localizing gamma ray bursts via interplanetary-spacecraft

(sean) writes:

Craig Markwardt wrote in message ...
(sean) writes:
[ ... ]
The 20 per cent fact is derived from NASA gcn statistics of how many
IPN localizations were made and followed up with observations divided
into how many of those follow ups produced an observed afterglow. ...

You keep repeating the same mantra over and over. I am challenging
the *basis* of your conclusions. If the bases of your argument are
unsound, then your conclusions are irrelevant. You continue to
blithely ignore the observational biases that I mentioned (example:
HETE is only sensitive on the night side of the earth). You continue
to ignore the practical considerations (such as: a full-sky annulus
cannot be practically observed). You naively assume that "follow-up"
is restricted to optical or radio. You continue to claim that
"somehow" the IPN has cooked their numbers, but can't/won't say how.

I dont use the word `cooked` and I say exactly why they cant get
results contrary to your baseless claims that I dont. Do you want it
again? Here we go : Its because c is variable and IPN does not realize
this.

Your supposition that the speed of light is varies is not
substantiated by observation. [refs. 1-4]

... You keep on saying that my conclusions are etc etc, yet you
fail to explain how the statistical results that I have made are
invalid. Yes, if one were to do more analysis of data other trends
could arise although you havent shown any proof that there *are* other
trends that could refute the original conclusion my data analysis.

Your analysis appears to be highly suspect. From my own analysis, I
conclude that there are
IPN Solutions of any type 300 (since GCN 100)
IPN Box solutions 108
IPN Small box solutions 29 (50 sq. arcmin., night sky)
Optical / Radio searchs 21
Counterparts found 8

So, if we judge success by number of counterparts found per search,
it's approximately 8 / 21 = 38 %, with a Poissonian statistical
uncertainty given by sqrt(8) / 21, or
success ratio of = 38 +/- 13 %

These are all GRBs where an independent IPN box solution existed,
regardless of any other localization (GRBs 000630, 000911, 000926,
001007, 020813, 990506, 991208, 991216). The constraints on night sky
and box size are relevant since ground observatories cannot observe
during the daytime, and most do not have large fields of view.

The same search in the HETE data shows:
HETE-2 localizations since launch 36
Optical / Radio searches 33
Counterparts found 14

Similar success ratio = 42 +/- 11 %

(GRBs 000323 000408 000429 000607 000616 000623 000811 000812 000820
000830 000911 000925 001004 001007).

Thus, to within the statistical limits, the fractional success rates
(as defined) for both IPN and HETE are consistent with each other.
HETE obviously has far more follow-up observations, since they have a
dedicated and coordinated follow-up observation team, while IPN does
not. Of course, the analysis also ignores the role that IPN had in
improving the error boxes of the HETE positions, which is substantial.
This improves the HETE results at the expense of the IPN.

Also, it ignores that there are several GRBs which are optically and
radio "dark" and yet have X-ray afterglows localized to extremely high
precision with the Chandra X-ray Observatory, which would tend to
improve the success rates of both kinds of solutions.

Your claims are unsubstantiated. You ignored the fact that most of
the IPN solutions went unobserved by follow-up teams, and therefore
you woefully underestimated the success rate of IPN.


In addition, you still maintain that somehow the IPN solutions are
being manipulated, and yet every IPN solution that I am aware of to
date, has been consistent with a confirmed counterpart. You have not
provided a mechanism by which the solution could be manipulated.
Indeed, there is none, since it involves simple geometry and geometric
viewing constraints.



It is nonsense to think that IPN annuli are derived completely
independently from the supplied HETE error box . Maybe the methodolgy
for the two calculations are different but the data and source upon
which they are based is identical.

The gamma-ray data consist of several data elements per record. The
imaging technique uses one set of elements (positional), the IPN uses
a disjoint set (time+rate). Therefore your comment is irrelevant.


In other words your above statements essentially means the same as
what I have been saying in earlier posts in that that the error box
position is derived from the same recorded set of data as the time
flux history. Why say I am wrong and then agree with me?


Detector position information, and time+flux information are two
independent sets of quantities. Therefore your paraphrase is
incorrect. You do not seem to understand the concept of
"statistically independent." So indeed, the HETE SXC/WXM error boxes
can be derived completely independently of the time history.

CM

References
1. Will, Clifford, "The Confrontation between General Relativity and
Experiment",
http://www.livingreviews.org/Article...ill/index.html
2. Wolf, P. & Petit, G. 1997, Phys Rev A, 56, 4405
[ Test of constancy of speed of light with GPS ]
3. Shapiro, I. et al 1971, Phys Rev Lett, 26, 1132
[ Test of Shapiro time delay in Venus ranging ]
4. van Straten et al. Nature, 412, 158
(http://arxiv.org/abs/astro-ph/0108254)
[ Test of Shapiro delay in a binary pulsar system ]