one million galaxies
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ONE MILLION GALAXIES. Cosmography and Cosmology. Michael S. Vogeley Department of Physics Drexel University. Quantitative Large-Scale Structure: Lick Survey. 1 million galaxies! Lick observatory plates Counts by eye (Shane-Wirtanen), map by Seldner et al. 1977 - PowerPoint PPT PresentationTRANSCRIPT
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)
Michael S. Vogeley, Drexel University
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)
Michael S. Vogeley, Drexel University
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)
Michael S. Vogeley, Drexel University
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)
Michael S. Vogeley, Drexel University
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)
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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)
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
A Survey of SurveysA Survey of SurveysA Survey of SurveysA Survey of Surveys
Colless (1999)Vogeley (1999)
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
www.sdss.orgwww.sdss.org
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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%
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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
Michael S. Vogeley, Drexel University
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