Re: Swift grb satelitte

From: Craig Markwardt (craigmnet_at_REMOVEcow.physics.wisc.edu)
Date: 02/13/05 

Date: 13 Feb 2005 14:23:58 -0600

"sean" <jaymoseley@hotmail.com> writes:
> I notice that the SWIFT team has declined
> to release the lightcurve and spectrum of grb 050117.
> Is it because they have found that there is no redshift
> of GRBs as I predicted many times on this thread and
> others?

Or, could it be a more mundane explanation, as described in GCN Circ
2955 (Hill et al)? Namely, the automated burst follow-up sequence was
interrupted by the spacecraft passing into the South Atlantic Anomaly
(SAA), preventing the standard light curve or spectra from being
accumulated.

> ... Unable to explain the lack of redshift may
> have prompted the team to assume it was a technical
> glitch.

Putting your conspiracy theories aside, the burst did in fact occur
while the spacecraft was passing into the SAA; and it was in fact at
the edge of the Swift pointing constraints.

> ... Or maybe they also noticed that, as I predicted
> on google numerous times, the x ray lightcurve occurs
> later than the gammaray lightcurve by a small time
> amount(microseconds or even seconds possibly)

This is not a very useful prediction. The difference between a 1
microsecond and a 1 second delay is a factor of one million. Why
don't you predict a delay of nanoseconds to years, to cover all your
bases?

> I wonder about this as on day of the burst NASA said a
> spectrum and lightcurve would be posted in a couple of
> hours. 4 days later they give a press release saying
> that because the burst was near the edge of the field
> of view a data analysis is impossible. If thats the
> case then surely they would have known this at the time
> of the burst and even before that.

Since the times and positions of GRBs are completely unpredictable,
how could they have known *before* the burst that it would be
constrained? Huh? The Swift spacecraft and instruments can respond
totally autonomously, depending on conditions, so it follows no one
can know in advance when or where Swift will point with surety.

Could Burrows et al (GCN Circ 2951) have known that the burst was near
the edges of multiple observing constraints? Probably, but GCN 2951
appeared to be focussed on getting an accurate position out to the
follow-up community. The follow-up people don't necessarily care
about Swift's constraints.

> Did it take them this long to realize a key limitation of
> their satelitte?

Umm, no. The Swift pointing constraints have been known for a long
time. It's just that no one can predict where the next GRB will occur
on the sky.

> ... Anyways, I expect that the next burst
> will give the final proof that GRB`s do not have redshifts
> and are phenomena that occur locally at the point of
> observation not unlike the similar phenomenae of a mirage
> or sonic booms
...

So do you care to make some predictions? I.e., exactly how much delay
do you predict there will be between 25-150 keV and 2-10 keV X-rays?
While you are at it, please also provide your prediction for the time
delay difference between the 25-50, 50-100 and 100-200 keV bands. And
no, "microseconds to seconds" is not a useful prediction. I can
predict the sun will rise tomorrow too, but that's not a very powerful
prediction.

CM

Relevant Pages

  • Re: Swift grb satelitte
    ... > to release the lightcurve and spectrum of grb 050117. ... "It was in the midst of exploding, as Swift ... > of the burst and even before that. ...
    (sci.astro)
  • Re: Swift grb satelitte
    ... to release the lightcurve and spectrum of grb 050117. ... Is it because they have found that there is no redshift ... that because the burst was near the edge of the field ...
    (sci.astro)
  • Re: swift grb data rules out beamed theory
    ... confirmable z value....If SWIFT is able to take multiple ... Optical of any GRB. ... afterglow and determines its redshift, ... The ground based spectra isnt valid in my opinion. ...
    (sci.astro)
  • Swift grb satelitte
    ... The Swift grb satelitte launches tommorow!! ... initially extremely blue shifted to shorter wavelengths then gamma. ... After the emmision spectrum has been observed in gamma it will seen ...
    (sci.astro)
  • Swift Satellite Detects Unusual Cosmic Explosion (Forwarded)
    ... SWIFT SCIENCE CONTACT AT PENN STATE: ... Director of the Swift Mission Operations Center ... Amateur astronomers in the northern hemisphere with a good telescope in dark skies also can view the source. ... The explosion has the trappings of a gamma-ray burst, the most distant and powerful type of explosion known. ...
    (sci.astro)