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SEGUE Meeting AM Talks towards a task list: pipeline changes/updates Target Selection updates

SEGUE Meeting AM Talks towards a task list: pipeline changes/updates Target Selection updates. SDSS Collaboration Meeting Oct 2, 2004 Pittsburgh. Over-arching Question: Can the SEGUE imaging and spectroscopy meet the basic

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SEGUE Meeting AM Talks towards a task list: pipeline changes/updates Target Selection updates

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  1. SEGUE Meeting AM Talks towards a task list: pipeline changes/updates Target Selection updates SDSS Collaboration Meeting Oct 2, 2004 Pittsburgh

  2. Over-arching Question: Can the SEGUE imaging and spectroscopy meet the basic science goals, as laid out in the SEGUE white paper and various SEGUE proposals? Reminder: 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.

  3. Fibers per plate Pair: WD 25 CWD 10 BHB 125 F TO 150 G 375 K III 125 Low Fe150 K V 125 Ms 50 AGB 10 SKY 96 QA 15 RED/SP 16

  4. Saturday Oct 2, 2004 AM (Room: Allen 318) 9:00 Intro 9:10 J. Bochanski SDSSWhite Dwarf/M-Dwarf pairs, red Star update 9:30 J. A. Smith Photometry Update, WD/MD stars 9:45 C. Rockosi Radial Velocities for SEGUE 10:15-10:45 Break 10:45 C. Allende-P. Metalicity, Gravity determination 11:15 R. Wilhelm Metalicity, Gravity determination – hot stars 11:45 T. Beers Atmospheric Parameter determination in stars 12:30-1:30 Lunch 1:30-3:30 Open discussion spectroscopic pipeline, SEGUE science 4:00-5:30 SEGUE target selection category by category

  5. Observing strategy: Imaging: 3900 sq deg, mostly at low |b| Spectra: 240,000 stellar spectra (520 plate-equivalents) of stars of a range of colors.

  6. -44 -41 -38 -35 -32 -29 -26 -23 -20 -17 -14 -11 Strip 1100S (l=50 deg) CMDs (g-r,g)

  7. SEGUE Level 0 Deliverables: Medium latitude frames (|b| > 10 deg) processed through PHOTO, initial calibration with PT patches to roughly SDSS-I accuracy (i.e. g-r errors of 2%). Flat file format ok (tsObj catalogs). [turn around in time for Target Selection: one month or one year time scales, can use SDSS-I imaging] Target Selection Pipeline for SEGUE TS, with documentation, including usual TS items: skies, guide stars, redden standards, plPlugMapT input files. Spectro plates processed through existing SDSS-I 2D+1D pipelines with improved Radial Velocities from ELODIE template fits (or equivalent) for all stars with S/N>~5. First-pass estimation of stellar atmos params: Teff, [Fe/H], log g for stars with g < ~18.5. 'Value added Catalog' format. Matches to existing Proper motion data when available. Design, observation, processing of 'calibration/standard' plates with stars of known [Fe/H], RV, log g, etc.

  8. Enhanced Goals: Imaging processing: Ability to process imaging in regions of high stellar density (|b| < 10 deg), producing accurate catalogs stellar magnitudes and positions in these regions. Calibration: Use crossing scans or other techniques to improve photometry from ~2% RMS to ~1% with fewer outliers. Spectroscopy: Incorporate parameter (i.e. [Fe/H]) estimation into pipeline processing. Database: Insert Imaging catalogs and spectra w/ all parameters (i.e. PPM matches, Rvs), into indexed database (i.e. CAS-style) in addition to DAS style flat field access.

  9. To Do List: Great interest has been expressed by current and new partners in SEGUE and the other SDSS-II science projects. Note that we are currently effort limited, and need to organize a team to handle development and operations as well as science analysis aspects of SEGUE, and we hope and expect to draw resources from many of you.

  10. Development tasks (broad categories: target selection, imaging, spectro, data processing, Q/A, calibration/standards, science analysis, database and distribution [and, of course, documentation]): Target Selection tasks: Refine, verify SEGUE Target Selection algorithm in each of the 10 Stellar Categories (F turnoff, G dwarf, K giant, BHB/A, Low Metalicities) [There are at least projects for 10 people here!]: [Weight low-metal stars to bright mags < 18, improve K-giant efficiency from current 20%] Are we selecting the right stars enough stars in each category to do the science (trace halo streams or disk structure, explore metalicity history of the Milky Way or Chemical gradients in the Galaxy. Are we selecting enough stars in each category to have sufficient statistics to do the science? [More F stars to trace streams?] Web link to target selection color/mag cuts and links to early SEGUE plates. (A more formal web page is coming) http://www-sdss.fnal.gov/yanny/seguets/

  11. Imaging: Plan, obtain and reduce SEGUE imaging stripe data. Analyze photometric accuracy as f(stellar density). Update imaging pipeline to work at high density [i.e. stars-only 'DAOPHOT' mode] Analyze photometric accuracy as f(dust/variable sky). Update imaging pipeline to work in variable sky background conditions (i.e. |b| ~0. Spectroscopy: Plan, obtain and process SEGUE plate pairs. Analyze RV accuracy as f(S/N), stellar color/type. Update RV templates as needed to reach goals. [Do we have enough sky fibers? New ELODIE templates to insert zeropoints, N best fit (now 12)] Develop algorithms for [Fe/H], Teff, log g of stars as f(S/N), stellar type. [Expanded Lick indicies, continuum-subtracted spectra in blue, smoothing, unskysubtracted-sky spectra availability] Incorporate algorithms into pipeline processing.

  12. Quality Assurance: During observing 2004-2008, monitor imaging and spectra data as they occur. Within one month timescale for imaging (turn around for Target Selection), check tracking, photometric accuracy, S/N depth of images. Color magnitude diagrams. Search for 'special regions to scan' i.e. if a new 'great stream appears'. Spot check spectra of each type vs. S/N estimates and science requirements. Calibration/Standards: (IM) target and process 'PT' patches along SEGUE stripes for initial 2% rms calibration (in time for Target Selection). scan crossing scans as needed to allow photometric ties of SEGUE 'constant l' stripes to each other and to SDSS imaging. process crossing scan and other available photometric calib info. (SP) Obtain samples of stars with known Rvs, Metals, log g, spectral types to calibrate algorithms for parameter estimation. i.e. plates on Globular and Open Clusters of known RV, [Fe/H]. Match to USNO-B2.0 or other catalogs of known info proper motions.

  13. Databases/Data distribution/Documentation: Support initial catalogs and value-added information as 'Flat Files' in SDSS 'DAS' format, with web sites Design/Modify 'indexed-database' design to include new parameters/information (data model changes). Publish (in some form), TS algorithm, selection function, goals and science background. Science Analysis: Stellar Atmosphere modeling and parameter estimation is still a bit of a 'black art', we need your experts and expertise. SEGUE has potential to revolutionize this field!! Think Big! Work on the key project or some of the other '57' science projects with initial sample (~20,000 SEGUE stars already available in Aug/Sep 04) with intent to determine feasibility of the science.

  14. Papers: Metals in Sag stream Metals in Mono/Canis Major Stream Spectra of everything selection function, stellar spectral atlas SDSS DR2/DR3 selection function, target selection algorithm Metalicity Distribution in the MW (DR2 and beyond) The Lowest Metal Stars Techinques for measures stellar atmosphere parameters in large sample of R~2000 SDSS spectra. SEGUE Target Selection and early results.

  15. 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.

  16. 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

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

  18. WD A/BHB F Turnoff G III +V Low Metals K III K V M V AGB Cool Wds SEGUE currently has 10 categories, (we have openings for G dwarf specialists)

  19. -250 -200 -150 -100 -50 0 50 km/s G dwarf Radial Velocity histograms, by Magnitude (dist)

  20. 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

  21. N=25 White Dwarf Issues: ?

  22. N=10 Issues: Proper Motion > 30mas/yr Cool White Dwarf Candidate

  23. N=125 BHB Star, probe outer halo, streams to 150 kpc Issues: Are we getting essentially 'all' of these?

  24. -400 -300 -200 -100 0 100 km/s

  25. N=150 Issues: Do we need more faint Fs per plate for streams? What about P1 cut? F turnoff star, trace streams, halo, low [Fe/H] to 20kpc

  26. -400 -300 -200 -100 0 100 km/s

  27. N=375 Issues: Giants vs. Dwarfs? Color band ok? G dwarf, largest SEGUE sample, probe disk/inner halo 1.5kpc to 8 kpc distances, Stream Giants also here

  28. -400 -300 -200 -100 0 100 km/s

  29. N=125 K Giants Issues: Color cuts ok, selection efficiency still low?

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

  31. N=125 Issues: Faint cutoff? USNO Match? Disk Science ok? K dwarf , kinematics from match to USNO-B, +RV photometric parallax – probe disks from 0.5 – 2 kpc

  32. N=150 Issues: Wish to weight much more towards bright g<18.5 Low metalicity candidate, [Fe/H] = -2.6, g=15.8, g-r=0.47 Pop III exploration, gradients in inner/outer halo

  33. N=50 M dwarfs Issues: sub-dwarf alg, brown dwarf alg, PPM cut modify? How faint?

  34. N=10 Issues: Efficiency, use only on Sag/Mon? color cuts? 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

  35. Globular Cluster Plates 1960-1962 (M15/M2) Open Cluster Plates M67, Hyades? RV standards, go down stellar locus Issues: Exposure times for GC plates? When will be ready to tackle Open Clusters? Peregrine's cross scan on open clusters for this Fall? Redo Hyades, M67?

  36. 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.

  37. 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.

  38. Cool White Dwarf Candidate

  39. 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.

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

  41. K Giants

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