# Presentation: 668483

## 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 2004  1260 N  38 sq deg
-            291 N 104
- Sep 2004  1100 N 105
-           1260 S  60
-           1100 S 107
-             72 S 117
-             72 N  62
- Oct 2004    72 N  55
-           1300 N  52
-           1300 S  47
- ---------------------
-                  747 sq deg
- + earlier scans: 255
- ---------------------
-                 1002 sq deg
-                     25% of SEGUE goal

- Drillable imaging
- (filled Stripes N&S):
-      1100 N&S   200 sq.
-      1220 N&S   175 sq.
-    portions of:
-          72 N&S   200 sq.
-       1300 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

-   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
-                     ---------------------------
-                     18 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 

- 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 

- 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)

- -250     -200   -150    -100    -50    0     50 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.

- +1
- 0
- -1
- [Fe/H]
- -2
- -3

- 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.