re gamma ray bursters where are they in article steinly apr topaz ucsc edu steinly topaz ucsc edu steinn sigurdsson writes this does not propose a mechanism for grbs in the oort and no anti matter annihilation does not fit the spectra at least as far as i understand annihilation spectra big difference that s ignoring the question of how you fit a distribution to the oort distribution when the oort distribution is not well known in particular comet aphelia which are not well known are not a good measure of the oort cloud distribution merging neutron stars is at least a mechanism with about the right energy except it doesn t explain why there is no apparent correlation with galaxies or galaxy structure there is no mechanism for getting all the energy out in gamma rays with any significant amount of baryons around there will be a lot of pair production which makes a plasma which thermalizes the energy it has trouble generating enough energy to explain the most powerful bursts ergs it happens too fast compared to the burst duration and it is hard to make tight binaries of neutron stars another cosmological mechinism is the catalytic conversion of a neutron star to a strange star or the merger of two strange stars but that uses pretty far out physics my point is that we don t have a good mechanism at any distance so grb s are likely to be happening by an unknown mechanism so we can t rule out the oort cloud what would be the spectrum of an event which converts a comet to strange matter the spectra for primordial black holes eating comets and antimatter comets colliding with matter comets aren t quite right but perhaps there is an unusual mechanism which modifies the spectrum the energy matches very well for both of these mechanisms according to trevor weeks if the tunguska meteorite was a mini black hole collision with the earth then there are likely to be enough mini black holes around that the rate for bh comet collisions matches the grb rate well the fact that we don t know the distribution of comets in the oort cloud isn t a reason to rule them out it makes it harder to rule them out the point of the cited paper was that if we assume they got the right distribution for the oort cloud it is hard but not impossible to match that up with the distribution of grb s if they got the wrong distribution for the oort cloud they can t constrain any oort cloud grb s at all executive summary we don t know enough to rule out out the oort cloud
