In and Around the Milky Way with 2MASS
Professor Michael Skrutskie
University of Virginia
4:15-5:15 Tuesday
February 4,
2003
Abstract
The Two Micron All Sky Survey (2MASS) has imaged the entire celestial
sphere in the near-infrared J (1.25um), H (1.65um), and K_s (2.16um)
bandpasses from two 1.3-meter telescopes located at Mt. Hopkins,
Arizona and Cerro Tololo, Chile. The 7.8 seconds of integration time
accumulated for each 2" pixel on the sky has yielded a 10-sigma
detection level of better than 15.8, 15.1, and 14.3 mag. at J, H, and
K_s-bands respectively. Bright sources have photometric accuracy of
2-3% and astrometric accuracy of order 100 milliarcseconds. 2MASS
final data processing is complete and final products are nearing
release. The data release covers nearly 100% of the celestial sphere
and includes an image atlas with 1" pixels (spatially resampled from 6
independent 1.3s observations), a point source catalog containing 470
million objects, and an extended source catalog containing nearly 2
million sources -- most of which are galaxies.
This talk focuses on all-sky near-infrared color-selection of tracers
of Galactic disk and halo structure. We present a reconstructed view
of the Milky Way disk using 30,000 color-selected carbon star
candidates. The extracted sources serve as crude standard candles
with a dispersion of ~0.3 mag. The complete stellar bar and the far
edge of the Galactic disk are evident in this analysis. We further
trace a 3-dimensional view of debris from the Sgr dwarf galaxy by
applying similar inferences to color selected M-giants.