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SEGUE Target Selection on-going SEGUE observations DR3 Update

SEGUE Target Selection on-going SEGUE observations DR3 Update. SDSS Collaboration Meeting Sep 30, 2004 Pittsburgh. DR3 Update DR3 CAS+DAS is now public: 141 Million objects (Galaxies, QSOs,Stars) 480,000 unique spectra, ~5000 square degrees Something like 12,000+ SQL queries

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SEGUE Target Selection on-going SEGUE observations DR3 Update

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  1. SEGUE Target Selection on-going SEGUE observations DR3 Update SDSS Collaboration Meeting Sep 30, 2004 Pittsburgh

  2. DR3 Update DR3 CAS+DAS is now public: 141 Million objects (Galaxies, QSOs,Stars) 480,000 unique spectra, ~5000 square degrees Something like 12,000+ SQL queries attempted per day, worldwide to the CAS. Approx 18 Tbytes transferred from DAS+CAS (DR1+DR2). 2 help-desk queries/day. Lots of Papers appearing. Plunge in! Don't wait!! www.sdss.org/dr3

  3. Somebody's (not Hawking's) theorem says: 'Information' in Astrophysics is of a 'Fractal' nature. Cosmological and large scale structure studies are of great interest, but the objects are so far away, it's hard to get lots of detail. With the Galaxy, we can get lots of detail on each star. SEGUE part of SDSS-II hopes to do for Galactic Studies what SDSS-I has done for Large scale structure and galaxy/quasar work. Key project SEGUE science drivers: 1. Map Halo structure – trace streams such as the Sagittarius and Monoceros-- Canis Major streams around the Galaxy. Constrain Dark Matter potential/shape. 2. Disk(s) Structure – Study the thin/thick disk transition, and the transition to the halo/spheroid in number counts (model parameters scale lengths, falloffs w/ radius, metalicities, kinematics and formation history.

  4. SEGUE as of September 30, 2004 Black= completed stripe or plate pair 750/3900 sq deg imaging: 19% complete, 29/400 plates 7% complete.

  5. History of SEGUE observations (data thru Jun 2004 is under SDSS): June-July 2003: Stripe 1220 (175 square deg) Oct-Nov 2003: ~4 SEGUE test plates, RV test, super sky test June-July 2004: Refine SEGUE TS algorithm (v2_0), design layout of 3900 sq degrees and ~ 400 plates Strip 205N (Sag) ~80 sq deg Aug 2004: 17 SEGUE plates observed 35 sq deg Strip 1260 N Sep 2004: 12 SEGUE plates observed Strip 291N (cross) 50 sq deg Stripe 1100 N&S 200 sq deg Strip 1260 S 40 sq deg Stripe 72 N&S 100 sq deg Plan going forward: Oct 2004: Observe M15/M2 Globular Cluster Metalicity standard plates Oct 20, 2004: Refine SEGUE TS (v3_0), design plates for Nov, Dec

  6. '57' varieties of Science projects with SEGUE: 1. Shape/Orientation of the Dark Matter Halo 2-11. Structure of the Thick Disk (scale length), is it a puffed-up Thin Disk or an independent structure (big merger), some of each? 12. Estimate of the Mass of the Galaxy, within say r=100 kpc from center (Rvs of distant stars). 13-18. Merger history of the Galaxy 19-27. Chemical Evolution of the Galaxy.

  7. 28-35. GC's go down to [Fe/H]= -2.2 or so, BUT NO LOWER!! But, Field stars in the halo go down to [Fe/H] = -3, and even down to [Fe/H] = -4. Why is this? What does it mean? Is this Pop III? 36-38. Chemical gradients in the halo and disks? How strong are they? With precision photometry and spectroscopy we can measure this around the Galaxy. 39. Dark Matter Clumpiness affects stream orbits.

  8. 40-43. Proper motions (from USNO-2B) catalog add greatly to investigation of thin/thick disk kinematics,supplemented by Radial Vels and photometric parallaxes of G and K stars. Complete velocity ellipsoid information within 1kpc of sun is available. 44-49. Rare stellar type catalogs: White dwarfs Cool white dwarf candidates M sub-dwarfs (halo metalicies and kinematics) L,Tdwarf candidates at lower |b| than regular SDSS survey. AGB stream red giants

  9. 50-51. Trace the most distant BHBs and K giants, potentially out to several hundred kpc from Galactic center, if they are there. 52-54. Probe into the murk of very low |b| < 8 deg. 55-56. Star forming regions, open clusters, IMF studies. Extinction and reddening model refinements. 57. First year of SEGUE will not worry about the (difficult to process and interpret) very low latitude data, out years will take up the challenge. [Come to the meeting if you are interested in this].

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

  11. SEGUE as of September 30, 2004 Black= completed stripe or plate pair

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

  13. 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

  14. WD A/BHB F Turnoff G III +V Low Metals K III K V M V AGB Cool Wds Spectroscopic targets selected to probe variety of distances from the sun from < 1 kpc to > 100 kpc, basically through a 'standard candle' color cut to select stars representative of each distance.

  15. WD A/BHB F Turnoff G III +V Low Metals K III K V M V AGB Cool Wds SEGUE currently has 10 categories and aims to observe a total of 240,000 stars arount the sky. Samples of the stellar categories:

  16. White Dwarf

  17. Cool White Dwarf Candidate

  18. BHB Star, probe outer halo, streams to 150 kpc

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

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

  21. -250 -200 -150 -100 -50 0 50 km/s G dwarf Radial Velocity histograms, by Magnitude (dist)

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

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

  24. Low metalicity candidate, [Fe/H] = -2.6, g=15.8, g-r=0.47 Pop III exploration, gradients in inner/outer halo

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

  26. 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

  27. 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.

  28. We are 'new' to the rich field of stellar kinematic and population analysis, with implications for dark matter and galaxy history studies on the Galaxy easiest to observe. We need your help! [Meeting Oct 2] There are many opportunities to contribute, including student projects.

  29. -44 -41 -38 -35 -32 -29 -26 -23 -20 -17 -14 -11 Strip 1100S (l=50 deg) CMDs (g-r,g)

  30. K Giant: Narrower lines, features less deep. K dwarf Stronger features, broader lines.

  31. 1100S Binned 6x3deg Photo in crowded fields as we pass thru |b| = 0 plane, will be improved in SEGUE outyears. -43 -37 -31 -25 l =50 deg at 4 b's. Possible stream present, but need to model spheroid.

  32. SEGUE footprint as of Sep 30, 2004 Black= completed stripe/plate 29/400 plates 7% done.

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