectrum shows no evidence of other elements and so suggests that the helium clump must be fairly pristine, made of hydrogen and helium gas left over from the big bang, without much contamination from heavier elements produced by stars. Theory and simulations in the vicinity of particularly massive galaxies from these epochs predict that there should be pockets of pristine gas surviving in the halo, and these may collapse and form Population III star clusters. Image credit: NASA, ESA, CSA, Ralf Crawford (STScI)

In future Webb observations, Maiolino, Übler, and their team will explore GN-z11 in greater depth, and they hope to strengthen the case for the Population III stars that may be forming in its halo.

Astronomy & Astrophysics has accepted the research on the pristine gas clump in GN-z11’s halo for publication. The study results of GN-z11’s black hole were published in the journal Nature. The data was obtained from the JWST Advanced Deep Extragalactic Survey (JADES), a joint project between the NIRCam and NIRSpec teams.

Source: National Aeronautics and Space Administration

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openingnightposts · 9 months ago

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#AllisonM.Williams #BillyPorter #Encores!#JellyRollMorton #LeslieUggams #MamieDuncan-Gibbs #NewYorkCityCenter #StephanicPopeLofgren #TulisMcCall

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ulkaralakbarova · 9 months ago

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Both dumped by their girlfriends, two best friends seek refuge in the local mall. Eventually, they decide to try and win back their significant others and take care of their respective nemeses. Credits: TheMovieDb. Film Cast: Rene: Shannen Doherty T.S. Quint: Jeremy London Brodie: Jason Lee Brandi: Claire Forlani Shannon: Ben Affleck Gwen: Joey Lauren Adams Tricia: Renée Humphrey Silent Bob: Kevin Smith Jay: Jason Mewes Willam: Ethan Suplee Stan Lee: Stan Lee Ivannah: Priscilla Barnes Svenning: Michael Rooker La Fours: Sven-Ole Thorsen Security Guard: Carol Banker Arresting Cop #2: Steven Blackwell Pull Toy Kid: Kyle Boe TV Executive #1: David Brinkley Fan Boy: Walt Flanagan Guy Contestant #1: Ethan Flower Girl with Easter Bunny: Chelsea Frye TV Executive #2 – Bentley Garrison: Jeff Gadbois Guy Contestant #2: Ed Hapstak Cop #1: Terry Hempleman Game Show Host: Art James Steve Dave: Bryan Johnson Child at Kiosk #2: Mikey Kovar Fan at Comic Store: David Klein Roddy: Scott Mosier Saleslady at Lingerie Store: Crystal Muirhead-Manik Kid at Poster Kiosk: Tyson Nassauer Gill: Brian O’Halloran Passerby in Parking Lot: Aaron Preusse Child at Kiosk #1: Britt Swenson Teacher: Mary Woolever Team La Fours: Brad Fox Team La Fours: Gino Gori Team La Fours: Zach Perkins Team La Fours: Brad Giddings Team La Fours: Bryce Mack Team La Fours: Christopher O’Larkin Audience Member (uncredited): Earl R. Burt Shopper (uncredited): Tammara Melloy Screaming Girl in Audience (uncredited): Rachel Oliva Shoobie Shake Girl (uncredited): Jessica Sibinski Comic Book Fan (uncredited): Joel Thingvall Film Crew: Supervising Sound Editor: Richard LeGrand Jr. Producer: Sean Daniel Producer: James Jacks Thanks: John Hughes Supervising Music Editor: J.J. George Casting: Don Phillips Writer: Kevin Smith Stunts: Phil Chong Producer: Scott Mosier Stunts: Sven-Ole Thorsen Stunt Coordinator: Robert Apisa Director of Photography: David Klein Original Music Composer: Ira Newborn Editor: Paul Dixon Production Design: Dina Lipton Executive Producer: Caldecot Chubb ADR Mixer: Alan Holly Set Decoration: Diana Stoughton Line Producer: Laura Greenlee Stunts: Chuck Zito Production Supervisor: Beth DePatie Post Production Supervisor: Terra Abroms Foley Artist: Joan Rowe Stunts: Carl Ciarfalio Sound Effects Editor: Charles Maynes ADR Editor: Bob McNabb Makeup Artist: Toni G Main Title Designer: Mike Allred Executive In Charge Of Production: Donna Smith First Assistant Director: Fernando Altschul Stunts: Eric D. Howell Casting Assistant: Ethan Flower Script Supervisor: Carol Banker Second Assistant Director: Louis Shaw Milito Sound Re-Recording Mixer: Michael C. Casper Set Costumer: Roseanne Fiedler Costume Supervisor: Dana Kay Hart Foley Artist: Diane Marshall Sound Re-Recording Mixer: Daniel J. Leahy Location Manager: Ralph B. Meyer Sound Designer: Harry E. Snodgrass Key Makeup Artist: Brigette A. Myre Foley Mixer: James Bolt Sound Editor: William Hooper Sound Recordist: Charlie Ajar Jr. Sound Editor: William Jacobs Costume Design: Dana Allyson Music Supervisor: Kathy Nelson Color Timer: Dennis McNeill Title Designer: Dan Perri Orchestrator: Don Nemitz Stunts: Jake Crawford Prosthetic Makeup Artist: Crist Ballas Supervising ADR Editor: Norval D. Crutcher III Assistant Sound Editor: Samuel Webb Negative Cutter: Gary Burritt Assistant Sound Editor: Michelle Pleis Boom Operator: Anton Herbert Production Coordinator: Lisa Bradley Music Supervisor: Jeff Saltzman First Assistant Editor: Richard J. Rossi Location Manager: Bob Medcraft Art Direction: Sue Savage Cableman: Matthew Magrattan Second Second Assistant Director: Shari Nicotero Assistant Editor: Paul Kieran Hairstylist: Sherry Heart Sound Mixer: Jose Araujo Casting Associate: Dee Dee Wehle Assistant Editor: Elisa Cohen Hair Assistant: Kristin Mosier Movie Reviews: JPV852: Only the second time seeing this (last was probably in the early 2000s on DVD) and thought it was okay but guess like others, this has grown on me. Laughed throughout even when the dialogue wasn’t the greatest, but I have an appreciation...

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spacetimewithstuartgary · 2 months ago

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Weird galaxy with gas outshining its stars

The discovery of a "weird" and unprecedented galaxy in the early Universe could "help us understand how the cosmic story began", astronomers say.

GS-NDG-9422 (9422) was found approximately one billion years after the Big Bang and stood out because it has an odd, never-before-seen light signature — indicating that its gas is outshining its stars.

The "totally new phenomena" is significant, researchers say, because it could be the missing-link phase of galactic evolution between the Universe's first stars and familiar, well-established galaxies.

This extreme class of galaxy was spotted by the $10billion (£7.6billion) James Webb Space Telescope (JWST), a joint endeavour of the US, European and Canadian space agencies, which has been designed to peer back in time to the beginning of the Universe.

Its discovery was made public today in a research paper published in the Monthly Notices of the Royal Astronomical Society.

"My first thought in looking at the galaxy's spectrum was, 'that's weird,' which is exactly what the Webb telescope was designed to reveal: totally new phenomena in the early Universe that will help us understand how the cosmic story began," said lead researcher Dr Alex Cameron, of the University of Oxford.

Cameron reached out to colleague Dr Harley Katz, a theorist, to discuss the strange data. Working together, their team found that computer models of cosmic gas clouds heated by very hot, massive stars, to an extent that the gas shone brighter than the stars, was nearly a perfect match to Webb's observations.

"It looks like these stars must be much hotter and more massive than what we see in the local Universe, which makes sense because the early Universe was a very different environment," said Katz, of Oxford and the University of Chicago.

In the local Universe, typical hot, massive stars have a temperature ranging between 70,000 to 90,000 degrees Fahrenheit (40,000 to 50,000 degrees Celsius). According to the team, galaxy 9422 has stars hotter than 140,000 degrees Fahrenheit (80,000 degrees Celsius).

The researchers suspect that the galaxy is in the midst of a brief phase of intense star formation inside a cloud of dense gas that is producing a large number of massive, hot stars. The gas cloud is being hit with so many photons of light from the stars that it is shining extremely brightly.

In addition to its novelty, nebular gas outshining stars is intriguing because it is something predicted in the environments of the Universe's first generation of stars, which astronomers classify as Population III stars.

"We know that this galaxy does not have Population III stars, because the Webb data shows too much chemical complexity. However, its stars are different than what we are familiar with – the exotic stars in this galaxy could be a guide for understanding how galaxies transitioned from primordial stars to the types of galaxies we already know," said Katz.

Cameron, Katz, and their research colleagues are now identifying more galaxies to add to this population to better understand what was happening in the Universe within the first billion years after the Big Bang.

"It's a very exciting time, to be able to use the Webb telescope to explore this time in the Universe that was once inaccessible," Cameron said.

"We are just at the beginning of new discoveries and understanding."

TOP IMAGE: This image of galaxy GS-NDG-9422, captured by the James Webb Space Telescope's NIRCam (Near-Infrared Camera) instrument, is presented with compass arrows, scale bar, and colour key for reference. Credit NASA, ESA, CSA, STScI, Alex Cameron (Oxford)

LOWER IMAGE: This comparison of the Webb data with a computer model prediction highlights the same sloping feature that first caught the eye of lead researcher Alex Cameron. The bottom graphic compares what astronomers would expect to see in a "typical" galaxy, with its light coming predominantly from stars (white line), with a theoretical model of light coming from hot nebular gas, outshining stars (yellow line). Credit NASA, ESA, CSA, Leah Hustak (STScI)

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spacenutspod · 10 months ago

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For a long time, our understanding of the Universe’s first galaxies leaned heavily on theory. The light from that age only reached us after travelling for billions of years, and on the way, it was obscured and stretched into the infrared. Clues about the first galaxies are hidden in that messy light. Now that we have the James Webb Space Telescope and its powerful infrared capabilities, we’ve seen further into the past—and with more clarity—than ever before. The JWST has imaged some of the very first galaxies, leading to a flood of new insights and challenging questions. But it can’t see individual stars. How can astronomers detect their impact on the Universe’s first galaxies? Stars are powerful, dynamic objects that wield a potent force. They can fuse atoms together into entirely new elements, an act called nucleosynthesis. Supernovae are especially effective at this, as their powerful explosions unleash a maelstrom of energy and matter and spread it back out into the Universe. Supernovae have been around since the Universe’s early days. The first stars in the Universe are called Population III stars, and they were extremely massive stars. Massive stars are the ones that explode as supernovae, so there must have been an inordinately high number of supernovae among the Population III stars. New research examines how all of these supernovae must have affected their host galaxies. The paper “How Population III Supernovae Determined the Properties of the First Galaxies” has been accepted for publication by the Astrophysical Journal. The lead author is Ke-Jung Chen from the Institute of Astronomy and Astrophysics, Academia Sinica, Taiwan. Stellar metallicity is at the core of this work. When the Universe began, it was comprised of primordial hydrogen, helium, and only trace amounts of lithium and beryllium. If you check your periodical table, these are the first four elements. Elements heavier than hydrogen and helium are called “metals” in astronomy, and metallicity in the Universe increases over time due to stellar nucleosynthesis. But hydrogen dominated the Universe then as it does now. Only once the first stars formed and then exploded did other elements start to play a role. “The birth of primordial (Pop III) stars at z ~ 20 ~ 25 marked the end of the cosmic dark ages and the onset of the first galaxy and supermassive black hole (SMBH) formation,” the authors of the new paper write. But their role as creators of astronomical metals is at the heart of this research. The researchers used computer hydrodynamical simulations to examine how Pop III stars shaped early galaxies. They looked at core-collapse supernovae (CCSNe), pair-instability supernovae (PISNe), and Hypernovae (HNe.) Stars can only form from cold, dense gas. When gas is too hot, it simply isn’t dense enough to collapse into protostellar cores. The researchers found that when Pop III stars exploded as supernovae, they produced metals and spread them into the surrounding gas. The metals cooled the star-forming gas quickly, leading to faster formation of more stars. “Our findings indicate that SNRs from a top-heavy Pop III IMF <initial mass function> produce more metals, leading to more efficient gas cooling and earlier Pop II star formation in the first galaxies.” The simulations showed that the supernova remnants (SNR) from the Pop III SN fall towards the center of the dark matter haloes they reside in. “These Pop III SNRs and the primordial gas are dragged by the halo gravity toward its center,” the authors explain. These SNRs sometimes collide and produce turbulent flows. The turbulence mixes the gas and the metals from the SN and “creates filamentary structures that soon form into dense clumps due to the self-gravity and metal cooling of the gas.” This leads to more star formation, though at this point, they’re still Pop III stars. These aren’t enriched by the earlier Pop III supernovae and are still made of primordial gas. Some of these later Pop III stars form before the initial ones reach the center of the halo. That creates a complicated situation. The second round of Pop III stars then “impose strong radiative and SN feedback before the initial Pop III SNRs reach the halo center,” the authors write. This figure from the research shows metallicity (top) and temperature (bottom) slices from the simulations, showing a 200 solar mass star forming, living a very short life, and then exploding as a supernova. The explosion creates feedback into the next stars. The left panels are right before the star forms, the middle panels are 1.5 myr after the formation, and the right panels show 0.5 myr after the star’s death. After it exploded, it formed a supernova remnant of hot and metal-rich ejecta. The metals in the ejecta would’ve contributed to cooling the gas, encouraging more rapid formation of the next generation of Pop II stars. Image Credit: Chen et al. 2024. The Pop III stars heat the surrounding gas with their powerful UV radiation, as shown in the figure above, inhibiting star formation. But they’re massive stars, and they don’t live very long. Once they explode, they spread metals out into their surroundings, which can cool gas and trigger more star formation. “After its short lifetime of about 2.0 Myr, the star dies as a PI SN, and its shock heats the gas to high temperatures (> 105 K) and ejects a large mass of metals that enhance cooling and promotes a transition to Pop II SF,” the authors explain. This is where the Pop III stars shaped the earliest galaxies. By injecting metals into the clouds of star-forming gas, they cooled the gas. The cooling fragmented the clouds of star-forming gas, making the following generation of Pop II stars less massive. “Due to the effective metal cooling, the mass scale of these Pop II stars shifted to a low mass end and formed in a cluster, as shown in the right panel of Figure 6.” This is Figure 6 from the research. It shows how Pop II stars have lower masses than Pop III stars and form in clusters in the fragmented clouds. “Due to the metal cooling and turbulence, these Pop II stars form into clusters along the dense filaments around the halo center,” the authors write. Image Credit: Chen et al. 2024. Pop III stars existed mostly in dark matter haloes. However, the research shows how they shaped the succeeding Pop II stars, which populated the early galaxies. One question astronomers have faced regarding the first galaxies is whether they were filled with extremely metal-poor (EMP) Pop II stars. But this research shows otherwise. “We thus find that EMP stars were not typical of most primitive galaxies,” the authors conclude. The post Even if We Can’t See the First Stars, We Could Detect Their Impact on the First Galaxies appeared first on Universe Today.

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