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The Arp Atlas of Peculiar Galaxies April 4, 2007

Posted by dorigo in astronomy, books, internet, personal, science.

Today I ordered my copy of “The Arp Atlas of Peculiar Galaxies“, by Jeff Kanipe and Dennis Webb (published by Willmann-Bell). If it is as good as it looks, I will receive it with joy. As a visual observer, I am always on the lookout for small, interesting galaxies to aim my 16” telescope at…

Of course, the structural details of many of the cataloged celestial bodies are out of reach with my instrument, but visual astronomers always love challenges! And with the spring constellations high in the night sky, my galaxy fever is high this year. Leo, Coma Berenices, Ursa Major and Virgo all contain scores of galaxies that are a treat to study.  

Here is an excerpt from the publisher’s site:

In 1966, astronomer Halton Arp compiled his Atlas of Peculiar Galaxies, which featured 338 images of some of the strangest looking galaxies and galaxy groups then known to exist. The purpose of the Atlas, Arp stated in his preface, was to graphically present structural peculiarities in galaxies “in order to build a realistic picture of what galaxies are really like.” At the time, astronomers were struggling to formulate a workable taxonomy of “symmetrical” galaxies using classification schemes such as Edwin Hubble’s tuning fork diagram. But the Atlas was comprised of the “Elephant Men” of galaxies, and their deformations challenged and defied astronomers’ attempts at galaxy classification.



1. Tony Smith - April 5, 2007

Halton Arp is an interesting person, particularly in the context of Astrophysics, Cosmology, Dark Energy, etc., and of unconventional ideas.

In his 1998 book “Seeing Red: Redshifts, Cosmology, and Academic Science” (Apeiron 1998), Arp says:

“… abandoning the accepted theory is a frightening step into chaos …[but]… The fact that the majority of professionals are intolerant of even opinions which are discordant makes change a necessity. …
if we do not understand why science is failing to self-correct, it will not be possible to fix it.

The .. first two chapters establish… that high redshift quasars emerge from the active nuclei of nearby galaxies.
The next two chapters show that smaller companions of nearby galaxies have intrinsic (non-velocity) redshifts …
Chapter 5 … shows how … redshifts decrease from the quasars down to the oldest galaxies …[for]… objects …[in]… the Local Supercluster …”.

Chapters 6 through the final Chapter 10 introduce more evidence for phenomena that are difficult to explain by establishment models, and discusss some problematic characteristics of scientific establishments. In Chapter 10, Arp says:

“… commmunication should be between individuals and the society as a whole …
An example … newer staff members competed in emulating acceptd concepts. When I [Arp] was faced with a directive to renounce observations of new phenomena, I chose early retirement. …
the goal …[should be]… to produce new knowledge. If the data is hijacked … by a group with a need to control beliefs, the whole enterprise is a failure.

So the most important people of all … are … researchers who can communicate all the data and in a form where it can be understood and debated.

That this is not presently possible is the insoluble problem which I … think will cause the whole juggernaut to inexorably decline and regress …”.

At the risk of overstating the obvious, I will conclude this comment by saying that
blogs such as this one exemplify “commmunication … between individuals and the society as a whole”
restrictive regulations by “group[s] with a need to control beliefs … will cause” the scientific enterprise to “inexorably decline and regress”.

Tony Smith

PS – As to what are Arp’s personal non-standard ideas, in Chapter 9, Arp says:
“… particle masses change on cosmic time scales … In .. Astrophysical Journal 405, 51, 1993, Narlikar and Arp present … the formal … mathematics … and show how it fits the data …
Mathematically it turns out that the conventional Big Bang solution and …[the]… variable mass solution are the same if one makes …[a]… conformal transformation …”.

It might be interesting to compare Arp’s variable masses with Louise’s variable c.

2. jasonwer - April 5, 2007

I had forgotten about this book until I read your post and may purchase it as well. After getting bored with observing the fainter NGC objects it’s interesting to find peculiar galaxies and try to visually tease out detail that is visible in Hubble photos or CCD images. Are you using digital setting circles for such objects are you star hopping from charts like myself?

3. dorigo - April 5, 2007

Hi Tony,

thank you for the interesting comment. I know Arp was a somewhat controversial figure… I share some of his views, quoted above by you, and that makes me nervous 😉

About variable masses and conformal transformations as alternatives to standard cosmology, I remember I heard a very interesting talk at the London OQC conference last week, by Philip Mannheim. His ideas are well summarized in a recent document, Astro-ph/0505266.


4. dorigo - April 5, 2007

Hi Jasonwer,

no, I star-hop… Digital setting circles are little short than cheating… The satisfaction one gets by framing a faint object in a star-poor region by following a geometrical path through the sky is priceless.


5. dorigo - April 5, 2007

And Jasonwer, what instrument do you use for your observations ? Where do you observe from ?

6. jasonwer - April 5, 2007

Hi Dorigo,

I couldn’t agree more – the challenge of finding a faint galaxy with little more than some charts and 2 aligned mirrors can’t be beat. Unfortunately 95% of the amateur astronomers that I come into contact with don’t agree – but I feel that because they can find faint objects so easily (computer assisted) that many fail to appreciate them and quickly more onto the next object.

I use a 18″ Dobsonian. The optics are from the US while the rest including the mirror cell was made locally. I observe at various sites approx. 100km out from Brisbane, Australia. As you probably know, Australia is mostly untouched by light pollution but we lack high altitude observing sites and moisture is often a problem being near the warm Pacific at only 27 degrees south.

There are some photos of my scope over at my blog page at http://jasonwerry.wordpress.com/photographic-bio/ … just scroll to the end.

By the way, what atlas do you use? Or do you create customized charts using astronomical software?

By the way, I’ve done comparisons with a 16″ dobsonian and I find the difference in viewing is quite small. Only when observing say a supernova near the limit of the 16″ is the difference noticeable.

I once has the chance to use a 30″ for an hour while my friend, Peter Robbins, had to grab some dinner (see http://www.sdmtelescopes.com.au/SDM001.html ). Viewing through that was certainly different to my 18″ !


7. dorigo - April 5, 2007

Hi Jason,

I deeply envy not so much your two additional inches, but the absence of light pollution! Here, trips of at least 100-150km are needed to get a decent sky.

I use TheSky, although I know there are better star-charting programs… If you know links to freeware software for charting which you recommend, please let me know.

30″ is a different class of instrument, but it is also something you cannot carry around. I find that 16-18″ are the most one can confidently carry and mount by oneself. Larger things rapidly become unmanageable by an individual.


8. jasonwer - April 5, 2007

I agree about the 30″ – a couple of times he has towed it to an observing site (all 700kg of it including trailer) only to be clouded out. Upon returning home he’s found that he has wasted many dollars in petrol! Of course the petrol cost is worth it when the skies are clear and he has some people on hand to help.

I haven’t tried any star-charting programs. I personally use the Herald-Bobroff AstroAtlas and find it is better than Tirion’s (not enough detail) and better than the Uranometria (too many charts and page flipping). More details can be found at http://www.heraldbobroff.com/

Although I must say that I have fond memories of using Tirion’s with my 4.5″ reflector many years ago. It is a good atlas for small scopes.


9. Tony Smith - April 6, 2007

Tommaso, thanks for the reference to Mannheim’s work and paper at astro-ph/0505266.

Mannheim’s conformal model is a bit different from Segal’s ideas that I use.

Segal used the conformal group SU(2,2) = Spin(2,4) and Mohapatra (in his book Unification and Supersymmetry 2nd ed Springer-Verlag (1992) section 14.6) showed how a MacDowell-Mansouri mechanism using that conformal group would give gravity in the form of Einstein-Hilbert action plus cosmological constant etc.

On the other hand, Mannheim says in astro-ph/0505266 that his conformal model gives “… the Weyl action …” and “… forbids a fundamental Planck mass, and … excludes any fundamental Newton constant or any fundamental Einstein-Hilbert action …”.

Since I like a fundamental Planck mass/energy and the Einstein-Hilbert action, I use a Segal/McDowell-Mansouri approach.

As to experimental/observational tests as to whether Segal/Einstein-Hilbert or Mannheim/Weyl is right or wrong,
note that Mannheim says that his model “… unambiguously predicts continuing acceleration above a redshift of one. Showing that the universe is in fact decelerating above a redshift of one would thus rule out …[Mannheim’s]… conformal theory …”.
On 24 February 2005, Serkan Cabi wrote in his blog:
“… yesterday we were lucky to have Mannheim here at MIT …
Regarding to cosmology he has a significant prediction. There should not be a deceleration period in the universe history. Universe was always accelerating! I reminded him the current claims about the evidence for deceleration. He said he is well aware of them and they are not precise enough yet. He claimed that the data fits both possibilities still in equal amount of certainty. Two-sigma contours cover his range also. …”.

However, even though I am skeptical about some aspects of Mannheim’s work, it seems to me that Mannheim’s approach to writing the Standard Model into the Energy-Momentum tensor T_munu is very interesting and useful. As Mannheim says in astro-ph/0505266:

“… kinematic particle sources in flat space … connection to the structure of the energy-momentum tensor … is … quite remote.
Thus we need to discuss what is to be expected of the energy-momentum tensor in a theory in which the action is built out of fields rather than particles, and in which the fields develop masses by spontaneous symmetry breakdown. …
To investigate what is to happen in the dynamical mass case, it is convenient to consider a spin one-half matter field fermion … which is to get its mass through a real spin-zero Higgs scalar boson field …
the … dynamical mass … energy momentum tensor is then found to take the form
T_munu = ( rho + p ) U_mu U_nu + rho eta_munu + /\ eta_munu

compare this dynamical theory of fermion masses with a strictly kinematic fermion mass theory in which …
T_munu = ( rho + p ) U_mu U_nu + rho eta_munu

The key distinction between ..[the two equations for T_munu]… is that …[the dynamical mass equation]… contains not just the energy on the fermion field, but also that of the Higgs field that gave it its mass, an energy which couples to gravity.
In dynamical theories of mass generation, gravity is thus sensitive to the Higgs field associated with the fermion, while in kinematic case it of course is not. …”.

Mannheim also says:
“… the Higgs field … could be a dynamical manifestation of an underlying symmetry breaking through bilinear fermion condensates …”.
which is consistent with seeing the Higgs as a Tquark condensate, which is useful in getting the 3 Tquark mass states of my model.

Even though, as Serkan Cabi said “… Mannheim … is the only man in the [Weyl conformal gravity] field … He did not get important criticism related to the fundamental principles after many talks across the country for many years. …”, Mannheim has been able to post his work on arXiv for posterity and to talk at places like MIT,
so that, even long after Mannheim’s lifetime, people in the future will be able to study his work and use those parts of it that seem to be useful.
That is not the case for those who are blacklisted by arXiv or prevented from presenting their ideas at conferences.
After they are dead and gone from the web, their ideas, to quote from the movie Blade Runner:
“… will be lost in time like tears in rain …”.

Tony Smith

10. dorigo - April 7, 2007

Hi Tony,

I know – it is disappointing and a real pity when interesting ideas do not find a proper place to be stored and retrieved. But the right idea, in science, succeeds in the end. Although, I must add, you are right in worrying that it usually the person who gets credit is not always the one which deserves it.

Upon coming back to work I will give a closer look at your comment – right now I have my kids pressing me for going to play in the snow…


11. dorigo - April 7, 2007


700kg! LOL… that fortifies my belief that 16″ are the right thing. For sure not more than 20 anyways. I live in Venice and bringing my instrument to my car is quite taxing, but I do it nonetheless a few times a year, and thank god I have a friend who also owns a similar instrument (been observing last night with his dob btw, we spent time on the UMA galaxies, the whale (NGC4631) and its companion, NGC4565, M98-99-100, M106, and then we carried out a comparison of my 25×100 binoculars with a similar pair from a more high-end brand).


12. daniel hershkovitz - May 18, 2007

Halton Arp is a great scholar and professional person, and I wanted to see on his new book more information about the interesting old and dwarf galaxies.


13. dorigo - May 19, 2007

Hi Daniel,

the book is not written by him, although it contains all the material of his old catalog, plus a lot of other historical information. You are right, the authors could have added more up-to-date information specific to the objects discussed in the catalog. They rather chose to write only information useful for amateur observing, which I find quite useful.


14. Sakib - August 3, 2008

I cannot honestly believe the flak aimed at Halton Arp, here’s a guy who’s willing to think outside the box and challenge what we regard as the truth. It is always a good idea to question what we know because quite likely, we might have the wrong answers without realising it. Did you know that no telescope time for the major observatories is allowed to be used to research Halton’s quasar redshift theories. Unfortunately I have not read this book as I can’t find it anywhere in Britain although I will buy it if I see it! I love obscure deep sky objects, one of my favourite Arps is Arp 9 in Camelopardalis. Check out http://www.338arps.com, it is the website of Richard Miller and he’s imaged every single Arp galaxy although with short exposures but that doesn’t matter. Some great images of Arps can be found at http://dg-imaging.astrodon.com

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