Characterizing the AB Doradus Moving Group Using High Resolution Spectroscopy and Kinematic Traceback
Abstract
We present a detailed analysis on 10 proposed F and G members of the nearby, young moving group AB Doradus (ABD). ABD is at an interesting point in stellar evolution where the F and G members have inflated surface gravities (log(g) ~ 4.55) and lower vsin(i) ( < 20 km/s) compared to other nearby moving groups (e.g. β Pictoris, Tucana-Horologium, Columba). The result is a large sample of well behaved (no vieling, non-LTE effects, blending from rotation), young stars which provide meaningful insights for stellar and planetary formation. Our sample was obtained using the 2.7m telescope at the McDonald Observatory with the 2dcoudé echelle spectrograph, achieving a resolving power over 60,000 with S/N ~ 200. We derive spectroscopic Teff, log(g), [Fe/H], and microturbulance using a combination of the TGVIT and MOOG software with Kurucz Atlas 9 models and implement ionization and excitation balance. Characterization of the ABD sample is performed in three ways: (1) Chemical homogeneity, (2) Isochrone agreement, and (3) Kinematic Traceback. To investigate chemical homogeneity, we measure the abundances of 10 elements (not including iron) using the abfind package in MOOG. Isochrones are measured by plotting our sample on top of several evolutionary models on the HR Diagram. Finally, we use a kinematic traceback to map the trajectory of these stars back in time to the estimated epoch of formation (125 Myr). In our sample of 10 stars, we identify 1 star which is a probable non-member, 3 stars which have questionable membership, and 6 confirmed members.
- Publication:
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American Astronomical Society Meeting Abstracts #223
- Pub Date:
- January 2014
- Bibcode:
- 2014AAS...22344202M