# Presentation: 116052

## SDSSII Supernova Survey

**SDSSII Supernova Survey**

**Zheng (Poster) **Mon *Exhibit Hall DE*
**Lampeitl (Oral)** Wed 10:45am *Exhibit Hall C*
**Dilday (Oral)** Thurs 2:30pm *Telus 111*
**Special Session** Thurs *“LSS in the SDSS”*

**Bob Nichol (Portsmouth)**

## Type Ia supernovae (SNe)
spectroscopically confirm and obtain “well-measured” light curves of ~300 SN Ia from z = 0.05 ~ 0.4
bridge low-z (z<0.05; LOSS, SNF) and high-z (0.3<z<1.0; ESSENCE, SNLS) sources
Anchor the Hubble diagram
understand and minimize systematics of SN Ia as distance indicators

- Type Ia supernovae (SNe)
- spectroscopically confirm and obtain “well-measured” light curves of ~300 SN Ia from z = 0.05 ~ 0.4
- bridge low-z (z<0.05; LOSS, SNF) and high-z (0.3<z<1.0; ESSENCE, SNLS) sources
- Anchor the Hubble diagram
- understand and minimize systematics of SN Ia as distance indicators

**SDSSII SNe Survey***Exploring DE & SNe at an epoch when DE dominates*

**Riess et al. (2004)**
**compilation**

**Astier et al. (2005)**

## Use the SDSS 2.5m telescope
September 1 - November 30 of 2005-2007
Scan 300 square degrees every 2 days
Obtain multi-color light curves
>90% efficiency after ~2 - 4 epochs

- Use the SDSS 2.5m telescope
- September 1 - November 30 of 2005-2007
- Scan 300 square degrees every 2 days
- Obtain multi-color light curves
- >90% efficiency after ~2 - 4 epochs

**SNe Survey**

- N

- S

## Results from 2005

**Results from 2005**

- <z> = 0.21

- 130 spectroscopically confirmed SN Ia
- Galaxy redshifts for 25 additional Ia candidates)
- International follow-up using ARC3.5m, HET, MDM, WHT, Subaru & NTT

## MDM

- ARC

- HET

- ARC

## Empirical Correlations

- SNIa’s are *“the most powerful and best proven technique for studying dark energy. The power of the experiment as reflected in the DETF figure of merit is much better known than for other techniques with the outcome depending on the uncertainties in supernova evolution and in the astronomical flux calibration.”*

- DETF Report 2006

- To understand uncertainties for future missions we need to look for empirical evidence of SNe evolution. Simulations can’t help us.
-  *Evolution with redshift,*
* **Correlations with galaxy properties,*
* **Correlations of SNIa properties*
*SDSS sample is ideal for this because of the size and quality of the dataset. Lots of ancillary information from main SDSS sample and superb photometric properties.*

## Luminosity (stellar mass)

**LOW  ****(0.013 < z < 0.155) **
**INTERMEDIATE ****(0.55 < z < 0.263)**
**HIGH ****(0.263 < z < 0.41)**

## Color (SFH)

**LOW  ****(0.013 < z < 0.155) **
**INTERMEDIATE ****(0.55 < z < 0.263)**
**HIGH ****(0.263 < z < 0.41)**

**BLUE**

**RED**

## Morphology (Dynamics)

**LOW  ****(0.013 < z < 0.155) **
**INTERMEDIATE ****(0.55 < z < 0.263)**
**HIGH ****(0.263 < z < 0.41)**

**spiral-like**

**elliptical-like**

## Comparison with all galaxies

**Comparison with all galaxies**

- Volume limited sample of SNIa’s and SDSS galaxies

***Statistically no evidence for any differences***

## Conclusions

**SDSS is up and running. Fastest SNIa discovery rate of any SNe search**
- International network of telescopes folowing up objects
- SDSS is ideal sample for detailed studies of SNe as “standard candles”
**No obvious correlations found. SNIa’s appear to be in a “random subsample” of galaxies**.
- More data to come over the next 18months