Re: Swift Data rules out beamed theory


"sean" <jaymoseley@xxxxxxxxxxx> writes:
Craig Markwardt wrote:
"sean" <jaymoseley@xxxxxxxxxxx> writes:
George, "Sean's" thinking is quite muddled in this regard. He never
quite got the difference between something that is proportional to
wavelength vs. proportional to the *difference* in wavelength. [ Even
though his "model" depends critically on it, he tried to get me to
define it for him :-]

As usual your dishonesty is offensive. The fact is I claim that
there is no difference between the two. You claim there is but are
unable to supply any argument or proof. My challenge to you still
stands. If you think there is a difference(which there isnt )
between the two, supply examples to the other readers here as
proof that there is. I believe you tried once but your maths
was so appalling and yourunderstanding of scientific concepts
so dim that your proof was as laughable as it was incorrect.

Case in point, you are again asking me to define your theory.


There are other more serious questions that arise. For example,
according to his web page, optical and radio light curves are
stretched versions of the gamma-ray burst. However, from the
photoshopped figure that he shows, he must also be allowing himself
the freedom to shift the time axis as well. With so many freedoms,
it's not surprising that he finds some match-ups. He often confuses a
*detection* of an afterglow with the *peak* of the afterglow, hence he
will claim an IR detection that "comes after" an optical detection as
support for his theory, when in fact one often doesn't really know
what the IR was doing before that time. This accounts for many of his
claimed successes.

To start with t0 in gamma is actually 5 seconds after the burst
is detected in the graph. Technically t0 in gamma is about t-5
as thats where the count rate is measurebly increasing above
background. And if you look at my graph t0 in radio and optical
both are at t-5 in gamma on the graphs time axis. Hence no
artificial alignment in the time axis. All three have t0 at the
same spot on my graph.
So you are wrong again Craig!!

Again, case in point. You have the radio light curve rising at "T-5",
however the radio observations did not start until *after* the burst.
As your photoshopped graph shows, you have not only stretched but also
shifted the light curves (so the T=0 values do not overlap), which
means you allowed additional freedoms, which makes your claimed
association still more dubious.

....
George
dishman wrote in an earlier article...


Take care Sean, I'm not saying the spectra
are definitive or unambiguous, I haven't seen
many and I can't remember the papers I saw to
check whether they were SWIFT grism spectra or
ground based folllow-ups. What I am saying is
that Lyman break data are pefectly valid as a
rough indicator which when combined with ground
data, which is also valid, has allowed the
redshift of many GRBs to be deterined. It may
be less than half as you say, but even that
contains many which are definitely at high
redshift so I think that rules out your local
source idea.

George

If I can respond with some of the latest data from
GRB research. Here are 2 recent gcn posts.
The first claims to supply Lyman break evidence in
optical spectra.

No it doesn't. What it says is quite clear:

"We observed the optical transient of GRB 060512
... under POOR OBSERVING CONDITIONS ...

We report a break in the continuum around 4800A
and bluewards which, IF IDENTIFIED as the onset
of the Lyman-alpha forest, indicates a redshift in the
range z ~ 2.7-2.9. The signal-to-noise is TOO LOW to
allow identification of further lines."

(My emphasis)
Im aware of the seeing conditions in that gcn. After all I posted it
here.
But let me put it this way. If they didnt think that their observation
indicated z ~ 2.7-2.9 then why did they post that in their gcn?

As it turns out, it was a data reduction error, as you can read about
in Starling et al. (GCN #5149):

"In both the TNG and the VLT spectra we see no break in the continuum
emission and no obvious features in either absorption or emission."

There is some more discussion about the possible solutions in that GCN.

However, even if there wasn't a data reduction error, there will
occasionally be cases of low significance features where the
interpretation is not clear. That of course does *not* invalidate
other cases with highly significant redshift indicators.
Its true some of the redshift determinations are not ambiguous.
Ive always said that only some are ambiguous . Read my quotes
from other posts.
And usually thats because they are either single spectra, or
spectras where a suspected host galaxy is included or where a
spectra only of a suspected host galaxy is studied. Youll find
that the occasion where more than one spectra of an grb
afterglow is made and where no host galaxy is present that
there are far fewer unambiguous redshift interpretations.

However, this criticism is irrelevant. It's the *HOST* galaxy. The
source is in the galaxy!


....

No Matter what spin you try to put on this the plain fact of it is that

they observed a spectra and felt there was strong enough indication
to merit a gcn posting saying there is a Lyman break at 4800A. If there

was no evidence of a break Im sure they would not have mentioned it.
And that contradicts the other gcn redshift. Thats called ambiguity,

No. See above. As George quite correctly points out, the authors
originally said, "*IF*" the break-like feature could be identified as
the onset of the Ly-alpha forest, then z ~ 2.7-2.9. Please, clear
your head of conspiratorial "spin" theories for just a second and look
at the conditional, "IF." GCN's are for rapid dissemination of new
results, so speculation like that is allowed, and in fact welcomed.
Since afterglows fade quickly, it's better to know about something
interesting (but perhaps wrong) now, than it is to wait three months
for the correct result.
Now we know its been retracted but: my point is this. IF they
didnt think that feature had looked like the onset of the
Lyman A break then they wouldnt have put that in the gcn.


One final time: the claim was *conditional*. The purpose of making
rapid (and possibly incorrect) announcements is to spur rapid
follow-up confirmations. Better to say what something *might* be than
to not say anything and lose the opportunity. So your point is irrelevant.

....

CM
.

Relevant Pages

  • Re: Swift Data rules out beamed theory
    ... redshift of many GRBs to be deterined. ... Here are 2 recent gcn posts. ... optical spectra. ... As it turns out, it was a data reduction error, as you can read about ...
    (sci.astro)
  • Re: Swift Data rules out beamed theory
    ... publishing anything else would be misleading ... That's what the GCN system is for. ... here and others of mine outlining how redshift determination ... discernible from the spectra. ...
    (sci.astro)
  • Re: Swift Data rules out beamed theory
    ... wavelength vs. proportional to the *difference* in wavelength. ... redshift of many GRBs to be deterined. ... optical spectra. ... Im aware of the seeing conditions in that gcn. ...
    (sci.astro)
  • Re: Swift Data rules out beamed theory
    ... publishing anything else would be misleading ... here and others of mine outlining how redshift determination ... discernible from the spectra. ... feature absorbtion cited by the authors at about 4300A. ...
    (sci.astro)
  • Re: Swift Data rules out beamed theory
    ... the spectra was before it was reinterpreted to support ... I said your reason for dismissing the ... redshift interpretations of the data were made under the ... How would an alternative interpretation provide ...
    (sci.astro)
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