1. The Optically Unbiased GRB Host (TOUGH) sample Palli Jakobsson Centre for Astrophysics & Cosmology University of Iceland TOUGH 1: Survey Design and Catalogues (Hjorth et al.) TOUGH 2: Fundamental Properties (Malesani et al.) TOUGH 3: Redshift Distribution (Jakobsson et al.) TOUGH 4: Lyα Emitters (Milvang-Jensen et al.) TOUGH 5: Radio Survey at z < 1 (Michałowski et al.) TOUGH 6: Host Luminosity Function (Schulze et al.)

2. Jens Hjorth (PI) Jóhán Fýnbó (Icelandic expert) Bo Milvang-Jensen (Eurovision expert) Daniele Malesani (GCN expert) Bob Chapman (Dr. Who expert) Nial Tanvir (world record expert) The TOUGH Guys Thomas Krühler (X-shooter expert)

3. 69 Host Galaxies (R-band)

4. Redshift Distribution Before TOUGH: = 2.39

5. Redshift Distribution Before TOUGH: = 2.39 TOUGH (FORS): = 2.23

6. Redshift Distribution TOUGH (FORS): = 2.23 Before TOUGH: = 2.39 15 new redshifts 68/69 hosts have a redshift constraint TOUGH (X-shooter): = 2.23 77% (53/69) redshift completion

7. 1. A Swift-detected GRB with t 90 > 2 s. 2. XRT afterglow position distributed within 12 hours. 3. Small foreground Galactic extinction: A V < 0.5 mag. 4. Favorable declination: -70° < δ < 27°. 5. Afterglow error radius < 2”. March 2005 – August 2007: 69 GRBs 75% had an optical/NIR afterglow TOUGH Sample Selection Criteria 55% had a reported redshift (38/69)

8. Blue: short bursts Empty circles: without an X-ray afterglow Filled circles: with an X-ray afterglow Crosses: untriggered bursts Sample Selection: Sky Map

9. R-band detections: 53/69 = 77% K-band detections: 24/60 = 40% How Many Hosts Detected (R-band)?

10. -15 > M B > -22 GRB hosts are mostly subluminous In line with previous findings based on smaller and less complete samples Host Properties

11. Blue colours: ~ 3 Blue: with OA Red: no OA Only 1/56 ERO Host Properties Tanvir et al. (2008) Jaunsen et al. (2008) Perley et al. (2009) Levesque et al. (2010) Krühler et al. (2011)

12. Redshift Determination (R < 25 mag)

13. Redshift Determination (z = 0.84) (z = 1.92) (z = 0.84)

14. Cumulative Redshift Distribution KS: < 1% KS: 52%

15. SFR1 (Li 2008 modified by Langer & Norman 2006 low-metallicity correction) SFR2 (Model A from Schmidt 2009) SFR Density Histories

16. Lyα and the Role of Dust