Rotation and Macroturbulence in Metal-poor Field Red Giant and Red Horizontal Branch Stars

Abstract

We report the results for rotational velocities, Vrot sin i, and macroturbulence dispersion, zeta(RT), for 12 metal-poor field red giant branch stars and 7 metal-poor field red horizontal branch stars. The results are based on Fourier transform analyses of absorption line profiles from high-resolution (R ~ 120,000), high-S/N (~ 215 per pixel) spectra obtained with the Gecko spectrograph at CFHT. We find that the zeta(RT) values for the metal-poor RGB stars are very similar to those for metal-rich disk giants studied earlier by Gray and his collaborators. Six of the RGB stars have small rotational values, less than 2.0 km/sec, while five show significant rotation, over 3 km/sec. The fraction of rapidly rotating RHB stars is somewhat lower than found among BHB stars. We devise two empirical methods to translate the line-broadening results obtained by Carney et al. (2003, 2008) into Vrot sin i for all the RGB and RHB stars they studied. Binning the RGB stars by luminosity, we find that most metal-poor field RGB stars show no detectable sign, on average, of rotation. However, the most luminous stars, with M(V) <= -1.5, do show net rotation, with mean values of 2 to 4 km/sec, depending on the algorithm employed, and these stars also show signs of radial velocity jitter and mass loss.

arXiv commentaccepted for publication in the Astronomical Journal

References in corpus (7)

• RVSAO 2.0: Digital Redshifts and Radial Velocities
• The Y^2 Stellar Evolutionary Tracks
• Rotation Velocities of Red and Blue Field Horizontal-Branch Stars
• A Keck/HIRES Doppler Search for Planets Orbiting Metal-Poor Dwarfs. I. Testing Giant Planet Formation and Migration Scenarios
• Mass motions and chromospheres of RGB stars in the globular cluster NGC 2808
• Line Broadening in Field Metal-poor Red Giant and Red Horizontal Branch Stars
• HST Observations of Chromospheres in Metal Deficient Field Giants

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