1. Type Ia Supernovae in the SDSS Stripe 82 SDSS-KSG Workshop 2008. 2. 18-20 Du-Hwan Han and Changbom Park Kyungpook National University Kyungpook National University Korea Institute for Advanced Study Korea Institute for Advanced Study Progress report

2. SDSS Supernovae survey  Part of the SDSS-II project  Aim to discover SN Ia in “redshift desert” from z=0.05 to 0.4  Well-calibrated photometry in multi-band.  Extensive spectroscopic follow-up ARC, HET, MDM, Subaru, WHT, Keck, NMSU, …

3. SDSS Supernovae survey  Larger spatial volume than previous SN survey. southern equatorial Stripe 82.  Repeat imaging during Fall month of 2005-2007

4. Supernova Sample  Distribution of SNe : total ~1,500 SNe SN Ia -- 148 in 2005, 332 till 2006, 497 till now

5. Supernova Sample  Distribution of SNe total ~1500 SNe 148 SN Ia in 2005 332 SN Ia till 2006 497 SN Ia till now

6. Supernova Sample  Host galaxies of Type Ia SN from photometric & spectroscopic catalogs 72 hosts overlapping with the Main galaxies in the M r -z space 72 hosts overlapping with the Main galaxies in the M r -z space

7.  (u-r) color similar to the distribution of the Main galaxies of each type  Slight preference of SN Ia for bluer galaxies Properties of Host Galaxy

8.  (g-r) color similar to the distribution of the Main galaxies of each type

9. Properties of Host Galaxy  Luminosity + extinction + K-correction  SN Ia prefers galaxies with M r ~ M * -0.5

10. Properties of Host Galaxy  Local density 5 th nearby galaxy Δv=±1000 km/s  Definite preference of SN Ia for galaxies in low density regions

11. Properties of Host Galaxy  Distance to the nearest galaxy

12. Summary  SDSS-II Supernova Survey (Fall month of 2005-7) discovered about 500 SN Ia (now)  Properties of Host galaxy -(u-r) & (g-r) color -Luminosity -Local density -Distance to r 1  Future work - dependence of SN Ia properties on hosts and environment - analysis with additional SN Ia samples (2007) & luminous main galaxies (DR7) - analysis with additional SN Ia samples (2007) & luminous main galaxies (DR7)