The galactic environment of Gamma Ray Bursts can provide good evidence about the nature of the progenitor system , with two old arguments implying that the burst host galaxies are significantly subluminous .
New data and new analysis have now reversed this picture : ( A ) Even though the first two known host galaxies are indeed greatly subluminous , the next eight hosts have absolute magnitudes typical for a population of field galaxies .
A detailed analysis of the 16 known hosts ( ten with red shifts ) shows them to be consistent with a Schechter luminosity function with R ^ { * } = -21.8 \pm 1.0 , as expected for normal galaxies .
( B ) Bright bursts from the Interplanetary Network are typically 18 times brighter than the faint bursts with red shifts , however the bright bursts do not have galaxies inside their error boxes to limits deeper than expected based on the luminosities for the two samples being identical .
A new solution to this dilemma is that a broad burst luminosity function along with a burst number density varying as the star formation rate will require the average luminosity of the bright sample ( > 6 \times 10 ^ { 58 } ph \cdot s ^ { -1 } or > 1.7 \times 10 ^ { 52 } \cdot erg \cdot s ^ { -1 } ) to be much greater than the average luminosity of the faint sample ( \sim 10 ^ { 58 } ph \cdot s ^ { -1 } or \sim 3 \times 10 ^ { 51 } erg \cdot s ^ { -1 } ) .
This places the bright bursts at distances for which host galaxies with a normal luminosity will not violate the observed limits .
In conclusion , all current evidence points to GRB host galaxies being normal in luminosity .