Swift Survey Finds 'Missing' Active Galaxies

Most large galaxies contain a giant central black hole. In an active galaxy, matter falling toward the supermassive black hole powers high-energy emissions so intense that two classes of active galaxies, quasars and blazars, rank as the most luminous objects in the universe. Thick clouds of dust and gas near the central black hole screens out ultraviolet, optical and low-energy (or soft) X-ray light.

Although there are many different types of active galaxy, astronomers explain the different observed properties based on how the galaxy angles into our line of sight. We view the brightest ones nearly face on, but as the angle increases, the surrounding ring of gas and dust absorbs increasing amounts of the black hole's emissions.

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Most big galaxies contain big black holes. Not just big, supersized, with millions of times the sun's mass. Some of these black holes are actively devouring gas. This drives particle jets that can spew matter millions of light-years into space, and it also makes the holes a source of penetrating, or hard, X-rays. At these energies, the sky glows in every direction, even far away from bright sources.

Astronomers have long suspected that active supermassive black holes in galaxies were responsible, but they just couldn't find enough of them to account for the X-ray glow — especially the peak of the energy spectrum. Now, astronomers using NASA's Swift satellite confirm that a largely unseen population of black-hole-powered galaxies is out there.

There are so many that scientists say they might fully account for the cosmic X-ray background. What emission we detect from an active black hole is a function of how we see it — whether we're looking face-on and into one of it's jets, or viewing it from the side, through the disk of gas and dust that surrounds it.

The brightest active black holes, which include quasars and blazars, are those we see face-on. But as the viewing angle increases, the surrounding disk absorbs increasing amounts of radiation. Astronomers have always assumed that many active galaxies were oriented edgewise to us, but because the disk of gas smothers most of their X-rays, these sideways black holes just weren't detected.

And that's where Swift comes in. Since 2004, the satellites Burst Alert Telescope has been building up the largest, most sensitive X-ray map of the sky. Using these data, astronomers found that the most heavily absorbed galaxies create the energy peak in the cosmic X-ray background.

What does it all mean? When the universe was about half its present age, about 7 billion years ago, galaxies crashed together more frequently and these collisions produced gas rich galaxies with heavily obscured black holes.

The Swift survey shows that galaxy mergers helped activate these black holes by feeding them torrents of fresh gas. The new findings are consistent with idea that the X-ray background peaked around this time, when our own galaxy was young and before our solar system was born.
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[Desertphile]

@questionsleadtotruth ; Considering the current state of humanity and society, I suspect nobody will be born 500 years from now.

[CreatedByBrett]

"Penetrating or hard." Hee hee hee!
"Torrents of fresh gas." Tee hee!

[YourBrainOnReligion]

@seanc46 In short, things in space used to be closer together causing more collisions and allowing for more black holes to form. Black holes cause background radiation (BR) and due to these higher numbers, it may account for the BR we hear in space (the fuzzy sound on your radio or tv = BR from space). The gases surrounding the quasars absorb most of the light, so they're hard to see from the side, making them harder to detect. Could be an alternative explanation for BR, sounds like...?

[liketheuniverse]

I understand that we must respect each others opinion, but it is really hard when you know that God exists and people believe otherwise! Because it is just a matter of believing! Then He proves to you that He exists! People should think harder about this: just because many don't believe it doesn't mean He doesn't exist! You must have faith! The Bible is the word of God, He sent His son to show us what to do to save our souls! Jesus paid for our sins! We are not only flesh bodies, we have souls!!

[broodyart]

I can't get the idea out of my mind, that at the center of galaxies, are huge solids. Giant, dense matter. It just seems logical. That our matter, has it's limits on size. Especially when it goes down to partical level. I argued about this with someone, that there IS a "down", beyond fundimental particals, he stood firm, there is not! If any partical exists, it must exist in an area. The AREA is infinite, not the particle. But he could not grasp that. Forces & fields?, we need better machines!

[Edcastaneda]

@datawraith3080 I really don't want to argue but I personally believe black holes do exist. We can see rays or bursts of light coming from black holes called gamma ray bursts. This happens when a planet is sucked up by the black hole. Its those bursts that Infrared Radiation detects. We never truly see the black hole but we do see tremendous jet like energy burst coming from them. Also we know they are there because we see planets orbiting unseen paths. We assume its a black hole...

[blackchaos]

So wait, can someone re-explain the Intensity part. How does our viewing angle affect the amount of radiation taken in by the surrounding disc? And how is it possible for us to view a galaxy so far away from us at different angles? Even though the Earth, and our solar system rotates, doesn't it still give us a 2-dimensional picture considering the amount of space between us and the galaxy (even with zooming in). Maybe it has something to do with how Swift works..

[turtlezilla]

@MrMurraypants I used to think the same way as you do. About how youtube comments might be a reflection of societies actual mindset. But I realized I was wrong when I started reading the comments in a lot of other places. It all depends where your looking really. It seems that the large majority of people who actually comment on youtube videos don't really have anything to say or contribute. But if your looking in the right place a few comments can make you hopeful for your fellow man.

[Jrez]

@MrMurraypants I see, so when you're wrong about one thing you change the subject. I admire your honesty in knowing to admit when you've made a mistake. Really, I'm the same way, I can appreciate it in other people. Still, if youtube comments are any reflection of the makeup of society then society depresses me. Just go to any video containing police and black people and look at the comments and you'll see why I am ashamed. I don't know anybody like that, but just look at the plethora there.

[MrMurraypants]

@Jrezky you should actually judge society via youtube comments b/c youtube comes from the thoughts of real people in the real world aka society. In fact, Youtube is damn near one of the greatest examples on how you gauge peoples intelligence by what they write and vlog about. I am actually honest with myself about my ignorance towards certain things and im not ashamed of it...if im corrected then i take it in stride as a learning experience and move on but the dialogue doesn't have to end there

[MrMurraypants]

@ThatsSoBS you are part of the fail in the comments, guy....what have you said?...hmmm. i see to things you wrote, 1. you said i was wrong on sooo many levels you can't even start....then 2. so much fail in comments you want to cry....advice to you, try interacting socially with people here about the video and have a dialogue like me and whatshisface. But you just want to make a quick bash at people and go about your business right. No substance, no insight, and no questions...thats Fail.

[MrMurraypants]

@Jrezky nope...never said that. i just said you're plain arrogant. I graduated high school then went on to college, then the Army, then college again but im not a knowitall. There is stuff i remember and there is stuff that slips through the cracks just like any natural born human that ever lived. I will not judge you for dropping out, cus shit happens right, but i will say that we as a species have a long long way to go in terms of knowledge and how to use it properly.

[MrMurraypants]

@Jrezky if you aren't pretending, then you're just plan arrogant. How old are you? Im 28, and its been quite awhile since i was in high school much less middle school so excuse me for not have a photographic memory for these things. I didn't necessarily say that that one particular thing was an intricacy...i was saying that there are loads more things to know about the universe than what we know now. Ok... the fucking sun will never be a supernova...next.

[MrMurraypants]

@Jrezky ok obviously i am not winning in our mini arguement here but i have yet to take a proper astrophysics class...maybe one day i will hopefully. True that 'plenty' of people know this but my point is that the majority of people living on our blue earth does not know the intricacies of what goes on in the cosmos...i know a little not a lot by comparison to what can be known and you would probably fit in to that catagory as well. Don't pretend to be more than you are unless you have a degree.

[MrMurraypants]

hmmm....i wouldn't go as far as to say 'black hole powered galaxies'. I could be wrong but aren't black holes the 'effect' of having some much gas and pressure compounded towards the center of a galaxy. The bigger the galaxy the bigger the black hole. Not all black holes are super massive..some the size of a golf ball infact. I also have theory that would state that a black hole is essentially antimatter...and alot of it. Its a fact that anitmatter destroys matter so....why not.

[YourBrainOnReligion]

@BlackRaptor31 Ah, I interpreted it as this could potentially downplay the significance of CBR relative to the big bang (since black holes also generate it and now are thought to be in higher numbers...?) *shrug*

[bimblinghill]

@gaynorglowellxsingh There's thought to be just the one 'supermassive' black hole, at the centre, which are the subject of this vid. There are about a dozen stellar mass black holes known or suspected from observations in the Milky Way, but there are likely to be many more found as our observations improve.

[shoa]

The world should all come together now with one goal in mind, to explore space looking for anything and everything. Built Deep Space stations, station on the Moon and Mars. Walk around Titan, lighting a cigarette, you know things like that, Instead we fight among each other for a piece of land on one stupid planet.

[gulllars]

@MrMurraypants i believe the term you're looking for is eidetic memory, not photographic memory. Photographic memory is coloquial for photo-eidetic memory, which is an ability to recall images with extreme precision and abundance. Most humans have this kind of memory with smells, but not with other faculties. I am an auditory eidetic :)

[Jrez]

@MrMurraypants How am I arrogant again? I said the sun won't supernova, you said it would, I said no, we know it won't. It's predicted. Now I'm an arrogant knowitall? I certainly don't remember everything either but if we teach something to middle school kids you can be damn sure that it's common knowledge.