- ID:
- ivo://CDS.VizieR/J/ApJ/862/174
- Title:
- Spectroscopy obs. of RAVE J094921.8-161722
- Short Name:
- J/ApJ/862/174
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a high-resolution (R~35000), high signal-to-noise ratio (S/N>200) Magellan/MIKE spectrum of the star RAVE J094921.8-161722, a bright (V=11.3) metal-poor red giant star with [Fe/H]=-2.2, identified as a carbon-enhanced metal-poor (CEMP) star from the RAVE survey. We report its detailed chemical abundance signature of light fusion elements and heavy neutron-capture elements. We find J0949-1617 to be a CEMP star with s-process enhancement that must have formed from gas enriched by a prior r-process event. Light neutron-capture elements follow a low-metallicity s-process pattern, while the heavier neutron-capture elements above Eu follow an r-process pattern. The Pb abundance is high, in line with an s-process origin. Thorium is also detected, as expected from an r-process origin, as Th is not produced in the s-process. We employ nucleosynthesis model predictions that take an initial r-process enhancement into account, and then determine the mass transfer of carbon and s-process material from a putative more massive companion onto the observed star. The resulting abundances agree well with the observed pattern. We conclude that J0949-1617 is the first bonafide CEMP-r+s star identified. This class of objects has previously been suggested to explain stars with neutron-capture element patterns that originate from neither the r- nor the s-process alone. We speculate that J0949-1617 formed in an environment similar to those of ultra-faint dwarf galaxies like TucanaIII and ReticulumII, which were enriched in r-process elements by one or multiple neutron star mergers at the earliest times.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJS/53/791
- Title:
- Spectroscopy of AB stars in halo
- Short Name:
- J/ApJS/53/791
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Reticon spectroscopy has been obtained for 224 high-latitude AB stars chosen from the Curtis Schmidt objective-prism survey of Preston and Schectamn. Additional spectra of radial velocity standards, globular cluster blue horizontal-branch and RR Lyrae stars, and Population I late B and early A stars have been obtained. Radial velocities have been determined for all the program objects by cross-correlating the spectra with those of radial velocities standards. The standard error in a single observation is 11km/s.
- ID:
- ivo://CDS.VizieR/J/AJ/136/1645
- Title:
- Spectroscopy of bright QUEST RR Lyrae stars
- Short Name:
- J/AJ/136/1645
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a sample of 43 bright (V<16.1, distance <13kpc) RR Lyrae stars (RRLs) from the QUasar Equatorial Survey with spectroscopic radial velocities and metallicities, we find that several separate halo substructures contribute to the Virgo overdensity (VOD). While there is little evidence of a halo substructure in the spatial distribution of these stars, their distribution in radial velocity reveals two moving groups. These results are reinforced when the sample is combined with a sample of blue horizontal branch stars that were identified in the Sloan Digital Sky Survey, and the combined sample provides evidence for one additional moving group.
- ID:
- ivo://CDS.VizieR/J/ApJS/175/462
- Title:
- Spectroscopy of Coma early-type galaxies
- Short Name:
- J/ApJS/175/462
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The long-slit spectra obtained along the minor axis, offset major axis, and diagonal axis are presented for 12 E and S0 galaxies of the Coma Cluster drawn from a magnitude-limited sample studied before. The rotation curves, velocity dispersion profiles, and the H_3_ and H_4_ coefficients of the Hermite decomposition of the line-of-sight velocity distribution are derived. The radial profiles of the H{beta}, Mg, and Fe line strength indices are measured too. In addition, the surface photometry of the central regions of a subsample of four galaxies recently obtained with the Hubble Space Telescope is presented. The data will be used to construct dynamical models of the galaxies and study their stellar populations.
- ID:
- ivo://CDS.VizieR/J/A+A/549/A104
- Title:
- Spectroscopy of {delta} Scuti star KIC 5988140
- Short Name:
- J/A+A/549/A104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We used high-quality Kepler photometry and spectroscopic data to investigate the Kepler binary candidate KIC 5988140. Using the spectrum synthesis method, we derived the fundamental parameters (T_eff_, logg, [M/H], vsini) and the abundances. Frequency analyses of both the photometric and the spectroscopic data revealed the same two dominant frequencies. We also detected in the photometry the signal of nine more, significant frequencies located in the range 10-15c/d. The light and radial velocity curves follow a similar, stable double-wave pattern. We considered three different scenarios: binarity, co-existence of Gamma Doradus and Delta Scuti pulsations and rotational modulation. We confirm the occurrence of various independent Delta Scuti-type pressure modes in the Kepler light curve. However, we argue that the physical cause of low frequencies in the light and radial velocity variations of this late A-type star remain unexplained by any of the presently considered scenarios.
- ID:
- ivo://CDS.VizieR/J/AJ/116/2738
- Title:
- Spectroscopy of early-type galaxies
- Short Name:
- J/AJ/116/2738
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present central velocity dispersion measurements for 325 early-type galaxies in eight clusters and groups of galaxies, including new observations for 212 galaxies. The clusters and groups are the A262, A1367, Coma (A1656), A2634, Cancer, and Pegasus Clusters and the NGC 383 and NGC 507 Groups. The new measurements were derived from medium-dispersion spectra that cover 600{AA} centered on the Mg I b triplet at {lambda}~5175{AA}. Velocity dispersions were measured using the Tonry & Davis (1979AJ.....84.1511T) cross-correlation method, with a typical accuracy of 6%. A detailed comparison with other data sources is made.
- ID:
- ivo://CDS.VizieR/J/AJ/114/122
- Title:
- Spectroscopy of edge-on spirals
- Short Name:
- J/AJ/114/122
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present H I line observations of 744 edge-on spiral galaxies, extracted from the Flat Galaxy Catalog of Karachentsev et al. (1993AN....314...97K). Fluxes, systemic velocities and line widths are given for 587 detected galaxies, as well as search parameters for 157 undetected systems. Widths are corrected for instrumental broadening, smoothing, signal-to-noise and profile shape, and an estimate of the error on the width is given. When corrected for turbulent broadening and inclination angle of the disks, the velocity widths presented here can provide the appropriate line width parameter needed to derive distances via the Tully-Fisher relation.
- ID:
- ivo://CDS.VizieR/J/AJ/152/1
- Title:
- Spectroscopy of EG And over roughly 14 years
- Short Name:
- J/AJ/152/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze a roughly 20yr set of spectroscopic observations for the symbiotic binary EG And. Radial velocities derived from echelle spectra are best fit with a circular orbit having an orbital period of P=483.3+/-1.6 days and semi-amplitude K=7.34+/-0.07km/s. Combined with previous data, these observations rule out an elliptical orbit at the 10{sigma} level. Equivalent widths of HI Balmer emission lines and various absorption features vary in phase with the orbital period. Relative to the radius of the red giant primary, the apparent size of the H ii region is consistent with a model where a hot secondary star with effective temperature T_h_~75000K ionizes the wind from the red giant.
- ID:
- ivo://CDS.VizieR/J/AJ/145/95
- Title:
- Spectroscopy of {epsilon} Ori
- Short Name:
- J/AJ/145/95
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a time series analysis of 130 echelle spectra of {epsilon} Ori (B0 Ia), acquired over seven observing seasons between 1998 and 2006 at Ritter Observatory. The equivalent widths of H{alpha} (net) and HeI{lambda}5876 were measured and radial velocities were obtained from the central absorption of HeI{lambda}5876. Temporal variance spectra (TVS) revealed significant wind variability in both H{alpha} and HeI{lambda}5876. The HeI TVS have a double-peaked profile consistent with radial velocity oscillations. A periodicity search was carried out on the equivalent width and radial velocity data, as well as on wavelength-binned spectra. This analysis has revealed several periods in the variability with timescales of two to seven days. Many of these periods exhibit sinusoidal modulation in the associated phase diagrams. Several of these periods were present in both H{alpha} and HeI, indicating a possible connection between the wind and the photosphere. Due to the harmonic nature of these periods, stellar pulsations may be the origin of some of the observed variability. Periods on the order of the rotational period were also detected in the HeI line in the 1998-1999 season and in both lines during the 2004-2005 season. These periods may indicate rotational modulation due to structure in the wind.
- ID:
- ivo://CDS.VizieR/J/AJ/151/26
- Title:
- Spectroscopy of five {gamma} Dor variables
- Short Name:
- J/AJ/151/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have determined the spectroscopic orbits of five {gamma} Dor variables, HD776, HD6568, HD17310, HD19684, and HD62196. Their orbital periods range from 27.8 to 1163days and their eccentricities from 0.01 to 0.65. Of the five systems, only HD19684 shows lines of its binary companion, but those lines are always so weak and blended with the lines of the primary that we were unable to measure them satisfactorily. The velocity residuals of the orbital fits were searched for periodicities associated with pulsation. No clear, convincing case for velocity periodicities in the residuals was found in four of the five stars. However, for HD17310 we identified a period of 2.13434days, a value in agreement with the largest amplitude period previously found photometrically for that star. The velocity residuals of HD62196 have a long-term trend suggesting that it is a triple system.
