- ID:
- ivo://CDS.VizieR/J/AJ/124/1144
- Title:
- Orbits of 171 single-lined spectroscopic binaries
- Short Name:
- J/AJ/124/1144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 25,563 radial velocity measurements are reported for 1359 single-lined stars in the Carney-Latham sample of 1464 stars selected for high proper motion; for 171 of these, spectroscopic orbital solutions are derived. The radial velocities of nearly all of the 1464 stars defined in Paper XII (J/AJ/107/2240) have been monitored with the CfA Digital Speedometers (see Latham 1985, in IAU Colloq. 88, 21; and 1992, in IAU Colloq. 135, 110). Three nearly identical instruments have been used on the Multiple Mirror Telescope and 1.5 m Tillinghast Reflector at the F.L. Whipple Observatory atop Mount Hopkins, Arizona, and on the 1.5m Wyeth Reflector located at the Oak Ridge Observatory in the town of Harvard, Massachusetts. Echelle spectrographs have been used with photon counting intensified Reticon detectors to record about 45Angstroems of spectrum in a single order. Most of the spectra were centered near 5187Angstroems, but a significant number of the early spectra were centered near 5197Angstroems. The shift in central wavelength was adopted in order to include all three lines of the Mgb triplet, after it was fully appreciated that all the other lines in our spectral window became extremely weak for our most metal-poor stars. The spectral resolution is about 8.5km.s-1 for all our exposures, and the signal-to-noise ratios range from about 5 to 50 per resolution element.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/371/1159
- Title:
- Orbits of 30 spectroscopic binaries
- Short Name:
- J/MNRAS/371/1159
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Three of the six southern Clube Areas that were mainly observed at the European Southern Observatory and whose principal results are given in Paper XVI (Griffin & Cornell 2006, Cat. <J/MNRAS/371/1140>) are marginally observable from Haute-Provence. Additional measurements obtained on several observing runs there enabled orbits to be determined (in most cases rather poorly, owing to the paucity of data) for 30 of the newly discovered spectroscopic-binary systems; they are presented in this paper. One object, HD 33978, seems to be of such significance that special efforts have been made, largely by Drs J. Andersen and H. Lindgren, to obtain additional radial-velocity measurements. That system is shown to be a double-lined binary with a period of only 10.67d despite one of its components being a late-type giant. The giant star has a projected rotational velocity of almost 40km/s; it could be expected to exhibit RS CVn-type photometric variations, which have not yet been observed, in addition to the 'ellipsoidal variation', discovered by Hipparcos, which occasioned its designation as VV Lep.
- ID:
- ivo://CDS.VizieR/J/A+A/430/223
- Title:
- Parameters of cool companions of sdB stars
- Short Name:
- J/A+A/430/223
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of a high-resolution, high-quality sample of optical spectra for 76 subdwarf B (sdB) stars from the ESO Supernova Ia Progenitor Survey (SPY, Napiwotzki et al., 2001A&A...367..973N). Effective temperature, surface gravity, and photospheric helium abundance are determined simultaneously by fitting the profiles of hydrogen and helium lines using synthetic spectra calculated from LTE and NLTE model atmospheres. We perform a detailed comparison of our measurements with theoretical calculations, both for single star evolution and for binary population synthesis models of close binary evolution.
- ID:
- ivo://CDS.VizieR/V/41
- Title:
- Physical parameters of spectroscopic binaries
- Short Name:
- V/41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalogue contains all stars listed in the 7th Catalogue of Spectroscopic Binaries (Batten, 1967PDAO...13..119B), supplements by Pedoussaut et al.: 1971A&AS....4..253P (11), 1973A&AS...10..105P (12) and 1977A&AS...27...55P (13), and data picked up by the authors from current publications up to the beginning of 1978.
- ID:
- ivo://CDS.VizieR/J/A+A/530/A28
- Title:
- Priority targets for the MUCHFUSS project
- Short Name:
- J/A+A/530/A28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The project Massive Unseen Companions to Hot Faint Underluminous Stars from SDSS (MUCHFUSS) aims at finding sdBs with compact companions like supermassive white dwarfs (M>1.0M_{sun}_), neutron stars or black holes. The existence of such systems is predicted by binary evolution theory and recent discoveries indicate that they are likely to exist in our Galaxy. A determination of the orbital parameters is sufficient to put a lower limit on the companion mass by calculating the binary mass function. If this lower limit exceeds the Chandrasekhar mass and no sign of a companion is visible in the spectra, the existence of a massive compact companion is proven without the need for any additional assumptions. We identified about 1100 hot subdwarf stars from the SDSS by colour selection and visual inspection of their spectra. Stars with high velocities have been reobserved and individual SDSS spectra have been analysed. In total 127 radial velocity variable subdwarfs have been discovered. Binaries with high RV shifts and binaries with moderate shifts within short timespans have the highest probability of hosting massive compact companions. Atmospheric parameters of 69 hot subdwarfs in these binary systems have been determined by means of a quantitative spectral analysis. The atmospheric parameter distribution of the selected sample does not differ from previously studied samples of hot subdwarfs. The systems are considered the best candidates to search for massive compact companions by follow-up time resolved spectroscopy.
- ID:
- ivo://CDS.VizieR/J/AJ/150/97
- Title:
- Radial velocities in M67. I. 1278 candidate members
- Short Name:
- J/AJ/150/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from 13776 radial-velocity (RV) measurements of 1278 candidate members of the old (4Gyr) open cluster M67 (NGC 2682). The measurements are the results of a long-term survey that includes data from seven telescopes with observations for some stars spanning over 40years. For narrow-lined stars, RVs are measured with precisions ranging from about 0.1 to 0.8km/s. The combined stellar sample reaches from the brightest giants in the cluster down to about 4mag below the main-sequence turnoff (V=16.5), covering a mass range of about 1.34M_{sun}_ to 0.76M_{sun}_. Spatially, the sample extends to a radius of 30arcmin (7.4pc in projection at a distance of 850pc or 6-7 core radii). We find M67 to have a mean radial velocity of +33.64km/s (with an internal precision of +/-0.03km/s) well separated from the mean velocity of the field. For stars with >=3 measurements, we derive RV membership probabilities and identify RV variables, finding 562 cluster members, 142 of which show significant RV variability. We use these cluster members to construct a color-magnitude diagram and identify a rich sample of stars that lie far from the standard single star isochrone, including the well-known blue stragglers, sub-subgiants and yellow giants. These exotic stars have a binary frequency of (at least) 80%, more than three times that detected for stars in the remainder of the sample. We confirm that the cluster is mass segregated, finding the binaries to be more centrally concentrated than the single stars in our sample at the 99.8% confidence level (and at the 98.7% confidence level when only considering main-sequence stars). The blue stragglers are centrally concentrated as compared to the solar-type main-sequence single stars in the cluster at the 99.7% confidence level. Accounting for measurement precision, we derive an RV dispersion in M67 of 0.80+/-0.04km/s for our sample of single main-sequence stars, subgiants and giants with V{<=}15.5. When corrected for undetected binaries, this sample yields a true RV dispersion of 0.59_-0.06_^+0.07^km/s. The radial distribution of the velocity dispersion is consistent with an isothermal distribution within our stellar sample. Using the cluster RV dispersion, we estimate a virial mass for the cluster of 2100_-550_^+610^M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/AJ/139/1383
- Title:
- Radial velocities in M35 (NGC 2168)
- Short Name:
- J/AJ/139/1383
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 5201 radial-velocity (RV) measurements of 1144 stars as part of an ongoing study of the young (150Myr) open cluster M35 (NGC 2168). We have observed M35 since 1997, using the Hydra Multi-Object Spectrograph on the WIYN 3.5m telescope.
- ID:
- ivo://CDS.VizieR/J/ApJ/639/1069
- Title:
- Radial velocities in the Cas OB6 association
- Short Name:
- J/ApJ/639/1069
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of time-resolved spectroscopy of 13 O-type stars in the Cas OB6 stellar association. We conducted a survey for radial velocity variability in search of binary systems, which are expected to be plentiful in young OB associations.
- ID:
- ivo://CDS.VizieR/J/A+A/528/A127
- Title:
- Radial velocities in the globular NGC 2808
- Short Name:
- J/A+A/528/A127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The formation mechanism of hot horizontal branch (HB) stars is still one of the most uncertain points of stellar evolution theories. In the past decade, models based on their binary origin have been very successful in reproducing the properties of field subdwarf-B stars, but the observations of their analogues in globular clusters has posed new problems. In addition, the discovery of multiple populations offered an appealing alternative scenario for the formation of these stars. We search for binaries of period P<=200days among a sample of 83 blue horizontal branch stars (Teff=12000-22000K) in NGC 2808, a cluster known to host three distinct stellar populations and a multimodal horizontal branch. The final sample, after the rejection of stars with incomplete observations or poor quality data, consists of 64 targets. The radial velocity of the targets was measured in fourteen epochs, spanning a temporal interval of ~75days. The significant variations were identified by means of a detailed error analysis and a statistical study.
- ID:
- ivo://CDS.VizieR/J/A+A/638/A131
- Title:
- Radial velocities of 643 DA white dwarfs
- Short Name:
- J/A+A/638/A131
- Date:
- 14 Jan 2022 08:18:09
- Publisher:
- CDS
- Description:
- Close double degenerate binaries are one of the favoured progenitor channels for type Ia supernovae, but it is unclear how many suitable systems there are in the Galaxy. We report results of a large radial velocity survey for double degenerate (DD) binaries using the UVES spectrograph at the ESO VLT (ESO SNIa Progenitor surveY - SPY). Exposures taken at different epochs are checked for radial velocity shifts indicating close binary systems.We observed 689 targets classified as DA (displaying hydrogen-rich atmospheres), of which 46 turned out to possess a cool companion. We measured radial velocities (RV) of the remaining 643 DA white dwarfs.We managed to secure observations at two or more epochs for 625 targets, supplemented by eleven objects meeting our selection criteria from literature. The data reduction and analysis methods applied to the survey data are described in detail. The sample contains 39 double degenerate binaries, only four of which were previously known. 20 are double-lined systems, in which features from both components are visible, the other 19 are single-lined binaries. We provide absolute RVs transformed to the heliocentric system suitable for kinematic studies. Our sample is large enough to sub-divide by mass: 16 out of 44 low mass targets (<=0.45M_{sun}_) are detected as DDs, while just 23 of the remaining 567 with multiple spectra and mass >0.45M_{sun}_ are double. Although the detected fraction amongst the low mass objects (36.4+/-7.3%) is significantly higher than for the higher-mass, carbon/oxygen-core dominated part of the sample (3.9+/-0.8%), it is lower than the detection efficiency based upon companion star masses of 0.05M_{sun}_ or higher and a 100% binary fraction. This suggests either companion stars of mass below 0.05M_{sun}_ or some of the low mass white dwarfs are single.
