Arp 272, a third galaxy? (APOD 30 Apr 2008)

[Case]

How do you know friction and currents do not apply here? Currents apply in electricity. Magnetism can be like friction in dragging elements along or hindering their forward motion.

I don't know that it doesn't apply, but I find it unlikely, as there has not been found any sign that dark matter interacts with normal matter on electricity or magnetism; only gravity. In contrast, you seem to be willing to apply methods like friction and current, only based on shape, without knowing if these methods are applicable on interstellar scale, nor coming up with any reason why they would.

"Walking on water is against the law of gravity!"

It is not gravity that prevents mortal men from walking on water. By mixing water with some chemicals, you can even alter the properties of the liquid to make the walk possible. www.youtube.com/watch?v=f2XQ97XHjVw

[henk21cm]

Henck - your lumb of stars is a computer simulation only

I ran an odd 50 simulations, different orientations, angles, etc. I can not reproduce the image in todays APOD.

Computer simulations are operated by the imagination of people.

The simulations on the GalCrashWeb are based on the laws of physics. There are other websites with similar applets. In science it is common practice to come with a model for a phenomenon observed. It is the first step in understanding what is happening, find an answer for the hows, the whys and the howmuches. A model is usually a simplification of the real processes, since these processes are too complicated for our limited resources. A good model encompasses the (most) basic principles, in this case the gravitational forces between stars. Nothing difficult, even you can do it.

So start writing down the equations of motion for all stars, in three dimensions. In combination with the initial conditions (location and velocity) you will end up with 3*N!/(2!*(N-1)!) equations and you will solve them numerically as a function of time. That is just basic science, "not the imagination of people". When you go the APOD home page and follow the link Education, you will find a link ASCL: The Astrophysics Source Code Library where you can find software to solve these equations. Download a Fortran compiler and 'off you go". Simulations are operated by the laws of physics. Interpretation of the results is human work and thus prone to errors.

[BMAONE23]

I wouldn't expect any simulation to give these exact results nor any similar result as there are an infinite number of factors that will influence the outcome. Everything from the location of stars within their local group orbits to the location within their galactic orbits at the time of the interaction, to the relative speed and angle of interraction of all galaxies involved. You could likely run the same simulation twice and get different interractions every time. But likely, the end result, over a couple billion years time, will almost always be an eliptical galaxy.

[apodman]

Everyone sees what they like in this picture of four galaxies.

If anyone has some red shift or other relevant data, now would be the time to come forward. That might cast a meaningful vote in the debate over the distances of the galaxies.

My best guess is that #3 is farther away than #1 and #2, and that #4 is the farthest away. I have no information about their absolute sizes, but their apparent sizes put them in that order. On the other hand, #3 could be smaller and closer (an idea supported by its relative brightness).

If they are all part of the same galaxy cluster (also something I don't know for sure), then they are gravitationally bound; but you would have to know the distances between them to know how much they are affecting each other - my guess is that they are affecting the paths of the two colliding galaxies slightly and affecting the shape of the collision almost not at all. Pretty loose terms, but that's my offer.

Meanwhile, what about the odd shape of the bright area in the nucleus of the large galaxy on the right?

Meanwhile, what about the odd shape of the bright area on one side of the nucleus of galaxy #3?

[astrolabe]

Hello apodman and all,

This is quite a scene! The galaxy on the left appears to have more visible matter than its counterpart to the right, however, the one one the right seems to have more energetic star-forming regions around its perimeter. The general color difference between the two could indicate older stars in the left one and may mean a more mature, powerful structure than the more transparent right one.

I don't notice much in the way of stars being formed in the one at 12:00 so even if it is influencing the apparently larger ones I feel it'll be "third man in" and is at some distance away.

P.S. Just a thought: Since dark matter is affected by gravity only and regions of star formation in collisions increases dramatically could the two phenoms be related, i.e., dark matter coaleses into stars when a gravity well becomes unstable or experiences flux lines that are reduced as they are stretched out?

[astrolabe]

Me again,

What I mean to say is if the strengths of gravitational fields in a galaxy's outer edges become equalized by the fields of an approaching galaxy to the point at which matter begins to be lost then it could be like weightlessness and dark matter can begin to attract dark matter into greater mass and start the gravitational process of making stars.

[Sputnick]

How do you know friction and currents do not apply here? Currents apply in electricity. Magnetism can be like friction in dragging elements along or hindering their forward motion.

I don't know that it doesn't apply, but I find it unlikely, as there has not been found any sign that dark matter interacts with normal matter on electricity or magnetism; only gravity. In contrast, you seem to be willing to apply methods like friction and current, only based on shape, without knowing if these methods are applicable on interstellar scale, nor coming up with any reason why they would.

"Walking on water is against the law of gravity!"

It is not gravity that prevents mortal men from walking on water. By mixing water with some chemicals, you can even alter the properties of the liquid to make the walk possible. www.youtube.com/watch?v=f2XQ97XHjVw

I really don't see why posters here speak as if Dark Matter were a reality when it is still theoretical, same with Dark Energy.

And of course, to walk on water all one has to do is wait until it freezes thick enough, no added chemicals needed.

What I am saying about theoretical time tunnels, friction against theoretical Dark Matter and Dark Energy, is no more or less fact at mankind's present level of understanding than computer simulations. No one yet knows what the Pioneer Anomaly is (unless I'm behind the times, and I just read about the Pioneer Anomaly in the latest edition of Scientific American) and the distance Pioneer has travelled is just a blip .. and yet has uncovered some unknown variations on the laws of everything (or, as the article says, simply a software glitch).

"I think I'm right - therefore I am" when written in the anti-universe is, "I think I'm wrong, therefore I am not." We really have to be open to possibilities for the sake of a balanced identity .. a non-tyrany over ourselves.

[starnut]

Orin - I think the counter-revolving galaxies will slow each others' rotation and their merge will create a globular galaxy. This photo http://spdext.estec.esa.nl:81/science-e ... ctid=42670 in my opinion being merged, stopped-revolution galaxies
whose stellar wind will drive the dark gas/particle clouds away and leave a clear, globular galaxy.

Sorry for joining the discussion late.

Do you have proof this is what will happen? Pictures of global galaxies? I have never heard of a global galaxy being formed from a merger of two counter-revolving galaxies, but I know that such merger would result in an elliptical galaxy. Is that what you meant?

[Sputnick]

Everyone sees what they like in this picture of four galaxies.

If anyone has some red shift or other relevant data, now would be the time to come forward.

Sputnick Writes: This will be seen as sacriledge, but not long ago, before the discovery of theoretical Dark Matter, someone suggested that Red Shift was the result of absorbtion of light by matter, and not result of speed. Another suggestion was the creation of the universe through electromagnetic flow and not the Big Bang. Of course that someone was ridiculed by the mainstream. Is the universe really expanding? Or are we all just flowing along together?


Apodman writes: Meanwhile, what about the odd shape of the bright area in the nucleus of the large galaxy on the right?

Meanwhile, what about the odd shape of the bright area on one side of the nucleus of galaxy #3?

Sputnick writes: Yes, the two large galaxies appear almost as dinner plates, and the one on the left is 'stacking' from behind into the one on the right. Of course, when viewed edge on, they will almost certainly appear to be normal spirals, bulged in the nucleus, nearly flat arms. This, my friends, is why my theoretical Time Tunnels are created by friction of the galaxies (static materials create sparks of light, with static balloons clinging to the ceiling -static Galaxies create time?) against theoretical Dark Matter and Dark Energy. Work some computer simulations with totally unknown factors. Look for some effect separate from Gravity that Andromeda is having on the Milky Way.

[Sputnick]

Me again,

What I mean to say is if the strengths of gravitational fields in a galaxy's outer edges become equalized by the fields of an approaching galaxy to the point at which matter begins to be lost then it could be like weightlessness and dark matter can begin to attract dark matter into greater mass and start the gravitational process of making stars.

Astro - Deep thinking! But I prefer time funnels created by friction of the spiral turning against Dark Matter and Dark Energy. I think evidence for that can be seen in the abrupt straight edge of the arm of the large galaxy on the right side .. that arm being sharply edged because its stars are being swept abruptly downwards by the funnel created by the left sided galaxy - that tunnel revolving clockwise.

[Sputnick]

Orin - I think the counter-revolving galaxies will slow each others' rotation and their merge will create a globular galaxy. This photo http://spdext.estec.esa.nl:81/science-e ... ctid=42670 in my opinion being merged, stopped-revolution galaxies
whose stellar wind will drive the dark gas/particle clouds away and leave a clear, globular galaxy.

Sorry for joining the discussion late.

Do you have proof this is what will happen? Pictures of global galaxies? I have never heard of a global galaxy being formed from a merger of two counter-revolving galaxies, but I know that such merger would result in an elliptical galaxy. Is that what you meant?

Starnut - No, I mean merging spirals could theorectically create a globe after passing through each other a few times, slowing each other's tragectories, altering each other's shape until a globe is left. Of course, as the photo under discussion suggests is possible, two spirals could join 'face to face' 'front to back' 'back to front' so to speak .. and create a larger or denser spiral. I have seen some photos of merging spirals (provided other posters' urls in this thread, which do look as if two merging spirals are creating a globe. I will repeat that we know very little about the stars, we have seen next to nothing in comparison with what is,
anything seems to be possible.

[Case]

If anyone has some red shift or other relevant data, now would be the time to come forward. That might cast a meaningful vote in the debate over the distances of the galaxies.

Here you go:
The left big one, NGC 6050, has a redshift of z=0.0319, representing a speed of 9572 km/s.
The right big one, IC 1179, has a redshift of z=0.0371, representing a speed of 11127 km/s.
Just taking the expansion of the universe into account, those redshifts would point to distances of 132 and 153 Mpc. But these are likely moving towards each other, and the Herculus Cluster as a whole is moving about, so these distances based on redshift alone are not so accurate here.
Still, I would have thought that the redshifts of colliding galaxies would be closer in value.

[Sputnick]

Redshift -

This will be seen as sacriledge, but not long ago, before the discovery of theoretical Dark Matter, a scientist whose name I can't remember wrote a book suggesting that Red Shift was the result of absorbtion of light by matter, and not result of speed. Another of his suggestions was that the creation of the universe was through electromagnetic flow and not the Big Bang. Of course that someone was ridiculed by the mainstream, and probably called Communist because he commented that everyone should receive fair wages for their work. Is the universe expanding? Or are we all just flowing along together, galaxies drifting together because birds of a feather flock together.

Galaxy walls - in the flow of river currents I have mentioned, at lines where current meets placid, or currents of different speed form an edge, several foaming whirlpools can be created along the line where the different flows meet. Would this be seen as a "wall" if they were galaxies?

[bystander]

The left big one, NGC 6050, has a redshift of z=0.0319, representing a speed of 9572 km/s. The right big one, IC 1179, has a redshift of z=0.0371, representing a speed of 11127 km/s. Just taking the expansion of the universe into account, those redshifts would point to distances of 132 and 153 Mpc. But these are likely moving towards each other, and the Herculus Cluster as a whole is moving about, so these distances based on redshift alone are not so accurate here. Still, I would have thought that the redshifts of colliding galaxies would be closer in value.

Is there any data on the red shift of the bright knot at 12 o'clock? Can it be confirmed as being a part of either of the two main galaxies? Or is it, in fact, a separate galaxy?

[bystander]

Orin - I think the counter-revolving galaxies will slow each others' rotation and their merge will create a globular galaxy. This photo, Arp 220, in my opinion being merged, stopped-revolution galaxies whose stellar wind will drive the dark gas/particle clouds away and leave a clear, globular galaxy.

Do you have proof this is what will happen? Pictures of global galaxies? I have never heard of a global galaxy being formed from a merger of two counter-revolving galaxies, but I know that such merger would result in an elliptical galaxy. Is that what you meant?

Starnut - No, I mean merging spirals could theorectically create a globe after passing through each other a few times, slowing each other's tragectories, altering each other's shape until a globe is left. Of course, as the photo under discussion suggests is possible, two spirals could join 'face to face' 'front to back' 'back to front' so to speak .. and create a larger or denser spiral. I have seen some photos of merging spirals (provided other posters' urls in this thread, which do look as if two merging spirals are creating a globe. I will repeat that we know very little about the stars, we have seen next to nothing in comparison with what is, anything seems to be possible.

And your "global" or globular" galaxy is different from an elliptical galaxy how? After all a globe is an ellipsoid (a circle is an ellipse). Current thinking seems to be that elliptical galaxies (especially the larger ones) are the results of mergers, probably more than one.

I think, if the rotational planes of two merging spirals are nearly parallel, there's a good chance that the resulting galaxy will be a spiral (or at least lenticular). If the inclination is approaching perpendicular, the resulting merger will be elliptical (especially if the masses are similar). However, with two counter-rotating galaxies like these, I'm not sure what to expect, probably chaos and a "starburst" galaxy.

[orin stepanek]

Orin - next time you're standing on a bridge over a river or canal, or on a riverbank, search the currents for spiral galaxies of foam and debris where current lines meet.

I watched the whirlpools meet in a river! They break up! Did you ever notice that the surface of the river is two dimensional? What happens below the surface we can't see. Also the current of the river usually is pretty strong which helps break up the whirlpools. I don't think you can compare two whirlpools with the merger of two galaxies. Probably better to compare two tornadoes dancing around each other; pretty devastating. I'm not saying that I know what would happen. I was speculating; same as most everyone. I'm not saying your wrong either; you seem to have studied the matter more than I did. Either way I'm not going to hang around long enough to find out; I wish I could; I find it very intriguing!
I Never knew I could get so windy--most of my posts are pretty short.
Orin

[Sputnick]

Bystander - An elipse of course is an oval - an elongated circle - while a globe is just that, a sphere. However .. galaxies seem to come in unrestricted shapes, and I think I remember seeing on APOD a picture of a square galaxy, the sides of which being slightly curved inward - that galaxy I think would be formed by being bordered on the four sides by a time funnel. I think it's thought-hindering to adhere to 'current thinking', as concensus can build walls around the mind where nothing gets in or out... doora and windows are important, but I prefer to avoid concensus .. as probably is obvious in my posts.

Orin - Lovely to watch a river, eh! Yes, the whirlpools break up .. but before they live out their short lives they often travel along the line of fastest flow, if there are a few or several in a line, they travel together, and their lines might be seen as walls if they were galaxies). I spend more time studying nature close at hand then the stars because close at hand is cheap and accessible .. but I have concluded that studying one form of nature will give insight about all forms of nature .. a flower will give insight into stars. Also, I seem to remember that one theory about the shape of the universe is curtain-like - and if so, and if the universe is flowing, and if it has differing currents, then whirlpools of energy and matter would form. But even if it is a globe, currents are likely, as within the globe are areas of cold bordered by areas of heat - nature works to even things out, and currents would be one way of doing so.

[makc]

how does one know if a galaxy is counter-revolving? maybe it's just us who revolves faster.

[Qev]

Redshift -

This will be seen as sacriledge, but not long ago, before the discovery of theoretical Dark Matter, a scientist whose name I can't remember wrote a book suggesting that Red Shift was the result of absorbtion of light by matter, and not result of speed.

Not sacrilege, just wrong. 'Tired light' theories never seem to hold up to scrutiny.

[Sputnick]

Yes Mac - maybe the galaxy is revolving properly but we are revolving contrary .. that would explain a LOT of things about our planet's societies and individuals. Posting this is making me dizzy.

[Sputnick]

Javachip wrote:
The putative supermassive black hole at the center of our Milky Way is much too low in mass to exert gravitational influence on stars outside its nearby vicinity. So, if the Milky Way (and other spiral galaxies) are not whirling around a central black hole, then what are they whirling around?
(Regarding April 27, 2008 apod)

Okay .. so we know the galaxy is revolving around its centre -- and at its centre is a black hole, but that hole has insufficient power to turn the galaxy.

This then, supports my theory that Dark Matter and Dark Energy are flowing like a river, with currents, and creating whirlpools which are spiral galaxies - like the small whirlpools in a river where current lines meet. Just like the river whirlpools, the galactic spiral at its centre is a 'hole' into which everything is not drawn by gravity, but is pushed into the hole, by energy generated as the lines softly massage each other .. as you will see by examining the small river whirlpools. However - in a river whirl, the centre creates a funnel downward into the depths .. whereas the spiral galaxy creates a funnel outwards from its face .. 'outwards' of course could also be looked at as downwards or upwards depending on your ups and downs. Very interesting, these forums.

[orin stepanek]

how does one know if a galaxy is counter-revolving? maybe it's just us who revolves faster.

While we can't say a galaxy is clockwise of counter clockwise; can't we tell which way it is revolving by the way the arms trail around the hub?
Orin

[Sputnick]

I'm sure that it's a 'given' that the shape of the arms indicates which way the galaxy is rotating. We can say 'clockwise' if when we're looking at the face of the galaxy it's rotating in the direction of an earthly clock - same as a bicycle wheel is rotating clockwise or counter clockwise depending on which side we are viewing from and which direction it is turning ..
which gives me an idea - if my theory is true that Dark Matter and or Dark Energy currents are creating the spirals, then the highest rate of flow might be determined by a slight compression or flattening somewhere along the edge where flow, and therefore pressure, is greatest.

[azutjw]

http://antwrp.gsfc.nasa.gov/apod/image/ ... t_full.jpg
Here I am again, with yet another silly question:

What is the formation just above the 'middle' of the collision? Is it really an 'eddy', or merely an optical delusion?jw

[azutjw]

Hi all...my apologies for starting a new thread without first reading this one...I'll try to be more observant in the future...

As for the debate about whirlpools, I have a few comments: First, I believe these are more commonly known as 'eddies', or an 'eddy'. Second, keep in mind these are ALL 3D+ structures of necessity! Third, if you seek an analogue somewhere between rivers and galaxies, look at the 'surface' of Jupiter!

I come from aerodynamics by way of hydraulics, where these phenomena are called 'vortexes', which is actually grammatically incorrect - there is a vortex, there are vortices. These things are of great interest to aero- and hydro- dynamicists, for there increase in drag and warping of energy flow. I have long been fascinated by these, going back to the mariner's nightmare, the 'maelstrom'.

N E HOO - - I prefer the approach that we really don't KNOW anything about any of this, and won't, CAN'T, until we make direct measurements ourselves. Which I'm guessing is going to take a pretty long time...jw