Astrophysics and Cosmology - Discuss the Universe here

[FallenSeraph]

Awesome new deep field pic from Hubble using gravitational lensing of giant galaxy cluster Abell 2744 to image galaxies as far ast 12 billion light years away. 

The Hubble exposure reveals nearly 3,000 of these background galaxies interleaved with images of hundreds of foreground galaxies in the cluster. The many background galaxies would otherwise be invisible without the boost from gravitational lensing. Their images not only appear brighter, but also smeared, stretched, and duplicated across the field.  Thanks to the gravitational lensing phenomenon, the background galaxies are magnified to appear up to 10 to 20 times larger than they would normally appear. What's more, the faintest of these highly magnified objects have intrinsic brightnesses roughly 10 to 20 times fainter than any galaxies ever previously observed.

Full story here

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I feel small. 

[zeebo]

I feel small. 

This is M87, which is a monster galaxy in the Virgo cluster of galaxies.    Ok so it's not much to look at, being just a big fuzzball as opposed to it's more elegant spiral cousins, however, it impresses in other ways. 

It containes several trillion stars (as opposed to our mere hundreds of billions).  It's so massive that it's the gravitational center of the huge Virgo cluster of many other galaxies which flit about it as if they were just little planets circling a star.  The supermassive black hole at it's center weighs in at a staggering 6.6 billion suns.  It has a colossal jet of material streaming out from it that's around 5000 light years long.  That's right, it's the big dog on the block.

Anyway one time I heard a cosmologist speaking about it (which was cool as I'd seen it for myself with my backyard telescope some time before).  He mentioned that if you lived there as part of an advanced civilization complete with light-speed travel and life-extension technologies to keep you going for thousands of years etc., there would still be no reason to ever leave your home galaxy as you simply would never have enough time to explore it all.  It's basically it's own universe.  And that's just one galaxy amongst the billions of galaxies out there.   

Yep makes me feel small sometimes, but also it's all so mind-boggling that the sheer amazement of it makes me feel part of something big, real big. 

[attachimg=1]

[steelbot]

This is M87, which is a monster galaxy in the Virgo cluster of galaxies.    Ok so it's not much to look at, being just a big fuzzball as opposed to it's more elegant spiral cousins, however, it impresses in other ways. 

It containes several trillion stars (as opposed to our mere hundreds of billions).  It's so massive that it's the gravitational center of the huge Virgo cluster of many other galaxies which flit about it as if they were just little planets circling a star.  The supermassive black hole at it's center weighs in at a staggering 6.6 billion suns.  It has a colossal jet of material streaming out from it that's around 5000 light years long.  That's right, it's the big dog on the block.

Anyway one time I heard a cosmologist speaking about it (which was cool as I'd seen it for myself with my backyard telescope some time before).  He mentioned that if you lived there as part of an advanced civilization complete with light-speed travel and life-extension technologies to keep you going for thousands of years etc., there would still be no reason to ever leave your home galaxy as you simply would never have enough time to explore it all.  It's basically it's own universe.  And that's just one galaxy amongst the billions of galaxies out there.   

Yep makes me feel small sometimes, but also it's all so mind-boggling that the sheer amazement of it makes me feel part of something big, real big. 

[attachimg=1]

nice pic - love the subject matter!

[Agent : Orange]

This is M87, which is a monster galaxy in the Virgo cluster of galaxies.    Ok so it's not much to look at, being just a big fuzzball as opposed to it's more elegant spiral cousins, however, it impresses in other ways. 

It containes several trillion stars (as opposed to our mere hundreds of billions).  It's so massive that it's the gravitational center of the huge Virgo cluster of many other galaxies which flit about it as if they were just little planets circling a star.  The supermassive black hole at it's center weighs in at a staggering 6.6 billion suns.  It has a colossal jet of material streaming out from it that's around 5000 light years long.  That's right, it's the big dog on the block.

Anyway one time I heard a cosmologist speaking about it (which was cool as I'd seen it for myself with my backyard telescope some time before).  He mentioned that if you lived there as part of an advanced civilization complete with light-speed travel and life-extension technologies to keep you going for thousands of years etc., there would still be no reason to ever leave your home galaxy as you simply would never have enough time to explore it all.  It's basically it's own universe.  And that's just one galaxy amongst the billions of galaxies out there.   

Yep makes me feel small sometimes, but also it's all so mind-boggling that the sheer amazement of it makes me feel part of something big, real big. 

[attachimg=1]

This is a really interesting galaxy! In fact M87 is really more of a nearby quasar. The galaxy has a huge jet of gas being blown out of it by the central black hole. You can see a small hint of structure here near the center of it in the picture you posted. The jet is thousands of parsecs long (1 parsec = 3.26 light years). The narrow jet is a result of electrons spiraling around the highly collimated magnetic fields blown out by the black hole at the center of the galaxy and can be seen all the way from X-rays to the radio end of the spectrum. Here's a picture of the jet itself with some more details:

And a time lapse movie of the jet over a decade or so is in this article
http://www.astronomy.com/~/link.aspx?_id=b490f89a-b57d-4663-a48f-ad61953a1279

[maureen]

Awesome new deep field pic from Hubble using gravitational lensing of giant galaxy cluster Abell 2744 to image galaxies as far as 12 billion light years away. 

The Hubble exposure reveals nearly 3,000 of these background galaxies interleaved with images of hundreds of foreground galaxies in the cluster. The many background galaxies would otherwise be invisible without the boost from gravitational lensing. Their images not only appear brighter, but also smeared, stretched, and duplicated across the field.  Thanks to the gravitational lensing phenomenon, the background galaxies are magnified to appear up to 10 to 20 times larger than they would normally appear. What's more, the faintest of these highly magnified objects have intrinsic brightnesses roughly 10 to 20 times fainter than any galaxies ever previously observed.

Full story here

[attachimg=1]

fascinating to think of "galaxy clusters"

[West of the Rockies]

Zeebo, you said, "The supermassive black hole at it's center weighs in at a staggering 6.6 billion suns.  It has a colossal jet of material streaming out from it that's around 5000 light years long." 

I am a bit confused (or under-informed anyway).  I thought a black hole drew matter into its center, but you say this one is streaming material from its center....  So a black hole can be a creator as much as it can be a destroyer?  It's the Kali of the cosmos!

[maureen]

This is a really interesting galaxy! In fact M87 is really more of a nearby quasar. The galaxy has a huge jet of gas being blown out of it by the central black hole. You can see a small hint of structure here near the center of it in the picture you posted. The jet is thousands of parsecs long (1 parsec = 3.26 light years). The narrow jet is a result of electrons spiraling around the highly collimated magnetic fields blown out by the black hole at the center of the galaxy and can be seen all the way from X-rays to the radio end of the spectrum. Here's a picture of the jet itself with some more details:

And a time lapse movie of the jet over a decade or so is in this article
http://www.astronomy.com/~/link.aspx?_id=b490f89a-b57d-4663-a48f-ad61953a1279

I am totally in awe!! Ane very grateful for the brilliant posters!!!

[steelbot]

Zeebo, you said, "The supermassive black hole at it's center weighs in at a staggering 6.6 billion suns.  It has a colossal jet of material streaming out from it that's around 5000 light years long." 

I am a bit confused (or under-informed anyway).  I thought a black hole drew matter into its center, but you say this one is streaming material from its center....  So a black hole can be a creator as much as it can be a destroyer?  It's the Kali of the cosmos!

Isn't it called Hawking's Radiation.  And yes, black holes can only swoop up so much matter before it essentially "burps" and some burps are huge gamma bursts or other fantastic energies such as hawking radiation.

[maureen]

in the words of Christopher Fry, a comet is "an excess of celestial phlegm on its way to a heavenly spitoon,"  ...so, an exploding black hole might be cosmic flatulence?... 

[DigitalPigSnuggler]

Zeebo, you said, "The supermassive black hole at it's center weighs in at a staggering 6.6 billion suns.  It has a colossal jet of material streaming out from it that's around 5000 light years long." 

I am a bit confused (or under-informed anyway).  I thought a black hole drew matter into its center, but you say this one is streaming material from its center....  So a black hole can be a creator as much as it can be a destroyer?  It's the Kali of the cosmos!

He didn't say that it was streaming from the black hole.  There is a magnetic field formed by the disk of material spiraling around and into the black hole.  This magnetic field propels hot gas outwards in a constricted stream that is believed to follow the structure of the magnetic field.

[DigitalPigSnuggler]

Isn't it called Hawking's Radiation. 

No, Hawking Radiation is something else entirely.  You can look it up for a more detailed explanation, but here's the Reader's Digest version.

Pairs of "virtual" particles are being formed from energy all the time, even in "empty" space.  One particle is matter, and the other is its anti-matter twin.  Usually they recombine and turn back into energy in a very short period of time, although occasionally that have a somewhat longer lifetime.

Hawking postulated that at the "event horizon" (the boundary beyond which no matter can escape the gravitational attraction of the black hole) there are virtual particles being formed, just as they are everywhere else, and that sometimes one of the pair of virtual particles is captured by the black hole, while the other moves off into space and becomes a "real" particle.  Based on some formulas, it's possible to calculate how long it will take for a black hole to "evaporate."  It's also believed that the particles carry other properties that resolve some of the theoretical problems about information and entropy disappearing into black holes and thus out of the universe as we know it.

You would not be able to image this kind of radiation to produce pictures like what are seen in the article.

[West of the Rockies]

He didn't say that it was streaming from the black hole.  There is a magnetic field formed by the disk of material spiraling around and into the black hole.  This magnetic field propels hot gas outwards in a constricted stream that is believed to follow the structure of the magnetic field.

Ah, good catch, DigitalPig... I misinterpreted Zeebo's words. 

Not that it matters really, but isn't Zeebo one of our far-too-few female posters?  (Not sure what leads me to think so, but I do....)

[zeebo]

First:  For the record, I am male.  And please note, it takes a real man to have a squirrel for an avatar. 

Second:  I'm not sure how the jets work, I'm sure Agent Orange or area51drone know more.  I think the jet is stuff that doesn't quite get drawn into the black hole (i.e. past the event horizon) and is instead ejected violently outward somehow.  So it's coming from the area of the black hole but not from the inside as nothing can do that.

[West of the Rockies]

My mistake, Zeebo!  Hey, is there a Zeebo character in the web series The Guild?

[zeebo]

My mistake, Zeebo!  Hey, is there a Zeebo character in the web series The Guild?

Hmm don't know, that name popped into my head for no particular reason due to a combination of sleep deprivation and whiskey and temporary Noory-induced madness the night I signed up here.   

[Agent : Orange]

What a horribly busy few weeks!

Anyway, DigitalPigSnuggler described the nature of the black hole jets very well. The environments around black holes are some of the most violent and active places in the universe and all of that produces a huge amount of luminosity. Most of the black holes we know of have first been observed from high energy emission from the accretion disk around them which produces tangled magnetic fields that are blown out of the disk. These magnetic fields carry plasma with them and you get a tightly collimated flow of material from the inner regions of the disk out to great distances, producing huge jets.

In more complex environments a black hole can attract nearby gas clouds, triggering a burst of star formation as the clouds begin to orbit the hole. So there are entire populations of stars that are born on the periphery of black holes.

It's poetic that even in the darkest corners of the universe the light from newborn stars still shines.

[Yorkshire pud]

This is pretty damned exciting stuff, wanna take a ride? 


http://www.bbc.co.uk/news/science-environment-25814454

[DigitalPigSnuggler]

Most of the black holes we know of have first been observed from high energy emission from the accretion disk around them which produces tangled magnetic fields that are blown out of the disk.

I recall John Wheeler, who was the physicist who popularized the term "black hole," explaining how they knew they had black hole candidates, way back in the old days when the observations didn't have the resolution that they have now.  He made the analogy of a formal ball, where the men are dressed in their black tuxedos, and the women in their white evening gowns.  As they whirled around on the dance floor, the lights would go low, and all you could see was the women twirling around; you couldn't see the men at all.  Nevertheless, you knew that they were there, because something had to be keeping the women in "orbit."  Of course since that time the observations have become much more precise and the photographs far more pleasing.

[Mind Flayer Monk]

So eventually the gravity of a black hole becomes stronger than the strong electromagnetic force (it can rip apart molecules)?

[Agent : Orange]

I recall John Wheeler, who was the physicist who popularized the term "black hole," explaining how they knew they had black hole candidates, way back in the old days when the observations didn't have the resolution that they have now.  He made the analogy of a formal ball, where the men are dressed in their black tuxedos, and the women in their white evening gowns.  As they whirled around on the dance floor, the lights would go low, and all you could see was the women twirling around; you couldn't see the men at all.  Nevertheless, you knew that they were there, because something had to be keeping the women in "orbit."  Of course since that time the observations have become much more precise and the photographs far more pleasing.

That's a beautiful way of putting it and still very accurate, too. The physical presence of black holes will always be inferred through gravity. We have now observed accretion disks directly but what lies at their exact center is still inferred.

When I get a bit more time I'll see if I can find and post some simulations of the gravitational distortions of black holes accretion disks that I've seen in the literature. Just like gravitational lensing on galaxy scales lensing effects also happen when viewing accretion disks edge on, so the black hole mass between an observer and the far side of the disk makes some pretty interesting images and warps the appearance of the disk from what you'd expect in flat spacetime.

[Agent : Orange]

So eventually the gravity of a black hole becomes stronger than the strong electromagnetic force (it can rip apart molecules)?

Yes but this happens far inside the event horizon. If an astronaut fell in feet first, eventually the difference in gravitational force between his head and feet are so great he gets stretched out like taffee (which has the great name "spaghettification"). The electrons orbitals around atoms would get pulled apart in the same way too. The best description we have of the inside of a black hole is that right at the center gravity becomes effectively infinite, so it will overpower all the other forces. There are other interesting ways in which space and time rotate into one another, and the only direction which really makes sense past the event horizon is toward the black holes center. The only way to get out is to go back in time, or faster than the speed of light, and those options are physically impossible. So once you cross the event horizon you're doomed.

Of course the gravitational field might only look infinite to us because we're using Einstein's general relativity to describe gravity. It's generally thought that a full theory of quantum gravity should prevent those kinds of infinite gravitational field strengths from coming up at the centers of black holes but all quantum gravity theories are speculative right now anyway. So this is where our understanding becomes very hazy. No one really knows what happens at the center of a black hole but our best description today gives us the picture above.

[DigitalPigSnuggler]

Just like gravitational lensing on galaxy scales lensing effects also happen when viewing accretion disks edge on

I guess you can't post gif files here, but I found a link of one that shows what you describe above.

http://upload.wikimedia.org/wikipedia/commons/0/03/Black_hole_lensing_web.gif

[Agent : Orange]

Here's a neat view of a disk around a non-rotating black hole. The disk is smooth and continuous, like a CD or a record with the black hole at the center. When you look at it you will see the gravity of the black hole distort the paths of light rays so to an outside observer the disk no longer looks the way you'd expect in flat spacetime. The color scheme of the disk was chosen based on the simulation of an accretion disk temperature profile. I notice it has some clumps in it as well so it may be a bit more complicated than what I say but the picture gets the point across. It came from this article which has a bunch of other interesting stuff in it as well: http://iopscience.iop.org/1367-2630/10/12/125014/fulltext/

Here's a more artistic interpretation

From a brief review article on the Astronomical Review journal website, http://astroreview.com/issue/2011/article/how-black-holes-affect-gravity

[Agent : Orange]

I guess you can't post gif files here, but I found a link of one that shows what you describe above.

http://upload.wikimedia.org/wikipedia/commons/0/03/Black_hole_lensing_web.gif

Very similar, this is a black hole passing in front of a spiral galaxy disk. The lensing in this case is somewhat less extreme than what happens to an accretion disk but it gives the same idea and is a very cool animation

[Mind Flayer Monk]

While looking through my binoculars at the night sky yesterday, I saw in the SE, two very close stars that looked like they were in a little cloud or round patch of fuzziness. Was this a nebula?

[Agent : Orange]

While looking through my binoculars at the night sky yesterday, I saw in the SE, two very close stars that looked like they were in a little cloud or round patch of fuzziness. Was this a nebula?

Could be. What constellation were they in? What is your lattitude or viewing location?

[zeebo]

While looking through my binoculars at the night sky yesterday, I saw in the SE, two very close stars that looked like they were in a little cloud or round patch of fuzziness. Was this a nebula?

Hopefully it's not one of those "fingerprint nebulas".   

[DigitalPigSnuggler]

Here's a neat view of a disk around a non-rotating black hole. The disk is smooth and continuous, like a CD or a record with the black hole at the center. When you look at it you will see the gravity of the black hole distort the paths of light rays so to an outside observer the disk no longer looks the way you'd expect in flat spacetime. The color scheme of the disk was chosen based on the simulation of an accretion disk temperature profile. I notice it has some clumps in it as well so it may be a bit more complicated than what I say but the picture gets the point across. It came from this article which has a bunch of other interesting stuff in it as well: http://iopscience.iop.org/1367-2630/10/12/125014/fulltext/

Here's a more artistic interpretation

From a brief review article on the Astronomical Review journal website, http://astroreview.com/issue/2011/article/how-black-holes-affect-gravity

So am I correct in assuming that the thin line "inside" the black hole space is a lensing artifact?

[Mind Flayer Monk]

Could be. What constellation were they in? What is your lattitude or viewing location?

I'm not sure of the constellation. My latitude was 33.7884° N and I viewed it at around 8pm. It was at about 45 degrees from the horizon.

Hopefully it's not one of those "fingerprint nebulas".   

hehe

[zeebo]

I'm not sure of the constellation. My latitude was 33.7884° N and I viewed it at around 8pm. It was at about 45 degrees from the horizon.

It's possible you saw some of the galaxies in the Virgo cluster, which is around the constellation Berenice's Hair, and can be seen as diffuse nebulas (or you might have seen all the stars that make up the constellation itself, which is a kind of start cluster).  This would be below and to the right of the Big Dipper.  If what you saw was above it instead, you may have seen Bode's galaxies pair which is one of my fave objects to view, one being edge-on one being top-down.