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The Apache Point Observatory Galactic Evolution Experiment (APOGEE). Ricardo Schiavon 1 (for the team). 1 Gemini Observatory. Construction and Evolution of the Galaxy Princeton, Feb 27, 2009. SDSS-III. http://www.sdss3.org.
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The Apache Point Observatory Galactic Evolution Experiment(APOGEE) Ricardo Schiavon1 (for the team) 1 Gemini Observatory Construction and Evolution of the Galaxy Princeton, Feb 27, 2009
SDSS-III http://www.sdss3.org APOGEE: an infrared, high resolution spectroscopic survey of the stellar populations of the Galaxy BOSS: will measure the cosmic distance scale via clustering in the large-scale galaxy distribution and the Lyman-α forest SEGUE-2: will map the structure, kinematics, and chemical evolution of the outer Milky Way disk and halo MARVELS: will probe the population of giant planets via radial velocity monitoring of 11,000 stars
APOGEE People • APOGEE LeadershipS. Majewski (PI, UVa) • M. Skrutskie (Instrument Scientist, UVa) • J. Wilson (Deputy Instrument Scientist, UVa) • R. Schiavon (Survey Scientist, Gemini Observatory) • C. Allende-Prieto (Abundances and Stellar Parameters Task Leader, Mullard) • M. Shetrone (Spectral Reduction Task Leader, HET) • J. Johnson (Field/Target Selection Task Leader, Ohio State) • P. Frinchaboy (Field/Calibration Task Leader, U.Wisc., NSF Fellow) • D. Bizyaev (Radial Velocities Task Leader, APO) • I. Ivans (Princeton), J. Holtzman (NMSU) • Significant Contributors to DateK. Cunha, V. Smith (NOAO),R. O’Connell (Uva), Neil Reid (STScI), • R. Barkhouser, S. Smee (JHU), J. Gunn (Princeton), T. Beers (Michigan State) • C. Henderson, B. Blank (Pulseray Machine & Design), D. Spergel (Princeton) • G. Fitzgerald, T. Stolberg (NEOS), T. O’Brien (OSU), E. Young (UofA) • J. Crane (OCIW), S. Brunner, J. Leisenring (Uva)
APOGEE Context: it seems like we live in a -CDM Universe => Does the Milky Way fit in that picture?
APOGEE at a glance • Bright time 2011 to 2014 • 300 fiber, R ~ 24,000, cryogenic spectrograph • H-band: 1.51-1.68 • Typical S/N = 100/pixel @ H=12.5 for 3-hr integration • Typical RV uncertainty < 0.5 km/s • 0.1 dex precision abundances for ~15 chemical elements • 105 2MASS-selected giant stars probing all Galactic populations
Advantages of a High Res. H-band Survey • Red giants/red clump are bright in NIR. • Complete point source sky catalogue to H > 14 available from 2MASS, augmented by GLIMPSE and • UKIDSS where available. • No need for new photometry!
Advantages of a High Res. H-band Survey AV = 1 boundary • AH / AV = 0.17 2 flux for AV =1; 100 flux for AH =1 • Access to dust-obscured galaxy • Precise velocities and abundances for giant stars across the Galactic plane, bar, bulge, halo => HOMOGENEITY • Low atmospheric extinction makes bulge accessible from North • Avoids thermal background problems of longer l
APOGEE Depth Solar metallicity RGB tip star: int (hr) HlimAVd(kpc) 3 12.5 5 27 10 13.4 10 27 [Fe/H]= -1.5 RGB tip star: int (hr) Hlim AVd(kpc) 3 12.5 0 40 10 13.4 0 60
APOGEE in Context Deeper at high Av than everybody else Gal.Cen. AV 5 10
APOGEE Spectrograph The APOGEE Dewar will be housed in the basement of the support building about 40 meters from the base of the telescope. The red line approximates the main fiber run. A plug on the cartridge end will insert into a fiber coupling receptacle on the cartridge. Slit head is cryogenic and permanently housed in the instrument. 2.5-meter cartridge coupler APOGEE SDSS-III Sloan Review - APOGEE
Refractive Camera VPH Fold (2) Teledyne H2RG Detectors Slit-head (300 fibers) Spherical Collimator (Zerodur) Vibration Isolators 75” dia Dewar LN2 Tanks 394 mm Blanche et al 2004 Refractive Camera (Si & Fused Silica) VPH mosaic grating (265 x 450 mm illuminated) 300 fiber pseudo-slit embedded in fold mirror Three HAWAII-2RG arrays (NIRCam-style detector mount) 1.7 m Fiber feedthroughs 2.1 m LN2 cooled Dewar Collimator
Science Goals • A3-D chemical abundance distribution(many elements), MDFs across Galactic disk, bar, bulge, halo. • Probecorrelations between chemistry and kinematics(note Gaia proper motions eventually as well). • ConstrainSFR and IMFof bulge/disk as function of radius, metallicity/age, chemical evolution of inner Galaxy. • Determine nature ofGalactic bar and spiral armsand their influence on abundances/kinematics of disk/bulge stars. • Measure Galacticrotation curve(include spec. p., Gaia pm) • Search for and probe chemistry/kinematics of (low-latitude) halo substructure(e.g., Monoceros Ring). • Combine with existing/expected optical, NIR and MIR data andmap Galactic dust distributionusing spec. p’s, constrain variations in extinction law • Find Pop III stars
Science Goals • A3-D chemical abundance distribution(many elements), MDFs across Galactic disk, bar, bulge, halo. • Probecorrelations between chemistry and kinematics(note Gaia proper motions eventually as well). • ConstrainSFR and IMFof bulge/disk as function of radius, metallicity/age, chemical evolution of inner Galaxy. • Determine nature ofGalactic bar and spiral armsand their influence on abundances/kinematics of disk/bulge stars. • Measure Galacticrotation curve(include spec. p., Gaia pm) • Search for and probe chemistry/kinematics of (low-latitude) halo substructure(e.g., Monoceros Ring). • Combine with existing/expected optical, NIR and MIR data andmap Galactic dust distributionusing spec. p’s, constrain variations in extinction law • Find Pop III stars?
Top Level Science Requirements Reliable statistics:(level of solar neighborhood) in many (R, q, Z) zones • APOGEE seeks to construct similar figures for many elements and for many other discrete Galactic zones. • e.g., GCE models predict variations in these distributions and in radial [X/H] gradients differing at few 0.01 dex level per radial bin • for gradients requires: ~0.01 dex in <[X/H]> or >100 stars with 0.1 dex per radial bin • for [X/H]-[Fe/H] distributions requires (100 stars)(~20 [Fe/H] bins)(dozens of zones) 105 stars Venn et al. (2004) 781 compiled stars
Orders of Magnitude • order of magnitude leaps: • ~1-2 orders more high S/N, high R spectra ever taken • ~3 orders larger than any other high R GCE survey • ~3 orders more high S/N, high R near-IR spectra than ever taken • First week of observations will exceed all previous work!
High-Res. Abundances in H-band • Numerous lines of molecular CN, OH, CO to give LTE-based CNO abundances (most abundant metals in universe) • Plenty of clean lines of Fe, a-elements (O, Mg, Si, S, Ca, Ti, Cr), Fe peak (V, Mn, Ni), and some odd-Z (e.g., Na, K, Al) Simulated APOGEE spectra
Simple Ideas • APOGEE will make possible straightforward tests of Galaxy formation scenarios by verifying how relevant quantities vary with time.
Simple Ideas • Dias et al. (2003) catalogue of open clusters
Simple Ideas Various elemental abundances in open clusters Yong et al. 2005 Age RGC
Simple Ideas • APOGEE targets will be seen at large distances even at very large extinction • 1% of APOGEE sample, ~5 stars/cluster, ~200 clusters!
Galactic Bulge • We know: star formation in the center, old stars (e.g. Baade window), presence of a bar, high metallicity (Rich 88), probably an abundance gradient (Zoccali et al. 2007), mostly alpha-enhanced (Fullbright et al.). • Which fraction of the bulge stellar mass was formed in situ, which fraction from mergers, which fraction from secular evolution driven by bar instabilities (e.g., Norman et al. 1996)?
Galactic Bulge • Kobayashi (2004): CDM-based 124 SPH simulations of elliptical galaxies, including radiative cooling, star formation, SN and wind feedback, chemical enrichment • Solid symbols are monolithic collapse, open symbols are systems with a lot of previous merging • The more merging, the shallower the abundance gradients
Spectrum Synthesis Arcturus Synthesis Ti Mg Mg Mg Allende Prieto
Anticipated Deliverables • -calibrated, sky-subtracted, telluric absorption-corrected, 1-D spectra • RVs to ~0.5 km/s external accuracy • log(g), [Fe/H], Teff (making use of 2MASS colors) • elemental abundances to within 0.1 dex accuracy for 15 elements, including CNO, other , Fe-peak, Al, K)
Signed MOUs. Univ. of Arizona Cambridge Univ. Case Western Univ. Univ. of Florida German Participation Group (AIP, MPE, MPIA, ZAH) Johns Hopkins Univ. Korean Institute for Advanced Study Max Planck Astroph., Garching New Mexico St. Univ. New York Univ. Ohio State Univ. Univ. of Pittsburgh Univ. of Portsmouth Princeton Univ. UC Santa Cruz Univ. of Utah Univ. of Washington Vanderbilt Univ. Virginia MSU/ND/JINA Brazilian PG (ON and four Univ.) Near-term possibilities: Fermilab French PG (APC, IAP, CEA,…) UC Irvine LBNL Penn State Univ. Spanish PG (three CSIC units) Univ. of Tokyo/IPMU Other institutions and individuals are in discussions. Institutional Members
What We Want to Talk to You About • Theorists: we need you to produce models for us to rule out. • All: the survey is being defined. If I were you, I would get involved now. Bring your ideas. Let’s discuss.