J/A+A/586/A125 Neutron-capture elements abundances in Cepheids (da Silva+ 2016) On the neutron-capture elements across the Galactic thin disk using Cepheids. da Silva R., Lemasle B., Bono G., Genovali K., McWilliam A., Cristallo S., Bergemann M., Buonanno R., Fabrizio M., Ferraro I., Francois P., Iannicola G., Inno L., Laney C.D., Kudritzki R.-P., Matsunaga N., Nonino M., Primas F., Przybilla N., Romaniello M., Thevenin F., Urbaneja M.A. =2016A&A...586A.125D (SIMBAD/NED BibCode) ADC_Keywords: Milky Way ; Stars, variable ; Abundances ; Spectroscopy Keywords: stars: abundances - stars: variables: Cepheids - stars: oscillations - open clusters and associations: general - Galaxy: disk Abstract: We present new accurate abundances for five neutron-capture (Y, La, Ce, Nd, Eu) elements in 73 classical Cepheids located across the Galactic thin disk. Individual abundances are based on high spectral resolution (R∼38000) and high signal-to-noise ratio (S/N∼50-300) spectra collected with UVES at ESO VLT for the DIONYSOS project. Taking account for similar Cepheid abundances provided either by our group (111 stars) or available in the literature, we end up with a sample of 435 Cepheids covering a broad range in iron abundances (-1.6<[Fe/H]<0.6). We found, using homogeneous individual distances and abundance scales, well defined gradients for the above elements. However, the slope of the light s-process element (Y) is at least a factor of two steeper than the slopes of heavy s- (La, Ce, Nd) and r- (Eu) process elements. The s to r abundance ratio ([La/Eu]) of Cepheids shows a well defined anticorrelation with of both Eu and Fe. On the other hand, Galactic field stars attain an almost constant value and only when they approach solar iron abundance display a mild enhancement in La. The [Y/Eu] ratio shows a mild evidence of a correlation with Eu and, in particular, with iron abundance for field Galactic stars. We also investigated the s-process index -- [hs/ls] -- and we found a well defined anticorrelation, as expected, between [La/Y] and iron abundance. Moreover, we found a strong correlation between [La/Y] and [La/Fe] and, in particular, a clear separation between Galactic and Sagittarius red giants. Finally, the comparison between predictions for low-mass asymptotic giant branch stars and the observed [La/Y] ratio indicate a very good agreement over the entire metallicity range covered by Cepheids. However, the observed spread, at fixed iron content, is larger than predicted by current models. Description: The abundances of Fe, Y, La, Ce, Nd, and Eu for our sample of 73 Cepheids plus data available in the literature for other 362 Cepheids are shown. We first show the abundances derived based on individual spectra for the 73 stars, then the averaged values, and finally the data from the literature. The original abundances available in the literature were rescaled according to the zero-point differences listed in Table 5. The priority was given in the following order: we first adopt the abundances provided by our group, this study (TS) and Lemasle et al. (2013A&A...558A..31L, LEM), and then those provided by the other studies, Luck & Lambert (2011AJ....142..136L, LIII), and Luck et al. (2011AJ....142...51L, LII). File Summary: FileName Lrecl Records Explanations ReadMe 80 . This file table2.dat 123 120 Fe, Y, La, Ce, Nd, and Eu abundances for the 73 Cepheids based on individual spectra table3.dat 110 73 Mean abundances of Fe, Y, La, Ce, Nd, and Eu for the 73 Cepheids table4.dat 23 165 Hyperfine structure list for some of the lines in our linelist table7.dat 109 435 Y, La, Ce, Nd, and Eu abundances for the whole sample of 435 Galactic Cepheids (the current 73 plus 362 from the literature) See also: J/AJ/142/51 : Galactic Cepheids abundance variations (Luck+, 2011) J/AJ/142/136 : Spectroscopy of Cepheids. l=30-250° (Luck+, 2011) Byte-by-byte Description of file: table2.dat Bytes Format Units Label Explanations 1- 9 A9 --- Name Cepheid name 12- 20 F9.3 --- MJD Modified Julian Day 23- 27 F5.2 --- [Fe/H] Metallicity [Fe/H] based on FeI and FeII 30- 33 F4.2 --- e_[Fe/H] Standard deviation on [Fe/H] 36- 38 I3 --- NFeI Number of FeI lines used 41- 42 I2 --- NFeII Number of FeII lines used 45- 49 F5.2 --- [Y/H] Yttrium abundance [Y/H] 52- 55 F4.2 --- e_[Y/H] Dispersion around the mean on [Y/H] 58 I1 --- NY Number of YII lines used 61- 65 F5.2 --- [La/H] ? Lanthanum abundance [La/H] 68- 71 F4.2 --- e_[La/H] ? Dispersion around the mean on [La/H] 74 I1 --- NLa ? Number of LaII lines used 77- 81 F5.2 --- [Ce/H] ? Cerium abundance [Ce/H] 84- 87 F4.2 --- e_[Ce/H] ? Dispersion around the mean [Ce/H] 90 I1 --- NCe ? Number of CeII lines used 93- 97 F5.2 --- [Nd/H] ? Neodymium abundance [Nd/H] 100-103 F4.2 --- e_[Nd/H] ? Dispersion around the mean [Nd/H] 106-107 I2 --- NNd ? Number of NdII lines used 110-114 F5.2 --- [Eu/H] ? Europium abundance [Eu/H] 117-120 F4.2 --- e_[Eu/H] ? Dispersion around the mean [Eu/H] 123 I1 --- NEu ? Number of EuII lines used Byte-by-byte Description of file: table3.dat Bytes Format Units Label Explanations 1- 9 A9 --- Name Cepheid name 12- 17 F6.4 [d] logP logarithmic pulsation period 20- 24 I5 kpc RG Galactocentric distance 27- 29 I3 kpc e_RG Error in the Galactocentric distance 32- 36 F5.2 --- [Fe/H] Metallicity [Fe/H] based on FeI and FeII 39- 42 F4.2 --- e_[Fe/H] Standard deviation on [Fe/H] 45- 49 F5.2 --- [Y/H] Yttrium abundance [Y/H] 52- 55 F4.2 --- e_[Y/H] Dispersion around the mean on [Y/H] 58- 62 F5.2 --- [La/H] ? Lanthanum abundance [La/H] 65- 68 F4.2 --- e_[La/H] ? Dispersion around the mean on [La/H] 71- 75 F5.2 --- [Ce/H] ? cerium abundance [Ce/H] 78- 81 F4.2 --- e_[Ce/H] ? Dispersion around the mean on [Ce/H] 84- 88 F5.2 --- [Nd/H] ? Neodymium abundance [Nd/H] 91- 94 F4.2 --- e_[Nd/H] ? Dispersion around the mean on [Nd/H] 97-101 F5.2 --- [Eu/H] ? europium abundance [Eu/H] 104-107 F4.2 --- e_[Eu/H] ? Dispersion around the mean on [Eu/H] 110 I1 --- Nsp ? Number of spectra available for each star Byte-by-byte Description of file: table4.dat Bytes Format Units Label Explanations 1- 5 A5 --- Ion Atomic line identification 8- 15 F8.3 0.1nm lambda Spectral line central wavelength 18- 23 F6.3 [-] loggf Logarithmic statistical weight of the lower level multiplied by the oscillator strength Byte-by-byte Description of file: table7.dat Bytes Format Units Label Explanations 1- 9 A9 --- Name Cepheid name 12- 16 F5.2 --- [Y/H]L ? [Y/H] abundance from literature (original) 19- 23 F5.2 --- [Y/H] ? [Y/H] abundance from literature (rescaled) 26- 29 A4 --- r_[Y/H]L ? Reference for the literature abundances (1) 32- 36 F5.2 --- [La/H]L ? [La/H] abundance from literature (original) 39- 43 F5.2 --- [La/H] ? [La/H] abundance from literature (rescaled) 46- 49 A4 --- r_[La/H]L ? Reference for the literature abundances (1) 52- 56 F5.2 --- [Ce/H]L ? [Ce/H] abundance from literature (original) 59- 63 F5.2 --- [Ce/H] ? [Ce/H] abundance from literature (rescaled) 66- 69 A4 --- r_[Ce/H]L ? Reference for the literature abundances (1) 72- 76 F5.2 --- [Nd/H]L ? [Nd/H] abundance from literature (original) 79- 83 F5.2 --- [Nd/H] ? [Nd/H] abundance from literature (rescaled) 86- 89 A4 --- r_[Nd/H]L ? Reference for the literature abundances (1) 92- 96 F5.2 --- [Eu/H]L ? [Eu/H] abundance from literature (original) 99-103 F5.2 --- [Eu/H] ? [Eu/H] abundance from literature (rescaled) 106-109 A4 --- r_[Eu/H]L ? Reference for the literature abundances (1) Note (1): The references are identified as follows: TS = this study LII = Luck et al., 2011AJ....142...51L, Cat. J/AJ/142/51 LIII = Luck & Lambert, 2011AJ....142..136L, Cat. J/AJ/142/136 LEM = Lemasle et al., 2013A&A...558A..31L Acknowledgements: Ronaldo Da Silva, ron.oliveirasilva(at)gmail.com