SIMBAD references

2013ApJ...775...57K - Astrophys. J., 775, 57 (2013/September-3)

The absolute magnitude of RRc variables from statistical parallax.

KOLLMEIER J.A., SZCZYGIEL D.M., BURNS C.R., GOULD A., THOMPSON I.B., PRESTON G.W., SNEDEN C., CRANE J.D., DONG S., MADORE B.F., MORRELL N., PRIETO J.L., SHECTMAN S., SIMON J.D. and VILLANUEVA E.

Abstract (from CDS):

We present the first definitive measurement of the absolute magnitude of RR Lyrae c-type variable stars (RRc) determined purely from statistical parallax. We use a sample of 242 RRc variables selected from the All Sky Automated Survey for which high-quality light curves, photometry, and proper motions are available. We obtain high-resolution echelle spectra for these objects to determine radial velocities and abundances as part of the Carnegie RR Lyrae Survey. We find that M_V, RRc_= 0.59±0.10 at a mean metallicity of [Fe/H] = -1.59. This is to be compared with previous estimates for RRab stars (M_V, RRab_= 0.76±0.12) and the only direct measurement of an RRc absolute magnitude (RZ Cephei, M_V, RRc_= 0.27±0.17). We find the bulk velocity of the halo relative to the Sun to be (Wπ, Wθ, Wz) = (12.0, -209.9, 3.0) km/s in the radial, rotational, and vertical directions with dispersions (σWπ, σ_Wθ, σWz) = (150.4, 106.1, 96.0) km/s. For the disk, we find (Wπ, Wθ, Wz) = (13.0, -42.0, -27.3) km/s relative to the Sun with dispersions (σWπ, σ_Wθ, σWz) = (67.7, 59.2, 54.9) km/s. Finally, as a byproduct of our statistical framework, we are able to demonstrate that UCAC2 proper-motion errors are significantly overestimated as verified by UCAC4.

Abstract Copyright: ∼

Journal keyword(s): distance scale - Galaxy: fundamental parameters - Galaxy: kinematics and dynamics - Galaxy: structure - stars: distances - stars: variables: RR Lyrae

Simbad objects: 7

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2013ApJ...775...57K and select 'bookmark this link' or equivalent in the popup menu