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Redshift anomaly

  1. Nov 14, 2003 #1

    wolram

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    http://arxiv.org/abs/astro-ph/0203466

    We present new spectroscopic observations of an old case of anomalous redshift--NGC 7603 and its companion. The redshifts of the two galaxies which are apparently connected by a luminous filament are z=0.029 and z=0.057 respectively. We show that in the luminous filament there are two compact emission line objects with z=0.243 and z=0.391. They lie exactly on the line traced by the filament connecting the galaxies. As far as we are aware, this is the most impressive case of a system of anomalous redshifts discovered so far.
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    can anyone explain what is going on here?
     
  2. jcsd
  3. Nov 15, 2003 #2

    wolram

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    John Baez wrote: [parts snipped]


    http://www.lns.cornell.edu/spr/2003-03/msg0049676.html

    Specific anomalies that repeatedly show up and are not addressed by
    present theory are the existence of multiple periodicities of redshifts
    and the strong association of QSO at high redshift with the axes of
    spiral galaxies at low redshift. It is quite clear that there is more
    to redshift than a simple relation to distance.
     
  4. Nov 15, 2003 #3

    selfAdjoint

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    I followed your link and I didn't find Baez saying those things. He was quoted as saying scientists should "think outside the box" in general terms. All the stuff about anomalies came from the fellow who was quoting him.
     
  5. Nov 15, 2003 #4

    wolram

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    Last edited: Nov 16, 2003
  6. Nov 15, 2003 #5
    This is one of the most confusing bits of astronomical data anomolies ever to be confirmed, it basically states that the connecting Galaxies, which are all located in a specific area, but their redshifts are different. I seem to remember a number of follow ups, and the scientific community seems to be rallying to 'ignore' what is being observed and actually are treating the data with contempt.

    All the more amazing is the fact that 'filiments' have been observed in other non-quasar-stella-objects. A redifining of Hubble/Doppler paramiters are definetly in the making.
     
  7. Nov 16, 2003 #6

    wolram

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    All the more amazing is the fact that 'filiments' have been observed in other non-quasar-stella-objects. A redifining of Hubble/Doppler paramiters are definetly in the making.
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    im not sure if the theory is wrong, it could be something
    distorting the readings, but whatever i think these puzzles
    are not being solved and that leaves room for the fringe
    element, it would be nice if matters like this could be
    discused openly instead of being buried.
     
  8. Nov 16, 2003 #7

    wolram

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    http://www.eps.org/aps/meet/APR03/baps/abs/S3890.html

    The theory and measurement of optical spectra impact a wide range of scientific fields including spectroscopy and astrophysics. Under certain conditions, the spectral lines from sources and from scattering media can be shifted and spread or narrowed relative to their natural wavelengths and linewidths. These spectral modifications have been predicted from optical coherence theory by Wolf (Phys Rev Lett 56, p1370, 1986) and others and demonstrated in a host of experiments. The underlying physical mechanism involves correlations among the components of the radiating medium. The correlations may be understood at the microscopic level as due to interactions between the atoms induced by their radiation fields. However, the main features of this effect may be understood from a purely classical theory employing macroscopic optical correlation functions. We will present a high level, hopefully intuitive, overview of this theory. We will show that, under reasonable physical conditions, the predicted effects include spectral line shifts to longer wavelengths (redshifts) that are independent of wavelength and may be arbitrarily large. These are common features of the redshifts due to cosmic expansion. Application of the theory to the redshifts from quasars is found in the companion presentation.
     
  9. Nov 16, 2003 #8

    wolram

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    lots more interesting stuff on this site, i dont know if
    any of it is correct or not.
     
  10. Nov 16, 2003 #9

    wolram

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    http://www.newtonphysics.on.ca/DOPPLER/Doppler.html

    We saw that the Doppler interpretation of the redshifts of the hot stars belonging to binaries, to star clusters surrounding a nebula, or to the hot stars of a cluster, require many ad hoc hypotheses in order to explain only partially some observations. Even with all these hypotheses, we have seen that many observations disagree with the predictions deduced from the model. Many serious questions remain unsolved without our theory. For example, why don't we see a blue shift from binary stars, since half the time the mass exchange between stars is such that the mass is approaching us? In the case of the Gould belt, how can an expansion take place only in two dimensions? Why don't we observe the K effect coming from either of the double expansions that would make the Olano model compatible with observations? Why is the redshift of early-type stars in clusters always positive? How can the solar limb [5] be redshifted?
     
  11. Nov 20, 2003 #10

    Nereid

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    HST observations of NGC 7603

    Seems there are at least two HST observations of NGC 7603 with cameras, one of which includes the filament and companion galaxy. The two knots the authors refer to are also clearly visible in the 'preview GIF'.

    Just from this GIF, there seem to be quite a few objects that look like the 'knots in the filaments'; perhaps NGC 7603 just happens to be in front of a couple of more distant, relatively sparce clusters?

    Lopez-Corredoira and Gutierrez, in their paper which wolfram's first post quotes from, do give a simple calculation of the likelihood of their knots arising by chance projection ("That is, there should be one object like these per each square of 3-7 arcminute size (20 arcminute size for NGC 7603B); much larger than the area of the filament (~100 arcsec2)"), but this seems to be just a general field calculation, with no consideration of clusters.

    Since the HST images are now in the public domain, and as tools to extract data from FITS images is both public and free, any reader of this post can get the data and do their own analysis on the faint smudges, at least to test the hypothesis that there may be at least one (background) cluster. I cannot guess why Lopez-Corredoira and Gutierrez didn't at least mention this alternative explanation.
     
  12. Nov 21, 2003 #11

    wolram

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    hi NEREID,

    as you say all this information is open to the public
    but without an expert such as you we have little chance
    of finding the truth to these matters.
    maybe someone could highlight some of the problems
    involved when taking redshift readings.
     
  13. Nov 21, 2003 #12
    Interesting site, and the original paper for NGC 7603/NGC 7603B clearly needs a explination, I have no access to the HST or data banks, but I have been interseted in this anomoly for a number of years, my own personal basic assumption is that the foreground Galaxy(NGC 7603) is 'emmiting' onto the Background Galaxy (NGC 7603B)along the observed filament.
     
    Last edited: Dec 9, 2003
  14. Nov 21, 2003 #13

    wolram

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    http://www.innerx.net/personal/tsmith/SegalConf3.html#redshift


    Segal spent much time and effort on a quadratic cosmological redshift that he claimed was implicit in the physics of the Conformal Group. Segal's redshift was described by Bertram Kostant, who had Segal as advisor for his 1954 Chicago Ph.D., in another of the obituaries in the Notices of the AMS 46 (June/July 1999) 659-668.:

    John Baez, who had Segal as advisor for his 1986 MIT Ph.D., says: "... That's the generator of Minkowski time translations. ... If you use the Minkowski Hamiltonian everywhere (there's one for each observer) you don't get the redshift. ... ".]
    ----------------------------------------------------------------------
    an interesting paper, it seems that redshift is more
    contravertial than i expected.
     
  15. Nov 21, 2003 #14

    Nereid

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    wolfram, your reply is so rich!

    What is 'truth'? What is the benefit of making HST data public? What is the 'cost' of empowering 'Joan Public' to make any kind of sense of such data? How sad is it that we live at a time when extraordinarily powerful scientific tools are available ... for free! to anyone!!* ... yet are so unused? I really, really would like Greg to open a part of PF to discuss these things properly.

    Redshift determinations take considerably more resources than pretty piccies.

    Take time. A broadband filter such as U, B, or V is ~100 nm wide; a good redshift determination requires wavelength (or frequency) resolution ~100 times as fine.

    Take space. Traditionally, redshifts in the optical region are determined by 'slit spectroscopy', which samples tiny, tiny regions of the sky. A lot has been done to improve the 'sky efficiency' of such approaches, yet they're still only ~1-5% as efficient as imaging in their use of sky space.

    Driven partly by these inefficiencies, astonomers have developed clever short-cuts, such as 'photometric redshifts', which make estimates of galaxy (and quasar?) redshift based on colours (observed intensity through various broadband filters).

    However, the greatest difficulty is economic. Use of leading edge observatories is highly competitive, and professional astronomers have to do good research to continue to feed themselves. This drives research proposals towards progressing the field, according to the consensus views. (I could go on for some time on this topic; suffice it to say that those who want to investigate views beyond the consensus had better learn how to use the cornucopia of 'public access' data and cheap, powerful software tools (and a good appreciation of the scientific method)).

    I'm curious, what makes you think I'm 'an expert'? :wink:

    *there are restrictions; as I understand it, some part of the vast US government decided that all (with exceptions?) science projects funded with public money had to make the data gathered publicly available, after a suitable time (to allow the principal investigators to do their work). As observatories such as HST are funded in part by (some) EU countries, and as the EU is increasingly unified in science policy, the US policy flowed to all residents and citizens of all EU countries in short order; the Canadians fell into line without a fight (don't tell Mr Parsons!); ... Tough for those living in China, India, Brazil, Indonesia, Nigeria, ...
     
  16. Nov 21, 2003 #15

    Nereid

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    But you do!

    Let's walk though one way you can get what Hubble has on NGC 7306.

    First, go to NED:
    http://nedwww.ipac.caltech.edu/

    Click on "By Name" under "Objects"

    Enter "NGC 7603" in the Search field.

    Click on object 1 (NGC 7603).

    Move down the page to the nice DSS piccie and click on "images". A new window will open. About halfway down the page is a preview of an HST image. Info in that row tells you quite a bit about the image. By clicking on "Retrieve" under "FITS image" you will get a 2279KB FITS file of one of the HST images taken of NGC 7603.

    There are other ways to get Hubble data, e.g. through MAST (http://archive.stsci.edu/).
     
  17. Nov 22, 2003 #16

    wolram

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    I'm curious, what makes you think I'm 'an expert'?

    an eccentric mermaid told me:wink:

    i would like to know much more on this topic ,im sure
    you are the person that can open up the subject and
    give us the nuts and bolts, i remember a little snippet

    send re enforcments we are going to advance, turned into
    send 3and 4 pence we are going to a dance

    so first hand info is allways best.
     
  18. Nov 26, 2003 #17

    Nereid

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    Empowerment

    So, how best to develop the capabilities to do one's own research? Some random thoughts.

    Access to the resources is the easiest to address - broadband internet access and a large hard drive are all you need. Some general rules of thumb about finding good websites also helps (always try to go to the source, use sensible science news sites to get a snapshot of the news, avoid crackpots, ...).

    If it's astronomy you're interested in, then taking a course from a public educational institution may be the way to go. People generally find it easier to learn new things in an interactive environment, with face-to-face the most effective. There are on-line courses available too (e.g. check out Swinburne's at
    http://astronomy.swin.edu.au/).

    Maths may be the hardest to get familiar with, but may also be the most satisfying in terms of being able to do your own work. IMHO, nothing beats a good maths teacher.

    Computing is tricky. It's very, very seductive, and the rewards can be wonderful. However, it may be all too easy to persuade yourself that you don't really need to understand the basic physics because 'the software will do it all for you'. On the other hand, computer simulations and modeling are playing an increasingly large part at the frontiers of astronomy.
     
  19. Nov 27, 2003 #18

    Nereid

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    similar 'knots' in Stephan's Quintet

    Those who've followed the 'anomolous redshift' stories over the years will recall that Stephan's Quintet was one of the early classic examples of an apparently interacting group of galaxies with very different redshifts.

    It turns out that the standard view of redshift - Hubble expansion and velocity dispersion in a cluster - fits Stephan's Quintet well - one of the spiral galaxies is much closer to us than the others (you can see it in the HST image, it looks grainy whereas the more distant spirals appear smoother).

    What's interesting about the HST image is the presence of knots in the tidal tail, in the NOAO image they look somewhat similar to those in NGC 7603 in the ground-based telescope image. In the HST image you can clearly see they are galaxies in a much more distant cluster, which just happen to be in a similar line of sight as the tidal tail. Another coincidence: the size of the objects - in square arcseconds - is roughly comparable.

    I like the HST image so much that I've made it the wallpaper on my PC!

    http://hubblesite.org/newscenter/newsdesk/archive/releases/2001/22/
     
  20. Nov 28, 2003 #19

    wolram

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    http://www.astr.ua.edu/gifimages/stephan.html

    Stephan's Quintet of galaxies, a well-known tight grouping in Pegasus near the bright spiral NGC 7331. From the small elliptical partially in the field at the western (right) edge, they are NGC 7317, 7318A, 7318B, 7319, and 7320. Much of the continued interest in Stephan's Quintet stems from the fact that NGC 7320 has a relatively small redshift (760 km/s) while the other four galaxies, three of which display signs of strong tidal interaction, all have redshifts near 6600 km/s. If redshift always correlates with distance, the presence of NGC 7320 is a chance foreground projection. NGC 7319 has a type 2 Seyfert nucleus. This color composite is from CCD images taken at the Kitt Peak National Observatory 2.1-meter telescope by W.C. Keel and R.E. White, III.
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    thanks for all your help NEREID, i think you just about quashed
    any doubts i had about redshift being an accurate tool.
    i see what you mean about the image, part of it reminds me of
    ET, but whatever its better than any painting an awesome.
     
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