#DECam

[eucanthos]

3.32 billion celestial objects

_ The Dark Energy Camera used for the 2nd release of the DECam Plane Survey — the largest such catalog so far. 

The data for this unprecedented survey were taken over two years with the Dark Energy Camera, built by the US Department of Energy, at the NSF’s Cerro Tololo Inter-American Observatory in Chile, a Program of NOIRLab.

https://www.techtimes.com/articles/286622/20230123/decam-captures-new-galactic-panorama-shows-over-3-billion-celestial-objects.htm

[netmassimo]

An image captured by the Dark Energy Camera (DECam) depicts the Coma Cluster, also known as Abell 1656, so named because it's part of the constellation Coma Berenices. DECam was designed to conduct a long-term investigation of dark energy but is also useful for other types of astronomical studies. The Coma Cluster is linked to the study of dark matter since the inconsistency between the estimate of its overall mass and the measurement of its gravitational effects stimulated the research that led to today's dark matter models.

[scienza-magia]

Fotografata la Mano di Dio nella nebulosa di Gum

La Mano di Dio immortalata dalla DeCam, un globulo cometario nella nebulosa di Gum. In questa immagine della Dark Energy Camera risalta il globulo cometario noto come Cg 4, una struttura solo apparentemente minacciosa a cui è stato dato il soprannome di "Mano di Dio". Non è ancora chiaro come queste nubi così difficili da individuare ottengano la loro struttura distintiva, ma gli astronomi ipotizzano che sia una conseguenza delle stelle calde e massicce che le circondano A circa 1300 anni luce di distanza, nella costellazione della Poppa, una mano spettrale sembra emergere dal mezzo interstellare e protendersi verso il cosmo. Questa struttura solo apparentemente minacciosa è Cg 4, un cosiddetto globulo cometario a cui è stato dato il soprannome di “Mano di Dio”. Si tratta di uno dei tanti globuli cometari presenti nella Via Lattea, la cui morfologia ha origini che sono ancora oggetto di dibattito tra gli astronomi.

Il globulo cometario Cg 4, soprannominato Mano di Dio, è uno dei tanti globuli cometari presenti all’interno della Via Lattea. Questa immagine è stata catturata dalla Dark Energy Camera montata sul telescopio di 4 metri Víctor M. Blanco presso l’Osservatorio Interamericano di Cerro Tololo. Crediti: Ctio/NoirLab/Doe/Nsf/Aura, T.A. Rector (University of Alaska Anchorage/Nsf’s NoirLab), D. de Martin & M. Zamani (Nsf’s NoirLab) I globuli cometari sono una sottoclasse delle nebulose oscure note come globuli di Bok: dense nubi isolate di gas e polveri cosmiche circondate da materiale caldo e ionizzato. Sono tra gli oggetti più freddi conosciuti in campo astrofisico, con temperature interne dell’ordine di 10 kelvin. Quando queste nubi presentano una scia simile a una lunga coda e vengono chiamate globuli cometari per la loro vaga somiglianza con le comete, anche se di fatto non hanno nulla in comune. Le caratteristiche tipiche di un globulo cometario sono difficili da notare in questa immagine catturata con la Dark Energy Camera (DeCam), montata sul telescopio di 4 metri Víctor M. Blanco presso il Cerro Tololo Inter-American Observatory (Ctio), del NoirLab dell’Nsf. La sua testa polverosa – con un diametro di 1,5 anni luce – e la sua debole coda – lunga circa 8 anni luce – fanno di Cg 4 un globulo di Bok relativamente piccolo. Individuati per la prima volta nel 1976 da immagini scattate con il telescopio Uk Schmidt in Australia, i globuli cometari sono rimasti a lungo inosservati dagli astronomi perché molto deboli. Le loro code, avvolte da scura polvere stellare, bloccano la maggior parte della luce. Ma con il suo speciale filtro H-alfa, DeCam è stata in grado di cogliere il debole bagliore rosso dell’idrogeno ionizzato presente all’interno della testa di Cg 4 e intorno al suo bordo esterno. Questa luce si produce quando l’idrogeno si eccita dopo essere stato bombardato dalle radiazioni delle stelle calde e massicce vicine. L’intensa radiazione generata da queste stelle massicce sta gradualmente distruggendo la testa del globulo e spazzando via le minuscole particelle che disperdono la luce stellare. Tuttavia, Cg 4 contiene abbastanza gas per alimentare la formazione attiva di diverse nuove stelle della dimensione del Sole.

In questo primo piano, sembra che Cg 4 stia per divorare la galassia a spirale Eso 257-19 (Pgc 21338). In realtà, questa galassia si trova a più di cento milioni di anni luce da Cg 4 e sembra esserle vicina solo per un allineamento prospettico. Vicino alla testa del globulo cometario si trovano due giovani oggetti stellari: stelle nella fase iniziale della loro evoluzione, prima di diventare stelle di sequenza principale, che spesso presentano caratteristiche come getti, flussi bipolari, dischi protoplanetari e altri indicatori della nascita di una nuova stella. Crediti: Ctio/NoirLab/Doe/Nsf/Aura, T.A. Rector (University of Alaska Anchorage/Nsf’s NoirLab), D. de Martin & M. Zamani (Nsf’s NoirLab) Sebbene gli astronomi abbiano osservato queste strutture in tutta la Via Lattea, la stragrande maggioranza di esse, compresa Cg 4, si trova all’interno di un’enorme macchia di gas incandescente chiamata Nebulosa di Gum, un probabile resto di supernova esplosa circa un milione di anni fa. Attualmente, la Nebulosa di Gum è nota per contenere almeno 31 globuli cometari, oltre a Cg 4. Il meccanismo con cui questi oggetti assumono la loro forma distintiva non è del tutto noto, ma gli astronomi hanno sviluppato due idee sulle loro origini. La prima è che potrebbero essere state originariamente delle nebulose sferiche – come la ben nota Nebulosa Anello – successivamente sconvolte dall’esplosione di una supernova vicina, forse la stessa che ha creato la Nebulosa di Gum. La seconda idea è che i globuli cometari siano modellati da una combinazione di venti stellari e dalla pressione delle radiazioni provenienti dalle vicine stelle calde e massicce. In effetti, tutti i globuli cometari trovati all’interno della Nebulosa di Gum sembrano avere code che puntano lontano dal centro della nebulosa, dove si trovano il resto della supernova Vela e la pulsar Vela. Quindi è possibile che i venti stellari della pulsar e la pressione delle radiazioni stiano modellando i globuli vicini. La Mano di Dio, un globulo cometario forgiato da una pulsar, immortalato dalla Dark Energy Camera Read the full article

[unboundwanderers]

( death prompt / looney ) this was it. it was . . . over? the ground of her home felt unstable beneath her feet as if it shook with every breath she took. crystalline irises were wide as she couldn't even muster to raise her chin; she was frozen. in grief. in pain. in every breath that she took without him, she felt like a piece of her crumbled. his last words are hazy; they feel like an indescribable cacophony of distant sounds. too far away to grasp as they mixed into something incomprehensible. " he's . . . " a word spilled from dried-up lips. the deity did not recognize her own voice as she spoke; it was too heavy with pain. she still did not look up. it was the fear of seeing this world without him . . . they had explored it all together. even if it was not for eternity; even if it was just a ripple within the time she had spent living; it meant everything. it was the tidal wave that she needed; the crashing wave that woke her from an eternal slumber. slowly, her legs gave out; trembling limbs let her descend onto the ashen soil beneath her. " he's gone . . . " the hot tears brimming her eyes almost went unnoticed with the way her heart banged against her ribcage. it was screaming. everything was screaming. it was done. it is done. there is no going back. " no . . . i—i need to — " slowly would they cascade from her unblinking irises, glossing over reddened cheeks; sinking into the ground under her legs. her gaze narrowed as she let herself hunch over; it was like the realization itself had her topple over. shit. shit. shit. she should have asked. she should have stayed. she should have said so many more things but now . . . it was over. it was all over. no blue police box covered in rose petals. no one to get upset over the fact that they got everywhere. alone. she felt so incredibly alone. teeth & jaw clenched as the grief turned into something that she hadn't felt in so long; rage. " no . . . p—please. "

the lilies of the valley that rose from her tears shook with the earth they bloomed upon. it stopped. the tears, that was. they would dry upon her heated cheekbones as everything under her quaked. it was a numbing feeling; like the white fire of anger, though, much more volatile. she was angry at this world. she was angry at chaos. but mostly, she was angry at herself. perhaps, if she had been strong enough, she could have stopped this. she could have said what she wanted to. but it was too late . . . & thus, the earth rumbled one last time. in grief had this world come to a stop, mourning the loss of someone that never had the chance of walking alongside her.

THE DOCTOR IS DYING. I could do so much more.

             It took him about fifteen minutes to realize he hadn't actually died yet. When his eyes fluttered open and he felt that familiar chilly concrete, his face seemed to contort in this almost frustrated shape before he picked himself up off the ground. He rolled his shoulders and bent his back enough to hear a couple of snaps and cracks, which triggered a loud groan from him before he moved to stand up and rub his hands down his face. The memories were flooding back to him, now. He had helped Gaia get back home. A wrongfully exiled Goddess is being chased across The Universe by a malicious entity. The herculean task had death flags all over it. So why was he surprised when he felt that FAMILIAR HEAT wash through his veins. Regeneration. It was starting. The Longest sigh escaped him as he realized that.

             Across the open, now empty city where this had occurred- The POLICE BOX stood across a field. This heavy sigh escaped him as the thoughts of what might happen next ran through his mind. Would he even have the strength to make the short walk across the field? Would the change take him before that? He could already feel it swelling up. Taking this long inhale, he pushed that fire down. He held back his own regeneration. He knew that you could sometimes refuse to regenerate- but the choice had to be made the moment the process started. When he'd awoken from his state of unconsciousness, he'd been lucky by only a few seconds that it didn't ALREADY occur... so now all he could do was try to suppress it for as long as he could.

             WHEN YOU'RE HOLDING BACK DEATH, you feel like you're on top of the world. The adrenaline pumping through your veins, those prolonged seconds. You know in your mind that you can do SO MUCH MORE... and he wants to. He has the power too. He takes that first step across the field, and it's hard- every step is hard... but he knows he has to make it. Every movement, every strained muscle, every ounce of blood pumping through his veins- it was all incredibly painful. It was no surprise when he COLLAPSED halfway between where he'd started, and where he was going... and the tears- oh, how much more painful it was to hold them back. Even when he was alone, this incarnation refused to break. Beaten down by tireless forces that tried to keep him down, broken by the endless tragedy of watching a loved one walk to their death, or losing a friend, or accepting that you were most likely going to see a lot of that. Even as he felt it all crashing down on him, he persevered. Because he must.

             He stood back up, finally making it back to The Tardis. Sliding the key into the door, he knew this was the last time THESE eyes were going to look at it- so he took in the box for as long as he could. As if he was saying goodbye to a unique beauty. He finally pushed into the TARDIS- and the POLICE BOX faded from that place... But The Doctor wasn't done, no... not just yet. He had a few people he had to see... Firstly, he had to visit The Last Celestial-- and help her complete her journey to the stars... After that, he'd make sure a certain NIGHT ORCHID had everything she'd needed for an escape from a risky situation-- even if she hadn't known she was there... and finally... Oh, finally... he returned to the City of Freedom and said goodbye to a LAWRENCE KNIGHT... who'd been his true test. By the time all his goodbyes were over and finished with- he was tired... feeling this heavy drowsiness pass over him.

             PULLING DOWN THE TARDIS handbrake, leaning over the console for the last time. Leaning against it, with that weight of holding back the flames ravaging his chest, his lungs- his heart. He moved to step away from the console, pacing for just a moment as he knew he could do nothing more to hold it back... and finally, those tears spilled out, as he knew he was alone... ALONE. But not because he wanted to be, but because that was the kind of life he lived... and in this final moment, the words choked in his throat- he thought of anything to say... anything... and finally, in his mind... he felt it wash over him, and he just... said it.

             "Where there's change, there's hope. That's good enough for me..."

             WELL... HERE GOES NOTHING. He felt the golden energy beginning to spill out. As his fists tightened, this BRIGHT, GOLDEN STEAM emanated off of his hands, causing a bright gold to flood the interior of The TARDIS. His face and hands began to emanate with the warmth of REGENERATION ENERGY. Each pant that dragged out got harder and harder to take- and he felt the strength to keep it held down slipping from him. He sucked in that final exhale before it all slipped out.

             Like Rocket TRAILS- The Golden energy slipped out and caused vibrations to rock through the TARDIS. Sparks, flames, and explosions leak outward from all corners of the SPACESHIP. The Rotor wheezing, The TARDIS slipping out of flight- exploding, crashing. All the while, its pilot changed- morphed. His sunkissed skin got paler, his brown hair was flooded with a bright pink- and his deep brown eyes shined a bright and beautifully golden. He let out one final scream, but even his voice had changed- every cell... refreshed... changed... renewed... REGENERATED.

            HE ALMOST LOST HIS BALANCE when he spun on his ankle. Standing firm- quickly regained his balance. He heard an explosion, and that finally queued him to speak out, "Oh Great Heavens! What happened to the console room!?" He looked down, finally examining his body. He blinked, almost shocked by the change- how intense the process had been. Stumbling backward, he slapped his pectorals. He screamed out "What happened to me!?" He cried out, before another explosion rocked him into the console, and he finally realized that THE TARDIS WAS CRASHING. And he finally realized what had been going on- "Change!? CHANGE!! I've CHANGED!!" He began to laugh, moving forward- grabbing a switch, and YANKING IT DOWN-- Regardless of the sparks that popped out.

                                                                                                            "ABOUT TIME!!"

[astroimages]

Horizonte de Eventos - Episódio 45 - O Que Matou os Dinossauros?

[wonders-of-the-cosmos]

The two interacting galaxies making up the pair known as Arp-Madore 608-333 seem to float side by side in this image from the NASA/ESA Hubble Space Telescope.

Credits: ESA/Hubble & NASA, Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA, J. Dalcanton

[adrianl4u]

A spectacular galactic dance!

Two galaxies in the galactic triplet Arp 248 — also known as Wild's Triplet.

Distance: 200 million light-years from Earth.

Credit: ESA/Hubble & NASA, Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA, J. Dalcanton.

[spacetimewithstuartgary]

Dark Energy Camera probes the Coma Cluster, an inspiration for the theory of dark matter

The Dark Energy Camera has captured an image of the dazzling Coma Cluster, named after the hair of Queen Berenice II of Egypt. Not only significant in Greek mythology, this collection of galaxies was also fundamental to the discovery of the existence of dark matter.

The theory emerged in 1937 when Swiss astronomer Fritz Zwicky noticed that the Coma Cluster galaxies behaved as if they were under the influence of vast amounts of unobservable "dark" matter.

This densely populated image showcases an enormous cluster not of individual stars, but of entire galaxies, known as the Coma Cluster. The Coma Cluster is named for the constellation in which it lies, Coma Berenices. It is the only one of the 88 IAU constellations to be named after a historical figure. Its namesake is Queen Berenice II of Egypt, or more precisely her hair, with "coma" meaning "hair of the head" in Latin.

Berenice famously cut her hair off and presented it as a votive offering to the gods when her husband returned safely from war. The hair was placed in a temple, but went missing soon after. The court astronomer, Conon of Samos, claimed to identify Berenice's lost tresses in a rather unlikely spot—the night sky—suggesting that the goddess Aphrodite had catasterized (literally turned into a constellation) the queen's locks. This all took place around 245 BCE, meaning that Berenice's hair has enjoyed celestial recognition for an extraordinarily long time.

The data used to build this detailed picture were collected by the Department of Energy-fabricated Dark Energy Camera (DECam), which is mounted on the U.S. National Science Foundation Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory, a Program of NSF NOIRLab.

The 570-megapixel camera was built to carry out the Dark Energy Survey (DES)—an amazing 758-night run of observations between 2013 and 2019. DES was conducted with the intention to better understand the nature of dark energy—the unknown entity that is causing the expansion of our universe to accelerate.

The Coma Cluster is closely associated with dark energy's equally mysterious counterpart: dark matter. Nearly a century ago, in 1937, Swiss astronomer Fritz Zwicky observed several galaxies within the Coma Cluster. He calculated an approximation of the cluster's mass based on its luminous—in other words, observable—structures.

But he encountered something strange: the cluster seemed to be missing mass. In fact, the galaxies within the cluster were behaving as though the cluster contained 400 times more mass than his estimates suggested.

Zwicky reached this conclusion by observing how fast the galaxies within the cluster were moving. To explain this further, it is helpful to briefly revisit a key point about the nature of gravity. Gravity is one of the four known fundamental interactions that exist between all entities with energy or mass. The more mass that an object has, the stronger the gravitational pull it will exert. Therefore, less massive objects that are within a certain distance to a more massive object will be pulled uncontrollably towards it.

However, there is an additional factor to consider: velocity. If an object is moving fast enough, it can escape the gravitational pull of other objects. It is this principle that enabled Zwicky to infer that the Coma Cluster appeared to be "missing" matter.

He found that the galaxies were moving so fast that they should be escaping the cluster if it were being held together only by the observable mass. This led him to postulate that the cluster must be held together by vast amounts of unobservable "dark" matter, though this suggestion seemed far-fetched to much of the astronomical community.

It took until the 1980s for the majority of astronomers to be convinced of the existence of dark matter. The consensus moved as several studies came out reporting the same curious mass inconsistency that Zwicky observed, but on the scale of single galaxies rather than entire galaxy clusters.

One such study was done in 1970 by U.S. astronomers Kent Ford and Vera C. Rubin, who found evidence of invisible matter in the Andromeda Galaxy. And in 1979, astronomers Sandra Faber and John Gallagher performed a robust analysis of the mass-to-light ratio for over 50 spiral and elliptical galaxies, which led them to conclude that, "the case for invisible mass in the universe is very strong and getting stronger."

The existence of dark matter and dark energy is now widely accepted, and understanding their elusive nature is a main focus of modern astrophysics. A deeper understanding may be on the horizon with the upcoming 10-year Legacy Survey of Space and Time, which will be conducted by NSF–DOE Vera C. Rubin Observatory, named after the inspirational female astronomer who helped show the world that there is so much more to the universe than meets the eye.

[apod]

2022 November 8

Galaxies: Wild's Triplet from Hubble Image Credit: ESA/Hubble, NASA, Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA, J. Dalcanton

Explanation: How many galaxies are interacting here? This grouping of galaxies is called the Wild Triplet, not only for the discoverer, but for the number of bright galaxies that appear. It had been assumed that all three galaxies, collectively cataloged as Arp 248, are interacting, but more recent investigations reveal that only the brightest two galaxies are sparring gravitationally: the big galaxies at the top and bottom. The spiral galaxy in the middle of the featured image by the Hubble Space Telescope is actually far in the distance, as is the galaxy just below it and all of the other numerous galaxies in the field. A striking result of these giants jousting is a tremendous bridge of stars, gas, and dust that stretches between them -- a bridge almost 200,000 light-years long. Light we see today from Wild's Triplet left about 200 million years ago, when dinosaurs roamed the Earth. In perhaps a billion years or so, the two interacting galaxies will merge to form a single large spiral galaxy.

∞ Source: apod.nasa.gov/apod/ap221108.html

[latimeria-fell-from-heaven]

I wish there was more content of Lan ngl. DecaM seems like the only person who draws them… I was so happy when Mihoyo gave me the option to simp for Lan in Swarm Disaster. Please I want to be pierced through by their “arrow”

respect to mihoyo for giving us some cosmic eldritch beings that are far beyond our comprehension and making them sexy. like yes, let me bend over for lan and take their horse cock and have the absolute time of my life, thank you mihoyo for making them fuckable <33

[michaelgabrill]

NASA Volunteers Find Fifteen Rare Active Asteroids

Some extraordinary asteroids have “activity”–comet-like tails or envelopes of gas and dust.  NASA’s Active Asteroids project announced the discovery of activity on fifteen asteroids, challenging conventional wisdom about the solar system. To find these fifteen rare objects, more than 8000 volunteers combed through 430,000 images from the Dark Energy Camera (DECam) on the Victor M. […] from NASA https://ift.tt/nYMzK6l

[netmassimo]

Un'immagine catturata dalla Dark Energy Camera (DECam) ritrae l'ammasso della Chioma, conosciuto anche come Abell 1656, così chiamato perché fa parte della costellazione della Chioma di Berenice. La DECam è stata progettata per condurre una lunga indagine sull'energia oscura ma è utile anche per altri tipi di studi astronomici. L'ammasso della Chioma è legato allo studio della materia oscura dato che l'incoerenza tra la stima della sua massa globale e la misurazione dei suoi effetti gravitazionali stimolarono le ricerche che portarono agli odierni modelli sulla materia oscura.

[scienza-magia]

Consultabile online il nuovo Siena Galaxy Atlas 2020

Siena, un nuovo atlante con 380mila galassie, pubblicato online il Siena Galaxy Atlas 2020. È online il Siena Galaxy Atlas, un atlante dettagliato di quasi 400mila galassie, compilato utilizzando i dati dei telescopi NoirLab di Nsf e progettato per essere il principale atlante galattico digitale per le galassie grandi. Si tratta di un tesoro di informazioni, utili per lo studio di vari aspetti dell’universo, dalla formazione ed evoluzione delle galassie alla materia oscura e alle onde gravitazionali. Tutti i dettagli su ApJ.

Ngc 520, una collisione di due galassie iniziata più di 300 milioni di anni fa, è in realtà composta da due galassie a disco che alla fine si fonderanno per formare un sistema più grande e massiccio. Ngc 520 fu scoperta da William Herschel nel 1784 ed è una delle galassie più grandi e luminose del Siena Galaxy Atlas. Crediti: Ctio/ NoirLab/ Doe/ Nsf/ Aura; J. Moustakas (Siena College); T.A. Rector (University of Alaska Anchorage/Nsf’s NoirLab) & M. Zamani (Nsf’s NoirLab) & D. de Martin (Nsf’s NoirLab) Gli astronomi cercano da tempo di mappare i cieli notturni, non solo per avere una visione il più possibile completa dell’universo in cui viviamo, ma anche per supportare ulteriori ricerche. I cataloghi di oggetti astronomici servono a molti scopi: possono aiutare gli scienziati a individuare modelli generali in una popolazione di oggetti, a scoprire nuovi fenomeni come ad esempio eventi astronomici transienti, e a identificare quelli che potrebbero essere i candidati migliori per osservazioni mirate. Tuttavia, queste risorse devono essere regolarmente aggiornate per tenere conto dei risultati ottenuti grazie ai continui miglioramenti tecnologici dei telescopi. Ora è stato pubblicato un nuovo atlante con informazioni dettagliate su oltre 380mila galassie con un livello di precisione mai raggiunto prima. Si chiama Siena Galaxy Atlas (Sga) ed è una raccolta di dati provenienti da tre survey completate tra il 2014 e il 2017, note come Desi Legacy Surveys, effettuate per identificare le galassie target per la survey del Dark Energy Spectroscopic Instrument (Desi). I dati sono stati raccolti presso l’Osservatorio interamericano di Cerro Tololo (Ctio) e l’Osservatorio nazionale di Kitt Peak (Kpno), entrambi programmi del NoirLab della National Science Foundation (Nsf), e presso lo Steward Observatory dell’Università dell’Arizona. Le Desi Legacy Surveys hanno utilizzato strumenti all’avanguardia sui telescopi gestiti da NoirLab: la Dark Energy Camera Legacy Survey (DeCaLS), effettuata utilizzando la Dark Energy Camera (DeCam) costruita dal Doe sul telescopio da 4 metri Víctor M. Blanco al Ctio in Cile; la Mayall z-band Legacy Survey (MzLS) con la fotocamera Mosaic3 sul telescopio da 4 metri Nicholas U. Mayall al Kpno; e la Beijing-Arizona Sky Survey (Bass) realizzata con la fotocamera 90Prime sul telescopio Bok da 2,3 metri, gestito dallo Steward Observatory e ospitato presso Kpno. I dati delle Desi Legacy Imaging Surveys, così come una copia dell’intero Siena Galaxy Atlas, vengono forniti alla comunità astronomica tramite la piattaforma scientifica Astro Data Lab e l’Astro Data Archive presso il Community Science and Data Center (Csdc) di NoirLab. Sga contiene anche dati aggiuntivi provenienti da una survey condotta dal satellite Wide-field Infrared Survey Explorer (Wise) della Nasa, rielaborati da Aaron Meisner, astronomo del NoirLab. Queste survey hanno catturato immagini nelle lunghezze d’onda ottiche e infrarosse per mappare un’area totale di 20mila gradi quadrati – quasi la metà del cielo notturno, rendendola tra le più grandi survey sulle galassie. Riunendo questa ricchezza di informazioni in un unico posto, Sga offre dati precisi sulla posizione, la forma e le dimensioni di centinaia di migliaia di grandi galassie relativamente vicine. Oltre all’enorme numero di oggetti registrati, i dati nella raccolta Sga raggiungono anche un nuovo livello di accuratezza ed è la prima risorsa di questo tipo a fornire dati sui profili di luce delle galassie.

Mosaico ottico di 42 galassie del Siena Galaxy Atlas 2020 ordinate per diametro angolare crescente da sinistra in alto, a destra in basso. Le galassie vengono scelte casualmente da una distribuzione di probabilità uniforme nel diametro angolare. La barra bianca orizzontale nell’angolo inferiore sinistro di ciascun pannello rappresenta 1 minuto d’arco e i ritagli del mosaico vanno da 3,2 a 13,4 minuti d’arco. Questa figura illustra l’enorme gamma di tipologie, dimensioni, colori e profili di luminosità superficiale, struttura interna e ambienti delle galassie presenti nell’atlante. Crediti: Ctio/ NoirLab/ Doe/ Nsf/ Aura/ J. Moustakas «Le grandi galassie vicine sono importanti perché possiamo studiarle in modo più dettagliato di qualsiasi altra galassia nell’universo; sono i nostri vicini cosmici», osserva John Moustakas, professore di fisica al Siena College a capo del progetto Sga. «Non solo sono straordinariamente belle, ma contengono anche la chiave per comprendere come si formano e si evolvono le galassie, inclusa la nostra, la Via Lattea». Sga si basa su diversi cataloghi compilati nei secoli scorsi. L’iconico Catalogue des Nébuleuses et des Amas d’Étoiles (Catalogo delle nebulose e degli ammassi stellari), pubblicato nel 1774 dall’astronomo francese Charles Messier, fu una pietra miliare importante, così come lo fu il Nuovo Catalogo Generale delle Nebulose e degli Ammassi di Stelle (Ngc), pubblicato nel 1888 da John Louis Emil Dreyer. Più recentemente, nel 1991, gli astronomi hanno realizzato il Terzo Catalogo di Riferimento delle Galassie Luminose (Rc3). Negli ultimi due decenni sono stati pubblicati molti altri preziosi atlanti di galassie, ma la maggior parte di essi si basa sulle misurazioni su lastre fotografiche dell’Rc3, oppure mancano un numero significativo di galassie. Poiché Sga utilizza immagini digitali catturate con strumenti altamente sensibili, rappresenta un miglioramento sostanziale sia nella qualità che nella completezza dei dati. «Precedenti compilazioni di galassie erano afflitte da posizioni, dimensioni e forme errate delle galassie e contenevano anche voci che non erano galassie ma stelle o artefatti», spiega Arjun Dey, astronomo del NoirLab coinvolto nel progetto. «Sga ripulisce tutto questo per gran parte del cielo. Fornisce inoltre le migliori misurazioni della luminosità delle galassie, qualcosa che non avevamo mai avuto prima in modo affidabile per un campione di queste dimensioni».

IC 4212 è una galassia spirale barrata situata nella costellazione della Vergine. Si trova vicino all’equatore celeste, il che significa che in alcuni periodi dell’anno è visibile almeno in parte da entrambi gli emisferi. Crediti: Ctio/ NoirLab/ Doe/ Nsf/ Aura; J. Moustakas (Siena College); T.A. Rector (University of Alaska Anchorage/Nsf’s NoirLab) & M. Zamani (Nsf’s NoirLab) & D. de Martin (Nsf’s NoirLab) Questa risorsa versatile guiderà il progresso in numerosi rami dell’astronomia e dell’astrofisica aiutando gli scienziati a trovare i migliori campioni di galassie per l’osservazione mirata. Ad esempio, Sga migliorerà la ricerca su come i modelli di formazione stellare variano nelle diverse galassie, sui processi fisici alla base della vasta gamma di morfologie che le galassie mostrano e su come la distribuzione delle galassie è correlata al modo in cui la materia oscura si diffonde nell’universo. Agendo come una mappa, Sga aiuterà anche gli astronomi a individuare le sorgenti di segnali transitori come le onde gravitazionali e a comprendere gli eventi che ne danno origine. «Sga diventerà il più importante atlante galattico digitale per le grandi galassie», afferma Dey. Tuttavia, sottolinea, Sga non è riservato solo ai ricercatori accademici, ma è liberamente consultabile online per chiunque desideri conoscere meglio il nostro angolo di universo. «Il rilascio pubblico di questi dati spettacolari contenuti nell’atlante avrà un impatto reale non solo sulla ricerca astronomica, ma anche sulla capacità del pubblico di visualizzare e identificare le galassie relativamente vicine», conclude Chris Davis, direttore del programma Nsf per NoirLab. «Gli astrofili più appassionati lo apprezzeranno particolarmente in quanto risorsa a cui rivolgersi per saperne di più su alcuni degli obiettivi celesti che osservano». Per saperne di più: Leggi su The Astrophysical Journal l’articolo “Siena Galaxy Atlas 2020” di John Moustakas, Dustin Lang, Arjun Dey, Stéphanie Juneau, Aaron Meisner, Adam D. Myers, Edward F. Schlafly, David J. Schlegel, Francisco Valdes, Benjamin A. Weaver, and Rongpu Zhou - Esplora il Siena Galaxy Atlas 2020 Read the full article

[evansbby]

i think people are siding with stevie because theyre still recovering from having their puzzy ( and hearts ) being decamated by the POYT king. you put us thru it babe and we loved it 😭😭 smash ari and stevie in a room tgt with your recovering poyt addicts and our knees are bound to buckle babes.

BUT WG!STEVE SCARED THE LIFE OUT OF ME. like Ari atleast is like in your face- we got a good thing going kinda guy.

but Steve? Did he really not know that baby was aris side chick? Was he going to be soft with her at first but then realised shes ari's commision on a job well done playing basketball and then flipped? WG!Steve is scary now but what if he flips like poyt steve 😭😭 we're gonna get double of stevie and who can reject that?!? BUT ALSO ARI JUST SAY U LIKE US TOO PLEASE. I'LL CHOOSE U PIKACHU! JUST GIVE ME A SCRAP HERE 😭😭 and not your canon discharge! I meant scrap of affection!

I’m sorry but “Ari’s commission on a job well done playing basketball” KILLED MEEE 😭😭😭😂😂

Well, I think the recovering poyt addicts are all Steve girls at heart bc the MOMENT he was introduced in wicked games, 85% of y’all jumped ship 😭😭😭 I THOUGHT WE WERE ALL ARI GIRLIES BUT I RUINED IT BY MAKING ARI UNLIKABLE IN A FIC BAHAHAHA but idec y’all more for meeee!!!

Thank you sm bestieeee🩷🩷

[merelygifted]

A close-up image of the galaxy merger Arp-Madore 417-391 that was recently taken by the Hubble space telescope. A near-perfect ring of stars has been created by the gravitational forces of the massive cosmic collision. (Image credit: ESA/Hubble & NASA, Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA, J. Dalcanton

Magnificent ring of stars captured by Hubble is the result of two galaxies in head-on collision | Live Science

A pair of galaxies in the constellation Eridanus have been warped and twisted into a colossal, glowing ring of stars by the intense gravitational forces between them following a chaotic merger