spatial distribution of galaxies

Revealing the First Stellar and Supermassive Black Holes to EXIST

The epochs of origin of the first stars and galaxies, and subsequent growth of the first supermassive black holes, are among the most fundamental questions. Observations of the highest redshift Gamma-Ray Bursts (GRBs) will be the most compelling in …

Can We Trust GRB High Energy Correlations?

We show that several GRB correlations have common features indicative of an origin in selection effects. We focus on the possible origin of the Epk-Eiso correlation in Swift data due to detector threshold truncation. The existence of faint Swift …

XRF 060428B: Observational evidence for a strongly lensed burst

Long-duration GRBs and X-ray flashes (XRFs softer-spectrum brethren of long GRBs) are thought to occur following the core-collapse of massive stars. We report here on observations of a recent X-ray flash (XRF 060428B) that occurred 2.6$^″$ in …