CDROM/APJ/V475/P427 Abundance Analyses of RV Tauri Variables (Gonzalez+ 1997) ================================================================================ Abundance Analyses of the Field RV Tauri Variables: EP Lyrae, DY Orionis, AR Puppis, and R Sagittae Guillermo Gonzalez, David L. Lambert, and Sunetra Giridhar <1997, ApJ, 479, 427> =1997ApJ...479..427G ================================================================================ Abstract: Analyses of the photospheric compositions of the four field RV Tauri stars, EP Lyr, DY Ori, AR Pup, and R Sge, indicate that to varying degrees they have experienced fractionation processes that have preferentially depleted their atmospheres of elements with high condensation temperatures. The depletion, as indicated by, for instance, [S/Fe], is greatest for DY Ori, [S/Fe] = 2.5, and least for R Sge, [S/Fe] = 0.9. The initial composition, presumably indicated by the sulfur abundance, was nearly solar for AR Pup, R Sge, and DY Ori, while it was about 0.6 dex less than solar for EP Lyr. This implies that the RV Tauri stars as a group may not be as metal-poor as previously thought---they are instead ``metal-depleted.'' The field RV Tauri's are not halo stars, but probably belong to the thick disk. This brings to seven the number of type II Cepheids that show such a trend; the other three are IW Car and V1 in omega Cen, RV Tauri stars, and ST Pup, a W Virginis star. The 12C/13C ratios for EP Lyr and DY Ori are 9 +/- 1 and 6 +/- 3, respectively, indicating that CN-cycled material has been mixed with their surface layers. This is consistent with the general consensus that RV Tau stars are in a post-AGB evolutionary stage. There is also evidence that EP Lyr has a stellar mass companion, but additional observations are required to calculate an orbit; hence, EP Lyr could be a link to the group of metal-depleted, high-latitude A-F supergiants, all of which are binaries. Keywords: stars: abundances -- stars: AGB and post-AGB -- stars: variables: other (RV Tauri) Description: The data in tables 3 and 6 have multiple lines per atomic speicies, with a header record that gives the species and solar abundance, followed by several lines of data containing wavelength, low E.P., log gf, equivalent widths and abundances for that species. File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- table3.dat 53 234 Individual abundance results for EP Lyr table3.tex 64 257 AASTeX version of table3.dat table6.dat 64 129 Individual abundance results for R Sge table6.tex 75 153 AASTeX version of table6.dat -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- ----- Header record ----- 1- 5 A5 --- Species Atomic species 6-11 F6.2 --- eps_sun Solar abundance, log(eps) ----- Data records ----- 1- 7 F7.2 0.1nm Lambda Wavelength 8-13 F6.2 eV EP Low E.P. 14-20 F7.2 --- gf log gf value 21-25 F5.0 10-4nm W1 []? Equivalent width, 1994 June 25-27 26-31 F6.2 --- Eps1 []? Abundance, log(eps), 1994 June 25-27 32-36 F5.0 10-4nm W2 []? Equivalent width, 1995 June 10&12 37-42 F6.2 --- Eps2 []? Abundance, log(eps), 1995 June 10&12 43-47 F5.0 10-4nm W3 []? Equivalent width, 1996 Mar 3 48-53 F6.2 --- Eps3 []? Abundance, log(eps), 1996 Mar 3 -------------------------------------------------------------------------------- Byte-by-byte Description of file: table6.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- ----- Header record ----- 1- 5 A5 --- Species Atomic species 6-11 F6.2 --- eps_sun Solar abundance, log(eps) ----- Data records ----- 1- 7 F7.2 0.1nm Lambda Wavelength 8-13 F6.2 eV EP Low E.P. 14-20 F7.2 --- gf log gf value 21-25 F5.0 10-4nm W1 []? Equivalent width, 1992 May 22 26-31 F6.2 --- Eps1 []? Abundance, log(eps), 1992 May 22 32-36 F5.0 10-4nm W2 []? Equivalent width, 1994 June 24 37-42 F6.2 --- Eps2 []? Abundance, log(eps), 1994 June 24 43-47 F5.0 10-4nm W3 []? Equivalent width, 1994 July 29 48-53 F6.2 --- Eps3 []? Abundance, log(eps), 1994 July 29 54-58 F5.0 10-4nm W4 []? Equivalent width, 1995 June 12 59-64 F6.2 --- Eps4 []? Abundance, log(eps), 1995 June 12 -------------------------------------------------------------------------------- ================================================================================ (End) Lee E. Brotzman [ADS] 06-May-97