1. Edo Berger Carnegie Observatories Edo Berger Carnegie Observatories Probing Stellar to Galactic Scales with Gamma-Ray Bursts

2. Cosmic Structure Formation GRB afterglows probe all scales relevant for star formation GRBs pinpoint star-forming galaxies Short GRBs may pinpoint galaxy clusters

3. Afterglow Absorption Spectroscopy no proximity effect, small impact parameter, bright, high-z, fade away

4. Swift (Nov. 20, 2004)

5. The Carnegie GRB Program Swope 40-inch du Pont 100-inch Magellan 6.5-m

6. Berger et al. 2005a

7. GRB 050505: DLA at z = 4.275 Berger et al. 2005b Z ~ 0.06 Z  [Fe/S]: dust depletion

8. GRB 050505: SiII Fine-Structure Berger et al. 2006 SiII* has never been detected in a QSO sight-line! The fine-structure level is due to collisional excitation & requires a high electron density  n H ~ 10 2 -10 4 cm -3  r ~ 10 pc & M ~ 10 3 M 

9. GRB 050505: Progenitor Properties Berger et al. 2005 CIV extends over ~1000 km/s Wind from progenitor: WR winds easily account for 1000 km/s SiIV absorption is sensitive to metallicity and mass (Leitherer & Lamers 1991) SiIV upper limit  WC Wolf-Rayet star, Z < 0.1Z  and M < 25 M  At 0.1 Z  the minimum mass for a wind is 45 M   binary

10. GRB 051111: Fine-structure Transitions Penprase et al., Berger et al., Prochaska et al. 2006

11. Fe IIFe II*Fe II**Fe II***Fe II**** Berger et al. 2006 GRB 051111: Fine-structure Transitions Collisional excitation of FeII requires n e ~ 4000 cm -3 and T ~ 10 3 K Berger et al. 2005b

12. GRB-DLAs Berger et al. in prep.

13. GRB-DLAs Berger et al. 2005b

14. GRB 050904: z = 6.295 Kawai et al. 2005 log N H ~ 21.3; Z ~ 0.1 Z  ; x H <0.6 (95% c.l.)

15. GRB 050904: z = 6.295 Berger et al. 2006

16. Short GRB Host Galaxies z =0.546 star-forming galaxy Soderberg et al. 2006 Berger et al. 2005c z =0.257 elliptical galaxy

17. GRB 050813: z ~ 1.8 Galaxy Cluster Gladders & Berger in prep. Bridges “proto-clusters” at z>2 with clusters at z~1

18. Over-density of a factor of 40 compared to the field GRB 050813: z ~ 1.8 Galaxy Cluster All Early type 110 arcmin 2 vs. 1 arcmin 2 Blank field and narrow- band surveys are extremely inefficient for high-z clusters

19. Conclusions GRBs probe all the scales relevant for understanding star formation at high redshift: winds, star-forming regions, ISM High column density DLAs with abundance patterns similar to a warm disk Fine-structure excitation indicates a dense warm environment Metallicity-redshift relationship similar to QSO-DLAs, but with systematically higher metallicities Extending studies of the mass/luminosity-metallicity relation to z ~ 4 and beyond