Quote (Voyaging @ Aug 17 2012 12:22am)
Then why are distant gamma-ray bursts and supernovae distributed isotropically throughout the sky?
http://csep10.phys.utk.edu/astr162/lect/cosmology/batse2k.gif
That's outdated. Mind giving me a study and not just a picture?
Aims. We analyze and characterize the angular distribution of selected samples of gamma ray bursts (GRBs) from Batse and Swift
data to confirm that the division in two classes of short- and long-duration GRBs correspond also to the existence of two distinct
spatial populations.
Methods. The angular distribution is analyzed by using multifractal analysis and characterized by a multifractal spectrum of dimensions.
Different spectra of dimensions indicate different angular distributions.
Results. The spectra of dimensions of short and long bursts indicate that the two populations have two different angular distributions.
Both Swift and BATSE long bursts appear to be homogeneously distributed in the sky with a monofractal distribution. Short GRBs
follow instead a multifractal distribution for both the two samples. Even if BATSE data may not give a secure interpretation of their
angular distribution because of the instrumental selection effects that mainly favor the detection of near GRBs, the results from Swift
short GRBs confirm this behavior, also when are included GRBs corrected by the redshift factor. The distributions traced by short
GRBs, up to z = 1, depict a universe with a structure similar to that of a disordered porous material with uniformly distributed
heterogeneous irregular structures, appearing more clustered than what expected.
z=1 Multifractality of Swift short GRBs?
Fabrizio Tamburin