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691. {Epsilon} CrA components radial & orbital velocity
ID:
ivo://CDS.VizieR/J/AJ/160/104
Title:
{Epsilon} CrA components radial & orbital velocity
Short Name:
J/AJ/160/104
Date:
21 Oct 2021
Publisher:
CDS
Description:
High-resolution spectroscopic observations of the W UMa-type binary {Epsilon}CrA obtained as a time-monitoring sequence on four full and four partial nights within two weeks have been used to derive orbital elements of the system and discuss the validity of the Lucy model for description of the radial-velocity data. The observations had more extensive temporal coverage and better quality than similar time-sequence observations of the contact binary AW UMa. The two binaries share several physical properties and show very similar deviations from the Lucy model: the primary component is a rapidly rotating star almost unaffected by the presence of the secondary component, while the latter is embedded in a complex gas flow and appears to have its own rotation-velocity field, in contradiction to the model. The spectroscopic mass ratio is found to be larger than the one derived from the light-curve analysis, as in many other W UMa-type binaries, but the discrepancy for {Epsilon} CrA is relatively minor, much smaller than for AW UMa. The presence of the complex velocity flows contradicting the assumption of solid-body rotation suggests a necessity of modification to the Lucy model, possibly along the lines outlined by Stepien in his concept of energy transfer between the binary components.
692. Epsilon Indi Ba and Bb IR spectra
ID:
ivo://CDS.VizieR/J/A+A/510/A99
Title:
Epsilon Indi Ba and Bb IR spectra
Short Name:
J/A+A/510/A99
Date:
21 Oct 2021
Publisher:
CDS
Description:
The discovery of epsilon Indi Ba, Bb, a binary brown dwarf system very close to the Sun, makes possible a concerted campaign to characterise the physical parameters of two T dwarfs. Recent observations suggest substellar atmospheric and evolutionary models may be inconsistent with observations, but there have been few conclusive tests to date. We therefore aim to characterise these benchmark brown dwarfs to place constraints on such models. We have obtained high angular resolution optical, near-infrared, and thermal-infrared imaging and medium-resolution (up to R~5000) spectroscopy of epsilon Indi Ba, Bb with the ESO VLT and present VRIzJHKL'M' broad-band photometry and 0.63-5.1 micron spectroscopy of the individual components. The photometry and spectroscopy of the two partially blended sources were extracted with a custom algorithm. Furthermore, we use deep AO-imaging to place upper limits on the (model-dependent) mass of any further system members. We derive luminosities of log L/L_{sun}=-4.699+/-0.017 and -5.232+/-0.020 for epsilon Indi Ba, Bb, respectively, and using the dynamical system mass and COND03 evolutionary models predict a system age of 3.7-4.3Gyr, in excess of previous estimates and recent predictions from observations of these brown dwarfs. Moreover, the effective temperatures of 1352-1385K and 976-1011K predicted from the COND03 evolutionary models, for epsilon Indi Ba and Bb respectively, are in disagreement with those derived from the comparison of our data with the BT-Settl atmospheric models where we find effective temperatures of 1300-1340K and 880-940K, for epsilon Indi Ba and Bb respectively, with surface gravities of logg=5.25 and 5.50. Finally, we show that spectroscopically determined effective temperatures and surface gravities for ultra-cool dwarfs can lead to underestimated masses even where precise luminosity constraints are available.
693. Equivalent width of 21 RR Lyrae stars
ID:
ivo://CDS.VizieR/J/MNRAS/447/2404
Title:
Equivalent width of 21 RR Lyrae stars
Short Name:
J/MNRAS/447/2404
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have analysed a sample of 18 RR Lyrae stars (17 fundamental-mode - RRab - and one first overtone - RRc) and three Population II Cepheids (two BL Her stars and one W Vir star), for which high-resolution (R>=30000), high signal-to-noise (S/N>=30) spectra were obtained with either SARG at the Telescopio Nazionale Galileo (La Palma, Spain) or UVES at the ESO Very Large Telescope (Paranal, Chile). Archival data were also analyzed for a few stars, sampling >~3 phases for each star. We obtained atmospheric parameters (T_eff_, logg, v_t_, and [M/H]) and abundances of several iron-peak and {alpha}-elements (Fe, Cr, Ni, Mg, Ca, Si, and Ti) for different pulsational phases, obtaining <[{alpha}/Fe]>=+0.31+/-0.19dex over the entire sample covering -2.2<[Fe/H]<-1.1dex. We find that silicon is indeed extremely sensitive to the phase, as reported by previous authors, and cannot be reliably determined. Apart from this, metallicities and abundance ratios are consistently determined, regardless of the phase, within 0.10-0.15 dex, although caution should be used in the range 0<~{phi}<~0.15. Our results agree with literature determinations for both variable and non-variable field stars, obtained with very different methods, including low and high-resolution spectroscopy. W Vir and BL Her stars, at least in the sampled phases, appear indistinguishable from RRab from the spectroscopic analysis point of view. Our large sample, covering all pulsation phases, confirms that chemical abundances can be obtained for RR Lyrae with the classical EW-based technique and static model atmospheres, even rather close to the shock phases.
694. Equivalent widths and atomic data for GCs
ID:
ivo://CDS.VizieR/J/MNRAS/448/42
Title:
Equivalent widths and atomic data for GCs
Short Name:
J/MNRAS/448/42
Date:
21 Oct 2021
Publisher:
CDS
Description:
Detailed chemical abundances for five stars in two Galactic globular clusters, NGC 5466 and NGC 5024, are presented from high-resolution optical (from the Hobby-Eberley Telescope) and infrared spectra (from the SDSS-III APOGEE survey). We find [Fe/H]=-1.97+/-0.13 dex for NGC 5466, and [Fe/H]=-2.06+/-0.13 dex for NGC 5024, and the typical abundance pattern for globular clusters for the remaining elements, e.g. both show evidence for mixing in their light element abundance ratios (C, N), and asymptotic giant branch contributions in their heavy element abundances (Y, Ba, and Eu). These clusters were selected to examine chemical trends that may correlate them with the Sgr dwarf galaxy remnant, but at these low metallicities no obvious differences from the Galactic abundance pattern are found. Regardless, we compare our results from the optical and infrared analyses to find that oxygen and silicon abundances determined from the infrared spectral lines are in better agreement with the other {alpha}-element ratios and with smaller random errors.
695. Equivalent Widths in Pollux
ID:
ivo://CDS.VizieR/J/A+AS/42/391
Title:
Equivalent Widths in Pollux
Short Name:
J/A+AS/42/391
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
696. Equivalent Widths in the Spectrum of Sirius
ID:
ivo://CDS.VizieR/J/ApJS/126/461
Title:
Equivalent Widths in the Spectrum of Sirius
Short Name:
J/ApJS/126/461
Date:
21 Oct 2021
Publisher:
CDS
Description:
The equivalent widths of total 546 lines (26 elements are included) in the spectrum of the bright Am star Sirius from 380 to 930 nm are tabulated. The high-resolution, high signal-to-noise ratio spectrum was obtained with the Coude Echelle Spectrograph attached to the 2.16 m telescope at Beijing Astronomical Observatory (Xinglong, China). Here we also give the results of the equivalent widths comparison between our measurements and those of Strom et al. (=1966ApJ...146..880S) and Sadakane & Ueta (=1989PASJ...41..279S). Table 1. Observation Journal of Sirius: ---------------------------------------------------------------------------- Spectral Range Exposure Time Geocentric Radial Velocity (nm) Obs. Date (s) (km s-1) ---------------------------------------------------------------------------- 386.5-572.1 1997 Feb 18/19 180 12.75 (0.45) 383.3-661.9 1997 Feb 18/19 40+40+30 12.37 (0.96) 378.9-551.6 1997 Feb 18/19 40+40 12.31 (0.82) 380.7-649.3 1997 Feb 18/19 40+40 12.42 (0.93) 623.8-922.7 1999 Apr 01/02 300+300 15.49 (0.52) 624.8-930.4 1999 Apr 01/02 300+300 15.58 (0.69) ----------------------------------------------------------------------------
697. Equivalent widths of 6 binaries
ID:
ivo://CDS.VizieR/J/A+A/377/123
Title:
Equivalent widths of 6 binaries
Short Name:
J/A+A/377/123
Date:
21 Oct 2021
Publisher:
CDS
Description:
We performed a careful differential abundance analysis of individual components of six main sequence binaries with separations of a few hundreds of AU. To reduce analysis concerns, we selected systems with almost equal mass components. We were able to derive differential abundances of several elements with errors down to 0.01dex in the best cases. We found that in four systems the two components have the same chemical composition, within these very severe limits. However, clear differences were found for the two remaining systems (HD 219542 and HD 200466), in both cases the primaries being more Fe-rich than the secondaries, by 0.091+/-0.009 and 0.053+/-0.024dex respectively. Similar differences were found for most of the elements considered in our analysis; however, we found no appreciable difference for volatile elements and a trend for increasing abundance differences with increasing condensation temperature for individual elements, a result similar to that found for some single stars with planets by Smith et al. (2001AJ....121.3207S). Finally, we note that HD 219542A has a Li-abundance comparable to those of Li-rich stars in old open clusters, while no Li is detected in the slightly cooler HD 219542B. We suggest that the primaries of these two systems have accreted rocky planets or the inner dust-rich part of a protoplanetary disk, likely due to gravitational perturbation caused by the presence of the companion.
698. Equivalent widths of DIBs
ID:
ivo://CDS.VizieR/J/A+A/555/A25
Title:
Equivalent widths of DIBs
Short Name:
J/A+A/555/A25
Date:
21 Oct 2021
Publisher:
CDS
Description:
Stellar spectroscopic surveys may bring useful statistical information on the links between diffuse interstellar bands (DIBs) and the interstellar environment. DIB databases can also be used as a complementary tool for locating interstellar (IS) clouds. Our goal is to develop fully automated methods of DIB measurements to be applied to extensive data from stellar surveys. We present a method that is appropriate for early-type nearby stars, along with its application to high-resolution spectra of ~130 targets recorded with the ESO FEROS spectrograph and comparisons with other determinations. Using a DIB average profile deduced from the most reddened stars, we performed an automated fitting of a combination of a smooth stellar continuum, the DIB profile, and, when necessary, a synthetic telluric transmission.
699. Equivalent widths of 8 DIBs for 186 O & B stars
ID:
ivo://CDS.VizieR/J/ApJ/850/194
Title:
Equivalent widths of 8 DIBs for 186 O & B stars
Short Name:
J/ApJ/850/194
Date:
21 Oct 2021
Publisher:
CDS
Description:
We study the behavior of eight diffuse interstellar bands (DIBs) in different interstellar environments, as characterized by the fraction of hydrogen in molecular form (f_H2_), with comparisons to the corresponding behavior of various known atomic and molecular species. The equivalent widths of the five "normal" DIBs ({lambda}{lambda}5780.5, 5797.1, 6196.0, 6283.8, and 6613.6), normalized to E_B-V_, show a "lambda-shaped" behavior: they increase at low f_H2_, peak at f_H2_~0.3, and then decrease. The similarly normalized column densities of Ca, Ca+, Ti+, and CH+ also decline for f_H2_>0.3. In contrast, the normalized column densities of Na, K, CH, CN, and CO increase monotonically with fH2, and the trends exhibited by the three C_2_ DIBs ({lambda}{lambda}4726.8, 4963.9, and 4984.8) lie between those two general behaviors. These trends with f_H2_ are accompanied by cosmic scatter, the dispersion at any given f_H2_ being significantly larger than the individual errors of measurement. The lambda-shaped trends suggest the balance between creation and destruction of the DIB carriers differs dramatically between diffuse atomic and diffuse molecular clouds; additional processes aside from ionization and shielding are needed to explain those observed trends. Except for several special cases, the highest W{lambda}(5780)/W{lambda}(5797) ratios, characterizing the so-called "sigma-zeta effect," occur only at f_H2_<0.2. We propose a sequence of DIBs based on trends in their pair-wise strength ratios with increasing f_H2_. In order of increasing environmental density, we find the {lambda}6283.8 and {lambda}5780.5 DIBs, the {lambda}6196.0 DIB, the {lambda}6613.6 DIB, the {lambda}5797.1 DIB, and the C_2_ DIBs.
700. Equivalent widths of 26 metal-poor stars
ID:
ivo://CDS.VizieR/J/ApJ/655/492
Title:
Equivalent widths of 26 metal-poor stars
Short Name:
J/ApJ/655/492
Date:
21 Oct 2021
Publisher:
CDS
Description:
The chemical compositions of 26 metal-poor stars that exhibit strong CH and/or C2 molecular bands are determined. Twenty-two stars in our sample satisfy our definition for carbon-enhanced metal-poor (CEMP) stars based on the carbon abundance ratio ([C/Fe]) and the evolutionary status. In addition, we measure Na abundances for nine known carbon-enhanced stars. Combining our new sample with the results of previous work, we investigate the abundance and evolutionary status of a total of 64 CEMP stars.

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