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Existing Transient Surveys: Optical I: Big Apertures

Existing Transient Surveys: Optical I: Big Apertures. Geoff Bower. SN Ia. SN 2002hp From GOODS. Type Ia Supernovae and Cosmology. H0 = 72 +/- 8 km/s/Mpc. Omega_lambda = 0.7 Omega_m = 0.3. Filippenko 2003. Stretch Correction. Time dilation correction

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Existing Transient Surveys: Optical I: Big Apertures

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  1. Existing Transient Surveys:Optical I:Big Apertures Geoff Bower The Transient Universe: AY 250 Spring 2007

  2. SN Ia SN 2002hp From GOODS The Transient Universe: AY 250 Spring 2007

  3. Type Ia Supernovae and Cosmology H0 = 72 +/- 8 km/s/Mpc Omega_lambda = 0.7 Omega_m = 0.3 Filippenko 2003 The Transient Universe: AY 250 Spring 2007

  4. The Transient Universe: AY 250 Spring 2007

  5. Stretch Correction • Time dilation correction • The more luminous the SN, the longer the timescale The Transient Universe: AY 250 Spring 2007

  6. Corrections to Standard Candle Model Dust and intrinsic luminosity-corrected Filippenko 2003 The Transient Universe: AY 250 Spring 2007

  7. Nearby SNe Calibrate stretch relations Dependence on environment, SN host SN rate Physical understanding of progenitor(s), events, & calibrations Distant SNe Add points to magnitude-redshift relation Goals of Supernova Searches The Transient Universe: AY 250 Spring 2007

  8. Supernova Legacy Survey (SNLS) • Multi-color imaging with CFHT in 4 fields • Simultaneous science with deep field imaging • Square degree FOV • Observations every 3-4 nights • Goal of 700 SN Ia • 0.2 < z < 0.75 • Spectroscopic follow-up with VLT, Keck, Gemini Sullivan et al 2006 Results of 100 spectroscopic SNe The Transient Universe: AY 250 Spring 2007

  9. SN/Galaxy Identification The Transient Universe: AY 250 Spring 2007

  10. Host Galaxy Properties Vigorous star-forming galaxies Normal star-forming galaxies Passive galaxies The Transient Universe: AY 250 Spring 2007

  11. Two Component Origin Prompt component < 0.5 Gyr Tardy ~3 Gyr The Transient Universe: AY 250 Spring 2007

  12. Implications for Further Searches High redshift supernova should exist --- and belong to the prompt class The Transient Universe: AY 250 Spring 2007

  13. Stretch Depends on Galaxy Type The Transient Universe: AY 250 Spring 2007

  14. MACHO Search • Daily photometric LMC monitoring for 5.7 years • Search for microlensing from Galactic halo Alcock et al 2000 The Transient Universe: AY 250 Spring 2007

  15. Dark Matter The Transient Universe: AY 250 Spring 2007

  16. Microlensing Signature Einstein radius Paczynski 1996 The Transient Universe: AY 250 Spring 2007

  17. Microlensing Results Probable Type Ia SN Microlensing events The Transient Universe: AY 250 Spring 2007

  18. Data Selection • ~10 million stars • 21,570 images • 15 sq deg • 2067 days • 330 events • 301 are bumpers • 29 candidates • ~10 supernovae • 13-17 microlensing events total The Transient Universe: AY 250 Spring 2007

  19. MACHO Implications • Microlensing optical depth • ~1 x 10^-7 • Dark halo composed of MACHOs • Tau~5 x 10^-7 • 20% of MW halo mass in < 1 M_sun objects The Transient Universe: AY 250 Spring 2007

  20. Deep Lens Survey Transients • 7 x 4 sq deg fields • 5 years • Multiple imaging • Blanco & Mayall 4 m telescopes at CTIO and KPNO • Pipeline transient processing The Transient Universe: AY 250 Spring 2007

  21. Wide Range of Timescales Probed Becker et al 2004 The Transient Universe: AY 250 Spring 2007

  22. Moving Objects 75% of all transients 3600 total KBOs – 3”/hr NEO – 80”/hr The Transient Universe: AY 250 Spring 2007

  23. Photometrically Variable Objects • Several hundred variable stars • ~100 supernovae The Transient Universe: AY 250 Spring 2007

  24. Optical Transients Without Hosts • OT 20010112 • Spectrum looks like Type II SN at z=0.038 • 3 mag fainter than typical Type II SN • No Host to R > 27.6 mag The Transient Universe: AY 250 Spring 2007

  25. Rapid VariabilityT < 1000 s The Transient Universe: AY 250 Spring 2007

  26. Fast Transients are M dwarfs Kulkarni & Rau 2006 The Transient Universe: AY 250 Spring 2007

  27. The Fast Transient Fog • Blue flares from dwarf stars • Rate ~ 10^8 yr^-1 sky^-1 ~ 10 day^-1 sq deg^-1 • For B < 23.8 mag • GRB rate ~ 10^5 yr^-1 • SN rate ~ 10^8 yr^-1 • Nova rate ~ 10^8 yr^-1 Gpc^-3 The Transient Universe: AY 250 Spring 2007

  28. How to penetrate the fog? • Spectroscopy too expensive • Association with galaxy or cluster not conclusive • Use blue color of flare to select against • Careful field selection • NIR deep imaging The Transient Universe: AY 250 Spring 2007

  29. Summary • Big Transient Searches to Solve Big Problems • Dark matter • Dark energy • Fog of transients makes discovery/identification difficult • Solar system objects • Dwarf stars • One astronomers’s noise… • Matched filter for transient identification is powerful The Transient Universe: AY 250 Spring 2007

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