🚀 go-pugleaf

In article <1993Jan11.162143.3232@s1.gov>, lip@s1.gov (Loren I. Petrich) writes:
> In article <C0JL5B.6s4@well.sf.ca.us> metares@well.sf.ca.us (Tom Van Flandern) writes:
>>
>>wwadge@csr.UVic.CA (Bill  Wadge) writes:
>>
> : [Lerner's] book is very persuasive, but I'm not a physicist - any opinions?
> 
>>and rhine@bigbird.csd.scarolina.edu (Andrew P. Rhine) writes:
> 
> : it would seem that opposition to the big bang would have been dealt a major
> : blow by this year's results from COBE and recent observations (by the
> : balloon-based instruments) supporting it.
> 
>>     Not at all, Andrew.  Finding marginal but significant fluctuations in
>>the microwave background radiation saved the big bang for the moment, but did
>>no damage to alternatives.  Especially, it does not bear on Lerner's "proof"
>>that the microwave radiation must be coming from relatively local sources,
>>and can have nothing to do with a big bang fireball.  The essence of his
>>argument is that galaxy luminosity differences between infrared and radio
>>wavelengths show intergalactic absorption at such a level that the microwave
>>radiation could not penetrate through more than about z = 1 or so, let alone
>>the z = 10,000 or so required by the big bang.  [E.J. Lerner, Astrophys. J.
>>361, 63-68 (1990).]
> 

[Interesting discussion of intergal;actic extinction in a real universe with GR
deleted, but I think it makes some good points that Lerner has not addressed]

Its nice to see this discussion again, but I'm interested that it seems to have
gone to sci.physics from sci.astro. Was there too much heat in sci.astro for
the anti-BB camp? I'd appreciate followups sent to sci.astro as I don't get
sci.physics anymore.

Anyway, this has woken me up again, and at last I will get around to posting my
objections to Lerner's paper whic, I have to admit, I promised Tom about 6
months ago...

Lerner's paper is based on IRAS and radio data for a range of galaxies at
various distances. He uses the well known far-infrared (FIR)- radio flux
correlation relation (Helou Soifer & Rowan-Robinson ApJ. 298 L7) to predict a
galaxy's FIR flux based on its radio flux. He then calculates the difference
between observed and predicted FIR flux and finds a correlation between this
difference and galaxy redshoft. This is used ti infer that the FIR emission is
beign reduced in the more distant galaxies by absorption in the intervening
intergalactic medium.

There are a number of problems with this result which I will now describe. They
are not inescapable difficulties, and further work may be able to get round
them, but at this stage they are grounds for serious doubts on the paper's
conclusions, especially since these conclusions have wide reaching implications
for the CBR and the Big Bang. My doubts are as follows:

(1) The correlation coefficient for the decrease in FIR flux with redshift is
only 0.35 (it would be 1 for a perfect relationship), and there is visually a
great deal of scatter in the diagram. While such scatter might be expected
given the usual uncertainties with observational data, the scatter here is not
random. The bulk of the scatter is at the higher redshifts where the bulk of
the data lies. Worse than this, the marority of the correlation comes from a
small number of points at low redshift (very close to our own galaxy). Indeed,
if you remove the nearest 10 objects from the plot, visually the correlation
seems to go away. I have not done the statistics on this, but the change is
clear to the eye. This suggests to me that the 'correlation' is actually some
artifact introduced by some problem with the nearby objects, which makes them
seem to have either too much FIR flux, or too little radio emission.

(2) Two separate methods are used to extract the FIR data from the IRAS
satellite; ADDSCAN and COADD. The exact differences are not important, but the
applications of these methods is. ADDSCAN is used for more distant, smaller
galaxies, while COADD is used for nearer objects extended beyond 8'. There are
known to be systematic differences between the fluxes produced by these two
methods (I don't have a reference for theis I'm afraid. It was brought up at
the NATO ASI on Clusters and Superclusters in summer 1991). This could easily
account for the shift of the nearer objects relative to the more distant ones.

(3) There is a significant contaminating foreground componant in our galaxy,
the IRAS Cirrus, which can contaminate the integrated fluxes of large objects,
and so make them seem brighter in the FIR than they actually appear. This will
be especially problematic if the nearby objects are selected close to the
galactic plane, which they seem to be from Lerner's object lists.

(4) Of the closest 10 or so galaxies which I checked in catal;ogues, there are
problems with at least 4 of them. It should be noted that the radio-FIR
relationship seems only to work for spiral galaxies and those exhibiting a
significant star formation rate. Other objects might not fall on the relation,
ruining any results that assume they do. The problems are:

NGC55 This has a multiple nucleaus and so is probably not a spiral. Quite what
it is is unclear.

NGC110 is not a galaxy but a star cluster and so should not be included.

NGC 1569 is an Arp peculiar galaxy, and so should not e included.

NGC 3077 is an elliptical, a class of galaxy Lerner specifically excludes from
the sample.

These classifications are all based on NGC, and remove 4 of the closest 10
objects, already reducing the significance of the total correlation. I have not
investigated further due to lack of time, but I suggest that these problems all
suggest that the Lerner result is not as cast iron as TVF and others seem to
think it is.

It would be interesting to have Eric Lerner's comments on these issues.

Best wishes,
		Dave  

>>Tom Van Flandern / Washington, DC / metares@well.sf.ca.us
>>Meta Research was founded to foster research into ideas not otherwise
>>supported because they conflict with mainstream theories in Astronomy.
> 
> -- 
> /Loren Petrich, the Master Blaster
> /lip@s1.gov
-- 
================================================================================
Dave Clements, Oxford University Astrophysics Department
================================================================================
clements @ uk.ac.ox.vax			|  Umberto Eco is the *real* Comte de
dlc      @ uk.ac.ox.astro		|           Saint Germain...
================================================================================