ONE MILLION GALAXIES

XXXVth Recontres de Moriond, Energy Densities in the Universe

ONE MILLION ONE MILLION GALAXIESGALAXIES

Cosmography and Cosmology

Michael S. VogeleyDepartment of PhysicsDrexel University

Michael S. Vogeley, Drexel University

Quantitative Large-Scale Structure: Lick SurveyQuantitative Large-Scale Structure: Lick SurveyQuantitative Large-Scale Structure: Lick SurveyQuantitative Large-Scale Structure: Lick Survey

1 million galaxies!

Lick observatory plates

Counts by eye (Shane-Wirtanen), map by Seldner et al. 1977

Analyses by Peebles, Groth, and Fry, et al.

Angular correlation functions: 2, 3, 4-pt

Groth &

Peebles (1977)


Hints of Greatness: The Shift to 3DHints of Greatness: The Shift to 3DHints of Greatness: The Shift to 3DHints of Greatness: The Shift to 3D

The Photon-Counting Cowboys

KOSS (1981):50 Mpc/h Void in BootesAnomalous?Truly empty?Formation mechanism?

Center for Astrophysics (1982):Power-law 3D correlationsPairwise velocity dispersionPredict gravity fieldComparison with N-body sim’s“Frothy…filamentary superclusters”

Davis & Peebles (1983)

Kirshner et al. (1981)


Voids, Walls, and Peaks: Death to CDM?Voids, Walls, and Peaks: Death to CDM?Voids, Walls, and Peaks: Death to CDM?Voids, Walls, and Peaks: Death to CDM?

CfA slice(1986), CfA2, SSRS:Structures as large as surveyVoids fill spaceP(k) rules out SCDM

APM galaxy catalog (1990):Too much large-scale powerfor SCDM

BEKS pencil-beams (1990):128 Mpc/h Peaks in 1D P(k)

Characteristic scales in LSS?Maddox et al. (1990)

Geller & Huchra (1988)


All-Sky: The IRAS z SurveysAll-Sky: The IRAS z SurveysAll-Sky: The IRAS z SurveysAll-Sky: The IRAS z Surveys

IRAS 2Jy (1989), 1.2Jy (1993)QDOT (1991), PSCz 0.6Jy (1999)

Selection of galaxies independentof photo plates, Galactic extinctionIR-selected trace same structureswith lower density in clusters

Similar statistics, but lower clustering amplitudeClear evidence for biasing onall scales

All-sky benefits: spherical windowdensity-velocity study

Saunders et al. (2000)


CCD-Based Surveys and the Era of MultiplexingCCD-Based Surveys and the Era of MultiplexingCCD-Based Surveys and the Era of MultiplexingCCD-Based Surveys and the Era of Multiplexing

Las Campanas Redshift Survey:R-band CCD driftscan photometry100 Fiber-fed spectrograph

Ubiquitous voids and walls- the end of “greatness”?

Peak in the 2D power spectrum nearsame scale as BEKS

Limited by geometryWhat if we survey the whole sky?

Landy et al. (1996)

Shectman et al. (1996)


Current Status on Large-Scale StructureCurrent Status on Large-Scale StructureCurrent Status on Large-Scale StructureCurrent Status on Large-Scale Structure

• What drives structure formation?– Gravity!

• Cosmological parameters?

• Components of mass-energy density?– Baryon fraction (?), CDM, HDM?, what else?– Is the cosmological “constant” constant?

• Galaxy formation: connecting mass to light– Gastrophysics and biasing

7.0,1,4.02.0 hmattermatter


Critical Issues for Large-Scale StructureCritical Issues for Large-Scale StructureCritical Issues for Large-Scale StructureCritical Issues for Large-Scale Structure

• Features in P(k) at peak scale and beyond– Is the peak too sharp?– Wiggles in the spectrum?– Structure on Gpc scales?

• Messy details about galaxies– Galaxy segregation (“biasing”)– Galaxy evolution (purely

local?)– Voids: Are they too empty?

Blanton et al. (1999)

Vogeley (1999)


Features in the 3D Power SpectrumFeatures in the 3D Power SpectrumFeatures in the 3D Power SpectrumFeatures in the 3D Power Spectrum

Eisenstein & Hu (1998)

Baryonic Wiggles

LSS+CMB

Gawiser & Silk (1998)

Slope agreement at small scaleLinear to non-linear transition Feature at 0.1-0.2h/Mpc Peak at 0.03-0.04h/MpcSlope, ampl <0.03?

Physics on peak scale? LSS vs. CMB


Voids and Void GalaxiesVoids and Void GalaxiesVoids and Void GalaxiesVoids and Void Galaxies

De Lapparent, Geller, & Huchra (1986)

Diaferio et al. (1999)

Cen & Ostriker (1998)

Data vs. N-body+hydro: sim voids too empty?Data vs. N-body+SAMs: sim void edges not sharp?

Galaxy evolution at Need color, spectra, low SB, mag range

8.0


Desiderata for New Galaxy SurveysDesiderata for New Galaxy SurveysDesiderata for New Galaxy SurveysDesiderata for New Galaxy Surveys

Photometry• Large area• Consistent, accurate

calibration• Galactic extinction

Spectroscopy• Large depth• Complete sampling• Careful target selection

• Multi-wavelength• Surface-brightness

• Resolve features• Wavelength range

Observational Systematics Measured Galaxy Properties


A Survey of SurveysA Survey of SurveysA Survey of SurveysA Survey of Surveys

Colless (1999)Vogeley (1999)


Volume and Number SurveyedVolume and Number SurveyedVolume and Number SurveyedVolume and Number Surveyed

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

1.00E+08

1.00E+09

1.00E+04 1.00E+05 1.00E+06 1.00E+07 1.00E+08 1.00E+09 1.00E+10 1.00E+11

Volume in Mpc 3

No

of

ob

jec

ts

LCRS

SDSSmain

SDSSred

SDSSabs line

SDSSphoto-z

2dFRCfA+SSRS

SAPMQDOT

2dF

1.00E+03

1.00E+04

1.00E+05

1.00E+06

1.00E+07

1.00E+08

1.00E+09

1.00E+04 1.00E+05 1.00E+06 1.00E+07 1.00E+08 1.00E+09 1.00E+10 1.00E+11

Volume in Mpc 3

No

of

ob

jec

ts

LCRS

SDSSmain

SDSSred

SDSSabs line

SDSSphoto-z

2dFRCfA+SSRS

SAPMQDOT

2dF


www.sdss.orgwww.sdss.org


Unique 2.5m telescope, located at Apache Point, NM3 degree diameter field of view

Two surveys in one:Photometric survey in 5 bandsSpectroscopic redshift survey

CCD Mosaic Camera30 CCDs 2K x 2K (imaging)22 CCDs 2K x 400 (astrometry)

Two double spectrographs2 x 320 fibers (3 arcsec diameter)resolution / =2000Spectral coverage from 3900Å to 9200Å

Automated data reductionOver 70 man-years of development effort (Fermilab + collaboration scientists)

Very high data volume40 TB of raw dataAbout 1 TB of catalog dataData made available to the public

Features of the SDSSFeatures of the SDSSFeatures of the SDSSFeatures of the SDSS


Northern Galactic Cap

drift-scan imaging of 10,000 square degrees5 broad-band filterspixel size is 0.4 arcsec > 800 billion pixels x 5 filters20 TB raw imaging data pipeline

100,000,000 galaxies50,000,000 stars

Southern Galactic Capmultiple scans (> 30 times) of one stripeanother 20 TB of raw imaging data

detect fainter, variable, and moving objects

Continuous data rate of 8 Mbytes/sec

SDSS: The Photometric SurveySDSS: The Photometric SurveySDSS: The Photometric SurveySDSS: The Photometric Survey


The First Stripes: 600 sq.deg. done, 9400 to go!The First Stripes: 600 sq.deg. done, 9400 to go!The First Stripes: 600 sq.deg. done, 9400 to go!The First Stripes: 600 sq.deg. done, 9400 to go!

Camera: 5 color imaging of 600 square degrees Multiple scans across the same fields Photometric limits as expected PSF variations taken out in software

Camera: 5 color imaging of 600 square degrees Multiple scans across the same fields Photometric limits as expected PSF variations taken out in software


Spectroscopic targets: 1 million galaxies (main + BRG)

100,000 quasars100,000 starsselected objects from other catalogs

Two high-throughput spectrographsspectral range 3900-9200 Å640 spectra simultaneouslyresolution / =2000

Automated reduction of spectraredshiftspectral featuresclassification

SDSS: The Spectroscopic SurveySDSS: The Spectroscopic SurveySDSS: The Spectroscopic SurveySDSS: The Spectroscopic Survey

The result: A redshift map to z=0.2 and beyondThe result: A redshift map to z=0.2 and beyond


Status Report on SDSS SpectroscopyStatus Report on SDSS SpectroscopyStatus Report on SDSS SpectroscopyStatus Report on SDSS Spectroscopy

r’=18 galaxyz=0.19

12 plug-plate fields

Both spectrographs fully operational>7,000 test spectra at survey spec.

Measured throughput: 15%, 20%Redshift completeness: 98%


Discovery of the Highest-Redshift QuasarsDiscovery of the Highest-Redshift QuasarsDiscovery of the Highest-Redshift QuasarsDiscovery of the Highest-Redshift Quasars

Eight of the ten highest redshift Eight of the ten highest redshift quasars have been found in the quasars have been found in the

first SDSS test data first SDSS test data

Eight of the ten highest redshift Eight of the ten highest redshift quasars have been found in the quasars have been found in the

first SDSS test data first SDSS test data


Finding Rare ObjectsFinding Rare ObjectsFinding Rare ObjectsFinding Rare Objects

The SDSS analysis pipeline automatically discovers candidate objects for spectroscopic followup

The SDSS analysis pipeline automatically discovers candidate objects for spectroscopic followup

Distant QSO’s are outliers in color-color space

Distant QSO’s are outliers in color-color space


SDSS Commissioning-Data ScienceSDSS Commissioning-Data ScienceSDSS Commissioning-Data ScienceSDSS Commissioning-Data Science

High-z quasarsMethane, L dwarfsStructure of Galactic halo with RR LyraeGalaxy-galaxy weak lensing

Magnification bias from lensingClusters of galaxies, X-ray sourcesCompact groups of galaxies and correlationsAngular correlations of galaxiesIR, FIRST sourcesQuasar-galaxy cross-correlationsCarbon starsQSO absorption line systems

Fischer et al. (1999)

Galaxy-galaxy lensing detected in 1/44 of SDSS


SDSS 2.5m Observation ScheduleSDSS 2.5m Observation Schedule SDSS 2.5m Observation ScheduleSDSS 2.5m Observation Schedule

May 1998 - March 1999First light imaging - equatorial onlyCamera and software commissioning

April 1999Telescope pointing modelGreat circle scan testsSpectrograph flexure tests

May 1999Spectrograph testingGreat circle driftscan imaging

June 1999First astronomical spectroscopy

Fall 1999Spectroscopic commissioningTarget selection tests

March 2000Survey proper begins


Outlook: A Golden Age for Structure FormationOutlook: A Golden Age for Structure Formation**Outlook: A Golden Age for Structure FormationOutlook: A Golden Age for Structure Formation**

* “You fool, there were no good old days. You’ve simply romanticizedthe agony of freezing all night in the prime-focus cage.” - F. Zwicky (perhaps)

Independent probes of structure out to 1Gpc High-resolution power spectra Sampling the same wavelength scales at z=0, 1000

Multi-variate distribution of galaxies Photometric, spectroscopic properties Evolution of populations Segregation and “biasing”

Multi-wavelength data bases Integration of X-ray, UV, Optical, IR, Radio surveys On-line digital data access Data mining methods

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ONE MILLION GALAXIES