SDSS-III Science

Myungshin Im (SNU)

Scientific Themes

• Dark energy and cosmological parameters (BOSS)

• The structure, dynamics, and chemical evolution of the Milky Way (SEGUE-2, APOGEE)

• The architecture of planetary systems (MARVELS)

SDSS-III Projects (2008-2014)

• BOSS (Baryon Oscillation Spectroscopic Survey)

• SEGUE-II (Sloan Extension for Galactic Understanding and Exploration)

• APOGEE (The APO Galactic Evolution Experiment)

• MARVELS (Multi-object APO Radial Velocity Exoplanet Large-area Survey)

BOSS – Dark Energy and the Geometry of Space

• Precision cosmology with baryon acoustic oscillation. • Measure the eq. of state parameters (w=P/rho) at high a

ccuracy (+-0.08), using..,• 1.5 million luminous red galaxies (LRGs) out to z ~ 0.7 (I

< 20 AB mag; vs 18.5 current) over 10,000 sq. degree.• Lyman-alpha forest spectra of 160,000 QSOs at 2.2 < z

< 4.• 1,000-fiber spectrograph (7 deg2,resolution R ~ 2000, im

proved CCD efficiency (vs 640 fibers)• Wavelength: 360-1000 nm• Fall 2009 – Spring 2014

BOSS - Baryon Acoustic Oscillation• Imprint of the acoustic phenomena caused by the coupling of the photo

n and gas perturbations in the early-universe (< 0.4 Myr). • The physical scale is well-understood, thus can be used as a standard

ruler.• It shows up as an enhanced overdensity with a characteristic scale of

~ 150 Mpc.

(From D. Eisenstein) (www.sdss3.org)

BOSS – BAO constraints on cosmological parameters

• P=w ρ

BOSS Science Topics• Precision cosmology: Eq. of state parameter (and its z-evolution), test of general r

elativity, Hubble constant (1% accuracy).• Galaxy-galaxy lensing: LRG-mass cross correlation (dark matter halo profile,dark

matter auto-correlation function).• Large-scale structure: 7 x increase over SDSS-II (k < 0.2 Mpc-1).• Evolution of red, massive galaxies: stellar population, fundamental plane, dark

matter halo study, number density and luminosity function, environment – provides an important pivot point to study the higher redshift population

• Galaxy lensing by LRGs: mass profile of early-types (e.g., SLACS: Bolton et al. 2006).

• QSO survey: study of the fainter QSOs at the peak of QSO activity (z=2.5) such as LF, clustering, AGN feedback.

• High-z QSOs: High redshift QSO survey (z = 3.6 – 6.0 QSOs, x2).

z=0.245

z=0.08

2.2”

New grav. Lens (Im et al. 2008, in prep.)E/S0s at z < 1(Im et al. 2002)

SEGUE-2• Imaging + Spectroscopic survey of galactic structures.• 250,000 stars to g=19 mag.• Measure abundances and metallicity of stars (0.3 dex in [Fe/H]), and radial

velocity (4 km/sec).• Discover merger remnants and explore the history of the Galactic evolution.• Also, study the galactic structure in conjunction with APOGEE and MARVLES.

SEGUE-2 • 1. Dark time during fall 2008 – spring 2009• 250,000 stars to g=19 mag• R-2000, S/N=25 spectra• Velocity error 4 km/sec, [Fe/H] error 0.3 dex.• 2. Bright time parallel program, 2010-2014, additional 100,000 stars to g=17 mag.• Mainly at b > 20 or < -20.

SEGUE Science Topics

• Galactic Stellar Populations: explore the physical connection among objects in the galactic structure (for disks, bulges, use APOGEE).

• Hierarchical Formation of the Galaxy: search of the residue of the merger process via velocity substructure and chemical finger printing determine the contribution of accretion history in the inner galaxy.

• Population III: discovery of Pop-III stars and study of the nucleosynthetic products of Pop-III stars.

• Halo Substructure: identification of halo substructures such as Monoceros ring (Newberg et al. 2002) mass of the disrupted parent satellite and limits on dynamical heating of streams in the dark halo.

• Chemo-dynamics of Halos: mapping of the velocity fields and abundance distribution of stars over large area (+ age) help understand the formation of the galactic halo.

• Legacy Survey of Star Clusters: large, systematic spectroscopic exploration globular and open clusters.

APOGEE• Systematic survey of > 105 (giant) stars in the Galactic disk and bulg

e (high extinction).• 1.52 – 1.69 micron (H-band), H < 13.5 mag (2MASS-selected), vel_

err ~ 0.5 km/sec at S/N ~ 100 and R ~ 20,000 (vs. S/N ~ 25, R ~ 2,000 of SEGUE).

• Measure abundances of > 15 elements, and precise radial velocities.

APOGEE – Galactic Chemodynamics• Bright time observations, spring 2011 – 2014• Understand the chemical enrichment process as a function of time and loca

tion out to 75 kpc.• 1.52 – 1.69 micron (H-band) – OH, CN, CO (C, N, O from Type-II SN); alpha-

elements (O, Mg, Si, S, Ca, Ti) from Massive stars (IMF constraint), iron peak elements (Cr, V, Mn, Fe, Co, Ni) from Type-Ia SNe; odd-Z elements (Na, K, and Al) from SN II.

• Precise radial velocity measurement (0.5 km/sec) dynamics of the galactic disk/bulge (e.g., rotation curve of the outer disk with spectroscopic parallax), isolation of dynamically distinct population of star clumps (merger remnants + chemical fingerprinting)

Keck H-band spectra of two globular cluster giants (Origlia et al. 2005) APOGEE will give 0.1 dex accuracy in [X/Fe]

[Fe/H]=-0.60 [Fe/H]=-0.17

APOGEE Science Topics

• Galactic Stellar Populations: explore the physical connection between the bulge, thin disk, thick disk, and halo populations through chemical, dynamical information.

• Hierarchical Formation of the Inner Galaxy: search of the residue of the merger process via velocity substructure and chemical finger printing determine the contribution of accretion history in the inner galaxy.

• Population III: discovery of Pop-III stars and study of the nucleosynthetic products of Pop-III stars.

• Halo Substructure: identification of halo substructures such as Monoceros ring (Newberg et al. 2002) at low-b mass of the disrupted parent satellite and limits on dynamical heating of streams in the dark halo.

• Galactic Dynamics: determine large scale dynamics of the Milky Way with spectroscopic parallaxes and the radial velocity measurements rotation curve to the outermost reaches of the disk (MW follows TF-relation? Flynn et al. 2006).

• The Galactic Bulge: mapping of the velocity fields and abundance distribution of bulge stars over large area (+ age) help understand the formation of the galactic bulge.

• The Galactic Bar: provides insight on the little known dynamics and chemistry of the galactic bar.

• Legacy Survey of Low-Latitude Star Clusters: largest systematic spectroscopic exploration of low-b globular and open clusters.

• Star Formation: constrain the shape of the IMF (α and odd-Z elements). • Interstellar Extinction: map the 3-D distribution of Galactic dust and constrain variation

s in the interstellar extinction law (with other wavelength data).

MARVLES• Massive search of short-to-intermediate period giant

planets around a large, well-characterized stars.• Radial velocity monitoring of 10,000 MS stars and 1,000

giants.• Test theoretical models of the formation, migration,

dynamical evolution of giant planet systems.

MARVELS• Bright time observations, fall 2008 – spring 2014• Two 60-fiber interferometric spectrographs (DFDI, dispersed fixed-delay interf

erometer: proto-type used at KPNO 0.9m/2.1m, and also at Keck).• 10,000 main sequence stars, 1,000 giant stars, V = 8 – 12 mag.• 25-35 observations per star over 18 months• Velocity error: 12 m/sec at V=10 mag• Mass sensitivity at P=100 days: 0.35 M_jup (V=9.5), 0.7 M_Jup (V=11.5).• ~ 150 short-to-intermediate M > 0.2 M_jup stars (P < 1000 days)

(From Ge, 2002)

MARVEL Science• Test of the models of planet formation, migration, and dynamical evolution:

physics of planet migration through compilation of large number of M > M_Jup planets.

• Planets with large eccentricities: eccentricities/period data will constrain leading models.

• Multiple planet systems: MARVLE planets can be monitored for detecting longer period, lower mass companions.

• Host star properties: the correlation of planetary systems with metallicity, mass, age etc can be explored (e.g., Ida & Lin 2004; Santos et al. 2004).

• Planet transit study: ~ 10 transit system with follow-up obs. Unbiased sample.

• Rare classes of planetary systems: hot Juipters, rapidly interacting multiple planet systems, very-hot Jupiters, planets with extremely high exccentricities.

• Brown dwarf desert: Apparent paucity of 15 – 80 Mjup companions can be studied.

Organization

Data Release Plan

• Similar to the previous SDSSs

SDSS-III for Korean Astronmers

• Many things to do from cosmology, extragalactic astronomy, galactic astronomy (near-field cosmology), and exo-planet study.

• We need to explore science topics and make the maximal use of this extraordinary dataset.