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

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

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

The Transient Universe: AY 250 Spring 2007

Stretch Correction Time dilation correction The more luminous the SN, the longer the timescale

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

The Transient Universe: AY 250 Spring 2007 Goals of Supernova Searches 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

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

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

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

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

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

The Transient Universe: AY 250 Spring 2007 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 Dark Matter

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

The Transient Universe: AY 250 Spring 2007 Microlensing Results Probable Type Ia SNMicrolensing events

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

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

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

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

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

The Transient Universe: AY 250 Spring 2007 Rapid Variability T < 1000 s

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

The Transient Universe: AY 250 Spring 2007 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 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 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