1. The Robotic Palomar 60-inch Optical Afterglow Catalog: 2007 János Kelemen, Konkoly Observatory S. Bradley Cenko, CalTech. SRL Derek Fox, Penn State Univ. 1 2008 Nanjing GRB Meeting Session 4

2. - telescope - observations & data reductions - photometric results - some preliminary results - conclusions 2 2008 Nanjing GRB Meeting Session 4

3. 3 - telescope See reference: The Automated Palomar 60 Inch Telescope S. Bradley Cenko,11 Derek B. Fox,22 Dae-Sik Moon,1,31,3 Fiona A. Harrison,11 S. R. Kulkarni,44 John R. Henning,55 C. Dani Guzman,66 Marco Bonati,55 Roger M. Smith,55 Robert P. Thicksten,55 Michael W. Doyle,55 Hal L. Petrie,55 Avishay Gal-Yam,4,74,7 Alicia M. Soderberg,44 Nathaniel L. Anagnostou,8 and8 Anastasia C. Laity88 Publications of the Astronomical Society of the Pacific, 118:1396–1406, October 2006

4. 4 2008 Nanjing GRB Meeting Session 4 - telescope Filter characteristics Filter calibrations: Jordi et al. (2006).

5. 5 2008 Nanjing GRB Meeting Session 4 - observations & data reductions

6. 6 2008 Nanjing GRB Meeting Session 4 - observations & data reductions  No automatic methods  Data reduction by manual aperture photometry  Photometric standards: USNO, SDSS  Accuracy : 18  0.05 mg. 22  0. 2 mg. >22  0.3 – 0.5 mg.

7. 7 2008 Nanjing GRB Meeting Session 4 - some preliminary results Ref: Cenko et al, in preparation

8. 8 2008 Nanjing GRB Meeting Session 4 - some preliminary results Ref: A. Zeh, and S. Klose, and D.A. Kann, ApJ Vol. 637, 2006, pp. 889 - 900

9. 9 2008 Nanjing GRB Meeting Session 4 - some preliminary results: the case of „dark” bursts In our sample, nearly 50% of afterglows are “dark” bursts (OX < 0.5) Ref: Cenko et al, in preparation

10. 10 2008 Nanjing GRB Meeting Session 4 - some preliminary results: the case of „dark” GRB-s DEFINITION based on optical versus X ray spectral index : β OX < 0.5 (Jakobsson et al. 2004). Ref: Cenko et al, in preparation Correction for host absorption assuming β(optical) ~0.6 (average for bright SWIFT events)

11. 11 2008 Nanjing GRB Meeting Session 4 - some preliminary results: the case of „dark” bursts Ref: Cenko et al, in preparation Early period: optical to X –ray spectral index highly variable Later: became constant but below 0.5 => DARK burst

12. 12 2008 Nanjing GRB Meeting Session 4 - some preliminary results αZ

13. 13 2008 Nanjing GRB Meeting Session 4 - some preliminary results Color diagrams based on all 2005-2006-2007 P60 g, r, i, z, observations GRB OT

14. 14 2008 Nanjing GRB Meeting Session 4 - some preliminary results Color diagrams based on all 2005-2006-2007 P60 g, r, i, z, observations GRB OT Stars

15. 15 2008 Nanjing GRB Meeting Session 4 - some preliminary results Color diagrams based on all 2005-2006-2007 P60 g, r, i, z, observations GRB OT

16. 16 2008 Nanjing GRB Meeting Session 4 - some preliminary results Color diagrams based on all 2005-2006-2007 P60 g, r, i, z, observations GRB OT Stars

17. 17 2008 Nanjing GRB Meeting Session 4 - What about the individual colors? Z values from http://www.mpe.mpg.de/~jcg/grbgen.html Pseudo-redshift Calculator for G-Ray Bursts, A. Pélangeon & J-L. Atteia

18. 18 2008 Nanjing GRB Meeting Session 4 - some preliminary results What about the individual colors? 0 < Z < 2.5

19. 19 2008 Nanjing GRB Meeting Session 4 - some preliminary results (grb060206: 4.048; grb060210: 3.91; grb060906:3.686)

20. 20 2008 Nanjing GRB Meeting Session 4 - some preliminary results why the big scatter? What about the individual colors? offset at high Z

21. 21 2008 Nanjing GRB Meeting Session 4 - some preliminary results High redshift bump ??

22. 22 2008 Nanjing GRB Meeting Session 4 - some preliminary results High redshift bump synthetic colors based on polinomial regression of the redshift – magnitude(1Day) diagrams

23. 23 2008 Nanjing GRB Meeting Session 4 - some preliminary results synthetic colors based on polinomial regression (similar structure)

24. 24 2008 Nanjing GRB Meeting Session 4 - some preliminary results synthetic colors based on polinomial regression (similar structure)

25. - conclusions 25 2008 Nanjing GRB Meeting Session 4

26. - conclusions the case of the „dark” bursts 26 2008 Nanjing GRB Meeting Session 4

27. - conclusions the case of the „dark” bursts P60 80 % detection efficiency P60 was able to detect optical afterglow emission from a large fraction ( ∼ 80%) of events for which observations began within an hour of the burst trigger. 27 2008 Nanjing GRB Meeting Session 4

28. - conclusions the case of the „dark” bursts P60 80 % detection efficiency strange color-color diagrams 28 2008 Nanjing GRB Meeting Session 4

29. - conclusions the case of the „dark” bursts P60 80 % detection efficiency strange color-color diagrams further GRBs needed 29 2008 Nanjing GRB Meeting Session 4

30. - conclusions the case of the „dark” bursts P60 80 % detection efficiency strange color-color diagrams further GRBs needed 30 2008 Nanjing GRB Meeting Session 4 ADVERTISEMENT COMING SOON !!!

31. - conclusions the case of the „dark” bursts P60 80 % detection efficiency strange color-color diagrams further GRBs needed... Now this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning... Sir Winston Churchill, Speech in November 1942 31 2008 Nanjing GRB Meeting Session 4