Astronomers find runaway galaxies

April 23, 2015
This schematic illustrates the creation of a runaway galaxy. In the first panel, an "intruder" spiral galaxy approaches a galaxy cluster center, where a compact elliptical galaxy (cE) already revolves around a massive central elliptical galaxy. In the second panel, a close encounter occurs and the compact elliptical receives a gravitational kick from the intruder. In the third panel, the compact elliptical escapes the galaxy cluster while the intruder is devoured by the giant elliptical galaxy in the cluster center. Credit: NASA, ESA, and the Hubble Heritage Team

We know of about two dozen runaway stars, and have even found one runaway star cluster escaping its galaxy forever. Now, astronomers have spotted 11 runaway galaxies that have been flung out of their homes to wander the void of intergalactic space.

"These galaxies are facing a lonely future, exiled from the galaxy clusters they used to live in," said astronomer Igor Chilingarian (Harvard-Smithsonian Center for Astrophysics/Moscow State University). Chilingarian is the lead author of the study, which is appearing in the journal Science.

An object is a runaway if it's moving faster than escape velocity, which means it will depart its home never to return. In the case of a , that speed is more than a million miles per hour (500 km/s). A runaway galaxy has to race even faster, traveling at up to 6 million miles per hour (3,000 km/s).

Chilingarian and his co-author, Ivan Zolotukhin (L'Institut de Recherche en Astrophysique et Planetologie/Moscow State University), initially set out to identify new members of a class of galaxies called compact ellipticals. These tiny blobs of are bigger than star clusters but smaller than a typical galaxy, spanning only a few hundred light-years. In comparison, the Milky Way is 100,000 light-years across. Compact ellipticals also weigh 1000 times less than a galaxy like our Milky Way.

Prior to this study, only about 30 compact were known, all of them residing in galaxy clusters. To locate new examples Chilingarian and Zolotukhin sorted through public archives of data from the Sloan Digital Sky Survey and the GALEX satellite.

Their search identified almost 200 previously unknown compact ellipticals. Of those, 11 were completely isolated and found far from any large galaxy or .

This schematic illustrates the creation of a runaway galaxy. In the first panel, an "intruder" spiral galaxy approaches a galaxy cluster center, where a compact elliptical galaxy (cE) already revolves around a massive central elliptical galaxy. In the second panel, a close encounter occurs and the compact elliptical receives a gravitational kick from the intruder. In the third panel, the compact elliptical escapes the galaxy cluster while the intruder is devoured by the giant elliptical galaxy in the cluster center. Credit: NASA, ESA, and the Hubble Heritage Team

"The first compact ellipticals were all found in clusters because that's where people were looking. We broadened our search, and found the unexpected," said Zolotukhin.

These isolated compact galaxies were unexpected because theorists thought they originated from larger galaxies that had been stripped of most of their stars through interactions with an even bigger galaxy. So, the compact galaxies should all be found near big .

Not only were the newfound compact ellipticals isolated, but also they were moving faster than their brethren in clusters.

"We asked ourselves, what else could explain them? The answer was a classic three-body interaction," stated Chilingarian.

A hypervelocity star can be created if a binary star system wanders close to the black hole at the center of our galaxy. One star gets captured while the other is thrown away at tremendous speed.

Similarly, a compact elliptical could be paired with the big galaxy that stripped it of its stars. Then a third galaxy blunders into the dance and flings the compact elliptical away. As punishment, the intruder gets accreted by the remaining big galaxy.

This discovery represents a prominent success of the Virtual Observatory - a project to make data from large astronomical surveys easily available to researchers. So-called data mining can result in finds never anticipated when the original data was collected.

"We recognized we could use the power of the archives to potentially unearth something interesting, and we did," added Chilingarian.

Explore further: Entire star cluster thrown out of its galaxy

More information: Isolated compact elliptical galaxies: Stellar systems that ran away, Science 24 April 2015: Vol. 348 no. 6233 pp. 418-421. DOI: 10.1126/science.aaa3344

Related Stories

Entire star cluster thrown out of its galaxy

April 30, 2014

(Phys.org) —The galaxy known as M87 has a fastball that would be the envy of any baseball pitcher. It has thrown an entire star cluster toward us at more than two million miles per hour. The newly discovered cluster, which ...

Dark matter guides growth of supermassive black holes

February 18, 2015

Every massive galaxy has a black hole at its center, and the heftier the galaxy, the bigger its black hole. But why are the two related? After all, the black hole is millions of times smaller and less massive than its home ...

Galactic dinosaurs not extinct

February 27, 2015

One of the biggest mysteries in galaxy evolution is the fate of the compact massive galaxies that roamed the early Universe.

Hubble explores the mysteries of UGC 8201

March 19, 2015

The galaxy UGC 8201, captured here by the NASA/ESA Hubble Space Telescope, is a dwarf irregular galaxy, so called because of its small size and chaotic structure. It lies just under 15 million light-years away from us in ...

Measuring galaxy evolution with globular clusters

March 23, 2015

Globular clusters are gravitationally bound ensembles of stars, as many as a million stars in some cases, grouped in roughly spherical clusters with diameters as small as only tens of light-years. Globular clusters are typically ...

Recommended for you

Rocky planet found orbiting habitable zone of nearest star

August 24, 2016

An international team of astronomers including Carnegie's Paul Butler has found clear evidence of a planet orbiting Proxima Centauri, the closest star to our Solar System. The new world, designated Proxima b, orbits its cool ...

WISE, Fermi missions reveal a surprising blazar connection

August 24, 2016

Astronomers studying distant galaxies powered by monster black holes have uncovered an unexpected link between two very different wavelengths of the light they emit, the mid-infrared and gamma rays. The discovery, which was ...

China unveils 2020 Mars rover concept: report

August 24, 2016

China has unveiled illustrations of a Mars probe and rover it aims to send to the Red Planet at the end of the decade in a mission that faces "unprecedented" challenges, state media said on Wednesday.

52 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

JRi
1 / 5 (1) Apr 23, 2015
I would like to know, when the three images have been taken. (Probably said in the Science paper).
Benni
1.5 / 5 (8) Apr 23, 2015
There must be a Dark Matter Narrative in here somewhere. Massey where are you to explain to us how these Spirals with all their vaunted gravitational DM cosmic fairy dust get devoured by giant Ellipticals & not vice verse?

And to boot, you would think the Spiral's cosmic fairy dust would add so much gravity to the giant Elliptical that is absorbing it that it would be impossible for the small Elliptical to make a sudden getaway. Seems to be a simple case of energy input to a system results in energy output minus a certain waste.

The Spiral being absorbed by the Giant Elliptical most likely has a mass similar to the small Elliptical being ejected from the cluster. The interjection of additional mass has upset the equilibrium of the system that existed prior to the intrusion of the Spiral now being absorbed, but all-in-all somewhere in here must be a cosmic fairy dust narrative, we simply can't move ahead without that.

denglish
5 / 5 (10) Apr 23, 2015
Benni, how would *you* describe a galaxy's flat rotation curve?
Da Schneib
5 / 5 (10) Apr 23, 2015
Those aren't images, they're schematic representations.
Benni
1.6 / 5 (7) Apr 23, 2015
Benni, how would *you* describe a galaxy's flat rotation curve?


At this point, I'm wondering if you think ALL galaxies have a Rotation Curve. Do you?
someone11235813
5 / 5 (7) Apr 23, 2015
Rather patronising to say that these galaxies will face a lonely future. I applaud their boldness to venture forth into the mysterious void, to leave the cloistered confines of their tightly gravitationally bound existence and go where no galaxy has gone before.
RealScience
5 / 5 (7) Apr 23, 2015
I would like to know, when the three images have been taken. (Probably said in the Science paper).


@JRi: Da Schneib is correct - these are illustrations, not photographs.

The spiral galaxy is on the order of 100,000 light years across, so the distance it moves between the first and last frame is several hundred thousand light years. If it is moving in at the cluster's escape velocity, that is said to be up to ~3000 km/s, which is only ~1% of the speed of light, and several hundred thousand light years would take several tens of millions of years. Therefore if these images were photographs they would have to have been taken at least several tens of millions of years apart...
Steve 200mph Cruiz
4.4 / 5 (7) Apr 24, 2015
Benni,
If you spent a few days actually learning the math behind relativity, you would have the answer to your questions.
It's really not that hard, it's math, math by definition makes sense.
Da Schneib
5 / 5 (5) Apr 24, 2015
At this point, I'm wondering if you think ALL galaxies have a Rotation Curve. Do you?
Lenni, yes, all galaxies have a rotation curve. Even if it's flat. It's like asking if all ducks quack.
viko_mx
1 / 5 (4) Apr 24, 2015
"An object is a runaway if it's moving faster than escape velocity, which means it will depart its home never to return"

How we can understand that given galaxy is moving faster than escape velosity from the given group of galaxies? How we can caculate the escape velosity when we do not know the mass of galaxies with sufficient accuracy? In fact our cosmological calculations are based on unconfirmed bold hypotheses. By red shif of light we can not mesure the speed of cosmic objects, because it source is the interaction of light with structure of cosmic vacuum. Not the dopler effect which is only valid for static transmission medium.
viko_mx
1 / 5 (5) Apr 24, 2015
The point is that this cosmic structure and its parameters can be adjusted locally or globaly by the will of the Creator and is not the same everywhere. Which makes any space measurements and calculations only an exercise of mathematics.
Mike_Massen
3.4 / 5 (5) Apr 24, 2015
viko_mx claimed
The point is that this cosmic structure and its parameters can be adjusted locally or globaly by the will of the Creator and is not the same everywhere
viko_mx has just now accepted the creator he goes on about cannot predict future, as it did with so called "test" of Eve !

Why does a creator viko_mx NEED to adjust anything, isn't it smarter & of course far beyond the primitive emotionally feeble people who need a father figure who ONLY punishes to; instead start the universe off with implicit Rules & Self-assembly which is completely proven as observable & NOT step in now & then to make things happen it couldn't predict at beginning ?

viko_mx just described an entity more like a devil but, one that cannot predict and instead has to fiddle with things along the way !

viko_mx clams
Which makes any space measurements & calculations only an exercise of mathematics
Learn Physics.

viko_mx fails at logic

HOW does your creator communicate ?
thingumbobesquire
2 / 5 (1) Apr 24, 2015
Ha! The three body problem is the bette noir of the reductionists' pair-wise artificial intelligence assumptions.
katesisco
1 / 5 (3) Apr 24, 2015
The paper's authors say that there musing about what would cause this: the classic three-body interaction. Perhaps the bh is overloaded and the galaxy is not just sped on its way but warped on its way. The overloaded bh accomplishes sci fi by warping space time to deposit the star/galaxy some distance away with its original momentum increased. I think that is what happened to the Magellenic galaxy with its remnants visible as the LMC and the GMC. Their center galaxy is us, the Milky Way.
antialias_physorg
4.6 / 5 (11) Apr 24, 2015
The point is that this cosmic structure and its parameters can be adjusted locally or globaly by the will of the Creator

...and you know this because...?

Oh, right...I forgot. You have made the "Creator" in your own image. Whatever you imagine he can do, right?
Benni
2.6 / 5 (5) Apr 24, 2015
Benni said:
At this point, I'm wondering if you think ALL galaxies have a Rotation Curve. Do you?


Schneib said:
Lenni, yes, all galaxies have a rotation curve. Even if it's flat. It's like asking if all ducks quack.


.....proving how little you know about the gravitational forces governing the structure of Elliptical galaxies versus Spirals.

Ellipticals do not have Rotation Curves because the gravitational forces of these galaxy types function in perfect accord with Newtonian gravity & the Inverse Square Law. The outermost orbital stars of giant Ellipticals orbit the core at about 2 km/sec with orbital speed varying at a rate in perfect accord of the ISL.

The rate Spiral arms move about their cores is 100-200 km/sec, their rate of movement as a function of distance from the core is not governed by the Inverse Square Law as in the case of Ellipticals. I can tell Schneib by your response that you didn't know this or you would have already brought it up.
reset
1 / 5 (4) Apr 24, 2015
"An object is a runaway if it's moving faster than escape velocity, which means it will depart its home never to return"

How we can caculate the escape velosity when we do not know the mass of galaxies with sufficient accuracy? In fact our cosmological calculations are based on unconfirmed bold hypotheses.


Standard practice appears to be: Speculate that it is a 3 body interaction, Assign values M and V to each of the 3 bodies so that the illustrated interaction works mathematically and claim problem solved. Thank God we have math to guide us through these untestable hypothesies. Maybe one day it will be right about something....

Learn Physics.


Based on OUR last back and forth you should follow your own advice.

Benni
2.3 / 5 (6) Apr 24, 2015
Benni,
If you spent a few days actually learning the math behind relativity, you would have the answer to your questions.
It's really not that hard, it's math, math by definition makes sense.


Without a doubt Stevo -200, you should undertake some such studies, just try to avoid getting seriously bogged down by the Differential Equations in there Stevo -200. Your backwards reasoning is as backwards as Schneibo who has also never seen a Differential Equation he could solve much less as one having a basic understanding of the gravitational dynamics of Elliptical versus Spiral galaxies.

You've got three courses of Calculus to get through before you get to those Differential Equations by which to gain the most basic of comprehension the math in Einstein's GR. You say "It's really not that hard" only because you have no experience with it but that's what I learned during my six years in Engineering school studying Electrical & Nuclear Engineering.
denglish
5 / 5 (9) Apr 24, 2015
Benni, how would *you* describe a galaxy's flat rotation curve?


At this point, I'm wondering if you think ALL galaxies have a Rotation Curve. Do you?

Don't divert Benni.

My response was in the context of your post re: spiral galaxies. I'm curious to know your answer!
Benni
1.7 / 5 (6) Apr 24, 2015
Benni, how would *you* describe a galaxy's flat rotation curve?


At this point, I'm wondering if you think ALL galaxies have a Rotation Curve. Do you?

Don't divert Benni.

My response was in the context of your post re: spiral galaxies. I'm curious to know your answer!


......but you haven't responded to my question if you think all galaxies have a Rotation Curve. This leaves me to believe you have erroneously concluded, as Schneib has, that all galaxies have a Rotation Curve, and you like he never knew this is not the case until I pointed it out.

As I admonished you once before, take up a study of Ellipticals, learn something about Newtonian gravity & the Inverse Square Law & you won't look as silly as Schneib has made himself out to be.
denglish
4.5 / 5 (8) Apr 24, 2015
Benni, how would *you* describe a galaxy's flat rotation curve?


At this point, I'm wondering if you think ALL galaxies have a Rotation Curve. Do you?

Don't divert Benni.

My response was in the context of your post re: spiral galaxies. I'm curious to know your answer!


......but you haven't responded to my question if you think all galaxies have a Rotation Curve. This leaves me to believe you have erroneously concluded, as Schneib has, that all galaxies have a Rotation Curve, and you like he never knew this is not the case until I pointed it out.

As I admonished you once before, take up a study of Ellipticals, learn something about Newtonian gravity & the Inverse Square Law & you won't look as silly as Schneib has made himself out to be.

Oh boy. Ok, you win:

How would *you* explain the flat rotation curve observed in spiral galaxies?
RealScience
5 / 5 (7) Apr 24, 2015
Ellipticals do not have Rotation Curves because the gravitational forces of these galaxy types function in perfect accord with Newtonian gravity & the Inverse Square Law. The outermost orbital stars of giant Ellipticals orbit the core at about 2 km/sec with orbital speed varying at a rate in perfect accord of the ISL.


@Benni - that would NOT mean that elliptical galaxies don't have rotation curves. That would just mean that the rotation curves of elliptical galaxies match the predictions of the inverse square law.

(You appear to have assumed that Da Schneib said 'an ANOMALOUS rotation curve'.)
Da Schneib
5 / 5 (7) Apr 24, 2015
Ummmm, apparently Lenni doesn't understand the meaning of "curve" in this context; it includes straight lines. "This context" == mathematics.

This is like the old Carlin news routine: "And now for tomorrow's weather: Tomorrow there will be no weather." (laughter.)

Claiming there can be a galaxy without a rotation curve is exactly like that.
Da Schneib
5 / 5 (6) Apr 24, 2015
(You appear to have assumed that Da Schneib said 'an ANOMALOUS rotation curve'.)
Or that they're not rotating. Or that the mathematical definition of "curve" doesn't include a straight line (which is my guess- Lenni's not all that good with math).
Benni
1.7 / 5 (6) Apr 24, 2015
Ellipticals do not have Rotation Curves because the gravitational forces of these galaxy types function in perfect accord with Newtonian gravity & the Inverse Square Law. The outermost orbital stars of giant Ellipticals orbit the core at about 2 km/sec with orbital speed varying at a rate in perfect accord of the ISL.

@Benni - that would NOT mean that elliptical galaxies don't have rotation curves. That would just mean that the rotation curves of elliptical galaxies match the predictions of the inverse square law.

You appear to have assumed that Da Schneib said an ANOMALOUS rotation curve


You people are totally clueless about the dynamics of Rotation Curves of Spirals to which the Inverse Square Law has no application. Schneib was crystal clear in what he said, now you're trying to repair his gross mistake about Ellipticals having a Rotation Curve. You know I caught him & so does he, now in the damage control process you're simply heightening his mistake.
Benni
1.7 / 5 (6) Apr 24, 2015
(You appear to have assumed that Da Schneib said 'an ANOMALOUS rotation curve'.)
Or that they're not rotating. Or that the mathematical definition of "curve" doesn't include a straight line (which is my guess- Lenni's not all that good with math).


Give it up Schneibo, you screwed up big time & by now you know it because you've had time to get to Wikipedia & read over some material on Rotation Curves, something you should have done before you started shooting off your mouth about things of which you knew nothing until I pointed them out to you. You're just all bent out of shape because I've shown you up for all the hot air you've ever been known to be in addition to being a copycat poster.
Da Schneib
5 / 5 (4) Apr 24, 2015
Ha! The three body problem is the bette noir of the reductionists' pair-wise artificial intelligence assumptions.
Actually, the three-body (or more generally the n-body) problem has finite solutions; the problem is that they are based on series and because these series are intractable, and converge only very slowly, it's been shown that approximately 10⁸⁰⁰⁰⁰⁰⁰ (ten to the eight millionth power- a one followed by eight million zeros) terms of the series would need to be processed to consistently yield a definite result, a task that is beyond our current calculational capabilities. Thus, we use numerical integration to approximate the results on supercomputers, and the results are published in ephemerides, among other applications.

These two facts tend rather to deflate the assertion that "the three-body problem has no solutions." Just sayin'.
Benni
1.8 / 5 (5) Apr 24, 2015
Benni, how would *you* describe a galaxy's flat rotation curve?


At this point, I'm wondering if you think ALL galaxies have a Rotation Curve. Do you?

Don't divert Benni.
But you still won't answer the question

My response was in the context of your post re: spiral galaxies. I'm curious to know your answer!


......but you haven't responded to my question if you think all galaxies have a Rotation Curve as Schneib does, and you like he never knew this is not the case until I pointed it out.

As I admonished you once before, take up a study of Ellipticals, learn something about Newtonian gravity & the Inverse Square Law & you won't look as silly as Schneib has made himself out to be.

Oh boy. Ok, you win
I know.

How would *you* explain the flat rotation curve observed in spiral galaxies?


So first tell me if you've taken up that study of Ellipticals & tell me what you've learned.
Da Schneib
5 / 5 (5) Apr 24, 2015
You people are totally clueless about the dynamics of Rotation Curves of Spirals to which the Inverse Square Law has no application.
Ummm, you were just claiming there were galaxies which had no rotation curve.

So, are you now admitting you were wrong? And trying to cover it up before anyone notices?

Oops, too late. FAIL.
denglish
4.4 / 5 (7) Apr 24, 2015
denglish:

How would *you* explain the flat rotation curve observed in spiral galaxies?


Benni:

So first tell me if you've taken up that study of Ellipticals & tell me what you've learned.


Ok, you're a troll, and show very little wit. At least be entertaining.

3/10
Da Schneib
5 / 5 (6) Apr 24, 2015
Just for the record, you do realize that doppler measurements of individual stars within a galaxy permit detection of rotation of galaxies, and that ellipticals rotate, right? In an elliptical, instead of a curve, it's a multitude of curves, called the "velocity dispersion," but it's the equivalent measurement. You just need to do a little integration. It's not that hard, unless you don't know any math.

You really shouldn't try to discuss galactic dynamics without understanding mechanics and mathematics, Lenni.
Da Schneib
5 / 5 (6) Apr 24, 2015
Here, from a pretty good source: http://www.ifa.ha...sreg.pdf

An elliptical galaxy's rotation does not always correlate with its flattening... In such galaxies the rotation axis need not be parallel to the minor axis; such kinematic misalignments are indeed observed in some ellipticals.


Here, from another: http://ned.ipac.c...3_2.html

Kinematic observations of elliptical galaxies have provided several surprises. First, it was found that luminous ellipticals rotate slowly. A modern observation of NGC 1600 gives a rotational velocity of 1.9 ± 2.3 km s-1 along the major axis, resulting in a v / sigma < 0.013.


Looks like they rotate, Lenni. Another FAIL.
Benni
1.8 / 5 (5) Apr 24, 2015
You people are totally clueless about the dynamics of Rotation Curves of Spirals to which the Inverse Square Law has no application.


Ummm, you were just claiming there were galaxies which had no rotation curve.

So, are you now admitting you were wrong? And trying to cover it up before anyone notices


Totally Clueless Schneib, I caught you & you can't figure out a way to take back your statement:

"Lenni, yes, all galaxies have a rotation curve. Even if it's flat. It's like asking if all ducks quack."

Now that you've finally had some time to get over to WikiPedia & learn Rotation Curves apply only to Spirals & never to Ellipticals, you've simply turned to sarcasm because you refuse to recant your obviously erroneous staement. It's also obvious you've never seen the inside of a college physics classroom & you're here on a physics site just hoofing it along because you have nothing better to do with your time.

Da Schneib
5 / 5 (6) Apr 24, 2015
I just linked two astronomers who say you're wrong, Lenni: ellipticals rotate. That trumps Wikipedia.

Get over it.
Benni
1.7 / 5 (6) Apr 24, 2015
Kinematic observations of elliptical galaxies have provided several surprises. First, it was found that luminous ellipticals rotate slowly. A modern observation of NGC 1600 gives a rotational velocity of 1.9 ± 2.3 km s-1 along the major axis, resulting in a v / sigma < 0.013.


Looks like they rotate, Lenni. Another FAIL.


.....and you still can't get a grip on it can you Schneib. The issue between Ellipticals & Spirals is: ROTATION CURVE.

Can you comprehend the difference between the word "rotation", & ROTATION CURVE? I guess it must be subject matter that is beyond your comprehension. At least get over to WikiPedia & spend some time learning something rather than continuing to post your nonsensical foolishness about things of which you have no comprehension.
Da Schneib
5 / 5 (7) Apr 24, 2015
Ummm, let's make sure you don't obfuscate. Your original claim is that ellipticals do not have rotation curves. It's now clear that this was incorrect. Why are you still trying to cover this up?
Da Schneib
5 / 5 (8) Apr 24, 2015
BTW, the above reference from the University of Hawaii is from their Institute for Astronomy, and the class number is Astronomy 626, "Galaxies." The full coursework is available here: http://www.ifa.ha...626.html
Joshua Barnes, the author, is an astronomer at the IFA at U of H. He specializes in galactic astronomy, and is a full teaching faculty member and has been the chairman of their graduate program. He is currently on sabbatical in Japan.
Da Schneib
5 / 5 (7) Apr 24, 2015
And the second reference is from Cal Tech, by Tim de Zeeuw and Marijn Franx, published in Astronomy and Astrophysics as an Annual Review in 1991. So it's been known for twenty-four years at least that elliptical galaxies rotate; and that means they have at least one rotation curve (and in fact, they have many- but many is not none

Tim de Zeeuw is currently the Director General of the ESO (European Southern Observatory which is mostly around the Atacama Desert, and includes the VLT at Paranal, and ALMA, both of which are well known in astronomy and currently engaged in observations at the forefront of the field). He is an expert of long standing in galaxy dynamics.
Benni
1.7 / 5 (6) Apr 24, 2015
Ummm, let's make sure you don't obfuscate. Your original claim is that ellipticals do not have rotation curves. It's now clear that this was incorrect. Why are you still trying to cover this up?


.....so you're still trying to figure out how to create cover for your erratic funny farm science statement:

"Lenni, yes, all galaxies have a rotation curve. Even if it's flat. It's like asking if all ducks quack."

All I need to do is keep reminding you & the readers that you are the one who made that foolish statement. As you keep trying to find a fix for your blunder of the facts, each subsequent post only further reveals the shallow depths of your comprehension of the science. Keep posting your Comments, each subsequent followup you make only serves to make you look all the more foolish than the post before it.

Spare yourself the continuing embarrassment of trying to convolute somebody else's words so as to create cover for your blunders, study ROTATION CURVES.

Da Schneib
5 / 5 (7) Apr 24, 2015
so you're still trying to figure out how to create cover
Projection detected.

All I need to do is keep reminding you & the readers that you are the one who made that foolish statement.
It's substantiated by two astronomy professors, one of whom is the Director General of the ESO.

Are you claiming you know more galaxy astronomy than two astronomy professors, both galaxy experts, one of whom is the Director General of the ESO?

Just for the record.
Benni
1.7 / 5 (6) Apr 25, 2015


Are you claiming you know more galaxy astronomy than two astronomy professors, both galaxy experts, one of whom is the Director General of the ESO?


It has become clear that a study of Rotation Curves is beyond the limits of your comprehension. In the meantime you continue blundering around peddling funny farm science because you've never seen a Differential Equation in Einstein's GR that you could follow, but then how could you be expected to if you can't even follow the concept of Roatation Curves.
Da Schneib
5 / 5 (4) Apr 25, 2015
It has become clear that a study of Rotation Curves is beyond the limits of your comprehension
I thought you said there weren't any in elliptical galaxies.
Da Schneib
5 / 5 (3) Apr 25, 2015
Ellipticals do not have Rotation Curves
Your third post in this thread. I don't think there's anyplace to hide, Lenni. So, now you're admitting that ellipticals do have rotation curves, right?
Benni
1.8 / 5 (5) Apr 25, 2015
It has become clear Schneib that a study of Rotation Curves is beyond the limits of your comprehension
I thought you said there weren't any in elliptical galaxies.


....and here you are, still piddling around with the funny farm science crowd trying to apply Rotation Curves to Ellipticals where such gravitational dynamics are not warranted. Your links to Astronomers are guys who've had far less education in Nuclear Physics than I, meanwhile you're still mired in a grade school level of comprehension.

I understand very well why certain ones would try to apply Rotation Curves to Ellipticals, it's all about DM cosmic fairy dust & the narrative proposing it makes up 90% of all the mass in the universe. There are those who can't abide by Newtonian Gravity being the stand alone force of inherent gravity within giant Ellipticals which creates 99.9999999999999% of observed gravitational lensing, and you're just one more of many suckers falling for the fairy tale.

denglish
4.3 / 5 (6) Apr 25, 2015
There are those who can't abide by Newtonian Gravity being the stand alone force...


Something tells me this person doesn't know the difference between Newtonian and Einstien's gravity.

Da Schneib
5 / 5 (8) Apr 25, 2015
Nuclear physics isn't gravitation physics, Lenni, which if you actually knew any nuclear physics you'd know. There is no quantum theory of gravity, and nuclear physics is explicitly quantum physics.

Even if you did know nuclear physics, it wouldn't qualify you to dismiss the views of well-known astrophysicists like the Director General of the ESO.

Sorry, Lenni, you FAIL again.
SuperThunderRocketJockey
4.3 / 5 (6) Apr 26, 2015
Supercluster : There will be no elliptical galaxy rotation curves in MY region, young man!
Compact Galaxy : Oh yeah!? I'm leaving!

Good lord, folks, a quarter of elliptical galaxies have rotation curves.
http://ned.ipac.c...3_3.html

Did you mean maybe kinematically coupled rotation curves along a major axis? There's apparently a candidate for that too, but who knows if your instant coffee galaxy got stirred by a passing space monster or it happened naturally. I really hope this whole argument isn't over something this... is there a word that means "pedantic" and "semantic?" Maybe in German or something?
RealScience
5 / 5 (5) Apr 26, 2015
@STRJ - Nice link!

A slight correction - Section 3.3 says: "It was found that elliptical galaxies have complicated rotation curves". The one quarter of galaxies is in Section 3.3.1, which says that about 25% of all elliptical galaxies have kinematically distinct cores.

But don't expect Benni to accept your reference - he probably thinks he knows more astronomy than anyone at Caltech!

As for semantics, the question of whether ALL galaxies have rotation curves is semantic. In some ellipticals the bulk rotational velocity is low enough that the 'rotational curve' is almost a flat line at zero, but as someone pointed out earlier, mathematically a flat line is still a curve (but a non-technical person might not call it a curve). However in such ellipticals the stars individually still have significant velocities, so in this case the 'velocity curve' is more useful to study (for a spiral galaxy these two are essentially identical, and they are sometimes used interchangeably).
SuperThunderRocketJockey
4.3 / 5 (6) Apr 27, 2015
RealScience, thank you!

Honestly, I wasn't sure where I was going to end up falling on the issue when I hit the Internet to try and settle it. I did as Benni suggested and hit wikipedia, then a bunch of other sources. There are aggregate astronomy sites like this one that do have articles saying elliptical galaxies have no rotation curves. That's why I try and let matters fall on places that end in "edu" as a general rule. Otherwise, I found sites stating it both ways. I started to suspect it wasn't the movement, but their interpretation. I agree, 'velocity curve' is clearer in meaning.

As for Benni's motivations, I don't really care, since there are hundreds of millions of people who wouldn't even bother to try and dispute astronomy facts, and I could easily see how they might have gotten the information from either an over-generalizing teacher, or another website like this one. The link I found didn't come up readily. I'm just happy they want to participate.
Da Schneib
5 / 5 (5) Apr 27, 2015
Good work, STRJ! Well done. 5s for you. I been busy talkin' heavy duty quantum mechanics elsewhere.
Ultron
1 / 5 (1) Apr 27, 2015
Benni, actually I do have new theory which would be consistent with Newton gravity rotation curve in no rotating and slow rotating elliptical galaxies and flat rotation curve in spiral galaxies.

Do you have some links which would confirm, that elliptical galaxies rotation curve is in line with Newton gravity? It would help me with observational evidence supporting my theory.
RealScience
5 / 5 (1) Apr 27, 2015
There are aggregate astronomy sites like this one that do have articles saying elliptical galaxies have no rotation curves. That's why I try and let matters fall on places that end in "edu" as a general rule. Otherwise, I found sites stating it both ways. I started to suspect it wasn't the movement, but their interpretation. I agree, 'velocity curve' is clearer in meaning.


In addition to rotation being much less important for most ellipticals, the rotation is also much harder to measure. Not only is this partly BECAUSE it is less important (dominated by motions other than bulk rotation), but also because one of the ways to measure the velocity uses large gas clouds and ellipticals typically have many fewer of these than spiral galaxies do.

So the rotation curve in ellipticals is less important, harder to measure, and is often a degenerate curve (with your 25% link showing an important exception to this).

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.