Long gamma-ray bursts and core-collapse supernovae have different environments

Fruchter, A. S.; Levan, A. J.; Strolger, L.; Vreeswijk, P. M.; Thorsett, S. E.; Bersier, D.; Burud, I.; Cerón, J. M. Castro; Castro-Tirado, A. J.; Conselice, C.; Dahlen, T.; Ferguson, H. C.; Fynbo, J. P. U.; Garnavich, P. M.; Gibbons, R. A.; Gorosabel, J.; Gull, T. R.; Hjorth, J.; Holland, S. T.; Kouveliotou, C.; Levay, Z.; Livio, M.; Metzger, M. R.; Nugent, P. E.; Petro, L.; Pian, E.; Rhoads, J. E.; Riess, A. G.; Sahu, K. C.; Smette, A.; Tanvir, N. R.; Wijers, R. A. M. J.; Woosley, S. E.

Long gamma-ray bursts and core-collapse supernovae have different environments

Authors

Description

When massive stars exhaust their fuel they collapse and often produce the extraordinarily bright explosions known as core-collapse supernovae. On occasion, this stellar collapse also powers an even more brilliant relativistic explosion known as a long-duration gamma-ray burst. One would then expect that long gamma-ray bursts and core-collapse supernovae should be found in similar galactic environments. Here we show that this expectation is wrong. We find that the long gamma-ray bursts are far more concentrated on the very brightest regions of their host galaxies than are the core-collapse supernovae. Furthermore, the host galaxies of the long gamma-ray bursts are significantly fainter and more irregular than the hosts of the core-collapse supernovae. Together these results suggest that long-duration gamma-ray bursts are associated with the most massive stars and may be restricted to galaxies of limited chemical evolution. Our results directly imply that long gamma-ray bursts are relatively rare in galaxies such as our own Milky Way.
27 pages, 4 figures, submitted to Nature on 22 August 2005, revised 9 February 2006, online publication 10 May 2006. Supplementary material referred to in the text can be found at http://www.stsci.edu/~fruchter/GRB/locations/supplement.pdf . This new version contains minor changes to match the final published version