# Presentation: 584783

## Sloan Digital Sky Survey (SDSS-II) Status

Huan Lin

**Huan Lin**

## Collaboration: ~150 scientists from

**Collaboration: ~150 scientists from**
**	****Am. Museum Nat. History**
**	****Astrophysical Inst. Potsdam**
**	****U. Basel**
**	****Cambridge U.**
**	****Case Western Reserve**
**	****U. Chicago**
**	****Drexel U.**
**	****Fermilab**
**	****Institute for Adv. Studies**
**	****Japanese Participation Grp**
**	****Johns Hopkins U.**
**	****JINA**
**	****Kavli Institute for Part. Astro.**
**	****Korean Scientist Group**
**	****LAMOST (China)**
**	****Los Alamos Nat. Lab**
**	****Max Planck Inst. Astron.**
**	****Max Planck Inst. Astrophy.**
**	****New Mexico State U.**
**	****Ohio State U.**
**	****U. Pittsburgh**
**	****U. Portsmouth**
**	****Princeton U.**
**	****US Naval Obs.**
**	****U. Washington**
**	**

**Beamline**

**Calorimeter**

**Massive**
**Spectrometer**

- Review Briefing

- September 14, 2007

## SDSS-II: The sequelIts 3 year mission (2005-2008)

**Legacy:**
**Imaging and Redshift survey - Large scale structure**
**SEGUE:**
**Milky Way halo – mergers – Dark Matter probe**
**Supernovae**
**Low and intermediate redshift – Dark Energy probe**
**Funding:**
**NSF, Sloan, DOE, NASA, Max Planck Society, Higher Ed. Fund. Council, UK, Japanese Mongbukagakusho**

- Review Briefing

- September 14, 2007

## FNAL science interests, tasks,

** ****and resources in SDSS-II**

**Fermilab Science Interests**
** ****13 scientists**
** ****3 current postdocs **
** ****Leadership roles in SEGUE and Supernova survey**
** ****Galaxy clusters**
** ****Strong and weak lensing**
** ****Stripe 82 coadd**
** ****Photometric redshifts**

**Required Resources**
**4 FTE scientist (mainly from CD)**
**10 FTE CP, admin, tech.**
**Funding**
**Significant cost sharing with SDSS project ($1.2 million)**

**  ****Tasks****	****	****	****	**
** ****Survey planning****	****	**
** ****Legacy, SEGUE, SNe data processing**
** ****Data distribution**
** ****Plug plate design**
** ****Project mgmt.**
** ****Project director support**
** ****APO Engineering/Technical support**

- Review Briefing

- September 14, 2007

## Status - Legacy

- Imaging is complete (gap filled)!   Spectroscopy on track (one year left).

- Imaging Footprint (8000 sq deg)  Spectro footprint: 1700 plates

- Review Briefing

- September 14, 2007

## Slide 6

- Review Briefing

- September 14, 2007

## Gravitational Lensing

**Gravitational Lensing**

**X**

- Distant
- Galaxy
- z=2

- No
- intervening
- galaxy

- No lensing
- Keck Telescope
- ($100 million)

- Distant
- Galaxy
- z=2

- Intervening
- galaxy with
- dark matter
- z=0.5

- SDSS 2.5m telescope
- + Dark Matter Lens
- ($15 million)

- Benefit of Dark Matter: Net savings $85 million

***Active research in gravitational lensing using SDSS data, carried out by Fermilab Center for Particle Astrophysics scientists***

- Review Briefing

- September 14, 2007

## Search for Bright, High-Redshift, Gravitationally Lensed SDSS Galaxies

**Discovered via systematic searches of the SDSS DR5 data by FNAL scientists, with ongoing and proposed multi-wavelength follow-up from ground and space-based telescopes**** **

***The 8 O’Clock Arc, the brightest known lensed Lyman Break Galaxy (LBG), with a redshift z=2.73 (Allam et al. 2007, ApJ, 662, L51)***

***4 more newly confirmed ***
***lensed arc systems from ***
***SDSS, with high redshifts ***
***z=2.0-2.4***

**Search for Bright, High-Redshift, Gravitationally Lensed SDSS Galaxies**

- Review Briefing

- September 14, 2007

## Strong and Weak Lensing 

***Lens modeling to constrain masses of lensing galaxies/clusters (Buckley-Geer et al., in prep.)***

***First measurement of Coma Cluster mass using weak lensing, enabled by SDSS data (Kubo et al. 2007, ApJ, in press);  lowest redshift cluster for which this has been done****** ***

- 95% C.L. for arc production

***SDSS arc search set limits on cluster lensing probability (Estrada et al. 2007, ApJ, 660, 1176) and affects models of cluster mass distribution***

**Strong and Weak Lensing **
**Probes of Dark Matter**

- Review Briefing

- September 14, 2007

## SEGUE

**SEGUE**
**(v.): To proceed to what follows without pause**

- SEGUE footprint:

- Review Briefing

- September 14, 2007

## Ahead of

- Imaging
- baseline:
- In-line with
- Spectro
- baseline:

- Review Briefing

- September 14, 2007

## Slide 12

- Review Briefing

- September 14, 2007

## X(kpc)

- Y(kpc)

- Sun

- Fitting the orbit of the
- 'Orphan stream'  in 3-D can constrain
- the flattening of the Dark Matter
- Halo surrounding our Milky Way
- Galaxy.

- Star streams
- as probes
- of Dark Matter!
- Fit with q=1.0
- model  implies
- consistency with
- Spherical halo.

- q=1.0

- Example:

- Review Briefing

- September 14, 2007

## Slide 14

- Review Briefing

- September 14, 2007

## SDSS-II Supernova Survey

** ****Obtain a few hundred *****high-quality***** SNe Ia light curves in the “redshift desert” z~0.05-0.35, by scanning 280 deg****2**** SDSS Stripe 82 with 2-day cadence over 3 months each Fall**
** ****Probe Dark Energy**** using continuous Hubble diagram, connecting with complementary low- and high-redshift measurements**

- Review Briefing

- September 14, 2007

## Redshift Distribution for SNe Ia

- Largest SN Ia
- sample from a
- single survey

- Frieman et al. (2007), submitted; see also Sako et al. (2007), submitted

***Already 24 spectroscopically confirmed SNe (as of 09/18/2007) since 3rd season started in Sep. 2007***

## Hubble Diagram

**Hubble Diagram**

**SDSS 2005 Data**
**130 SNe Ia **
**~89 after cuts**
**Kessler, Miknaitis et al (2007) to appear**

- SNLS

- Low-z

**SDSS**

- Almost
- Preliminary

- ESSENCE

- Review Briefing

- September 14, 2007

## SDSS SN Publications

**The Peculiar Type Ia Supernova 2005hk: Do Some Type Ia Supernovae Explode as Pure Deflagrations? M. M. Phillips et al, PASP, 119, 360 (2007)**
**A Study of the Type Ia/IIn Supernova 2005gj from X-ray to the Infrared: Paper I, J. L. Prieto et al, astro-ph/0706.4088, submitted to AJ**
**The SDSS-II Supernova Survey: Technical Summary, J. Frieman et al., submitted to AJ**
**The SDSS-II Supernova Survey: Search Algorithm and Follow-up Observations, M. Sako et al., to be submitted to AJ**
**Light Curves from the SDSS-II Supernova Survey, J. Holtzman et al., to be submitted to AJ**
**First Year Spectroscopy of the SDSS-II Supernova Survey, C. Zheng et al., to be submitted to AJ**
**A Measurement of the Rate of type Ia Supernovae at Redshift 0.1 from the first season of the SDSS-II Supernova Survey, B. Dilday et al., to be submitted to ApJ**
**The Rate of type Ia Supernovae vs. Host-Galaxy Properties from the first season of the SDSS-II Supernova Survey, M. Smith et al., in preparation**
**Hubble Diagram and Cosmological Constraints from the first season of the SDSS-II Supernova Survey, R. Kessler, G. Miknaitis et al., in preparation**
**Late-time Photometry and Spectroscopy of SN 2005hk, S. Jha et al., in preparation**

- Review Briefing

- September 14, 2007

## SDSS Community Science Impact

**CAS SQL database: over 8,000,000 queries in '04 and '05**
**Over 60 Terabytes served over the internet**
**Over half of all publications by users of the data NOT affiliated with SDSS**

**Data Release 6 made public end of June 2007**
**Imaging area**
**8400 deg****2**** Legacy**
**1600 deg****2**** SEGUE**
**Over 1,200,000 spectra, including 100,000 from SEGUE**
**1581 refereed papers related to SDSS**
**Over 50,000 citations of these papers**

- Review Briefing

- September 14, 2007

## Slide 20

- Review Briefing

- September 14, 2007