1. The Transient Sky Eran Ofek CALTECH Shri Kulkarni Arne Rau Mansi Kasliwal Brian Cameron Avishay Gal-Yam Dale Frail Collaborators:

2. Talk Layout Transients along the EM spectrum (review) Motivation & the future Ongoing optical searches Individual transients (optical) M85 OT 2006-1 SN2006gy Kulkarni, Ofek et al. (2006 Nature submitted ) Rau et al. (2006) Ofek et al. in prep Ofek et al. (2006 ApJL submitted )

3. Transients along the EM (  -rays) Gamma rays Long-GRBs Short GRBs Soft  -ray repeaters Massive stars NS mergers? Neutron Stars (NS) ?

4. Transients along the EM (  -rays) Ofek et al. (2006 ApJ accepted) Z=0.09 Progenitor age<10Myr if NS merger: for kick velocity>35km/s

5. Transients along the EM ( ~cm) Radio Searching for radio transients Levinson, Ofek et al. (2002) Future: ATA SKA Comparison of 2 radio surveys Found: 2 genuine transients Transients in nearby galaxies Gal-Yam, Ofek et al. (2006) Ofek et al. in prep

6. Transients along the EM (visible) Many searches But usually focused on specific classes… Solar system Supernovae Microlensing …

7. Motivation New / rare kind of transients Peculiar members of known families Test models Standard candle systematics

8. Summary of physical motivation

9. The future - LSST 8.4m mirror 6.5m effective diameter Field of view = 9.65 sq. deg

10. The future - LSST

11. LSST details 6 filters: ugrizY ~7000 sq. deg. per night First light: 2013, Cerro Pachon ~1min transients alert Single image: r~24 mag After 10yrs r~28 mag Sky for everyone - No proprietary period!

12. Back to the present (Our) ongoing searches Nearby clusters Fornax, Perseus SDSS-II cadence improving Follow up Palomar 5m MPG 2.2m LCO 2.5m Palomar robotic 60” Palomar 48” (10 sq. deg) Nearby galaxies survey Palomar robotic 60” Kulkarni, Ofek, Rau, Kasliwal

13. Another strategy…

14. Individual transients M85 OT 2006-1 SN2006gy Kulkarni, Ofek et al. (2006) Rau et al. (2006) Ofek et al. in prep Ofek et al. (2006; ApJL submitted) In the past year: Follow-up of 6 transients Examples:

15. M85 Optical Transient 2006-1 Kulkarni, Ofek et al. (2006; Nature submitted) Rau et al. (2006; ApJL submitted) Ofek et al. in prep

16. M85 Optical Transient 2006-1

17. Width~350km/s

18. M85 Optical Transient 2006-1 Late time Spitzer observation

19. M85 Optical Transient 2006-1 Late time Spitzer observation

20. M85 Optical Transient 2006-1 Green to red color evolution 60 day plateau Peak abs. mag I~-13 Expansion velocity ~350 km/s Cool black-body at late time E~10 47 erg (in 3 months) a-spherical expansion?

21. M85 Optical Transient 2006-1 …like: M31-RV & V838 Mon

22. M85 Optical Transient 2006-1 …like: M31-RV & V838 Mon Favored model: Stellar merger (Soker & Tylenda)

23. M85 Optical Transient 2006-1 Searching for his brothers

24. SN 2006gy Ofek et al. (2006 ApJL submitted ) Discovered: 2006 Sep 18 (Quimby et al.) H  line AGN(?) - Prieto et al. (2006) Type-IIn supernova (SN) ? Harutyunyan et al. Foley et al. (2006) However, early type galaxy Abs mag @ peak ~-22 ~50 days rise time

25. SN Nucleus Dust lane FWHM ~0.”1 SN 2006gy Ofek et al. (2006 ApJL submitted )

26. SN 2006gy Ofek et al. (2006 ApJL submitted )

27. SN 2006gy Ofek et al. (2006 ApJL submitted ) S0 template with E B-V =0.16 extinction SN+galaxy @ day~45 SN+galaxy @ day~7

28. SN 2006gy Ofek et al. (2006 ApJL submitted )

29. SN 2006gy Ofek et al. (2006 ApJL submitted ) VLA – no detection Swift/XRT – no detection Chandra (PI: Pooly) Variable X-ray source @ galaxy center

30. Hybrid IIn/Ia SN (Type-IIa) SN 2002ic -20.1 ~20 late type galaxy SN 2005gj -20.4 ~55 blue Irr. M B ~-17 SN 1997cy -20.1 <30 blue LSB M B ~-17.7 SN 1999E <-19.5 <140 M B ~-15 spiral SN 2006gy -22.2 ~50 S0 galaxy Name Abs V-mag Rise time [d] Environment SN 2006gy Ofek et al. (2006 ApJL submitted )

31. energy Total radiated energy ~1.2x10 51 erg during 2 months Type-Ia SN features in spectra Assuming SN2006gy is a type-Ia SN kinetic energy of a Ia SN (~1-2x10 51 erg) radiation SN 2006gy Ofek et al. (2006 ApJL submitted )

32. Assuming SN2006gy is a type-Ia SN kinetic energy of a Ia SN (~1-2x10 51 erg) radiation Requires: Mass-loss rate ~10 -2 M /yr Over ~100yr Common envelope? (Livio & Riess 2003) SN 2006gy Ofek et al. (2006 ApJL submitted )

33. Summary First year – “listening” mode: The “known”: 1 LBV(?), 2+1(?) dwarf novae The “known unknown”: Out of 6 targets: The “unknown unknown” M85 OT 2006-1 SN 2006gy Still waiting…

34. End

35. Transients along the EM (  -rays) Ofek (2006b); Ofek et al. (2006a) Extragalactic SGRs

36. M85 Optical Transient 2006-1

37. Comparison with other types of transients

38. Transients along the EM ( ~cm) VLA J172059+38

39. VLA J121550+13 in NGC 4216

40. SN 2006gy Ofek et al. (2006) Peak absolute V-band magnitude ~-22.2 Summary Total radiated energy ~1.2x10 51 erg during 2 months Type-Ia SN features in spectra

41. SDSS-15207

43. Chandra (PI: Pooley) XRT – no detection VLA – no detection SN 2006gy Ofek et al. (2006 ApJL submitted )

44. M85 Optical Transient 2006-1 Searching for his brothers in nearby galaxies…