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SDSS-III Science

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).

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SDSS-III Science

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  1. SDSS-III Science Myungshin Im (SNU)

  2. 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)

  3. 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)

  4. 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 accuracy (+-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, improved CCD efficiency (vs 640 fibers) • Wavelength: 360-1000 nm • Fall 2009 – Spring 2014

  5. BOSS - Baryon Acoustic Oscillation • Imprint of the acoustic phenomena caused by the coupling of the photon 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. (www.sdss3.org) (From D. Eisenstein)

  6. BOSS – BAO constraints on cosmological parameters • P=w ρ

  7. z=0.08 2.2” z=0.245 BOSS Science Topics • Precision cosmology:Eq. of state parameter (and its z-evolution), test of general relativity, 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). E/S0s at z < 1 (Im et al. 2002) New grav. Lens (Im et al. 2008, in prep.)

  8. 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.

  9. 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.

  10. 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.

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

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

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

  14. 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.

  15. MARVELS • Bright time observations, fall 2008 – spring 2014 • Two 60-fiber interferometric spectrographs (DFDI, dispersed fixed-delay interferometer: 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)

  16. 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.

  17. Organization

  18. Data Release Plan • Similar to the previous SDSSs

  19. 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.

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