SEGUE Target Selection on-going SEGUE observations

SDSS/SEGUE status as of Nov. 10, 2004 Black= completed stripe or plate pair 1002/3900 sq deg imaging: 25% complete, 34/400 plates 8.5% complete.

SEGUE Imaging Aug-Oct 2004: Aug N 38 sq deg 291 N 104 Sep N S S S N 62 Oct N N S sq deg + earlier scans: sq deg 25% of SEGUE goal Drillable imaging (filled Stripes N&S): 1100 N&S 200 sq N&S 175 sq. portions of: 72 N&S 200 sq N&S 40 sq. Stripes 1100&72 were scanned in Aug/Sep and targetted/drilled for Nov/Dec observing (6 week turnaround)

SEGUE imaging sample Color-Magnitude diagrams in 10 square degree boxes towards one direction on the sky...

Color-Magnitude (g-r,g) diagram for Strip 1260N Dual turnoffs, indicates stream(s?) at 10 and 20 kpc from the sun. Thick Disk Fs Halo or stream(s)? Thin disk M stars

SEGUE spectroscopic sample: Radial Velocities of populations of similar stars, Metalicity, Teff, log g determinations Kinematic, Chemical population studies of the Milky Way and halo

25 WD 150 A/BHB 200 F 375 G III +V 150 Low Metals 100 K III 100 K V 30 sdM (and L/T candidates) 10 AGB 10 Cool Wds SEGUE target selection currently has 11 categories, freshly reviewed, and aims to observe a total of 240,000 stars arount the sky. Samples of the stellar categories: Numbers indicate allocation of fibers by spectral type per plate pair.

SEGUE spectroscopy to date: Aug 2004: 8 Bright, 8 Faint Sep 2004: 7 Bright, 6 Faint Oct 2004: 3 Bright, 2 Faint B 16 F 34/400 Plates done = 8.5% of SEGUE goal 43.6 plate equivalents To date we have approx. 16,000 classified spectra, grouped in these categories (approximately): 1500 A/BHBs, 3000 F, 6000 G, 150 K giants, 1500 K dwarf, 300 WD, 800 M dwarf, 2500 Low Metal candidates (F-K), plus assorted QSOs and stars of unknown type.

White Dwarf

Cool White Dwarf Candidate

BHB Star, probe outer halo, streams to 150 kpc

F turnoff star, trace streams, halo, low [Fe/H] to 20kpc

G dwarf, largest SEGUE sample, probe disk/inner halo 1.5kpc to 8 kpc distances, Stream Giants also here

G dwarf Radial Velocity histograms, by Magnitude (dist) km/s

K Giants - probe halo to 200 kpc, total Mass of MW,

K dwarf, kinematics from match to USNO-B, +RV photometric parallax – probe disks from 0.5 – 2 kpc

Low metalicity candidate, [Fe/H] = -2.6, g=15.8, g-r=0.47 Pop III exploration, gradients in inner/outer halo Lower Metals than the lowest metalicity Globular cluster!

M dwarfs, M,L,T dwarf candidates, M sub-dwarf cands sample of halo M dwarfs vs. low-metal F's

AGB candidate, Giants in Sagittarius/Monoceros streams? g = 16.5,g-r =1.12, u-g = 3.1, RV= -72km/s d(AGB) = 18 kpc

K Giant: Narrower lines, features less deep. K dwarf Stronger features, broader lines. How to tell a (distant) K giant from a (nearby) K dwarf, using SDSS/SEGUE spectra.

Sun SEGUE K giant stars used to probe halo to d> 50 kpc Using the spectra to separate giants from dwarfs, one can explore halo structure with K giants.

To test ability to determine metalicity of stars from SDSS/SEGUE spectra, we obtain spectra of objects with known Metals [Fe/H] = -1.6 Target cluster stars separate well from field stars, with spread of 1 sigma = 0.25 dex [Fe/H] Radial Velocity g-r g

With atmospheric parameters determined for stars, one can go from observed 'color-magnitude' diagrams to... Physical Hertzsprung- Russell diagrams: Green: cluster giants Red: Field stars Yellow: Proper motion definite cluster matches Teff surface gravity g-r g

SEGUE is doing well with the grant of Fall season observing during the last full year of SDSS-I. This 2004 data is available to all SDSS participants for analysis and papers.