More from Arp et al.

[turbo-1]

http://antwrp.gsfc.nasa.gov/cgi-bin/..._search?binary
APOD: 2002 July 11 - M51: X Rays from the Whirlpool
"Explanation: Fresh from yesterday's episode, a popular pair of interacting galaxies known as the Whirlpool debut here beyond the realm of visible light -- imaged at high energies by the orbiting Chandra X-ray Observatory. Still turning in a remarkable performance, over 80 glittering x-ray stars are present in the Chandra image data from the region. The number of luminous x-ray sources, likely neutron star and black hole binary systems within the confines of M51, is unusually high for normal spiral or elliptical galaxies and suggests this cosmic whirlpool has experienced intense bursts of massive star formation. The bright cores of both galaxies, NGC 5194 and NGC 5195 (right and left respectively), also exhibit high-energy activity in this false-color x-ray picture showing a diffuse glow from multi-million degree gas. An expanded view of the region near the core of NGC 5194 reveals x-rays from a supernova remnant, the debris from a spectacular stellar explosion, first detected by earthbound astronomers in 1994."

It appears improbable all '80 glittering glittering x-ray stars' are members of NGC 5194.

You claim that the HST imagery of Stefan's Quintet "proves" that NGC 7320 is closer than the other members because it better-resolved in optical wavelengths. I gave an example of a close interacting pair (M51) that defies your simplistic explanation. The stars in NGC 5195 are not well resolved in optical wavelengths even though it is at the same distance as NGC 5194. You "disputed" this fact by citing a paper about star clusters (6-8 parsecs in diameter - a bit larger than the typical star), and now you drag out an x-ray image of the system to "prove" your case. You ought to be embarrased. There is a tremendous amount of optical imagery of NGC 5195 - surely you can find one image that shows individual stars in its disk nicely resolved. If not, perhaps you should concede that NGC 5195 is not as resolved as NGC 5194 in optical wavelengths, and we can move on. You can then take a stab at explaining why NGC 7320 has a long tidal tail extending to NGC 7320c, which is supposedly ~8x more distant.

[antoniseb]

If not, perhaps you should concede that NGC 5195 is not as resolved as NGC 5194 in optical wavelengths, and we can move on.

That's nonsense, and I explained why on 18 June. NGC 5195 is an elliptical galaxy with no remaining giant stars. The only stars you can see individually in NGC 5194 are giants. The comparable region of NGC 5194 is at the very center where there has not been any dust or star formation for a long time, and it looks the same as NGC 5195.

turbo-1, I believe that you already knew this, and that your statement above to Thanatos was posturing, and not meant as genuine debate. Please keep this debate more honest.

[jlhredshift]

Greetings Starfighters (pun intended), I am a lifelong student of the history and philosophy of science and mathematics and therefore can not speak to your exact methodologies in which you pursue the attainment of new knowledge. However, I would like to point out that I see no issue with a galaxy speeding through a group of galaxies with discordant velocities and still be in essentially the same place at the same time and interact with them. If there is no center to the universe and the CMB is coming from everywhere why not baryonic material as well. It seems that the philosophy of setting a speed boundary of 1000 km/sec for proof of interaction alludes to there being a center and all Hubble flow is out (whatever that means) and not translational. Remember that analogy of the loaf of raisin bread from astronomy 101, well occasionally a raisin from the other side of the loaf would have enough time to pass by. Particularly if Hoyle, Narlikar, or Arp are correct.

[turbo-1]

That's nonsense, and I explained why on 18 June. NGC 5195 is an elliptical galaxy with no remaining giant stars. The only stars you can see individually in NGC 5194 are giants. The comparable region of NGC 5194 is at the very center where there has not been any dust or star formation for a long time, and it looks the same as NGC 5195.

NGC 5195 is actually a barred lenticular galaxy, but I do not believe that the interior structure was visible until it was imaged in IR. As for the "nonsense," is it at all possible that NGC 7318a and 7318b are deficient in giant stars? If so, it would be very difficult to resolve individual stars in them even if they are at the distance of NGC 7320. The argument that stellar resolution can provide reliable distances to galaxies is fraught with difficulties like this.

turbo-1, I believe that you already knew this, and that your statement above to Thanatos was posturing, and not meant as genuine debate. Please keep this debate more honest.

Honest? Really, is it honest to claim that NGC 5194 and NGC 5195 are equally resolvable to stars in the optical, and then "prove" that by citing a paper on 6-8 parsec star clusters or by linking to X-ray imagery? I am not the person obfuscating this discussion with non-sequiturs, and unless you have PM'd Thanatos, it seems that you are willing to let him continue those tactics, while scolding me.

As you are aware, there is a small group of us who are doing some serious work on bridged galaxy associations (like M51) and we have absolutely nothing to gain (and perhaps something to lose) by allowing this thread to be trivialized. If you have noticed, it is the mainstream who are making reference to "tap dancing", "moving the goalposts", "dodgeball" and other dismissive, childish statements. You have sat by quietly through all of that. I ask that you apply your standards even-handedly in the future.

[antoniseb]

As you are aware, there is a small group of us who are doing some serious work on bridged galaxy associations (like M51) and we have absolutely nothing to gain (and perhaps something to lose) by allowing this thread to be trivialized.

I appreciate the work, and I called you on this because I felt that you'd let this group down by making what, in my opinion, was an unreasonable claim. There is no question in my mind that good work is being done here, and agree that the mainstream side has done much less to support their side.

[dgruss23]

Let's revisit the controversy over 'switching the goal posts' from NGC 7320 to M51:

It was not a switch in the goal posts. It was provided as a counter example to the claim made by the mainstream that the resolution of stars in NGC 7320 "proves" it is foreground. Either the resolution argument works simply from looking at the pictures ... or it doesn't work and looking at the pictures is not enough.

Turbo-1 simply pointed out that if you look at the pictures of M-51, the companion does not appear as resolved as the main galaxy. Does this mean that NGC 5195 is in the background? Or course not. But that is not the point. The point is that the appearance of the image is not how we know NGC 5195 is at the same distance as NGC 5194. Other tests were used such as SBF and PNLF distances as well as the other studies you have provided Thanatos.

The point being ... "looks like" is not enough and so the mainstream NGC 7320 claim from the HST image is not convincing. Just as in the M51 example other evidence must be sought. We've provided some examples:

1. Tentative TFR distances to NGC 7319 and NGC 7320.
2. The bridge from NGC 7320 to NGC 7320c.
3. Arp's comments on the observed sizes of the HII regions in NGC 7318 and NGC 7320.

[Cougar]

If you have noticed, it is the mainstream who are making reference to "tap dancing", "moving the goalposts", "dodgeball" and other dismissive, childish statements.

Excuse me, but you do not get to toss off such a characterization without a serious objection. "Moving the goalposts" is a valid and meaningful criticism expressed in a short phrase that is well understood by most literate people. The history of the development of the "Arpian theories" is very aptly described by this phrase. To exclaim such a criticism is "dismissive and childish" is.... well, many words would fit here, but I think "wrong" is one of the foremost.

Likewise, "tap dancing" has serious meaning and has previously been presented as a serious criticism. If you don't understand the meaning, just ask.

[Thanatos]

NGC 5195 is actually a barred lenticular galaxy, but I do not believe that the interior structure was visible until it was imaged in IR. As for the "nonsense," is it at all possible that NGC 7318a and 7318b are deficient in giant stars? If so, it would be very difficult to resolve individual stars in them even if they are at the distance of NGC 7320. The argument that stellar resolution can provide reliable distances to galaxies is fraught with difficulties like this.

Honest? Really, is it honest to claim that NGC 5194 and NGC 5195 are equally resolvable to stars in the optical, and then "prove" that by citing a paper on 6-8 parsec star clusters or by linking to X-ray imagery? I am not the person obfuscating this discussion with non-sequiturs, and unless you have PM'd Thanatos, it seems that you are willing to let him continue those tactics, while scolding me.

Did I miss the part where I asserted optical resolution was the gold standard? I also brought up the Dawes limit in an earlier post. Do you know what the Dawes limit is for the Hubble at the presumed distance of M51? Might that explain why the cluster studies I reference deliberately excluded objects below 6-8 parsecs? - chances are they are mostly stars. If 'tactics' means addressing facts - I agree.

As you are aware, there is a small group of us who are doing some serious work on bridged galaxy associations (like M51) and we have absolutely nothing to gain (and perhaps something to lose) by allowing this thread to be trivialized. If you have noticed, it is the mainstream who are making reference to "tap dancing", "moving the goalposts", "dodgeball" and other dismissive, childish statements. You have sat by quietly through all of that. I ask that you apply your standards even-handedly in the future.

I have given solid references and, hopefully, well reasoned conclusions without 'tap dancing' around the obvious - like x-ray stars are well resolved in both galaxies. I am not the one who is asserting unsupported claims like 'NGC 5195 is less well resolved than NGC 5194". I made specific claims against that argument, and you 'moved the goal posts'.

[dgruss23]

Did I miss the part where I asserted optical resolution was the gold standard? I also brought up the Dawes limit in an earlier post. Do you know what the Dawes limit is for the Hubble at the presumed distance of M51? Might that explain why the cluster studies I reference deliberately excluded objects below 6-8 parsecs? - chances are they are mostly stars. If 'tactics' means addressing facts - I agree.I have given solid references and, hopefully, well reasoned conclusions without 'tap dancing' around the obvious - like x-ray stars are well resolved in both galaxies. I am not the one who is asserting unsupported claims like 'NGC 5195 is less well resolved than NGC 5194". I made specific claims against that argument, and you 'moved the goal posts'.

It was not a switch in the goal posts. It was provided as a counter example to the claim made by the mainstream that the resolution of stars in NGC 7320 "proves" it is foreground. Either the resolution argument works simply from looking at the pictures ... or it doesn't work and looking at the pictures is not enough.

Turbo-1 simply pointed out that if you look at the pictures of M-51, the companion does not appear as resolved as the main galaxy. Does this mean that NGC 5195 is in the background? Or course not. But that is not the point. The point is that the appearance of the image is not how we know NGC 5195 is at the same distance as NGC 5194. Other tests were used such as SBF and PNLF distances as well as the other studies you have provided Thanatos.

The point being ... "looks like" is not enough and so the mainstream NGC 7320 claim from the HST image is not convincing. Just as in the M51 example other evidence must be sought. We've provided some examples:

1. Tentative TFR distances to NGC 7319 and NGC 7320.
2. The bridge from NGC 7320 to NGC 7320c.
3. Arp's comments on the observed sizes of the HII regions in NGC 7318 and NGC 7320.

[dgruss23]

Did I miss the part where I asserted optical resolution was the gold standard? I also brought up the Dawes limit in an earlier post. Do you know what the Dawes limit is for the Hubble at the presumed distance of M51? Might that explain why the cluster studies I reference deliberately excluded objects below 6-8 parsecs? - chances are they are mostly stars. If 'tactics' means addressing facts - I agree.I have given solid references and, hopefully, well reasoned conclusions without 'tap dancing' around the obvious - like x-ray stars are well resolved in both galaxies. I am not the one who is asserting unsupported claims like 'NGC 5195 is less well resolved than NGC 5194". I made specific claims against that argument, and you 'moved the goal posts'.

Thanatos, I think you and Turbo-1 are disagreeing about things that you actually agree on. Nobody is actually claiming that the M-51 components are not at the same distance. There is ample cited research to show that they are at the same distance. So everybody agrees on that ... but what Turbo-1 is saying is that if you look at NGC 5194 and NGC 5195 the do not "look" as if they are resolved to the same degree.

In order to prove that they are in fact resolved to the same degree requires other tests. Why then - in the case of NGC 7320 - is the "looks like" argument used by the mainstream accepted without similar quantified proof to that which is available for the M-51 case?

In the case of Stephan's Quintet there are TFR distances, the bridge from NGC 7320 to NGC 7320 C, and Arp's own comments on the sizes of the HII regions that support the components being at the same distance.

BTW, why exactly does NGC7320 have such a long tidal bridge - if it is not interacting with any of those other galaxies? Where is the galaxy that created that tidal feature?

[turbo-1]

Thanatos, I think you and Turbo-1 are disagreeing about things that you actually agree on. Nobody is actually claiming that the M-51 components are not at the same distance. There is ample cited research to show that they are at the same distance. So everybody agrees on that ... but what Turbo-1 is saying is that if you look at NGC 5194 and NGC 5195 the do not "look" as if they are resolved to the same degree.

Yes. The fact that individual stars are not resolvable in NGC 5195 like they are in NGC 5194 may well be a function of the companion's history. As antoniseb pointed out, there may simply be no giant stars in NGC 5195, similar to the situation in the central bulge of NGC 5194. We know that these galaxies are at about the same distance by a number of means, so we cannot be fooled by their appearance in optical wavelengths.

Now if you look at optical images of any other galaxy pairing, can you judge their relative distances with the argument that both should be equally resolved to stars? Probably not. One may have a great many massive young stars and the other may be comprised of older redder stars. One may be more or less shrouded by dust, not only in its own environs, but in our own, as well. Certainly a galaxy located directly behind the dust cloud forming the Horsehead nebula would be impossible to see in the optical, but that's an extreme example. There are many thinner dust clouds that can partially obscure galaxies from our vantage point. The point I was trying to make by using M51 as a counter-example is that objects at the same distance from us can appear to be resolved to very different degrees, for different reasons, including stellar population, obscuration and re-radiation of starlight by dust, differential absorption by intervening materials, etc. When the stellar resolution of two apparently-interacting objects makes us think one or more of them are in the background ("that one looks like it's farther away"), and that idea conflicts with other more scientific means of establishing distances (as I think we have provided in sufficient quantity for Stefan's Quintet), then the "looks like" argument must yield to the preponderance of quantifiable observations to the contrary.

Here is an interesting link on NGC 5195's morphology.
http://www.journals.uchicago.edu/ApJ...513028205Guest

[upriver]

Excuse me, but you do not get to toss off such a characterization without a serious objection. "Moving the goalposts" is a valid and meaningful criticism expressed in a short phrase that is well understood by most literate people. The history of the development of the "Arpian theories" is very aptly described by this phrase. To exclaim such a criticism is "dismissive and childish" is.... well, many words would fit here, but I think "wrong" is one of the foremost.

Likewise, "tap dancing" has serious meaning and has previously been presented as a serious criticism. If you don't understand the meaning, just ask.

Tap dancing. A form of dancing where special shoes are used to accentuate rhythms. Tap dancers are admired for their nimble footed movement.

Is there a sport where they move they goalposts as part of the gameplay?

I have never seen a refereed paper/journal that used those terms.
If I were to judge this on which team was more professional........
But then that would be lowering myself, as this is supposed to be a scientific endevour.

[Cougar]

I have never seen a refereed paper/journal that used those terms.

This is a discussion, not a refereed paper/journal.

[turbo-1]

This is a discussion, not a refereed paper/journal.

Certainly, the participants (if they want to be taken seriously) should comport themselves with some level of decent behavior and not denigrate their opponents to try to score points. If you have a problem with a concept presented here, please explain WHY it is troubling to you, instead of resorting to junior-high nay-saying put-downs. We will gladly respond to you in the spirit of your post.

[Cougar]

...participants... should comport themselves with some level of decent behavior...

Well, let's see. You've recently offered "dismissive, childish, junior-high, nay-saying, put-downs." And you're lecturing me on comportment? Apparently you fail to see the hypocricy and humorous irony in such a posture.

May I suggest you cut out the provocative mischaracterizations, and we can get back to discussing science.... or psuedoscience, as the case may be.

[TomT]

Well, let's see. You've recently offered "dismissive, childish, junior-high, nay-saying, put-downs." And you're lecturing me on comportment? Apparently you fail to see the hypocricy and humorous irony in such a posture.

May I suggest you cut out the provocative mischaracterizations, and we can get back to discussing science.... or psuedoscience, as the case may be.

Could you guys quit the bickering over this stuff. There was a pretty high level discussion going on, and I hoped the moderator would keep it that way.
As far as the subject at hand, I think the bottom line is:
If two galaxies appear to be side by side and at the same distance from us, the fact that individual stars can be resolved optically in one, and not the other, does not necessarily indicate that: (1). the one with resolved stars is nearer, (2). that the two are at different distances, or (3). that the two cannot be at the same distance. There are too many other variables, so this is insufficient evidence for any conclusion.
TomT

[Thanatos]

Could you guys quit the bickering over this stuff. There was a pretty high level discussion going on, and I hoped the moderator would keep it that way.
As far as the subject at hand, I think the bottom line is: If two galaxies appear to be side by side and at the same distance from us, the fact that individual stars can be resolved optically in one, and not the other

You are assuming facts not in evidence

does not necessarily indicate that: (1). the one with resolved stars is nearer, (2). that the two are at different distances, or (3). that the two cannot be at the same distance. There are too many other variables, so this is insufficient evidence for any conclusion. TomT

Agreed, your argument is riddled with flaws and lacks substance - like references to supporting papers. Expect to be challenged with 'glee and fervor' when making unsupported claims here. Looking at pictures and asserting one is 'prettier' than the other is - not very scientific.

[dgruss23]

Here is an article on Stephan's quintet. You'll need to click on pdf and let the original source convert. At the end of the paper the images are not present but you can get to them by clicking on the links.

In general the authors argue that the evidence seems consistent with NGC 7320 being a foreground galaxy. However in section 6.1 and figures 4a/4c they note that there is H-alpha at the redshift of the higher z galaxies which is observed within the region defined by the disk of NGC 7320. What they note is that this region lacks any H-alpha emission at 800 km s-1 even though - based upon the symmetry of NGC 7320 - it should. They also note that HII regions at 800 km s-1 can be seen precisely where the 6500 km s-1 H-alpha feature ends. They note that this result would make sense if the 6500 km s-1 bridge was in front of NGC 7320.

[dgruss23]

Here is Arp's 1973 paper on Stephan's quintet in which he presents the data on the HII regions in NGC 7320 and NGC 7318 - the same information discussed in the conference report I linked to earlier in this thread.

The sizes of the HII regions are the same in both galaxies as can be seen in Arp's table. In addition, updating the calculated sizes at the redshift distance to the currently preferred H0=70, we would find that at the hubble distances the HII regions of the higher z galaxies would range from 650 parsecs to 2200 pc. This link may help put these sizes in perspective. Obviously these must be HII complexes even at the NGC 7320 distance (~15 Mpc). But the overlap of the diameter ranges supports them being at the same distance as was noted in the conference report.

It is also worth noting that in figure 6 Arp shows that the distribution of these HII regions is not random with respect to NGC 7320 and NGC 7318. The HII regions of NGC 7320 are most concentrated in the NW part of the galaxy while the HII regions in NGC 7318 are most concentrated in the SE.

[TomT]

You are assuming facts not in evidence - like references to supporting papers.

The last 2 or 3 pages of this thread are filled with references to this subject. I am making my conclusion based on those arguments.
At first the proposition that optically resolved stars in only one of the galaxies in a supposed pair, seemed to me to be good evidence that that galaxy was in the foreground. I believe this was Cougar's argument. Now that there has been pages of discussion and many references presented on these type of optically based arguments, I can see where this type of observation is not necessarily conclusive.
The discussion has influenced me to change my position on this to inconclusive. Isn't that one the purposes of this forum, to listen, learn, and decide with an open mind. The mostly high level of discussion in this forum makes that much easier to do.
TomT

[TomT]

You are assuming facts not in evidenceAgreed, your argument is riddled with flaws and lacks substance - like references to supporting papers. Expect to be challenged with 'glee and fervor' when making unsupported claims here. Looking at pictures and asserting one is 'prettier' than the other is - not very scientific.

Well, posts 1899 and 1901 above illustrate my points very well. I guess you can attack them with "glee and fervor" if you want, but calm, reasoned argument would but much more preferred and effective.
TomT

[TomT]

"Moving the goalposts" is a valid and meaningful criticism expressed in a short phrase that is well understood by most literate people. The history of the development of the "Arpian theories" is very aptly described by this phrase.

I disagree with the second sentence in your statement. In the case of Arp, "expanding the playing field" is a much more accurate portrayal, IMHO.
This is expected in science, as new discoveries and observations are made.
I think Tim Thompson stated the general case well in his post #7 in the "Big Bang Theory: What's Wrong With It?" thread. As he states, "tweaking of theories is usually very good science". I agree. Whether in Arp's cosmology, or the BB cosmology, there will be, and must be, constant tweaking.
TomT

[Cougar]

In the case of Arp, "expanding the playing field" is a much more accurate portrayal.... This is expected in science, as new discoveries and observations are made.... "tweaking of theories is usually very good science".

This would be all well and good, but as I understand it, the field as well as the rule book were expanded because the theory kept striking out. What is more "expected" in science is some fairly well defined theory that offers opportunities to test it and implies certain predictions that might be observed. After theories have gained some pretty strong support, then they might need some "tweaking," constraining the scope of the unknowns as new observations are made. But I'm unsure of the wisdom of continuing to mutate a theory after no real conclusive support is found.

All in The Grand Quest for the Intrinsic Redshift? Will it be found to be real or a mythological figure?

[TomT]

This would be all well and good, but as I understand it, the field as well as the rule book were expanded because the theory kept striking out. What is more "expected" in science is some fairly well defined theory that offers opportunities to test it and implies certain predictions that might be observed. After theories have gained some pretty strong support, then they might need some "tweaking," constraining the scope of the unknowns as new observations are made. But I'm unsure of the wisdom of continuing to mutate a theory after no real conclusive support is found.

All in The Grand Quest for the Intrinsic Redshift? Will it be found to be real or a mythological figure?

What I am talking about is the current topic of this thread which is the evidence for physical connections between objects of significantly differing redshift.
Arp first noticed such a connction between quasars and galaxies. He now has expanded the list of connected objects with disparate redshifts to include other types of objects.

The goal post is observations of such physical connections.

The playing field has been expanded to include the increase in the number of types of objects with such connections.

This is not all about the Grand Quest for Intrinsic Redshift. You have the cart and horse reversed. It is about whether the objects are really connected. If so, then explaining the reason for the anomolous redshifts becomes the question.
TomT

[Thanatos]

The bridges argument is interesting. The more important issue is making a pursasive argument they are real, as opposed to chance alignments. I'm not asserting all of the arguments claiming they are real should be dismissively waved away solely on the grounds of redshift. That would be bad science, IMO. There are other tests that can be applied. For example, if giant stars, planetary nebula, or inexplicably bright/dim supernova were observed in both members of an allegedly interacting pair of discordant redshift galaxies, it would be a quite a find.

I would like to start with the supernova approach. Have any supernova been observed that are inexplicably brighter or dimmer than expected based on their redshift?

[dgruss23]

The bridges argument is interesting. The more important issue is making a pursasive argument they are real, as opposed to chance alignments. I'm not asserting all of the arguments claiming they are real should be dismissively waved away solely on the grounds of redshift. That would be bad science, IMO. There are other tests that can be applied. For example, if giant stars, planetary nebula, or inexplicably bright/dim supernova were observed in both members of an allegedly interacting pair of discordant redshift galaxies, it would be a quite a find.

I would like to start with the supernova approach. Have any supernova been observed that are inexplicably brighter or dimmer than expected based on their redshift?

Unless you have some specific examples of supernova in bridges that can be applied as a test, you should start another thread on this topic to explore it.

[turbo-1]

The bridges argument is interesting. The more important issue is making a pursasive argument they are real, as opposed to chance alignments. I'm not asserting all of the arguments claiming they are real should be dismissively waved away solely on the grounds of redshift. That would be bad science, IMO.

Well, let's look at the "chance alignment" idea as a statistical exercise. Using NED, we find that the area subtended by NGC 7603b is about 0.102 arc-min². NGC 7603b is located about 2 arc-minutes from the core of its host, although some companions appear relatively closer to their hosts and some appear more widely separated. If we assume that the companion could have been located anywhere within 3 arc-minutes of the host, the area of that range is 28.26 arc-min² If we divide the area of the companion into the area of the permissable range of its appearance, we find that we can fit 277 companions into that range. Note that this is an extremely conservative number, since there is an overwhelmingly large chance for overlap in positions and this crude method treats the possible positions as being exclusive, which they are not. If our M51 samples are chance alignments, then for every M51-type system in our sample, there should be 277 counter-examples in which a disturbed or disrupted arm from a spiral galaxy ends up in empty space with no obvious partner to explain how the bridge came to be. In practice, of course, the number of counter-examples should be much, much higher because I used an method of calculating possible positions that was exclusive, and I did not allow for any overlap in positions.

In the case of NGC 7603, it is difficult to envision how a narrow tidal tail could erupt from the host without a companion passing through its disk to gravitationally pull material from it. There is no visible companion anywhere in the vicinity, apart from NGC 7603b, which exhibits an anomalous redshift. If the NGC 7603 system is a chance projection, where are the other 277 Seyfert hosts with tidal tails that terminate in empty space with no companions?

[Thanatos]

Thanks for the example. I appreciate your well intended efforts and objections, turbo. I also appreciate the fact you read the references and make well reasoned comments. I will have to do some homework before commenting on NGC 7603 . . I don't know very much about it.

[dgruss23]

I will have to do some homework before commenting on NGC 7603 . . I don't know very much about it.

NGC 7603 has been a very large part of the discussion on this thread during the last 3 months. You will find quite a few references starting with my 2 long posts on April 1. Although I'm not sure how you missed that since you've been participating in this thread regularly during the last 3 months.

[turbo-1]

Thanatos, here is a hot-link to the index for the "More from Arp et al" thread. Discussions of the NGC 7603 system figure prominently.

http://www.bautforum.com/showthread.php?t=41529