Short gamma-ray bursts can appear in stellar populations of all ages, implying that they can pinpoint stellar populations with a range of ages, in contrast to long GRBs which rely on current star formation. We have located a candidate short GRB at z~4, in a region extremely rich in EROs, including a galaxy with J-H(AB)~3. Photometric redshifts for these galaxies based on HST(ACS+NICMOS) and Spitzer(IRAC) observations imply that this burst may have occurred in a region of high mass density at high redshift. I will discuss the implications of this result, and the possibility of using short GRBs as beacons to high-z clusters in much the same way as long GRBs can be used to probe star formation.
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