Type Ia Supernovae in Type Ia Supernovae in the SDSS Stripe 82the SDSS Stripe 82

SDSS-KSG WorkshopSDSS-KSG Workshop

2008. 2. 18-202008. 2. 18-20

Du-Hwan Han and Changbom ParkDu-Hwan Han and Changbom Park Kyungpook National UniversityKyungpook National University

Korea Institute for Advanced StudyKorea Institute for Advanced Study

Progr

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SDSS Supernovae surveySDSS Supernovae survey

Part of the SDSS-II projectPart of the SDSS-II project Aim to discover SN Ia in “redshift desert” from z=0.05 to 0.4Aim to discover SN Ia in “redshift desert” from z=0.05 to 0.4 Well-calibrated photometry in multi-band.Well-calibrated photometry in multi-band. Extensive spectroscopic follow-upExtensive spectroscopic follow-up

ARC, HET, MDM, Subaru, WHT, Keck, NMSU, … ARC, HET, MDM, Subaru, WHT, Keck, NMSU, …

SDSS Supernovae surveySDSS Supernovae survey

Larger spatial volume than previous SN survey.Larger spatial volume than previous SN survey.southern equatorial Stripe 82.southern equatorial Stripe 82.

Repeat imaging during Fall month of 2005-2007Repeat imaging during Fall month of 2005-2007

Supernova Supernova SampleSample

Distribution of SNe : total ~1,500 SNe Distribution of SNe : total ~1,500 SNe

SN Ia -- 148 in 2005, 332 till 2006, 497 till nowSN Ia -- 148 in 2005, 332 till 2006, 497 till now

Supernova SampleSupernova Sample

Distribution of SNe Distribution of SNe total ~1500 SNe total ~1500 SNe

148 SN Ia in 2005148 SN Ia in 2005332 SN Ia till 2006332 SN Ia till 2006497 SN Ia till now497 SN Ia till now

Supernova Supernova SampleSample

Host galaxies of Host galaxies of Type Ia SNType Ia SNfrom photometric & from photometric & spectroscopic catalogsspectroscopic catalogs

72 hosts 72 hosts overlapping with the overlapping with the Main galaxies in the Main galaxies in the MMrr-z space-z space

(u-r) color(u-r) colorsimilar to the distribution similar to the distribution of the Main galaxies of of the Main galaxies of each typeeach type

Slight preference of SN Slight preference of SN Ia for bluer galaxiesIa for bluer galaxies

Properties of Host GalaxyProperties of Host Galaxy

Properties of Host GalaxyProperties of Host Galaxy

(g-r) color(g-r) color

similar to the distribution similar to the distribution of the Main galaxies of of the Main galaxies of each typeeach type

Properties of Host GalaxyProperties of Host Galaxy

LuminosityLuminosity

+ extinction+ extinction+ K-correction+ K-correction

SN Ia prefers galaxies SN Ia prefers galaxies with Mwith Mrr ~ M ~ M**-0.5-0.5

Properties of Host GalaxyProperties of Host Galaxy

Local densityLocal density

55thth nearby galaxy nearby galaxyΔΔv=±1000 km/sv=±1000 km/s

Definite preference of Definite preference of SN Ia for galaxiesSN Ia for galaxiesin low density regionsin low density regions

Properties of Host GalaxyProperties of Host Galaxy

Distance toDistance tothe nearest galaxythe nearest galaxy

SummarySummary

SSDSS-II Supernova Survey (Fall month of 2005-7)DSS-II Supernova Survey (Fall month of 2005-7)discovered about 500 SN Ia (now) discovered about 500 SN Ia (now)

Properties of Host galaxyProperties of Host galaxy-(u-r) & (g-r) color-(u-r) & (g-r) color-Luminosity-Luminosity-Local density-Local density-Distance to r-Distance to r11

Future workFuture work- - dependence of SN Ia properties on hosts and environmentdependence of SN Ia properties on hosts and environment

- analysis with additional SN Ia samples (2007) &- analysis with additional SN Ia samples (2007) & luminous main galaxies (DR7) luminous main galaxies (DR7)