#A quasi star is a star which is powered by a black hole at its core. The black hole survives off of constantly absorbing the star

[autumn-may]

Quasi-star type siblingship

[mysticstronomy]

IS QUASAR A BLACK HOLE??

Blog#289

Wednesday, April 19th, 2023

Welcome back,

A quasar is a supermassive black hole feeding on gas at the center of a distant galaxy.

Quasar is short for quasi-stellar radio source, because astronomers first discovered quasars in 1963 as objects that looked like stars but emitted radio waves.

Now, the term is a catch-all for all feeding, and therefore luminous supermassive black holes, also often called active galactic nuclei.

It’s a bit of a contradiction to call a black hole luminous; black holes themselves are, of course, black. In fact, almost every large galaxy hosts a black hole with the mass of millions to billions of Suns, and many of these black holes lurk in the dark. Our Milky Way’s behemoth weighs in at 4.3 million solar masses, but its starvation diet mutes all but faint flashes and flickers.

We know it’s there, though, from the orbits of stars around it. Other dormant black holes occasionally shred an infalling star, making their presence known by the flare of radiation that ensues.

But quasars are a different breed of black hole. They reside in galaxies with plentiful gas supplies, perhaps supplied by a recent galaxy-galaxy collision, and they gorge on the inflowing material.

The gas spirals around as it falls in, heating up in the process and emitting radiation across the electromagnetic spectrum.

Supermassive black holes in nearby galaxies typically do not have that much gas available to them, so quasars are typically found in distant galaxies. The nearest quasar is Markarian 231, which lies about 600 million light-years from Earth.

A quasar is not only the feeding black hole itself, but the light-producing structures that surround it. Visible and ultraviolet light come from the glowing disk of infalling material, while even hotter gas above the disk shines at X-ray energies. Jets shooting out along the black hole’s poles emit everything from radio waves to X-rays. Farther out from the black hole, the prolific dust and gas glow at infrared wavelengths.

The size of a quasar accretion disk, which scales with the mass of its black hole, is typically a few light-days across. That dwarfs in comparison to its host galaxy; the Milky Way for comparison is roughly 100,000 light-years across. Yet quasars often outshine their hosts.

Despite their brilliance, quasars are so small and distant that even the most powerful telescope cannot resolve all the structures within a quasar.

Astronomers have to ferret out the details using other techniques, such as analyzing spectroscopy (spreading out the light by wavelength) or light curves (spreading out the light by its arrival time).

While the details are still up for debate, we can use current knowledge to paint a general picture of a quasar. Just remember that this picture might change over time as we learn more!

Originally published on skyandtelescope.org

COMING UP!!

(Saturday, April 22nd, 2023)

"HOW LONG DO BLACK HOLES LAST??"

[jcmarchi]

MIT astronomers observe elusive stellar light surrounding ancient quasars

New Post has been published on https://thedigitalinsider.com/mit-astronomers-observe-elusive-stellar-light-surrounding-ancient-quasars/

MIT astronomers observe elusive stellar light surrounding ancient quasars

MIT astronomers have observed the elusive starlight surrounding some of the earliest quasars in the universe. The distant signals, which trace back more than 13 billion years to the universe’s infancy, are revealing clues to how the very first black holes and galaxies evolved.

Quasars are the blazing centers of active galaxies, which host an insatiable supermassive black hole at their core. Most galaxies host a central black hole that may occasionally feast on gas and stellar debris, generating a brief burst of light in the form of a glowing ring as material swirls in toward the black hole.

Quasars, by contrast, can consume enormous amounts of matter over much longer stretches of time, generating an extremely bright and long-lasting ring — so bright, in fact, that quasars are among the most luminous objects in the universe.

Because they are so bright, quasars outshine the rest of the galaxy in which they reside. But the MIT team was able for the first time to observe the much fainter light from stars in the host galaxies of three ancient quasars.

Based on this elusive stellar light, the researchers estimated the mass of each host galaxy, compared to the mass of its central supermassive black hole. They found that for these quasars, the central black holes were much more massive relative to their host galaxies, compared to their modern counterparts.

The findings, published today in the Astrophysical Journal, may shed light on how the earliest supermassive black holes became so massive despite having a relatively short amount of cosmic time in which to grow. In particular, those earliest monster black holes may have sprouted from more massive “seeds” than more modern black holes did.

“After the universe came into existence, there were seed black holes that then consumed material and grew in a very short time,” says study author Minghao Yue, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. “One of the big questions is to understand how those monster black holes could grow so big, so fast.”

“These black holes are billions of times more massive than the sun, at a time when the universe is still in its infancy,” says study author Anna-Christina Eilers, assistant professor of physics at MIT. “Our results imply that in the early universe, supermassive black holes might have gained their mass before their host galaxies did, and the initial black hole seeds could have been more massive than today.”

Eilers’ and Yue’s co-authors include MIT Kavli Director Robert Simcoe, MIT Hubble Fellow and postdoc Rohan Naidu, and collaborators in Switzerland, Austria, Japan, and at North Carolina State University.

Dazzling cores

A quasar’s extreme luminosity has been obvious since astronomers first discovered the objects in the 1960s. They assumed then that the quasar’s light stemmed from a single, star-like “point source.” Scientists designated the objects “quasars,” as a portmanteau of a “quasi-stellar” object. Since those first observations, scientists have realized that quasars are in fact not stellar in origin but emanate from the accretion of intensely powerful and persistent supermassive black holes sitting at the center of galaxies that also host stars, which are much fainter in comparison to their dazzling cores.

It’s been extremely challenging to separate the light from a quasar’s central black hole from the light of the host galaxy’s stars. The task is a bit like discerning a field of fireflies around a central, massive searchlight. But in recent years, astronomers have had a much better chance of doing so with the launch of NASA’s James Webb Space Telescope (JWST), which has been able to peer farther back in time, and with much higher sensitivity and resolution, than any existing observatory.

In their new study, Yue and Eilers used dedicated time on JWST to observe six known, ancient quasars, intermittently from the fall of 2022 through the following spring. In total, the team collected more than 120 hours of observations of the six distant objects.

“The quasar outshines its host galaxy by orders of magnitude. And previous images were not sharp enough to distinguish what the host galaxy with all its stars looks like,” Yue says. “Now for the first time, we are able to reveal the light from these stars by very carefully modeling JWST’s much sharper images of those quasars.”

A light balance

The team took stock of the imaging data collected by JWST of each of the six distant quasars, which they estimated to be about 13 billion years old. That data included measurements of each quasar’s light in different wavelengths. The researchers fed that data into a model of how much of that light likely comes from a compact “point source,” such as a central black hole’s accretion disk, versus a more diffuse source, such as light from the host galaxy’s surrounding, scattered stars.

Through this modeling, the team teased apart each quasar’s light into two components: light from the central black hole’s luminous disk and light from the host galaxy’s more diffuse stars. The amount of light from both sources is a reflection of their total mass. The researchers estimate that for these quasars, the ratio between the mass of the central black hole and the mass of the host galaxy was about 1:10. This, they realized, was in stark contrast to today’s mass balance of 1:1,000, in which more recently formed black holes are much less massive compared to their host galaxies.

“This tells us something about what grows first: Is it the black hole that grows first, and then the galaxy catches up? Or is the galaxy and its stars that first grow, and they dominate and regulate the black hole’s growth?” Eilers explains. “We see that black holes in the early universe seem to be growing faster than their host galaxies. That is tentative evidence that the initial black hole seeds could have been more massive back then.”

“There must have been some mechanism to make a black hole gain their mass earlier than their host galaxy in those first billion years,” Yue adds. “It’s kind of the first evidence we see for this, which is exciting.”

[spacetimewithstuartgary]

First map of outflows from nearby quasar I Zwicky 1

SRON astronomers have for the first time mapped the outflows from one of the closest quasars to Earth. Quasars are bright cores of galaxies powered by the supermassive black hole in their center. The team has probed gas outflows in I Zwicky 1, a close-by quasar, to map its system of clouds being blown away at tens to thousands of kilometers per second. Their findings are published in the journal Astronomy & Astrophysics.

Most galaxies, including our Milky Way, harbor a supermassive black hole in their center. These typically weigh millions of solar masses. Many of them keep lurking in the blackness of space, with little to give them away. Some have, however, large deposits of material in their vicinity to feed on. This turns the central region into a brilliant beacon, outshining the entire host galaxy.

Given their compact size and large distance from Earth, these active galactic nuclei appear as bright dots, like the Milky Way stars. This is also why they were historically classified as quasi-stellar objects (quasars).

Most quasars reside in the distant, early universe, but I Zwicky 1 is relatively close at less than a billion lightyears away from Earth. This provides astronomers with a convenient laboratory for studying the extreme conditions in quasars.

A team of astronomers led by Anna Juráňová (SRON), including Elisa Costantini (SRON), has now for the first time mapped its outflows. Using the Hubble Space Telescope, they recovered the properties of four outflows of ionized gas clouds, being blown out at speeds of 60, 280, 1950 and 2900 kilometers per second.

"I Zwicky 1 is very special in its properties," says Juráňová. "Other quasars have similar outflows, but in this one, everything is just right. Our viewing angle, the width of the lines in the spectrum, and so on. This allows us to dig much deeper into its processes. We have created a global picture of the motions of the ionized gas in a quasar, which is rare."

The team found that one of the outflows was trapped in the shadow of the other one. This results from the strong radiation from the quasar pushing the clouds out and away from the vicinity of the black hole. Ions of elements such as nitrogen, oxygen and carbon within the gas clouds absorb the quasar's ultraviolet light and get pushed away as a consequence. I Zwicky 1 is the nearest quasar offering concrete evidence of this mechanism at play.

The environment around I Zwicky 1 appears more dynamical than what astronomers often see around nearby supermassive black holes. Juráňová says, "Our data suggest that far more gas is being lifted and blown out from the disk around the black hole. Having this insight brings us closer to unraveling the way these supermassive black holes grow and interact with their surroundings."

IMAGE.....Artist's impression of outflows from a quasar. Credit: ESO/M. Kornmesser

[spacenutspod]

It’s an exciting time in astronomy today, where records are being broken and reset regularly. We are barely two months into 2023, and already new records have been set for the farthest black hole yet observed, the brightest supernova, and the highest-energy gamma rays from our Sun. Most recently, an international team of astronomers using the ESO’s Very Large Telescope in Chile reportedly saw the brightest object ever observed in the Universe: a quasar (J0529-4351) located about 12 billion light years away that has the fastest-growing supermassive black hole (SMBH) at its center. The international team responsible for the discovery consisted of astrophysicists from the Research School of Astronomy and Astrophysics (RSAA) and the Center for Gravitational Astrophysics (CGA) at the Australian National University (ANU). They were joined by researchers from the University of Melbourne, the Paris Institute of Astrophysics (IAP), and the European Southern Observatory (ESO). The paper that describes their findings, titled “The accretion of a solar mass per day by a 17-billion solar mass black hole,” recently appeared online and will published in the journal Nature Astronomy. First observed in 1963 by Dutch-American astronomer Maarten Schmidt, quasars (short for “quasi-stellar objects”) are the bright cores of galaxies powered by SMBHs. These black holes collect matter from their surroundings and accelerate it to near the speed of light, which releases tremendous amounts of energy across the electromagnetic spectrum. Quasars become so bright that their cores will outshine all the stars in their disk, making them the brightest objects in the sky and visible from billions of light-years away. As a general rule, astronomers gauge the growth rate of SMBHs based on the luminosity of their galaxy’s core region – the brighter the quasar, the faster the black hole is accreting matter. In this case, the SMBH at the core of J0529-4351 is growing by the equivalent of one Solar mass a day, making it the fastest-growing black hole yet observed. In the process, the accretion disk alone releases a radiative energy of 2 × 1041 Watts, more than 500 trillion times the luminous energy emitted by the Sun. Christian Wolf, an ANU astronomer and lead author of the study, characterized the discovery in a recent ESO press release: “We have discovered the fastest-growing black hole known to date. It has a mass of 17 billion Suns, and eats just over a Sun per day. This makes it the most luminous object in the known Universe. Personally, I simply like the chase. For a few minutes a day, I get to feel like a child again, playing treasure hunt, and now I bring everything to the table that I have learned since.” But what was most surprising was that this quasar was hiding in plain sight. “All this light comes from a hot accretion disc that measures seven light-years in diameter — this must be the largest accretion disc in the Universe,” said ANU Ph.D. student and co-author Samuel Lai. “It is a surprise that it has remained unknown until today, when we already know about a million less impressive quasars. It has literally been staring us in the face until now,” added co-author Christopher Onken, who is also an astronomer at ANU. As Onken explained, J0529-4351 showed up in images taken by the ESO Schmidt Southern Sky Survey dating back to 1980. It was only in recent years that it was recognized as a quasar, thanks to improved instruments and measurements. Finding quasars requires precise observations from large areas of the sky, resulting in massive datasets that often require machine learning algorithms to analyze them. However, these models are somewhat limited because they are trained on existing data, meaning candidates are selected based on previously observed objects. This image shows the region of the sky in which the record-breaking quasar J0529-4351 is situated. Credit: ESO/Digitized Sky Survey 2/Dark Energy Survey Since J0529-4351 is so luminous, it was dismissed by the ESA’s Gaia Observatory as being too bright to be a quasar and was ruled to be a bright star. Last year, the ANU-led team identified it as a distant quasar based on observations using the 2.3-meter telescope at the Siding Spring Observatory in Australia. They then conducted follow-up observations using the X-shooter spectrograph on the ESO’s VLT telescope to confirm their results. The quasar is also an ideal target for the GRAVITY+ upgrade on ESO’s Very Large Telescope Interferometer (VLTI), designed to accurately measure the mass of black holes. In addition, astronomers look forward to making observations with next-generation telescopes like the ESO’s Extremely Large Telescope (ELT). This 39-meter telescope, currently under construction in the Atacama Desert in Chile, will make identifying and characterizing distant quasars easier. Studying these objects and their central black holes could reveal vital details about how SMBHs and galaxies co-evolved during the early Universe. Further Reading: ESO, ESO Science Papers The post The Brightest Object Ever Seen in the Universe appeared first on Universe Today.

[donniesexceptionalmind]

I two things:

1, I love any and all of yet rambles, especially the space ones. Space is also one of my special interests, and it makes me so so so so happy whenever I see something about it on one of my favorite blogs!

If my brain wasn’t so stupid and actually let me remember stuff when I want to, perhaps I’d actually be able to keep all I learn >:(

2, Please remember to drink some water, eat some food even if it’s just a few crackers, and rest.

Ya can use this ask as an excuse to talk about space ^^

1. I AM CONSIDERED ONE OF YOUR FAVOURITE BLOGS? *falls from my gaming chair*

Thank you.

Astrophysics is a wonderful field of science.

Don't worry, I don't have the memory of an elephant, so I can't keep everything in mind. It's not bad to forget stuff. I like to reread & rewatch stuff & I feel happy when I read or see stuff that I already know. It's like: WHOOP, THAT I KNOW!

2. ... You got me there. When I'm in hyperfocus, it's really hard to remember to eat or drink. Sometimes, I don't even want to. A few minutes of nourishing my body feel like eternity even though I know that is JUST my emotional perception.

Oooooh, another infodump about space? Hehe...

You won't regret this, will you?

✨️Let's talk quasars! ✨️

'Quasar' is short for 'quasi-stellar radio source'.

Quasars got that name because they looked starlike when astronomers first discovered them in the earliest radio surveys of the sky in the 1950s.

Some of the radio sources discovered back then coincided with objects that appeared to be unusually blue stars, although photographs of some of these objects showed them to be embedded in faint, fuzzy halos.

But quasars aren’t stars.

They are, in fact, young galaxies located at vast distances from us, with their numbers increasing towards the edge of the visible universe.

The oldest quasar, currently, is J0313-1806. Its distance is approximately 13.03 billion light-years, & therefore, we see it as it was just 670 million years after the Big Bang.

Quasars are extremely bright, up to 1,000 times brighter than our Milky Way. We know that they’re highly active, emitting staggering amounts of radiation across the entire electromagnetic spectrum.

A quasar is a type of an 'active galactic nucleus', short AGN.

(There are actually many different types of AGNs, each with their own tale to tell.)

Theoretically, the intense radiation released by an AGN powers a supermassive black hole.

The powerful radiation comes from material in the accretion disk surrounding the black hole when it is superheated to millions of degrees by the intense friction generated by the particles of dust, gas & other matter in the disk colliding countless times with each other.

The inward spiral of matter in a supermassive black hole’s accretion disk – that is, at the centre of a quasar – is the result of particles colliding & bouncing against each other & losing momentum.

That material came from the enormous clouds of gas, mainly consisting of molecular hydrogen, which filled the universe in the era shortly after the Big Bang.

There is a maximum rate set by the Eddington limit at which a black hole can accrete matter before the heating of the infalling gas results in so much outward pressure from radiation that the accretion stops.

Some quasars have radio jets, which are highly collimated beams of plasma propelled out along the rotation axis of the accretion disk at almost the speed of light.

These jets emit beams of radiation that can be observed at X-ray & radio wavelengths (and less often at optical wavelengths).

What distinguishes an “active” galactic nucleus from other galactic nuclei (90–95 percent of large galaxies that are currently not quasars) is that the black hole in an active nucleus accretes a few solar masses of matter per year, which, if it is accreting at around 1 percent or more of the Eddington rate, is sufficient to account for a typical quasar with a total luminosity of about 10^39 watts. (The Sun’s luminosity is about 4 × 10^26 watts.)

Quasars are baby galaxies if you will.

Credis: STScI

Have a WELL-DESERVED cookie 🍪, this has gotten WAY out of hand.

Apologies.

[foxgirlchorix]

ive been posting these on https://cohost.org/vanadiya-cataclysm-athelya but now that i have more than one or two i figure ill put them together here:

It is a spindly thing- all drive vanes, steering assemblages, instrument booms. But it works- its tone-deaf cousin, sipping more power from its reactor than previously thought feasible, has just returned from a test run. Contingencies are bound up in its birth- this is self-evident from the furled solar panels, the vast main antenna, the section disconnect systems that leave their marks all over the ship. Despite its odd looks, anyone familiar with the most universal of principles behind its design would recognize it: It is the first true interstellar voyager of a budding species, ready for the looping trajectory needed for prompt data returns without such advanced features as FTL communications. ----- The ship writhes as it breaks into reality, its shattered systems struggling to dissipate the energy of its reemergence into space. Skittering across its battered hull are the many-legged forms of repair workers and the flitting bodies of tiny soldier craft, dueling with attacking pinnaces and the suited forms of Enemy crew alike. The ship's arrival in a star system has brought the battle to a pivotal turn- the defenders have the upper hand now, more reinforced from the phosphorous-boiling temperature of the desperately-radiating hull. Still, they don't need to win the battle- not when they can...

There. Hull panels jettison, others warp as the thrust of a torchdrive punches through their companions. The dying ship's payload bursts from it- a squadron of reproductive drones, off to find other ships to impart their genetic material to. The hive and its ship may be following their attackers into death, but their purpose is complete.

-----

Something has gone very wrong with the reactor.

The control arms still work, the ship's systems have not yet seen reason to try and shut it down- but something is very wrong. In the technological marvel- a caged, miniaturized star, ever so small yet still a working echo of its true-star kin- a failure state not previously considered has become evident. The star is simply too dense: the modified physics used to prolong its existence dictate this, and there is no way to change it now that it has formed. Time stretches in the inner volumes of the star, trapped light curves... at the very centre of the star, a black hole is birthed. The star is a veritable feast, over a thousand scale solar masses, but it could disperse in a supernova at this rate-

The star ripples. It expands rapidly- if it had a surface, it would be torn to shreds. It is in danger of dispersing completely... it collapses back inwards, and ever so gradually settles down. It is dead, but still alive: powered by its own collapse as usual, but counterbalanced by the power of a black hole. With a quasi-star in its main heart, the ship's systems can breathe a sigh of relief: This is an unexpected outcome, but a mostly stable one.

-----

She is not sure whether she should have a sense of self. One of many- many of one, perhaps? No way of telling which is true. Her mind flits between bodies on the laser-links coordinating the fleet, but the fleet tends to disperse- the minds can diverge as they please. But she was never meant to be so far from home, so bereft of guidance... and her libraries avoid the topic. It will take her a long time to decide.

[sunaleisocial]

MIT astronomers observe elusive stellar light surrounding ancient quasars

New Post has been published on https://sunalei.org/news/mit-astronomers-observe-elusive-stellar-light-surrounding-ancient-quasars/

MIT astronomers observe elusive stellar light surrounding ancient quasars

MIT astronomers have observed the elusive starlight surrounding some of the earliest quasars in the universe. The distant signals, which trace back more than 13 billion years to the universe’s infancy, are revealing clues to how the very first black holes and galaxies evolved.

Quasars are the blazing centers of active galaxies, which host an insatiable supermassive black hole at their core. Most galaxies host a central black hole that may occasionally feast on gas and stellar debris, generating a brief burst of light in the form of a glowing ring as material swirls in toward the black hole.

Quasars, by contrast, can consume enormous amounts of matter over much longer stretches of time, generating an extremely bright and long-lasting ring — so bright, in fact, that quasars are among the most luminous objects in the universe.

Because they are so bright, quasars outshine the rest of the galaxy in which they reside. But the MIT team was able for the first time to observe the much fainter light from stars in the host galaxies of three ancient quasars.

Based on this elusive stellar light, the researchers estimated the mass of each host galaxy, compared to the mass of its central supermassive black hole. They found that for these quasars, the central black holes were much more massive relative to their host galaxies, compared to their modern counterparts.

The findings, published today in the Astrophysical Journal, may shed light on how the earliest supermassive black holes became so massive despite having a relatively short amount of cosmic time in which to grow. In particular, those earliest monster black holes may have sprouted from more massive “seeds” than more modern black holes did.

“After the universe came into existence, there were seed black holes that then consumed material and grew in a very short time,” says study author Minghao Yue, a postdoc in MIT’s Kavli Institute for Astrophysics and Space Research. “One of the big questions is to understand how those monster black holes could grow so big, so fast.”

“These black holes are billions of times more massive than the sun, at a time when the universe is still in its infancy,” says study author Anna-Christina Eilers, assistant professor of physics at MIT. “Our results imply that in the early universe, supermassive black holes might have gained their mass before their host galaxies did, and the initial black hole seeds could have been more massive than today.”

Eilers’ and Yue’s co-authors include MIT Kavli Director Robert Simcoe, MIT Hubble Fellow and postdoc Rohan Naidu, and collaborators in Switzerland, Austria, Japan, and at North Carolina State University.

Dazzling cores

A quasar’s extreme luminosity has been obvious since astronomers first discovered the objects in the 1960s. They assumed then that the quasar’s light stemmed from a single, star-like “point source.” Scientists designated the objects “quasars,” as a portmanteau of a “quasi-stellar” object. Since those first observations, scientists have realized that quasars are in fact not stellar in origin but emanate from the accretion of intensely powerful and persistent supermassive black holes sitting at the center of galaxies that also host stars, which are much fainter in comparison to their dazzling cores.

It’s been extremely challenging to separate the light from a quasar’s central black hole from the light of the host galaxy’s stars. The task is a bit like discerning a field of fireflies around a central, massive searchlight. But in recent years, astronomers have had a much better chance of doing so with the launch of NASA’s James Webb Space Telescope (JWST), which has been able to peer farther back in time, and with much higher sensitivity and resolution, than any existing observatory.

In their new study, Yue and Eilers used dedicated time on JWST to observe six known, ancient quasars, intermittently from the fall of 2022 through the following spring. In total, the team collected more than 120 hours of observations of the six distant objects.

“The quasar outshines its host galaxy by orders of magnitude. And previous images were not sharp enough to distinguish what the host galaxy with all its stars looks like,” Yue says. “Now for the first time, we are able to reveal the light from these stars by very carefully modeling JWST’s much sharper images of those quasars.”

A light balance

The team took stock of the imaging data collected by JWST of each of the six distant quasars, which they estimated to be about 13 billion years old. That data included measurements of each quasar’s light in different wavelengths. The researchers fed that data into a model of how much of that light likely comes from a compact “point source,” such as a central black hole’s accretion disk, versus a more diffuse source, such as light from the host galaxy’s surrounding, scattered stars.

Through this modeling, the team teased apart each quasar’s light into two components: light from the central black hole’s luminous disk and light from the host galaxy’s more diffuse stars. The amount of light from both sources is a reflection of their total mass. The researchers estimate that for these quasars, the ratio between the mass of the central black hole and the mass of the host galaxy was about 1:10. This, they realized, was in stark contrast to today’s mass balance of 1:1,000, in which more recently formed black holes are much less massive compared to their host galaxies.

“This tells us something about what grows first: Is it the black hole that grows first, and then the galaxy catches up? Or is the galaxy and its stars that first grow, and they dominate and regulate the black hole’s growth?” Eilers explains. “We see that black holes in the early universe seem to be growing faster than their host galaxies. That is tentative evidence that the initial black hole seeds could have been more massive back then.”

“There must have been some mechanism to make a black hole gain their mass earlier than their host galaxy in those first billion years,” Yue adds. “It’s kind of the first evidence we see for this, which is exciting.”

[therealuniverse]

Galactic Afterburner Quasars, aka quasi-stellar radio sources, are incredibly energetic, luminous, and distant active galactic nuclei. These star-like objects are sources of X-ray and visible light, and outshine several galaxies combined. It wasn’t until the 1950’s that astronomers realized these extra-galactic bodies were actually producing vast quantities of radio energy; leading to the name “Quasi-stellar radio sources” or quasars for short. At the center of every quasar is a black hole from which it derives its power. The higher the rate at which the black hole devours matter and the more mass it has, the more powerful the quasar. Supermassive black holes do not devour all the material that gets sucked in. Most of the material falls toward the black hole, but some of it escapes and explodes outward in the form of a jet. Similar to the afterburners on fighter jets, these galactic jets move at speeds close to the speed of light.

NASA’s Chandra X-ray Observatory has captured one such jet in the quasar PKS 0637-752. What makes this jet particularly extraordinary is its being propelled outward at a distance of 2,000,000 light years! Even though these jets have been studied for several decades, astronomers are still puzzled by them. Afterburners in jet engines produce exhaust referred to as ‘shock diamonds’ – PKS 0637-752 is producing the same effect as seen by the light and dark regions in the photo. If these ‘shock diamonds’ are produced the same way in space as they are in a jet engine, then we can learn a great deal from the distance between each “diamond” or light area. These jets are believed to be the key to understanding galaxy formation and growth. -ALT Source: https://www.science20.com/news_articles/shock_diamonds_space_extragalactic_afterburner_pks_0637752-95488 Photo Credit: Dr Leith Godfrey, ICRAR and Dr Jim Lovell, UTas

[rhubarbplants]

Renegades Secret santa fluff. No spoilers

Danna held out a baseball cap with a few folded pieces of paper. Nova reached in first and pulled out one of the crumped papers, and then she watched as the rest of her teammates pulled their secret santa names out, one by one. She didn’t want to open it yet, she would save it for later. She watched as people opened their cards. Ruby blushed and Oscar just looked confused. Danna was smirking and honestly Nova didn’t have a clue what the look on Adrian’s face meant. His brow was furrowed but he had a small smile.

“Ok” Danna said. “Keep quiet about who you have, don’t tell anyone, and don’t get anything lame.”

Someone in the Renegades had suggested a secret santa tradition a few years ago and it had been slowly adopted until it had gained the name: adopted, quasi official tradition. It was officially secret snowflake as to not make it religious but no one called it that. Even Nova, who was an adamant atheist, called it secret santa. Adrian escorted her up to her room in the tower. She was on probation so she couldn’t be alone outside her room, so Adrian and the team had taken it upon themselves to be the ones who ‘escorted’ her everywhere. She would have been annoyed if it hadn’t been for the way they almost make her forget how bad her situation actually was.

It was basically luck she wasn’t in jail right now but her mind zoomed around the memory of that day. Forgetting was easier.

“Good night” Nova said, Adrian leaned down to press a kiss to her lips, before saying

“Good night to you too, I love you.”

She closed the door behind her and open her paper. She sighed and put her face in her hands. This was going to be awkward. She get her laptop and pulled up google, she scoured amazon for two whole hours but nothing popped out at her. Everything was either to effortless or just not right. She sighed and closed her computer, walking to bed and throwing back the covers. It was hard to sleep that night, her mind was so focused on the gift she couldn’t sleep, not that it was an issue, but since her curfew was set she had found it a nice was to pass the time.

She spent the next day obsessing over finding the right thing. Nothing that would upset their tenuous relationship. She was scribbling her way through archive paperwork when it came to her. She rushed out and immediately got to work. She worked for hours on end making sure every little element was perfect.

A few days later the team gathered in the space in front of Max’s quarantine where he still lived most of the time. All the presents were wrapped and Danna started the exchange,

“Ok, so the person who gets a present has to give theirs, Nova can start.”

“Oh, ok” Nova wasn’t ready but she lifted the light blue box adjusting the ribbon, before handing it to Danna. She looked surprised that she was on the receiving end of the gift, but unraveled the bow and lifted the present out of the box. It was an aerosol spray can and Danna looked at Nova questioningly.

“Its a spray that will make your butterfly wings fireproof and waterproof without compromising flying ability.” Nova explained.

“Nova that’s amazing how did you come up with this.”

“Well, I kind of had a genius chemistry teacher.”

Danna jumped up and hugged Nova tightly, before sitting down again and handing her present to Ruby. She unwrapped in to see a giant geology book, once again hugs were exchanged and then it was Ruby's turn to give her present. She practically chucked the red and white wrapped rectangular package. Oscar caught it and started to unwrap it,

“You got me?” He asked,

“Yeah, it took me forever to find anything,” she said. Oscar pulled the gift out of the paper and smiled. It was a picture of Ruby and Oscar in the snow and the frame was made or carved red stone.

“I have so much crystal lying around, I figured I could make something out of it.”

“It’s great, really really great.” He said, enveloping Ruby in a hug. Oscar handed a small square package to Max who carefully took the paper of, making sure he didn’t rip it. He pulled out a pair of small metal figurines,

“What are they for?” He asked

“You can use your metal manipulation powers to make them move around, and they can live in your model Gatlon city.”

Max looked at them intensely and they began to walk their movements slow but fluid.

“Oh my god! This is the best thing ever!” He gave Oscar a hug and the figurines ran over to give him a hug too. “Ok, my turn now”. He tossed Adrian a sloppily wrapped package and Adrian started to rip the paper. He was halfway through when a regular looking pen slipped out. Adrian looked at Max questioningly and Danna gave him a disapproving look,

“I thought we said no lame gifts” Danna said,

“It’s not, it’s not.” Max reassured, “it’s super cool, it can turn in to any color you want just just have to name which ones.” Adrian’s confused look turned to excitement and he picked up the pen and said,

“Indigo.” Then scrawled a little cat doodle on the floor. It was in fact indigo, a perfect shade too, then he pulled the cat into existence. The kitten walked over to max and snuggled up to him.

“The cat is my thank you note.” He said, smiling as the cat nuzzled Max’s leg. Then Nova realized she was the only one who hadn’t gotten a present, which meant Adrian was the one who had gotten her. Adrian’s present was going to be for her. He picked up a large rolled up piece of paper with a big blue bow. She unfurled the poster and saw a star map like the one she had on her desk. Her heart sank and Adrian must have seen the look on her face because he said,

“Look closer.” She did and noticed that some of the labels were different. A few constellations had different names.

Fornax, ‘The Furnace’ was labeled with Oscars name, which made Nova laugh. Pictor, ‘The Painter’ was Adrian, Ruby was Mars and Danna’s name was by a butterfly cluster. Max is by a black hole which is a dry kind of humor but the fact that he wears the charm now takes the edge off the joke, and she knows that Adrian would never make a joke that would actually hurt Max’s feelings. Nova was searching the poster for her name and when she found it, she gasped. Her name is printed in white bolded letters right under the constellation Perseus. The Hero. One last label pops out at Nova, just as she’s about to roll up the star chart. It simply said, Us. She took a closer look and saw it was by the constellation Argo. The crew of heroes who had become like a family over the course of their quest. Adrian was right about that, when she looked at the people around her that was what she saw. Not a team or colleagues or even friends. These were her family. Her stood and hugged Adrian, then pulled the rest of them in. She hadn’t felt this loved for years, but it felt perfect.

[sciencespies]

Astronomers detect the most distant quasar to date, over 13 billion light-years away

https://sciencespies.com/space/astronomers-detect-the-most-distant-quasar-to-date-over-13-billion-light-years-away/

Astronomers detect the most distant quasar to date, over 13 billion light-years away

A galaxy billions of light-years away is the most distant of its kind we’ve found to date, embodying yet another challenge to our models of black hole and galaxy formation, and offering a rare glimpse into the early Universe.

It’s named J0313-1806, a quasar over 13 billion light-years from Earth, fully formed with a bafflingly huge supermassive black hole at its centre, and churning out newborn stars at a furious rate – just 670 million years after the Big Bang.

A team of researchers led by the University of Arizona even found evidence of a hot quasar wind, blowing from the supermassive black hole at the centre of J0313-1806 at 20 percent of the speed of light.

“This is the earliest evidence of how a supermassive black hole is affecting its host galaxy around it,” said astronomer Feige Wang of UArizona’s Steward Observatory. “From observations of less distant galaxies, we know that this has to happen, but we have never seen it happening so early in the universe.”

Quasars – a shortening of “quasi-stellar radio sources” – are the incredibly bright result of an active galactic nucleus, with a supermassive black hole accreting material at such a rate that the heat generated blazes across the Universe. J0313-1806’s core is accreting material at a rate of 25 solar masses a year; but it’s so far away that only the combined might of some of our most powerful telescopes were able to detect it as an infrared dot at the dawn of time.

Then, the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile was used to study it in closer detail. Together, these observations reveal the most distant quasar yet, beating the previous record holder, J1342+0928, by 20 million years.

J1342+0928, identified at 690 million years after the Big Bang, was challenging enough, with a supermassive black hole clocking in at a tremendous 800 million solar masses. But J0313-1806 has it beat hand over fist – its supermassive black hole is twice as massive, at 1.6 billion solar masses.

That’s extraordinarily massive so soon after the Big Bang – and too massive for some of our current models. One of the models proposes that supermassive black holes start small and grow by accreting matter. Another proposes that they form via the direct collapse of dense clusters of stars.

These models can work for other quasars found in the distant Universe, such as J1342+0928, but not for J0313-1806. Even if the J0313-1806 supermassive black hole formed around 100 million years after the Big Bang, and grew as fast as modelling allows, it would still need to have started at 10,000 solar masses right from the outset, the team calculated.

There is, however, a third option.

“This tells you that no matter what you do, the seed of this black hole must have formed by a different mechanism,” said astronomer Xiaohui Fan of the UArizona Department of Astronomy. “In this case, one that involves vast quantities of primordial, cold hydrogen gas directly collapsing into a seed black hole.”

There are other reasons J0313-1806 is a fascinating object. There’s its star formation rate, around 200 solar masses a year, classifying it as what we call a starburst galaxy. This is an intense stage in a galaxy’s life; at such high rates of star formation, it’s only a matter of time before all the star-forming material runs out.

And that quasar wind – extreme hot plasma outflows from the accretion disc of material swirling around the supermassive black hole – isn’t helping matters. These winds are stripping the cold star-forming gas from the galaxy, which is thought to eventually extinguish, or quench, star formation.

“We think those supermassive black holes were the reason why many of the big galaxies stopped forming stars at some point,” Fan said.

“We observe this ‘quenching’ at lower redshifts, but until now, we didn’t know how early this process began in the history of the Universe. This quasar is the earliest evidence that quenching may have been happening at very early times.”

Eventually, there will be nothing left nearby for the supermassive black hole to devour, either, and its brilliant blaze will dim, at least from our point of view. Since the light reaching us from J0313-1806 is 13.03 billion years old, the galaxy probably looks very different now from what we are seeing.

Nevertheless, the quasar, and others like it, constitute a growing catalogue that is helping astronomers piece together the mysteries of how our Universe flared to life. And, as our instruments continue to grow more sensitive, so too will our understanding of the beginning of everything continue to grow.

“Future observations,” Wang said, “could make it possible to resolve the quasar in more detail, show the structure of its outflow and how far the wind extends into its galaxy, and that would give us a much better idea of its evolutionary stage.”

The research has been presented at the 237th meeting of the American Astronomical Society. It has also been accepted by The Astrophysical Journal Letters, and is available on arXiv.

#Space

[neuronium]

The Singularities of Infinity Stones

"Before creation itself, there were six singularities. Then the universe exploded into existence, and the remnants of these systems were forged into concentrated ingots... Infinity Stones."

The Infinity Stones, originally referred to as Infinity Gems or Soul Gems, are six immensely powerful fictional gems appearing in Marvel comic books and their screen adaptation, the Marvel Cinematic Universe. They were described as six different singularities existing before the beginning of the universe. They were scattered all over the universe once it was created.

The infinity stones itself may be pure fiction, but Marvel Comics might have done their research before constructing a background story of preexisting singularities upon the creation of the universe. In reality, the initial state of the universe we live in, at the beginning of the Big Bang, was once argued by physicists to have been a singularity.

What Are Singularities?

In mathematics, a singularity of a function is a limit at which the function is ill-defined — typically because of a discontinuity or infinity enters the equation. For example, the function f=1/x is singular at x = 0. The problem was raised from the fact that we could have singularities in mathematical equations of one of the fundamental forces that govern our universe. 

General relativity, Einstein's theory of space, time, and gravity, allows the existence of singularities. The theory of  general relativity characterizes gravity by the curvature of spacetime, as expressed by the metric tensor. The values of this tensor are given by the Einstein field equations, and solutions to these equations can be singular. They are known as gravitational singularities or spacetime singularities. 

In the context of spacetime theory, gravitational singularities or spacetime singularities are limits (or, loosely speaking, "regions") in which the Einstein field equations break down. This happens when mathematical value of a property (eg. the density) of a region in space reaches an infinite number. Because these equations are taken to be a fundamental description of spacetime itself, this is often taken to imply that these limits indicate an end, or "edge," of space and time. 

The reactions to the discovery of singular solutions to Einstein field equations was quite striking. In the period 1938-39, Oppenheimer and his students Snyder and Volkoff investigated what would happen in general relativity to a massive star that collapsed, and discovered what we now would call a ’black hole’ solution to the mathematical equations. Under certain conditions, Einstein field equation gives us two characterizations of a spacetime singularity:

(1) Curvature singularity, for which spacetime curvature grows beyond all bounds ("blows up"); which only happens in curvature singularity, and

(2) Non-curvature singularity, a singularity that cannot be removed by any choice of coordinates (e.g. conical singularity).

While these criteria work for black holes, however, they are not sufficient to capture all spacetime singularities. The standard characterization of a spacetime singularity had to be more general, and rely on the notion of the geodesics of a spacetime.

Geodesics are the "straightest-possible" lines of a space-time. They are the paths that an object in free-fall (i.e., not subjected to any non-gravitational forces, like the thrust of a rocket engine, or a pull of a rope) will follow. For any geodesic, we can ask whether it is possible to extend it without limit. If this is not possible, then the geodesic path comes to an end in some finite distance. 

Spacetime singularity was therefore defined as "geodesic incompleteness". In other words, a spacetime is singular if it contains geodesics that cannot be extended to infinity. In such cases, it seems that there is an "edge" or and "end" to spacetime, which lies some at some finite distance.

curved singularity in the center of a black hole

Nevertheless, Einstein himself rejected the idea that singularities exist in nature. He thought of it as an abomination, and adopted the attitude that nature would never allow such a thing. Einstein felt that it has to be assumed that general relativity itself, as a theory, would either:

(i) break down in the region of a singularity, and that some more advanced theory would rule out such singularities; or  (ii) that some as yet undetermined principle in GR would forbid such singularities. 

The authority of Einstein meant that few people spent any time investigating singular solutions to GR for some 20 years thereafter. However the situation changed dramatically in the 1960’s. Substantial progress was made when Hawking, Penrose, and Geroch proved several singularity theorems (The Penrose–Hawking singularity theorems).

Hawking and Penrose’s theorem implies that not only were the singular solutions legitimate solutions of the GR equations, they were almost inevitable if certain reasonable premises were satisfied. A singularity in solutions of the Einstein field equations is one of two things:

(1) space-like singularity: a situation where matter is forced to be compressed to a point (2) time-like singularity: a situation where certain light rays come from a region with infinite curvature

Space-like singularities are a feature of non-rotating uncharged black-holes, while time-like singularities are those that occur in charged or rotating black hole. Both of them have the property of geodesic incompleteness, in which either some light-path or some particle-path cannot be extended beyond a certain proper-time or affine-parameter (affine-parameter being the null analog of proper-time).

The theorem applies if the following four physical assumptions are made:

(i) Einstein's equations hold (with zero or negative cosmological constant). (ii) The energy density is nowhere less than minus each principal pressure nor less than minus the sum of the three principal pressures (the 'energy condition'). (iii)There are no closed timelike curves. (iv) Every timelike or null geodesic enters a region where the curvature is not specially alined with the geodesic. (This last condition would hold in any sufficiently general physically realistic model).

In common with earlier results, timelike or null geodesic incompleteness is used here as the indication of the presence of space-time singularities. 

The Penrose theorem guarantees that some sort of geodesic incompleteness occurs inside any black hole whenever matter satisfies reasonable energy conditions (It does not hold for matter described by a super-field, i.e., the Dirac field). The energy condition required for the black-hole singularity theorem is weak: it says that light rays are always focused together by gravity, never drawn apart, and this holds whenever the energy of matter is non-negative.

Hawking's singularity theorem is for the whole universe, and works backwards in time: in Hawking's original formulation, it guaranteed that the Big Bang has infinite density (Hawking later revised his position in 1988).

These theorems indicate that our universe began with an initial singularity, the "Big Bang." They also indicate that in certain circumstances, collapsing matter will form a black hole with a central singularity. This purely theoretical work coincided roughly with several other developments, all in the 1960’s, including the discovery of the microwave background, quasar (quasi-stellar objects), and pulsar.

It is now established that supermassive black holes, which contain what is predicted to be singularities at the center of these black holes, are at the centers of almost all galaxies, and that scattered throughout these galaxies are much smaller black holes left over from massive supernova explosions. Far from being a mathematical pathology, as Einstein thought, singularities may be a crucial part of our universe, probably ever since the very beginning of time and space. 

The Origin of The Universe - Before Creation Itself  

Big Bang Theory and Cosmic Inflation

We live in a finite expanding universe which has not existed forever, and that all the matter, energy and space in the universe was once squeezed into an infinitesimally small volume, which erupted in a cataclysmic "explosion" which has become known as the Big Bang. Current best estimates are that this occurred some 13.7 billion years ago.

The Big Bang theory describes the origin of the Universe, starting from a big initial explosion, from which Space and Time came to existence, followed by the first particles, first atoms, and in the end, planets, stars and galaxies. The theory was proposed the first time in 1927 by the Belgian priest and astronomer Georges Lemaître. He proposed that at the beginning of all things, there was an Initial Singularity, a point of infinite density and temperature thought to have contained all of the mass and space-time of the universe before it exploded and rapidly expand in the Big Bang and subsequent inflation, creating the present-day Universe. The initial singularity is part of the Planck epoch, the earliest period of time in the history of the universe. Observations seem to confirm this theory and its theoretical features. 

An absolute relevant evidence about the expansion of the Universe from an initial singularity is the famous Hubble's Law: even though it is related to the astronomer Edwin Hubble (because he confirmed the law itself), this mathematical relation was discovered by Lemaître himself, from the equations of General Relativity; it consists in the proportionality between the distance d and the recessional velocity v of distant galaxies:

where H0 is the so called Hubble constant". Because we talk about recessional velocity, it means that in a distant past (13.7 billion years ago, according to current measurement), all galaxies were closer from each others and, therefore, going back in time, all the matter of the Universe had to be contained in a single point of space.

In the late 1960s, substantial progress was made when some remarkable mathematical work by R Penrose, later extended by Penrose and Hawking, established that not only were the singular solutions legitimate solutions of the GR equations, but they were almost inevitable. To put this another way - no matter what kind of universe one had, there had to be singularities in it somewhere. 

These results indicated that singularities might be actual features of our universe, and this meant that their investigation was more than a theoretical exercise. It is worth noting that at the time, Lemaître, Prenrose, and Hawking, as well as all the other physicists, used only General relativity to arrive at the conclusion that at the beginning of the Universe, a body containing all mass, energy, and spacetime in the Universe was compressed to an infinitely dense point, an initial singularity. 

An evolutionary scenario, developed in the 1980s, called Inflation (or Cosmic Inflation), that implies an extremely exponential expansion in first instants of the Universe, due to an unknown particle or force: according to this theory, inflation started 10^-36 s after the Big Bang, and it lasted 10^-34 s, an infinitesimally short time in which the Universe expanded from a subatomic scale (10^-28 m), to a macroscopic scale (10^16 m ~ 1 light-year).

Over the last few decades, the use of only general relativity to predict what happened in the beginnings of the Universe has been heavily criticized. It is known that Einstein's equations are only a partial description of reality. The notion of a singularity, infinite density in an infinitely small volume, is anathema to physicists; physicists detest infinities. Infinities in an equation are always a sign that something is wrong. 

While singularities might be unavoidable in classical context, there are some reasons to suspect that quantum processes might prevent true singularities from developing. For example, the above-mentioned positive energy condition (one of the premises that have to be satisfied in Hawking’s singularity theorems proposed in 1973) can be violated by quantum fields, which means that the premises of the singularity theorems are not secure. Quantum mechanics becomes a significant factor in the high-energy environment of the earliest universe, and general relativity on its own fails to make accurate predictions. 

In 1988, Hawking revised his position in his book “A Brief History of Time,” where he stated that "there was in fact no singularity at the beginning of the universe" (p. 50). This revision followed from quantum mechanics, in which general relativity must break down at times less than the Planck time. Hence general relativity cannot be used to show a singularity.

In his more recent book, "The Grand Design," published in 2010, Hawking wrote the following about the Big Bang, where there are also calculations resulting in "singularities":

"Measurements of helium abundance and the CMBR [Cosmic Microwave Background Radiation] provided convincing evidence in favor of the big bang picture of the very early universe, but although one can think of the big bang picture as a valid description of early times, it is wrong to take the big bang literally, that is, to think of Einstein’s theory as providing a true picture of the origin of the universe. That is because general relativity predicts there to be a point in time at which the temperature, density, and curvature of the universe are all infinite, a situation mathematicians call a singularity. To a physicist this means that Einstein’s theory breaks down at that point and therefore cannot be used to predict how the universe began, only how it evolved afterward. So although we can employ the equations of general relativity and our observations of the heavens to learn about the universe at a very young age, it is not correct to carry the big bang picture all the way back to the beginning.

In other words, the fact that singularities are mathematically illogical cannot be used to claim that black holes (or the Big Bang) are existentially illogical. Black holes (and the Big Bang) are confirmed by massive amounts of information which does not include singularities. Singularities are simply mathematical results that show that something is missing or unknown in the mathematical equations. 

In response to the inaccuracy of considering only general relativity, a way to avoid infinities is to adopt a different theory of space and time. What is lacking to the picture of the origin of the universe is a theory that integrates gravity with quantum mechanics. On this matter, alternative theoretical formulations for the beginning of the Universe have been proposed.

One such theory is loop quantum gravity which says that there is a minimum unit of space and a minimum unit of time. Once a minimum unit of space is filled, nothing more can be crammed into it. If anything more is to be added, it has to fit into the next minimum unit of space. Hence, no infinities and no singularities.

Another theory proposed to reconcile gravity with quantum mechanics to explain the beginning of the universe is a string theory-based model in which two branes, enormous membranes much larger than the Universe, collided, creating mass and energy.

To return to the topics of the infinity stones by Marvel Comics, the story of their origin added a thin layer of science into an elaborate fiction. Released in 1972, Marvel Premiere Vol. 1 #1 introduced the green Soul Gem, the first of six such Gems identified in Avengers Annual #7. At the time, Lemaître’s theory of the big bang with preexisting initial singularity was the accepted theory to explain the beginning of the universe, not to mention Penrose’s and Hawking’s breakthrough that supported it then. Describing the origin of the infinity stones as singularities was a brilliant way to present their significance to the readers by employing scientific theories.

Source : Boston University | Max Planck Institute

Hawking, S., & Penrose, R. (1970). The Singularities of Gravitational Collapse and Cosmology. Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences, 314(1519), 529-548. Retrieved from http://www.jstor.org/stable/2416467

Penrose, Roger (2014).  Spacetime Singularities: The Story of Black Holes. University of Oxford. Retrieved from  http://pitp.physics.ubc.ca/quant_lect/2014/GR100/Spacetime+Gravity_B-BHoles.pdf

gifs : Infinity Stones @avengers-of-the-galaxy | Cosmos: A SpaceTime Odyssey 

[jcmarchi]

An X-ray image of half the universe - Technology Org

New Post has been published on https://thedigitalinsider.com/an-x-ray-image-of-half-the-universe-technology-org/

An X-ray image of half the universe - Technology Org

X-ray astronomy has an eventful 60-year history of exploring the extremes of the universe, from exploding stars to active galactic nuclei, which, with their supermassive black holes, are arguably the most efficient energy sources in the universe. While most X-ray telescopes were built to take a closer look at such phenomena, eRosita looks at the bigger picture. These include the largest structures in the universe and filaments of hot gas that connect powerful clusters of galaxies and could answer the biggest questions: how did the universe evolve, and why is it expanding?

The sky section of the eRosita All-Sky Survey Catalogue (eRASS1) in two different representations. The left image shows extended X-ray emission while the right image shows point-like X-ray sources. Image credit: MPE, J. Sanders für das eROSITA-Konsortium

The German eRosita consortium has today published its share of the data collected by the eRosita X-ray telescope on board the Spektrum-RG satellite during the first all-sky survey. The first eRosita All-Sky Survey Catalogue (eRASS1) is the largest collection of X-ray sources ever published, with around 900,000 individual sources. Along with the data, the consortium is publishing a series of scientific papers on new findings ranging from planetary habitability studies to the discovery of the largest cosmic structures. In the first six months of observation, eRosita has already discovered more X-ray sources than have been known in the 60-year history of X-ray astronomy. The data is available to the global scientific community.

More than 700.000 supermassive black holes

The eRASS1 observations with the eROSITA telescope were carried out from 12 December 2019 to 11 June 2020. The data published here cover half of the entire sky, the data share of the German eROSITA consortium. In the most sensitive energy range of the eROSITA detectors (0.2-2 keV), the telescope detected 170 million X-ray photons – a record number. In X-ray astronomy, it is possible to measure individual particles of light (photons) with their respective energy in the X-ray spectrum and their arrival time in the detector. The catalogue was then constructed – after careful processing and calibration – by detecting concentrations of photons in the sky against a bright, large-scale, diffuse background. After eRASS1, eROSITA has continued scanning the sky and accumulated several additional all-sky surveys. Those data will also be released to the world in the coming years.

The 900,000 sources include around 710 000 supermassive black holes in distant galaxies (active galactic nuclei), 180.000 X-ray emitting stars in our own Milky Way, 12.000 clusters of galaxies, plus a small number of other exotic classes of sources like X-ray emitting binary stars, supernova remnants, pulsars, and other objects. “These are mind-blowing numbers for X-ray astronomy,” says Andrea Merloni, eROSITA principal investigator and first author of the eROSITA catalogue paper. “We’ve detected more sources in 6 months than the big flagship missions XMM-Newton and Chandra have done in nearly 25 years of operation.”

Can X-rays from stars make planets uninhabitable?

Co-ordinated with the release, the German eROSITA Consortium has submitted almost 50 new scientific publications to peer-reviewed journals, adding to the more than 200 which had already been published by the team before the data release. Most of the new papers appear today with selected discoveries including: more than 1000 superclusters of galaxies, the giant filament of pristine warm-hot gas extending between two galaxy clusters and two new ‘Quasi-Periodically Erupting’ black holes. Further studies of how X-ray irradiation from a star may affect the atmosphere and water retention of orbiting planets, and statistical analysis of flickering supermassive black holes .

“The scientific breadth and impact of the survey is quite overwhelming; it’s hard to put into a few words,” says Mara Salvato, who as spokesperson for the German eROSITA consortium co-ordinates the efforts of about 250 scientists organised into 12 working groups. “But the papers published by the team will speak for themselves.”

This first eRASS data release (DR1) makes public not only the source catalogue, but images of the X-ray sky at multiple X-ray energies and even lists of the individual photons with their sky positions, energies and precise arrival times. The software needed to analyse the eROSITA data is also included in the release. For many source classes, supplementary data from other wavebands has also been incorporated into so-called “value-added” catalogues that go beyond pure X-ray information. “We’ve made a huge effort to release high-quality data and software,” added Miriam Ramos-Ceja, who leads the eROSITA Operations team. “We hope this will broaden the base of scientists worldwide working with high-energy data and help push the frontiers of X-ray astronomy.”

“The eROSITA collaboration has done an outstanding job with the data release and at the same time publishing all of these amazing new results,” says Kirpal Nandra, Director at MPE. “There’s a lot more to come from us, and we’re looking forward to seeing what the rest of the world will do with the public data.”

Keen eROSITA-watchers may know that the driving scientific objective that motivated the telescope was to constrain cosmological models using clusters of galaxies. The cosmology results, based on an in-depth analysis of the eRASS1 clusters, will be released in approximately two weeks. Watch this space!

HH, BEU

Additional Information

eROSITA is the soft X-ray instrument aboard Spektrum-RG (SRG), a joint Russian-German science mission supported by the Russian Space Agency (Roskosmos), in the interests of the Russian Academy of Sciences represented by its Space Research Institute (IKI), and the German Space Agency at DLR (Deutsches Zentrum für Luft- und Raumfahrt). The SRG spacecraft was built by Lavochkin Association (NPOL) and its subcontractors, and is operated by NPOL with support from the Max-Planck Institute for Extraterrestrial Physics (MPE).

The telescope was launched into space onboard the SRG mission on July 13, 2019. Its large collecting area and wide field of view are designed to perform to a deep all-sky survey in the X-ray band. Over the course of six months (December 2019 to June 2020), SRG/eROSITA completed the first survey of the whole sky at energies 0.2-8 keV, which is significantly deeper than the only existing all-sky survey with an X-ray imaging telescope, performed by ROSAT in 1990 at energies 0.1-2.4 keV. Three more scans of the entire sky were completed between June 2020 and February 2022.

The German eROSITA Consortium is led by the Max Planck Institute for Extraterrestrial Physics (MPE), and includes the Dr. Karl Remeis Observatory Bamberg, the University of Hamburg Observatory, the Leibniz Institute for Astrophysics Potsdam (AIP), and the Institute for Astronomy and Astrophysics of the University of Tübingen, with the support of DLR and the Max Planck Society. The Argelander Institute for Astronomy of the University of Bonn and the Ludwig-Maximilians-Universität Munich also participate in the science exploitation of eROSITA as associated institutes.The eROSITA data are processed using the eSASS software system developed by the German eROSITA consortium.

eROSITA has been placed in Safe Mode in February 2022, and has not restarted science operations since.

Source: MPG

You can offer your link to a page which is relevant to the topic of this post.

[spacetimewithstuartgary]

Astronomers observe elusive stellar light surrounding ancient quasars

Astronomers have observed the elusive starlight surrounding some of the earliest quasars in the universe. The distant signals, which trace back more than 13 billion years to the universe’s infancy, are revealing clues to how the very first black holes and galaxies evolved.

Quasars are the blazing centers of active galaxies, which host an insatiable supermassive black hole at their core. Most galaxies host a central black hole that may occasionally feast on gas and stellar debris, generating a brief burst of light in the form of a glowing ring as material swirls in toward the black hole.

Quasars, by contrast, can consume enormous amounts of matter over much longer stretches of time, generating an extremely bright and long-lasting ring — so bright, in fact, that quasars are among the most luminous objects in the universe.

Because they are so bright, quasars outshine the rest of the galaxy in which they reside. But the team was able for the first time to observe the much fainter light from stars in the host galaxies of three ancient quasars.

Based on this elusive stellar light, the researchers estimated the mass of each host galaxy, compared to the mass of its central supermassive black hole. They found that for these quasars, the central black holes were much more massive relative to their host galaxies, compared to their modern counterparts.

The findings, published today in the Astrophysical Journal, may shed light on how the earliest supermassive black holes became so massive despite having a relatively short amount of cosmic time in which to grow. In particular, those earliest monster black holes may have sprouted from more massive “seeds” than more modern black holes did.

“After the universe came into existence, there were seed black holes that then consumed material and grew in a very short time,” says study author Minghao Yue, a postdoc in the Kavli Institute for Astrophysics and Space Research. “One of the big questions is to understand how those monster black holes could grow so big, so fast.”

“These black holes are billions of times more massive than the sun, at a time when the universe is still in its infancy,” says study author Anna-Christina Eilers, assistant professor of physics. “Our results imply that in the early universe, supermassive black holes might have gained their mass before their host galaxies did, and the initial black hole seeds could have been more massive than today.”

Eilers’ and Yue’s co-authors include Kavli Director Robert Simcoe, MIT Hubble Fellow and postdoc Rohan Naidu, and collaborators in Switzerland, Austria, Japan, and at North Carolina State University.

Dazzling cores

A quasar’s extreme luminosity has been obvious since astronomers first discovered the objects in the 1960s. They assumed then that the quasar’s light stemmed from a single, star-like “point source.” Scientists designated the objects “quasars,” as a portmanteau of a “quasi-stellar” object. Since those first observations, scientists have realized that quasars are in fact not stellar in origin but emanate from the accretion of intensely powerful and persistent supermassive black holes sitting at the center of galaxies that also host stars, which are much fainter in comparison to their dazzling cores.

It’s been extremely challenging to separate the light from a quasar’s central black hole from the light of the host galaxy’s stars. The task is a bit like discerning a field of fireflies around a central, massive searchlight. But in recent years, astronomers have had a much better chance of doing so with the launch of NASA’s James Webb Space Telescope (JWST), which has been able to peer farther back in time, and with much higher sensitivity and resolution, than any existing observatory.

In their new study, Yue and Eilers used dedicated time on JWST to observe six known, ancient quasars, intermittently from the fall of 2022 through the following spring. In total, the team collected more than 120 hours of observations of the six distant objects.

“The quasar outshines its host galaxy by orders of magnitude. And previous images were not sharp enough to distinguish what the host galaxy with all its stars looks like,” Yue says. “Now for the first time, we are able to reveal the light from these stars by very carefully modeling JWST’s much sharper images of those quasars.”

A light balance

The team took stock of the imaging data collected by JWST of each of the six distant quasars, which they estimated to be about 13 billion years old. That data included measurements of each quasar’s light in different wavelengths. The researchers fed that data into a model of how much of that light likely comes from a compact “point source,” such as a central black hole’s accretion disk, versus a more diffuse source, such as light from the host galaxy’s surrounding, scattered stars.

Through this modeling, the team teased apart each quasar’s light into two components: light from the central black hole’s luminous disk and light from the host galaxy’s more diffuse stars. The amount of light from both sources is a reflection of their total mass. The researchers estimate that for these quasars, the ratio between the mass of the central black hole and the mass of the host galaxy was about 1:10. This, they realized, was in stark contrast to today’s mass balance of 1:1,000, in which more recently formed black holes are much less massive compared to their host galaxies.

“This tells us something about what grows first: Is it the black hole that grows first, and then the galaxy catches up? Or is the galaxy and its stars that first grow, and they dominate and regulate the black hole’s growth?” Eilers explains. “We see that black holes in the early universe seem to be growing faster than their host galaxies. That is tentative evidence that the initial black hole seeds could have been more massive back then.”

“There must have been some mechanism to make a black hole gain their mass earlier than their host galaxy in those first billion years,” Yue adds. “It’s kind of the first evidence we see for this, which is exciting.”

IMAGE....A James Webb Telescope image shows the J0148 quasar circled in red. Two insets show, on top, the central black hole, and on bottom, the stellar emission from the host galaxy. Credit Courtesy of Minghao Yue, Anna-Christina Eilers; NASA

[klaudiafmp]

Quasars

“A quasar is an extremely luminous active galactic nucleus, in which a supermassive black hole with mass ranging from millions to billions of times the mass of the Sun is surrounded by a gaseous accretion disk. As gas in the disk falls towards the black hole, energy is released in the form of electromagnetic radiation, which can be observed across the electromagnetic spectrum. The power radiated by quasars is enormous: the most powerful quasars have luminosities thousands of times greater than a galaxy such as the Milky Way.

The term quasar originated as a contraction of star-like radio source, because quasars were first identified during the 1950s as sources of radio-wave emission of unknown physical origin, and when identified in photographic images at visible wavelengths they resembled faint star-like points of light. High-resolution images of quasars, particularly from the Hubble Space Telescope, have demonstrated that quasars occur in the centers of galaxies, and that some host-galaxies are strongly interacting or merging galaxies. As with other categories of, the observed properties of a quasar depend on many factors including the mass of the black hole, the rate of gas accretion, the orientation of the accretion disk relative to the observer, the presence or absence of a jet, and the degree of obscuration by gas and dust within the host galaxy.

Quasars are found over a very broad range of distances, and quasar discovery surveys have demonstrated that quasar activity was more common in the distant past. The peak epoch of quasar activity was approximately 10 billion years ago. As of 2017, the most distant known quasar is ULAS at redshift z = 7.54; light observed from this quasar was emitted when the universe was only 690 million years old. The supermassive black hole in this quasar, estimated at 800 million solar masses, is the most distant black hole identified to date.”

“Quasars are part of a class of objects known as active galactic nuclei (AGN). Other classes include Seyfert galaxies and blazars. All three require supermassive black holesto power them.

Seyfert galaxies are the lowest energy AGN, putting out only about 100 kiloelectronvolts. Blazars, like their quasar cousins, put out significantly more energy.Many scientists think that the three types of AGNs are the same objects, but with different perspectives. While the jets of quasars seem to stream at an angle generally in the direction of Earth, blazars may point their jets directly toward the planet. Although no jets are seen in Seyfert galaxies, scientists think this may be because we view them from the side, so all of the emission is pointed away from us and thus goes undetected.”

“Many astronomers believe that quasars are the most distant objects yet detected in the universe. Quasars give off enormous amounts of energy - they can be a trillion times brighter than the Sun! Quasars are believed to produce their energy from massive black holes in the center of the galaxies in which the quasars are located. Because quasars are so bright, they drown out the light from all the other stars in the same galaxy.

Despite their brightness, due to their great distance from Earth, no quasars can be seen with an unaided eye. Energy from quasars takes billions of years to reach the Earth's atmosphere. For this reason, the study of quasars can provide astronomers with information about the early stages of the universe. “

“Shining so brightly that they eclipse the ancient galaxies that contain them, quasars are distant objects powered by black holes a billion times as massive as our sun. These powerful dynamos have fascinated astronomers since their discovery half a century ago.

In the 1930s, Karl Jansky, a physicist with Bell Telephone Laboratories, discovered that the static interference on transatlantic phone lines was coming from the Milky Way. By the 1950s, astronomers were using radio telescopes to probe the heavens, and pairing their signals with visible examinations of the heavens. However, some of the smaller point-source objects didn't have a match. Astronomers called them "quasi-stellar radio sources," or "quasars," because the signals came from one place, like a star. However, the name is a misnomer; according to the National Astronomical Observatory of Japan, only about 10 percent of quasars emit strong radio waves.Naming them didn't help determine what these objects were. It took years of study to realize that these distant specks, which seemed to indicate stars, are created by particles accelerated at velocities approaching the speed of light.”

To be honest I don’t actually know how do Quasars relate to my topic exept ‘space stuff’ but they are so freaky. Like black holes are already scary as they are beacue obviously people fear what they don’t know and nobody had ever been to a black hole or we have no footage or actuall proof of what the do other than specullations and hypothesesthat they simply suck up all matter. And everyone is clueless what happens after. They are said to also be forever expanding so if those are already scary imagine a giant quasar which is basically a supper boosted black hole in the middle of a galaxy that has already sucked up so much light its actually the most shining thing out there within that galaxy. And the closest one is apparently around 800 light years away. And I just reaserched Alpha Centauri that are only 4 light years away and people are already talking about how we should go there. When you think about it by the time we get to the Alpha Centauri the quasars which are basically just super ancient black holes on steroids are going to be so much bigger and closser to Earth by that point and I’m kinda glad I will definitely not be around by the time humans find out what it’s like to be in  a black hole because those things are freaky as.

https://en.wikipedia.org/wiki/Quasar

https://www.space.com/17262-quasar-definition.html

https://starchild.gsfc.nasa.gov/docs/StarChild/universe_level2/quasars.html

[2whatcom-blog]

Gravitational Waves Trace at a Black Gap Consuming a Neutron Star

Gravitational waves could have simply delivered the primary sighting of a black gap devouring a neutron star. If confirmed, it will be the primary proof of the existence of such binary methods. The information comes only a day after astronomers had detected gravitational waves from a merger of two neutron stars for less than the second time. At 15:22:17 UTC on 26 April, the dual detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) in america and the Virgo observatory in Italy reported a burst of waves of an uncommon kind. Astronomers are nonetheless analysing the info and doing laptop simulations to interpret them. However they're already contemplating the tantalizing prospect that they've made a long-hoped-for detection that might produce a wealth of cosmic info, from exact assessments of the overall concept of relativity to measuring the Universe's charge of growth. Astronomers world wide are additionally racing to look at the phenomenon utilizing various kinds of telescope. "I think that the classification is leaning towards neutron star-black hole" merger, says Chad Hanna, a senior member of LIGO's data-analysis crew and a physicist at Pennsylvania State College in College Park. However the sign was not very sturdy, which signifies that it might be a fluke. "I think people should get excited about it, but they should also be aware that the significance is much lower" than in lots of earlier occasions, he says. LIGO and Virgo had beforehand caught gravitational waves--faint ripples within the cloth of space-time--from two varieties of cataclysmic occasion: the mergers of two black holes, and of two neutron stars. The latter are small however ultra-dense objects fashioned after the collapse of stars extra huge than the Solar. The most recent occasion, provisionally labelled #S190426c, seems to have occurred round 375 megaparsecs (1.2 billion light-years) away, the LIGO-Virgo crew calculated. The researchers have drawn a 'sky map', exhibiting the place the gravitational waves are almost certainly to have originated, and despatched this info out as a public alert, in order that astronomers world wide might start looking out the sky for mild from the occasion. Matching gravitational waves to different types of radiation on this means can produce rather more details about the occasion than both kind of knowledge can alone. Mansi Kasliwal, an astrophysicist on the California Institute of Know-how in Pasadena, leads considered one of a number of initiatives designed to do this sort of follow-up work, known as International Relay of Observatories Watching Transients Occur (GROWTH). Her crew can commandeer robotic telescopes world wide. On this case, the researchers instantly began up one in India, the place it was evening time when the gravitational waves arrived. "If weather cooperates, I think in less than 24 hours we should have coverage in almost the entire sky map," she says. Two directly Astronomers have been already working in overdrive once they noticed the potential black hole-neutron star merger. At 08:18:26 UTC on 25 April, one other practice of waves hit the LIGO's detector in Livingston, Louisiana, and Virgo. (On the time, LIGO's second machine, in Hanford, Washington, was briefly out of fee.) That occasion was a clear-cut case of two merging neutron stars, Hanna says--nearly two years after the primary historic discovery of such an occasion was made in August 2017. Researchers can often make such a name as a result of the waves reveal the plenty of the objects concerned; objects roughly twice as heavy because the Solar are anticipated to be neutron stars. Primarily based on the waves' loudness, the researchers additionally estimated that the collision occurred some 150 megaparsecs (500 million light-years) away, says Hanna. That was round thrice farther than the 2017 merger. Iair Arcavi, an astrophysicist at Tel Aviv College who works on the Las Cumbres Observatory, considered one of GROWTH's rivals, was in Baltimore, Maryland, to attend a convention known as Enabling Multi-Messenger Astrophysics (EMMA)--the apply of observing these occasions in a number of wavelengths. The alert of the 25 April occasion got here at 5:01 a.m. "I set it up to send me a text message, and it woke me up," he says. A storm of exercise swept the assembly, with astronomers who would usually compete with one another exchanging info as they sat with their laptops round espresso tables. "We're losing our minds over here at #EMMA2019", tweeted astronomer Andy Howell. However on this case, not like many others, LIGO and Virgo have been unable to considerably slim down the path within the sky that the waves got here from. The researchers might say solely that the sign was from a large area that covers roughly one-quarter of the sky. They narrowed down the area barely the day after. Nonetheless, astronomers had well-honed machines for doing simply this sort of search, and the info they collected the next evening ought to in the end reveal the supply, Kasliwal says. "if it existed in that region, there's no way we would have missed it." Within the 2017 neutron-star merger, the mix of observations in several wavelengths produced a stupendous quantity of science. Two seconds after the occasion, an orbiting telescope had detected a burst of gamma rays--presumably launched when the merged star collapsed right into a black gap. And a few 70 different observatories have been busy for months, watching the occasion unfold throughout the electromagnetic spectrum, from radio waves to X-rays. If the 26 April occasion shouldn't be a black hole-neutron star merger, it's most likely additionally a collision of neutron stars, which might carry the overall detections of this kind as much as three. Lengthy-sought system However seeing a black gap sweep up a neutron star might produce a wealth of data that no different kind of occasion can present, says B. S. Sathyaprakash, a LIGO theoretical physicist at Pennsylvania State. To start with, it confirms that these long-sought methods do exist, originating from binary stars of very totally different plenty. And the orbits the 2 objects hint within the last phases of their strategy might be moderately totally different from these seen with pairs of black holes. Within the neutron star-black gap case, the more-massive black gap would twist area round it because it spins. "The neutron star will be swirled around in a spherical orbit rather than a quasi-circular orbit," Sathyaprakash says. For that reason, "neutron star-black hole systems can be more powerful test beds for general relativity", he says. Furthermore, the gravitational waves and the companion observations from astronomers might reveal what occurs within the last phases earlier than the merger. As tidal forces tear the neutron star aside, they may assist astrophysicist clear up a long-standing thriller: what state is matter in inside these ultra-compact objects. The LIGO-Virgo collaboration started its present observing run on 1 April, and had anticipated to see roughly one merger of black holes per week and considered one of neutron stars monthly. Thus far, these predictions have been met--the observatories have additionally seen a number of black-hole mergers this month. "This is just amazing," says Kasliwal. "The Universe is fantastic." This text is reproduced with permission and was first printed on April 26, 2019. Read the full article