Transcript APOGEE (The APO Galactic Evolution Experiment)

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
http://www.sdss3.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 (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) 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
Refractive Camera (Si & Fused Silica)
394 mm
VPH
VPH mosaic grating
Blanche et al 2004
(265 x 450 mm illuminated)
300Fold
fiber pseudo-slit
embedded in fold mirror
(2) Teledyne
Three HAWAII- H2RG
2RG arrays
Detectors
(NIRCam-style detector
Slit-head
(300
fibers)
mount)
Spherical
Collimator
(Zerodur)
1.7 m
Fiber feedthroughs
Vibration Isolators
75” dia Dewar
2.1 m
Collimator
LN2 cooled
LN2 Tanks
Dewar
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, 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
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
• l-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 a, Fe-peak, Al, K)
SDSS-III High-level Schedule
25
Institutional Members
• Signed MOUs.
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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.
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.