Galaxy collisions dominate the local universe

[telfrow]

<i>More than half of the largest galaxies in the nearby universe have collided and merged with another galaxy in the past two billion years, according to a Yale astronomer in a study using hundreds of images from two of the deepest sky surveys ever conducted. <br /><br />The idea of large galaxies being assembled primarily by mergers rather than evolving by themselves in isolation has grown to dominate cosmological thinking. However, a troubling inconsistency within this general theory has been that the most massive galaxies appear to be the oldest, leaving minimal time since the Big Bang for the mergers to have occurred. <br /><br />"Our study found these common massive galaxies do form by mergers. It is just that the mergers happen quickly, and the features that reveal the mergers are very faint and therefore difficult to detect," said Pieter van Dokkum , assistant professor of astronomy at Yale University, and sole author of the paper appearing in the December 2005 issue of the Astronomical Journal. <br /><br />The paper uses two recent deep surveys done with the National Science Foundation's 4-meter telescopes at Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory, known as the NOAO Deep Wide-Field Survey and the Multiwavelength Survey by Yale/Chile. Together, these surveys covered an area of the sky 50 times larger than the size of the full Moon and more than 5,000 times larger than the famous Hubble Deep Field. <br /><br />"We needed data that are very deep over a very wide area to provide statistically meaningful evidence," van Dokkum explains. "As happens so often in science, fresh observations helped inform new conclusions."</i><br /><br />Full story here: http://www.physorg.com/news8787.html<br /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[najab]

>...<i>most massive galaxies appear to be the oldest, leaving minimal time since the Big Bang for the mergers to have occurred. </i><p>Of course, the Universe was much smaller in those days. <img src="/images/icons/smile.gif" /></p>

 

[Leovinus]

If space is expanding, then the universe might actually have been larger in those days.<br /><br />For example, suppose in those early days a mile was the width of an atom. As space expanded, the mile grew to be what it is today. But back then, the universe could have been much smaller and much bigger at the same time. Likewise, it might be expanding and contracting at the same time too. Sort of like a "conservation of energy" law. <div class="Discussion_UserSignature"> </div>

 

[bonzelite]

if you believe such phenomena occur at all, the thread has a premise. <br /><br />the vast distances between any objects in space make myriad collisions of galaxies highly speculative at best --if not virtually unbelievable and inplausible. because of such commonality of galaxy pairs in close proximity, colliding, they may simply be divding, as in mitosis. <br /><br />but of course, this goes against the holy decree of standard theories. <br /><br />oh well. <br />

 

[telfrow]

Oh well. <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[bonzelite]

<font color="yellow">>...most massive galaxies appear to be the oldest, leaving minimal time since the Big Bang for the mergers to have occurred.</font><br /><br />one of many reasons why the theory is highly suspect. this belongs in the "phenomena" forum.

 

[neutron_star69]

what is the light in the middle fo that picture

 

[newtonian]

bonezelite - Galactic mergers were not the standard model for galaxy formation.<br /><br />It is prompted by more recent evidence discovered.<br /><br />We now know that Milky Way will merge with Andromeda in some billions of years from now.<br /><br />Milky Way also has merged with another galaxy - this was recently discovered btw. <br /><br />I will try to find the article on this in Scientific American.

 

[siriusmre]

<blockquote><font class="small">In reply to:</font><hr /><p>"one of many reasons why the theory is highly suspect. this belongs in the 'phenomena' forum.<p><hr /></p></p></blockquote><br />Agreed. <div class="Discussion_UserSignature"> </div>

 

[newtonian]

bonezelite - This is the article: <br /><br />Scientific American, 10/98, in an article entitled “Galaxies behind the Milky Way,” reports on the recent discoveries of galaxies, super clusters and the Great Attractor:<br /><br />Concerning Milky Way and Sagitarius:<br /><br />The article also discusses the newly discovered galaxy Sagattarius dwarf, which is only 80,000 light years from us, has a diameter of 28,000 light years and is inside of our galaxy!<br /><br />In other words, Milky Way and Sagittarius dwarf are already merging!<br /><br />“Many popular models of galaxy formation<br />postulate that large galaxies are<br />formed by a long process of aggregation<br />of many smaller galaxies. Such a process<br />should still be common today, yet has<br />been observed only rarely. Sagittarius<br />appears to have undergone some disruption<br />from the tidal forces exerted by the<br />Milky Way, but the disruption of the<br />core of Sagittarius is unexpectedly minor.<br />The dwarf may have orbited our<br />galaxy 10 times or more yet remains<br />largely intact, indicating that it is held<br />together by large amounts of dark matter<br />(as opposed to luminous matter such<br />as stars or gaseous clouds). Even so, its<br />demise is just a matter of time; some<br />studies suggest that Sagittarius may have<br />only another billion years to go before<br />being swallowed by our galaxy. Its discovery<br />has demonstrated that mergers<br />do happen, that they happen today and<br />that they do not necessarily wreck the<br />disk of the larger galaxy.” - Sciam, 10/98, pp. 55,56

 

[telfrow]

Oh well. <br /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[siriusmre]

<font color="yellow">"I will try to find the article on this in Scientific American."</font><br /><br />Can't wait to see that. I'm interested to find out how we "know" what will happen "some billions of years from now." Equally interesting is the concept that we can "know" that the Milky Way merged with another galaxy at some remote time in the past. Presumably, some billions of years ago...?<br /><br />All of this makes a HUGE assumption that a uniformitarian view of the universe--that is, that everything has pretty much behaved the way that we see it now for the past X billion years and will continue to do so for several more billions of years into the future--is the True one. <div class="Discussion_UserSignature"> </div>

 

[telfrow]

BTW, if you or bonzelite believe this thread belongs in another location, then go to "Suggestions and Announcements" and provide your reasoning to the mods under "Please Move This Thread."<br /><br />You can find it here:<br /><br />http://uplink.space.com/showflat.php?Cat=&Board=suggestions&Number=373131&page=0&view=collapsed&sb=5&o=0&fpart=<br /><br />We'll see what happens. <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[newtonian]

SiriusMrE - It is extrapolated from the data - call it an educated guess.<br /><br />I don't see how this would be a uniformitarain view. It is more in line with the opposite: catastrophism.<br /><br />Besides which I am well aware that current popular theories are wrong in some respects.<br /><br />For example, that our earth will be destroyed by our sun, etc. vs. my belief:<br /><br />(Psalm 37:29) . . .The righteous themselves will possess the earth, And they will reside forever upon it.<br /><br />I realize that our universe could not have been created as a closed system, and that God created both the heavens and the earth - Genesis 1:1.<br /><br />As for the laws of this universe, we are still learning:<br /><br />(Job 38:31-33) 31 Can you tie fast the bonds of the Ki´mah constellation, Or can you loosen the very cords of the Ke´sil constellation? 32 Can you bring forth the Maz´za·roth constellation in its appointed time? And as for the Ash constellation alongside its sons, can you conduct them? 33 Have you come to know the statutes of the heavens, Or could you put its authority in the earth?<br /><br />God can "conduct" galaxies so that they are fine tuned, even as our universe has been fine tuned.<br /><br />And we are still learning "the statutes of the heavens," many of which do have authority on the earth so that scientists can and have discovered many of these laws and properties.<br /><br />Whether the "cords," which include gravitational bonds, are loosened or will hold fast is currently a subject for scientific study.<br /><br />Certainly, gravity has been concentrated on by scientists, while magnetism has tended to be ignored.<br /><br />But not entirely - there was a good article in Scientific American concerning the IGM, intergalactic medium, that presented evidence that this is highly ionized and postulated that magnetic influences may have been, at least in part, responsible for galactic formation.<br /><br />In contrast, another recent Scientific American article concern

 

[siriusmre]

These are the words that pop out at me as I read this:<br /><br />“Many <b>popular</b> <font color="yellow">[Just 'cause something's popular don't make it right]</font>models of galaxy formation <br /><b>postulate</b> <font color="yellow">[And yet most pronounce these "postulations" as facts]</font>that large galaxies are <br />formed by a long process of aggregation <br />of many smaller galaxies. Such a process <br /><b>should</b> still be common today, <b>yet has <br />been observed only rarely.</b> <font color="yellow">[Anyone have any examples of this?]</font>Sagittarius <br /><b>appears</b> <font color="yellow">[Appearances CAN be deceiving]</font>to have undergone some disruption <br />from the tidal forces exerted by the <br />Milky Way, but the disruption of the <br />core of Sagittarius is <b>unexpectedly</b> <font color="yellow">[Do they <i>actually</i> mean that the theory didn't predict the smallness of the disturbance? <img src="/images/icons/shocked.gif" />]</font>minor. <br />The dwarf <b>may</b> have orbited our <br />galaxy 10 times or more yet remains <br />largely intact, <b>indicating that it is held <br />together by large amounts of dark matter</b> <font color="yellow">[There's a leap for ya!]</font><br />(as opposed to luminous matter such <br />as stars or gaseous clouds). Even so, <b>its <br />demise is just a matter of time</b> <font color="yellow">[Oh?]</font> some <br />studies <b>suggest</b> that Sagittarius <b>may have <br />only another billion years to go</b> <font color="yellow">[Again, ASSUMING that everything continues to uniformly go on as it does now]</font>before <br />being swallowed by our galaxy. Its discovery <br />has <b>demonstrated that mergers <br />do happen</b> <font color="yellow">[Really?]</font> that they happen today and <br />that they do not necessarily wreck the <br />disk of the larger galaxy.”<br /><br />Again, I point out all of t <div class="Discussion_UserSignature"> </div>

 

[newtonian]

telfrow - So how do you feel about the article you linked to - or the ones I cited?<br /><br />I certainly agree this belongs in space science - unless we need to delegate the scientific journals to phenomena!<br /><br />Of course, mergers are natural phenomena!<br /><br />I will study your linked article and respond better soon.

 

[siriusmre]

Those galaxies are "interacting." That does not necessarily mean that they collided. <div class="Discussion_UserSignature"> </div>

 

[telfrow]

NCG2207 and IC 2163 "interacting." <img src="/images/icons/rolleyes.gif" /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[telfrow]

<i>NASA's Chandra X-ray Observatory has discovered rich deposits of neon, magnesium, and silicon in a pair of colliding galaxies known as The Antennae. The deposits are located in vast clouds of hot gas. When the clouds cool, say scientists, a great number of stars and planets should form. These results may foreshadow the fate of our own Milky Way and its future collision with the Andromeda Galaxy.</i><br /><br />From: http://www.nasa.gov/missions/deepspace/08jan_antennae.html <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[newtonian]

telfrow - thanks for the picture! Yes, I am aware of many awesome photos that show various stages of mergers which are consistent with computer models of what mergers might do.<br /><br />However, some to the shapes do appear to be far more beautiful than one would expect from mere chance mergers.<br /><br />Rather like our moon just happenning to be in the right orbit due to a mere chance collision of some mass with earth.<br /><br />To me, the collision or merger of water molecules in a snowflake, while following laws and properties that were already created, show evidence of intelligent design.<br /><br />Likewise, just like snowflakes are awesome in design and variety, so likewise galactic mergers and galaxies in general are awesome in design and variety.<br /><br />Simply put: "star differs from star in glory." (1 Corinthians 15:41) - and this clearly also applies to galaxies.<br /><br />Like snowflakes, I doubt if you will find two galaxies totally alike! Yet they do follow precise laws and properties which govern our universe - even though we don't understand it all yet!

 

[siriusmre]

Right. Interacting. How do we know that they are "colliding?" Do we have a movie of it? <div class="Discussion_UserSignature"> </div>

 

[telfrow]

<img src="/images/icons/rolleyes.gif" /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[newtonian]

telfrow - your link refers to ancient galaxies not long after the big bang.<br /><br />Of course, this assumes we have the age of the universe right - astronomer Wendy Friedman estimates 12 billion years though some stars seem to be older than that.<br /><br />And this also assumes we have interpreted red shift entirely correctly, that nothing is skewing the calculations. I suspect it expansion may be more complex than assumed.<br /><br />Given all that, the article states:<br /><br />"In the past, people equated stellar age with the age of the galaxy," van Dokkum explains. "We have found that, though their stars are generally old, the galaxies that result from these mergers are relatively young." <br /><br />"It is not yet understood why the merging process does not lead to enhanced star formation in the colliding galaxies. It may be that massive black holes in the centers of the galaxies provide the energy to heat or expel the gas that needs to be able to cool in order to form new stars. Ongoing detailed study of the newly found mergers will provide better insight into the roles that black holes play in the formation and evolution of galaxies." <br /><br />OK, that is weird, since recent studies of other galactic mergers closer to us do show evidence of increased star formation.<br /><br />The presence of a supermassive black hole as a deterrent is simply false, since other more local galaxies that have increased stellar formation due to mergers also have supermassive black holes at their cores, if current interpretations of the data are correct.<br /><br />I see now why I was asked by someone here why new stars are formed in our galaxy near the location of the supermassive black hole at the core of Milky Way.<br /><br />To me, their is no contradiction here - black holes would not deter new star formation or else we would not observe both in local merging galaxies.<br /><br />BTW - stellar collisions can also be enhanced by mergers - more correctly: stellar mergers.<br /><br />I have

 

[newtonian]

Leovinus - Are you Sirius?<br /><br />Your post does not compute!<br /><br />Except on one point - conservation of energy - more accruate scientifically this would be conservation of matter and energy.<br /><br />The cause of the big bang, or creation, of our universe would have to involve incorporation of energy - i.e. an open system thermodynamically - as in God created the universe.<br /><br />Isaiah 40:22 indicates God is stretching out our universe like a fine gauze. It is true that when you stretch a gauze some bonds will loosen and break (Job 38:31-33) while others will hold fast, such that our local section of universe is contracting.<br /><br />However, the universe as a whole is expanding.<br /><br />The local motion towards the Great Attractor will likely include many mergers for us, i.e. Milky Way in the future quadrillions of years.<br /><br />Beyond that is anyone's guess - mine being a merger between our universe and another universe.<br /><br />Just a guess, btw.!

 

[newtonian]

telfrow - yes, those photos are interesting.<br /><br />Thank you again.<br /><br />Any reason you are ignoring my posts?