Mapping the Galactic Halo. VI. Spectroscopic Measures of Luminosity and Metallicity

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

28

Galaxy: Evolution, Galaxy: Halo, Galaxy: Kinematics And Dynamics

Scientific paper

We present our calibration of spectroscopic measures of luminosity and metallicity for halo giant candidates and give metallicities and distances for our first sample of spectroscopically confirmed giants. These giants have distances ranging from 15 to 83 kpc. As surveys reach farther into the Galaxy's halo with K giant samples, identification of giants becomes more difficult. This is because the numbers of foreground halo K dwarfs rise for V magnitudes of 19-20, typical for halo giants at ~100 kpc. Our photometric survey uses the strength of the Mg b/H feature near 5170 Å to weed K dwarfs out of the disk and thick disk, but we need spectroscopic measures of the strength of the Ca II K, Ca I λ4227, and Mg b/H features to distinguish between the very metal-poor dwarfs and halo giants. Using a full error analysis of our spectroscopic measures, we show why a signal-to-noise ratio of ~15 pixel-1 at Ca I λ4227 and ~10 at Ca II K is needed for reliable luminosity discrimination. We use the Ca II K and Mg b features to measure metallicity in our halo giants, with typical errors (random plus systematic) of 0.3 dex for [Fe/H] values from -0.8 to -3.0.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Mapping the Galactic Halo. VI. Spectroscopic Measures of Luminosity and Metallicity does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Mapping the Galactic Halo. VI. Spectroscopic Measures of Luminosity and Metallicity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mapping the Galactic Halo. VI. Spectroscopic Measures of Luminosity and Metallicity will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1370800

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.