the apache point observatory galactic evolution experiment (apogee)
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
The Apache Point Observatory Galactic
Evolution Experiment
(APOGEE)
Ricardo Schiavon1 (for the team) 1 Gemini Observatory
Construction and Evolution of the GalaxyPrinceton, Feb 27, 2009
SDSS-IIIAPOGEE: 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
http://www.sdss3.org
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 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 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
• Red giants/red clump are bright in NIR.• Complete point source sky catalogue to H > 14 available
from 2MASS, augmented by GLIMPSE andUKIDSS where available.
No need for new photometry!
Advantages of a High Res. H-band Survey
• 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
AV = 1 boundary
Advantages of a High Res. H-band Survey
APOGEE DepthSolar metallicity RGB tip star:
int (hr) Hlim AV d(kpc) 3 12.5 5 27 10 13.4 10 27
[Fe/H]= -1.5 RGB tip star:
int (hr) Hlim AV d(kpc) 3 12.5 0 40 10 13.4 0 60
SDSS-III Sloan Review - APOGEE
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.
APOGEE
2.5-meter
coupler
cartridge
75” dia Dewar
Spherical Collimator (Zerodur)
Slit-head (300 fibers)
Fold
VPHRefractive Camera
(2) Teledyne H2RG Detectors
LN2 Tanks
Vibration Isolators
300 fiber pseudo-slit embedded in fold mirror
Collimator
VPH mosaic grating (265 x 450 mm illuminated)
Three HAWAII-2RG arrays(NIRCam-style detector mount)
Fiber feedthroughs
Refractive Camera (Si & Fused Silica)
394 mm
Blanche et al 2004
1.7 m
2.1 m
LN2 cooled Dewar
• A 3-D chemical abundance distribution (many elements), MDFs across Galactic disk, bar, bulge, halo.
• Probe correlations between chemistry and kinematics (noteGaia 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 theirinfluence 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 (noteGaia 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 theirinfluence 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
Reliable statistics: (level of solar neighborhood) in many (R, , 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 starsVenn et al. (2004) 781 compiled stars
Top Level Science Requirements
• 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!
Orders of Magnitude
Simulated APOGEE spectra
• 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)
High-Res. Abundances in H-band
• APOGEE will make possible straightforward tests of Galaxy formation scenarios by verifying how relevant quantities vary with time.
Simple Ideas
• APOGEE targets will be seen at large distances even at very large extinction
• 1% of APOGEE sample, ~5 stars/cluster, ~200 clusters!
Simple Ideas
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
• -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)
Anticipated Deliverables
Institutional Members• 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.