NGC 1347

The following is a “lesser known” example of discordant redshifts from the southern hemisphere that is known by many names. NGC 1347 was first listed as Arp 39 in Dr. Halton Arp’s Atlas of Peculiar Galaxies published by Caltech in 1966.  It is listed in his and Barry Madore’s A Catalogue of Southern Peculiar Galaxies and Associations (Cambridge University Press, 1987) as AM 0327-222.  But it is also listed as AM 0328-222 in Dr. Arp’s book Quasars, Redshifts and Controversies (Interstellar Media, 1987) and his article published in Volume 263 of the The Astrophysical Journal in 1982.  The following is the best image I could find for this pair of objects.  It is a photograph taken with the 48-inch UK Schmidt Telescope in New South Wales, Australia sometime in the 1970’s.  I have cropped the original image a bit in order to fit it on this page but it is otherwise unaltered.

NGC 1347Although the photograph is somewhat grainy it is quite apparent that there is a smaller galaxy immediately adjacent to the main galaxy at its southern end.  It also appears quite possible that these two objects are physically connected.  However, if they are physically connected then how to account for their vastly discordant redshifts?  The redshift of the larger galaxy at 0.00587 z would place its distance at approximately 104 million light-years from Earth using a so-called Hubble Constant value of 55 (km/s)/Mpc.  And although NED does not list a redshift value for the smaller object, Dr. Arp measured it to be over 0.068 z which would indicate a supposed distance of over 1.15 billion light-years from Earth.  This is over 11 times the distance of the larger object.   A physical connection notwithstanding, if the smaller galaxy were to be viewed at the same distance as the larger galaxy it would appear over 3 times the size of the larger galaxy.  This would make it the largest galaxy ever observed for its type in the known Universe!  Obviously these measurements highlight some serious discreprencies and further observations of these objects need to be made.

The mission of the Discordancy Report is to show examples of redshift discordancies and present an opportunity to critically analyze the observations while also nurturing an interest to perform further observations.  NGC 1347 is a perfect example of an object that clearly questions the assumption that extragalactic redshifts are indicative of distance and the result of the expansion of the Universe since the “Big Bang”.  Yet, the best image I could find came from observations made over thirty years ago from a telescope less than a quarter of the size of those available today.  I was unable to find any images of NGC 1347 from any modern large telescope that covers the southern hemisphere including the SALT, the Gemini South or even the HST.  I will continue to pursue observational data from these and other large telescopes as their powerful optics could one day help finally bring to light the true connection between extragalactic objects and the true meaning of their discordant redshifts.

I encourage all visitors to this site to pursue their own observations and please feel free to contribute to the ones I present here and even submit your own.

Thanks for reading!


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6 Responses to “NGC 1347”

  1. Patrick Driessen says:

    You should also try to find pictures of NGC3067 which has a long trail of hydogen gas coming out of its center, and right in the middle sits the quasar 3C232 ! This was observed by Carilli in 1989, and I do not know if there has been any follow-up work on this.

    Nature 338, 134 – 136 (09 March 1989)

    Disturbed neutral hydrogen in the galaxy NGC3067 pointing to the quasar 3C232

    C. L. Carilli*, J. H. van Gorkom† & John T. Stocke‡

    THE quasar-galaxy pair 3C232 and NGC3067 was the first in which Ca II absorption was found in the higher redshift spectrum of the quasar at the lower redshift of the galaxy1. This has been taken as evidence that quasar absorption lines are due to gas associated with extended disks or spherical haloes of galaxies distributed along the line of sight2. Implicit in this is the assumption that redshifts are cosmological. We present new observations of neutral hydrogen at the redshift of NGC3067, both in emission and absorption against the radio-loud quasar. The hydrogen forms a long tail, apparently extending from the galaxy to the quasar and beyond, which seems to be a disturbed extension of one of the galaxy’s spiral arms. No companion to NGC3067, which might cause such a disturbance, can be seen. The extended gas distribution, mapped here for the first time in such a system, conforms neither to the extended disk, nor to the spherical halo model. We suggest that most low redshift absorption line systems arise in extended gas associated with interacting galaxies unless, of course, our line-of-sight passes through the optical disk of the associated galaxy.

    • sbsims says:

      If I can find any decent images of the pair I will certainly consider posting it as an example. Thanks for contributing! ~Shannon

  2. Jean Tate says:

    “This would make it the largest galaxy ever observed for its type in the known Universe!” I am particularly interested in large spiral galaxies, so this part of your write-up caught my eye.

    How did you conclude that the smaller galaxy would be so huge, if it were at a redshift of 0.068?

    • sbsims says:

      I assumed a standard diameter of 100,000 for the larger galaxy and used the inverse of the distance between the two to scale up the smaller object. Of course this is a rough estimate and it doesn’t really even qualify the object as the largest anymore so I may need to tweak my description. Since this example was posted scientist have come to determine that NGC 6872 is approximately 522,000 light years in diameter, more than five times the diameter of the Milky Way. But this is also measuring the galaxy from tip to tip, making this somewhat of a “fish tale”.

      • Jean Tate says:

        Hmm … I’m not familiar with 100k (I guess light-years) being a “standard diameter” for spirals; may I ask where you read this? And, taking the cue from “this is also measuring the galaxy from tip to tip”, doesn’t the size of a spiral galaxy (or any galaxy for that matter) depend on exactly how “diameter” is defined?

        As I said, and as you can easily discover from my posts in the Galaxy Zoo forum, I am very interested in huge spirals. From my own research, I have found that they can have effective radii (an objective, quantitative measure of ‘size’) as small as 1 kpc (thousand parsecs), and as large as 20 kpc. The Milky Way is not a particularly large spiral, but probably bigger than the mean.

        “scientist have come to determine that NGC 6872 is approximately 522,000 light years in diameter” – do you have a reference?

        • sbsims says:

          Perhaps I should have used the word “typical” or “average” instead of “standard”. The Milky Way is often referred to as an average sized galaxy or typical example of a spiral galaxy about 100,000 light-years in diameter. It is also generally accepted that the range of diameters of galaxies is from 1 to 100,000 parsecs. However this averages out to be about 150,000 light-years which is closer to the size of the Andromeda galaxy.

          Here is NASA’s GALEX page describing NGC 6872 in great detail:

          Notice that the vast majority of the galaxy is less than half the total estimated diameter with the rest consisting of the extremely long and tenuous spiral arms.

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