| |
 |
| Paper: |
State-of-the-Art Metal Abundances For Field RR Lyrae Variables |
| Volume: |
92, Formation of the Galactic Halo. . . . Inside and Out |
| Page: |
367 |
| Authors: |
Carretta, E.; Clementini, G.; Merighi, R.; Gratton, R. G.; Mould, J. R.; McCarthy, J. K. |
| Abstract: |
We present abundance analysis for 10 field ab-type RR Lyraes, using high S/N (>200), moderately high resolution ( ~ 18000) CCD spectra to obtain accurate metallicities. A new temperature scale was determined and non-LTE effects were fully taken into account. The derived metal abundances of the program stars span the range -2.50 < [Fe/H] < +0.17. We used our new [Fe/H] abundances, as well as values from Butler and coworkers (corrected to our system), to obtain a revised calibration of the Delta S index (Preston 1959): $[Fe/H] = -0.194(+/- 0.011)Delta S - 0.08 (+/- 0.18) $ Our new metallicity scale is then stretched on both low and high metallicity ends with respect to Butler's (1975) calibration. |
|
|
|
|
|
