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This picture of the Meathook Galaxy was taken by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at La Silla, Chile. This view includes the whole galaxy and the surrounding sky, and clearly shows the asymmetric spiral arms. The longer of the two arms has intense star formation, which is visible here as a pink glow.
Two complementary views of the so-called Meathook Galaxy, released today, show how astronomers are piecing together the history of this lopsided group of stars.
The galaxy, located about 50 million light years away in the southern constellation Volans (The Flying Fish), is recognized for its asymmetrical spiral arms. One is tightly folded in on itself and host to a recent supernova, and the other is dotted with new star formation and extends far out from the nucleus.
NASA / ESA / ESO
This close-up Hubble view of the Meathook Galaxy focuses on the more compact of its two asymmetric spiral arms as well as the central regions. The spiral arm was the location of a supernova that exploded in 1999. These Hubble observations were made in 2006 in order to study the aftermath of this supernova. Ground-based data from MPG/ESO 2.2-metre telescope were used to fill out parts of the edges of this image.
The broa- view image above was taken by the Wide Field Imager the MPG/ESO 2.2-meter telescope at La Silla, Chile. It clearly shows the double hook shape that gives NGC 2442, as it the galaxy is officially known, its nickname.
The lopsided appearance is thought to be due to the gravitational interactions of another galaxy, though the culprit remains unknown, the European Space Agency noted in an image advisory. This interaction is probably responsible for an episode of recent star formation, seen as the patches of pink and red, particularly in the longer of the two spiral arms.
These colors come from hydrogen gas in star forming regions, ESA explains. As the powerful radiation of newborn stars excites the gas in the clouds they formed from, it glows in a bright shade of red.
The close-up view from the Hubble Space Telescope focuses on the nucleus of the Meathook and the more compact of its two spiral arms. Not seen in the image is a massive star that exploded at the end of its life in a supernova, witnessed in 1999. By comparing older ground-based observations, previous Hubble images and these made in 2006, astronomers have been able to study the details of the star's violent death. By the time this image was made, the supernova had faded.
John Roach is a contributing writer for msnbc.com. Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).
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I've always wondered how much "distortion" is in perspectives like this Meathook galaxy. If the light from stars on the far side left 80-100,000 years earlier than the light from the near side, how much difference in their positions would there be ?
That's a REALLY good question...
It's probaby insignificant, and unimportant unless in a philisophical way. It takes the sun 250 million years for a spin around the block, 80 thousand wouldn't mean much. Neither would gravitational lensing.
Isn't part of the reason it looks the way it does is because we are looking at it at a slight angle? Not full face and not edge on, but in between, with the longer arm closer to us?
Even at a sharp angle it would still look nearly symmetrical if it were truly symmetrical. The visual distortion of the shape would only make it look like this from a truly symmetrical shape if it were impossibly long, if I'm correct. Given how far away it is even the length of an entire galaxy doesn't produce that much difference in perceived shape in an object of that size.
But couldn't it be "symmetrical", but there's more star producing gas in the near arm? How many wavelengths do we have this in? If it is only one or two, maybe the other arm will show in other wavelengths.
One arm pulled down would give this shortrnrd view even if they are the same size. Dark matter below that arm or a galaxy that passed on it's way going away and now hidden benind the central bulge can cause the distortion, and it didn't have to happen on this revolution we're looking at. It looks more to be our perspective of the view than a truly shorter arm.
That's what I was originally thinking, Dragon, and that there might be matter that isn't showing up in the photo, either because it's hidden or because it isn't visible in the spectrum we photographed.
Given the fact that the light on the left reached us (Hubble, Earth, et al) at the same time the light from the right reached us and given the expectation that both sets of light were traveling the same speed, the shift or distortion would be negligible if even in existence.
An additional set of thoughts for Halifax and Tony.
Give this is a spiral galaxy, would the rotation and position of the arms be necessarily circular in pattern? Possibly. I like the additional perspective that this is being viewed edge on. From that aspect and if the size of this galaxy is approximately 100,000 LY in diameter, I would take that distance to cause a possible approximated 0.2% rotational shift in the image that was brought up by edmgeno and V...
Give or take a mile or two. ;-)
What about the additional wavelength pictures? If we took pictures in visible, infra-red, ultra-violet, x-ray, microwave, etc. would we find that the picture is radically different? They've been finding a lot of things about Andromeda.
Looks more like a Cobra to me.
Here's some photos of other interacting galaxies for comparison:
http://csep10.phys.utk.edu/astr162/lect/galaxies/colliding.html
and a nifty animation showing how a spiral structure can result from the interaction of two globular structures:
http://www.plasma-universe.com/Galaxy_formation
Perhaps in this case, two formerly smaller ellipticals of unequal size came together relatively recently (on the cosmic scale) and formed this larger but lopsided spiral. In time (maybe a couple of billion years), perhaps it might even itself out?
I wonder if it actually is symmetrical mass-wise, but not in any visible or detectable wavelengths. There is that whole dark matter & dark energy guess as to why there is more mass that we can detect on the very large scale of the universe, but we possibly could be seeing (or rather NOT seeing) its effects in a much smaller region (if we can call a galaxy small).
It appears to have been involved in a collision with another galaxy. Note the gas trail emanating from the lower arm. As though the arm was pulled by gravitational interaction over millions of years of course.
nice picture... another screensaver thanks a million ...
Mike, a single galaxy is certainly small when compared to entire universe, but you do not want to get me started on "dark stuff" as the explanation for what we see here in the given photo, or anywhere else for that matter (pun intended).
I am extremely skeptical of hypotheses which invoke invisible, unknown undetectable stuff, whether it be in the form of matter or energy as explanations for observed phenomena. I am neither a trained astrophysicist or cosmologist, but I know enough of the history of science to know that many theoretical mistakes have been made which are later retracted when better measurement becomes possible. I also know that much of current astrophysics and cosmology depends upon calibrated assumptions regarding distance, mass, luminosity, gravity and other factors as well, and if certain calibrating factors are off, then the conclusions based upon those assumptions are also wrong.
Basically, I don't think we know enough yet about what we are really looking at. We don't even have a complete and verfied theory of how gravity works and why. Gravity waves? Apparently, according to the current theory they should exist, but we haven't detected any yet.
On the basis of things like that, I am not yet ready to accept the idea that there is some new kind of stuff out there (and shouldn't it also be nearby as well?), that we cannot see, perceive or detect in any way whatsoever except by the manner in which it supposedly affects the movements of extremely far off galaxies. There's too many other possibilities.
If this dark matter and dark energy are supposed to be scientifically provable hypotheses, what is the verifiable impirical evidence for their existence? So far as I know, there isn't any, and that's why they call it "dark", and to my mind that's not science, that's just lame excuses for "we can't figure it out yet". I would much prefer the direct and honest latter explanation than the mysterious obfuscation of the former, but that's just me.
See, I told ya didn't want to get me started. I'll shut up now. Bye.
Could not have said it better myself. I personally am okay with the dark matter theory for now. Until a better theory comes along. But it appears to me that the galaxy simply collided, or better yet...gravitationally interacted with another galaxy perhaps a billion or more years ago.
A galaxy has many types of stars ans some are very specific types concerning their spectra. Some of these are so specific that we can be CERTAIN of their mass and size. The redshift of these specific stars is used to determine their relative distance and from their we can determine the mass of the entire galaxy (counting stars the same way cops count people on the Mall in Washington). The determined mass has been found to be too low to maintain the integrity of the galaxy, meaning that it should have thrown off all its' stars by now. The only explination is that there is more mass than is determined by adding all the stars, ergo, unseem mass must exist. Untill we can detect that mass it has been decided to call it Dark Matter, but it does exist, it just doesn't block light and it doesn't emit any light itself. We can determine where it is and sometimes how much because it causes lensing and it affects galactic mass around it. It is not always part of an associated galaxy. I have seen depictions of a mass of Dark Matter that has disassociated from it's parent galaxy through a collision with another galaxy where the DM continued on, leaving the parent behind, escaping the collision, determined to be where it is by lensing measurements and gravitational distortion of the pair it left. Instead of denying it's existence, think of a way to detect it. It's more real than gravity waves.
Nicely said, Mikey.
Dragon master,
I'm well aware of how redshifts are used to calculate purported distances to far off galaxies. I'm also aware of how the luminosity of those galaxies is used to estimate their total mass. I'm also aware that the rotational rates of these galaxies are supposedly too fast for them to hold together based upon the mass that they supposedly possess. Rather than dwell on the details of these matters I summarized by referring to "calibrated assumptions of distance, mass, luminosity, gravity, etc..."
My issue with these assumed masses based upon luminosity which is calibrated by distance which is determined by redshift, is that nowhere in this complex chain of assumptions built upon calibrated calculated measurements is there ever any mention of the existence of plain old ordinary matter in the form of intergalactic dust and diffuse gas. You yourself mention that this supposed dark matter does not block light. Ordinary matter does. So if there is more ordinary matter in the form of gas and dust between us and these far off galaxies than has been accounted for (and I've never heard any mention of accounting for this in any description of how they do these calculations) then the luminosity measurements are too low and therefore there's actually more stars in these far off galaxies than we are currently estimating and therefore their mass is greater and therefore maybe there's enough mass to hold them together without resorting to mumbo-jumbo.
Or maybe I'm just talkin' out my azz... I dunno. Like I said, I'm not an expert in this stuff, I'm just a guy who likes things to make sense.
I think this is the most intelligent conversation I have ever seen on a message board. Every poster on here sounds like they were physics/astronomy majors in college.
This would definitely be a nice target for a 3d modeler!!...renderend in clay or such would be cool, but this is one that a good astro class showing the hypothesis of formation from different points of view as a 3d hologram overhead in a 3 or 4 foot cube format would garner more interest in cosmology than just a plain ole hologram of our own sol system...the whole idea is quite interesting, and rather marketable now that I think about it.....
If this formation is 50 million light years away, how do we know that a supernova exploded in one of the spiral arms in 1999, only twelve years ago? That is mentioned in the enlarged photo description. Wouldn't it still take about 50 million years for that image to reach earth? d.
The explosions light was detected in 1999 but the explosion itself would have actually occured roughly 50 million years ago. Whoever wrote the caption just didn't clarify it that well. You are correct in that the light from the explosion would have taken 50 million light years to arrive here for us to see it.
As Dean correctly explains, it exploded 50 million and twelve years ago. (Approximately).
The caption from the above figure could be revised as:
Missing masses, forces from unseen matter: Voids where ever they are found, as soon filled with ideas as how they were formed. (Theories rush in to fill the vacuum of explanations.)
http://www.eoht.info/page/Nature+abhors+a+vacuum
It its own way this narrative shows less of what we are now taught, than it shows that man believes his speculations more strongly than his observations.
From this man forms theories to match speculations, exerting every effort to match his ideas. Then it takes extraordinary effort by someone else to dismantle the speculation piece by piece also with extraordinary effort. Somewhere in idle moments, or while resting, a better idea appears (out of nowhere?). If there remains after this, method of exhaustion, any energy or incentive to continue a new theory emerges, new resources applied to overcome the superstitious defensiveness. Then if you live long enough, to succeed in providing an open public demonstrations, where something useful is produces, the pitch forks and hoes man be laid down and the new idea used.
The history of science is far more approachable to the lay reader, than to the modern scientist. The modern scientist is not taught from historical anecdotal narratives, so someone learning from the history of science cannot but experience disappointment with the prospects of success. The trials and tribulations of our beloved historical scientist are given so brief mention in scientific education that it not the habit of scientist to take time to see how what they are taught was first learned. The modern scientist is the product of streamlined scientific educators, who like everyone else in modern times is forced to produce product, least cost, least time, in the door out the door, and oddly for science never to look back to see if ever really worked.
I learned from one educator that we were not allowed to use the word “suck” in the context of force, or describing a vacuum, he deliver mini no nonsense lecture point out that nothing moves without force behind it, suction cup was not held by “no such thing as suck” but by the force of the atmosphere. Tension is cousin to the “suck” concept, except that a bolt or rope or for that matter liquid was held together tension, and that tension was not applicable to vast extent to neutral gases. This was his choice to make us focus on giving us some more basic notion that science was supposed to simplify things, not to make them more complicated, taking view of the world down to the microscopic level. The modern scientist or engineer today is required to know more, and think less than is at all reasonable, cannot without special talents delve into the historical narrative. The 40 year perspective comes down to this, in those days we could not afford to time to expand our knowledge, to compete in today’s world, we would, just after conducting a time machine, go backward in time and spend our entire educational career living in the library reading everything published to date, once we transported ourselves to today’s time, we could enter a science high school and hope for a passing grade. Still we have trouble transitioning from the old fashioned and incomplete microscopic view to today’s nanoscopic view where, nearly every idea developed in the last 40 years can now find its way into some practical application.
If course experience leads me to the cautionary tale, implied there in, we are sometimes required to battle pitch forks and hoes, but the future will be to also to battle the resistance to ideas of what narrow modern technology will be the next new thing, while having to discard and delay the 10,001 ideas that do need to be developed, hoping some of the profit of the new next thing well spent where that are needed.
The discussion of space-time, matter, gravity and the possibilities of gravity waves: I not satisfied the void idea where from ancient times it has been discussed in lots of interesting ways is not also relevant to the present discussion (comments or otherwise). I don’t understand space, time, or mass well enough to offer a solution, but I thought that gravity was a manifestation of space-time where matter caused the curvature and hence the so called force of gravity. Somewhere in the cobwebs of the mind is the notion that if space-time can be shaped by matter, then is not space-time somehow defined by that matter, so what really could cause space-time to vibrate when space-time was the root cause in the first place. I Don’t see way that gravity wave could produce by grudging slow to respond space-time universe.
Darn those gravity waves, the made me sneeze all morning. Correction to last paragraph follows maybe:
The discussion of space-time, matter, gravity and the possibilities of gravity waves: I am not satisfied the void idea has been completely exhausted in the modern conception of the big bang derived universe where since ancient times it had been discussed in lots of interesting ways. Is it not also relevant from the present discussion (comments or otherwise), where the we know something well enough to explain it, but not enough to leave it alone.. I don’t understand space, time, or mass well enough to offer a solution, but I thought that gravity was a manifestation of space-time where matter caused the curvature and hence the so called force of gravity. Somewhere in the cobwebs of the mind is the notion that if space-time can be shaped by matter, then is not space-time somehow defined by that matter, so what really could cause space-time to vibrate when space-time was the root cause in the first place. I don’t see a way that gravity wave could produce by grudging slow to respond space-time universe.
Gravity sucks.
Lest we get too carried away with the pretty colors, the Hubble images are all transmitted to earth in monochrome, using various filters. Then some unsung NASA art major colorizes the images, based on the relative amounts of various elements detected - hydrogen, oxygen, carbon, etc. Although beautiful, the final images may not look anything like the actual space objects, which are usually somewhat bland-looking in true color.
I can't vouch for the La Silla telescope image's color. It could be a true color image, or maybe not. Anyone know?
Looks more like "chicken wing" galaxy.
Great article and super great discussion. What a wonderous universe we live in.