The Apache Point Observatory Galactic Evolution Experiment APOGEE

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

http: //www. sdss 3. org SDSS-III 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 Leadership S. 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 Date K. Cunha, V. Smith (NOAO), R. O’Connell (Uva), Neil Reid (STSc. I), 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 (Uof. A) 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 2 MASS-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 2 MASS, 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

APOGEE Depth Solar metallicity RGB tip star: int (hr) Hlim AV 3 12. 5 5 10 13. 4 10 d(kpc) 27 27 [Fe/H]= -1. 5 RGB tip star: int (hr) Hlim AV 3 12. 5 0 10 13. 4 0 d(kpc) 40 60

APOGEE in Context Gal. Cen. Deeper at high Av than everybody else AV 10 5

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 (Si & Fused Silica) 394 mm VPH mosaic grating Blanche et al 2004 (265 x 450 mm illuminated) 300 Fold fiber pseudo-slit embedded in fold mirror (2) Teledyne Three HAWAII- H 2 RG arrays Detectors (NIRCam-style detector Slit-head (300 fibers) mount) Spherical Collimator (Zerodur) 1. 7 m Fiber feedthroughs Vibration Isolators 2. 1 m Collimator 75” dia Dewar LN 2 cooled Dewar Tanks

Science Goals • A 3 -D chemical abundance distribution (many elements), MDFs across Galactic disk, bar, bulge, halo. • Probe correlations between chemistry and kinematics (note Gaia proper motions eventually as well). • Constrain SFR and IMF of bulge/disk as function of radius, metallicity/age, chemical evolution of inner Galaxy. • Determine nature of Galactic bar and spiral arms and their influence on abundances/kinematics of disk/bulge stars. • Measure Galactic rotation 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 and map Galactic dust distribution using spec. p’s, constrain variations in extinction law • Find Pop III stars

Science Goals • A 3 -D chemical abundance distribution (many elements), MDFs across Galactic disk, bar, bulge, halo. • Probe correlations between chemistry and kinematics (note Gaia proper motions eventually as well). • Constrain SFR and IMF of bulge/disk as function of radius, metallicity/age, chemical evolution of inner Galaxy. • Determine nature of Galactic bar and spiral arms and their influence on abundances/kinematics of disk/bulge stars. • Measure Galactic rotation 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 and map Galactic dust distribution using 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, -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

Yong et al. 2005 Various elemental abundances in open clusters Simple Ideas 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 Ti Synthesis 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 2 MASS colors) • elemental abundances to within 0. 1 dex accuracy for 15 elements, including CNO, other , Fe-peak, Al, K)

SDSS-III High-level Schedule 25

Institutional Members • Signed MOUs. – – – – – – Princeton Univ. UC Santa Cruz Univ. of Utah Univ. of Washington Vanderbilt Univ. Virginia MSU/ND/JINA Brazilian PG (ON and four Univ. ) Univ. of Arizona Cambridge Univ. Case Western Univ. of Florida German Participation Group (AIP, MPE, MPIA, ZAH) Johns Hopkins Univ. • Near-term possibilities: – Fermilab Korean Institute for Advanced Study – French PG (APC, IAP, CEA, …) – UC Irvine Max Planck Astroph. , Garching – LBNL – Penn State Univ. New Mexico St. Univ. – Spanish PG (three CSIC units) New York Univ. – Univ. of Tokyo/IPMU Ohio State Univ. • Other institutions and individuals Univ. of Pittsburgh are in discussions. Univ. of Portsmouth

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.