- ID:
- ivo://CDS.VizieR/J/A+AS/136/509
- Title:
- Stellar kinematics in spiral galaxies. II.
- Short Name:
- J/A+AS/136/509
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a second dataset of absorption spectroscopy on the inner region of spiral galaxies. We have determined the central velocity dispersion for 42 Sa-Sc objects and, for 32 of them, stellar rotation curves and velocity-dispersion profiles. Some of these profiles are limited to the bulge, some others do reach a region dominated by the luminosity of the disk. These data are intended to provide basic material for the study of the mass distribution and dynamical status in the central regions of spiral galaxies. Although no elaborate bulge-and-disk photometric decomposition is performed, we estimate the effects of limited resolution and contamination by disk light on the central velocity dispersion of the bulge. All the material presented in this paper, in particular the spectra, is available on-line.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/603/A56
- Title:
- Stellar parameters and assumed wind parameters
- Short Name:
- J/A+A/603/A56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Recent observations have challenged our understanding of rotational mixing in massive stars by revealing a population of fast-rotating objects with apparently normal surface nitrogen abundances. However, several questions have arisen because of a number of issues (e.g., presence of numerous upper limits for the nitrogen abundance, unknown multiplicity status, mix of stars with different physical properties such as their mass and evolutionary state that are known to control the amount of rotational mixing), rendering a re-investigation necessary. We have carefully selected a large sample of bright, fast-rotating early-type stars of our Galaxy (40 objects with spectral types between B0.5 and O4). Their high-quality, high-resolution optical spectra were then analysed with the stellar atmosphere modelling codes DETAIL/SURFACE or CMFGEN, depending on the temperature of the target. Several internal and external checks were performed to validate our methods, notably comparing our results with literature data for some well-known objects, studying the effect of gravity darkening, or confronting the results provided by the two codes for stars amenable to both analyses. Furthermore, we have studied the radial velocities of the stars to assess their binarity. This first part of our study presents our methods and provides the derived stellar parameters, He, CNO abundances and the multiplicity status of every star of the sample. It is the first time that He and CNO abundances of such a large number of Galactic massive fast rotators are determined in a homogeneous way.
- ID:
- ivo://CDS.VizieR/J/A+A/530/A31
- Title:
- Stellar parameters in 10 globular cluster fields
- Short Name:
- J/A+A/530/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Here we publish the extracted stellar parameters from a recent large spectroscopic survey of ten globular clusters. A brief review of the project is also presented. Stellar parameters have been extracted from individual stellar spectra using both a modified version of the Radial Velocity Experiment (RAVE) pipeline and a pipeline based on the parameter estimation method of RAVE. We publish here all parameters extracted from both pipelines. We calibrate the metallicity and convert this to [Fe/H] for each star and, furthermore, we compare the velocities and velocity dispersions of the Galactic stars in each field to the Besanc,on Galaxy model. We find that the model does not correspond well with the data, indicating that the model is probably of little use for comparisons with pencil beam survey data such as this.
- ID:
- ivo://CDS.VizieR/J/AJ/159/287
- Title:
- Stellar parameters in Ophiuchus Stream with MMT
- Short Name:
- J/AJ/159/287
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new kinematic data for the Ophiuchus stellar stream. Spectra have been taken of member candidates at the Multiple Mirror Telescope (MMT) using Hectospec, Hectochelle, and Binospec, which provide more than 1800 new velocities. Combined with proper-motion measurements of stars in the field by the Gaia-DR2 catalog, we have derived stream membership probabilities, resulting in the detection of more than 200 likely members. These data show the stream extends to more than three times the length shown in the discovery data. A spur to the main stream is also detected. The high-resolution spectra allow us to resolve the stellar velocity dispersion, found to be 1.6{+/-}0.3km/s.
- ID:
- ivo://CDS.VizieR/J/A+A/400/939
- Title:
- Stellar parameters of 115 HQS sdB stars
- Short Name:
- J/A+A/400/939
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a spectral analysis of a large sample of subdwarf B stars selected from follow-up observations of candidates from the Hamburg Quasar Survey. Table 4 summarizes the results (effective temperatures, gravities, and helium abundances) of our analysis. Additionally, the equatorial and galactical coordinates, the B magnitudes and extinctions, the derived radial velocities, the absolute visual magnitudes, the distances from earth and from the galactic plane, and the references are given for all programme stars.
- ID:
- ivo://CDS.VizieR/J/AJ/161/288
- Title:
- Stellar population in M53
- Short Name:
- J/AJ/161/288
- Date:
- 18 Jan 2022
- Publisher:
- CDS
- Description:
- We present results from a study of 94 red giant stars in the globular cluster M53. We use low-resolution spectra to measure the strength of CN and CH features at ~3800 and 4300{AA}, respectively. The strengths of these features are used to classify stars into a CN-enhanced and CN-normal population and to measure C and N abundances in all 94 stars. We find the red giant branch stars to be evenly split between the two populations identified, and observe the presence of CN-enhanced stars on the asymptotic giant branch. In addition, we identify five CH star candidates based on the strength of their CN and CH band features, and the presence of a P-branch in their CH band. We compare our identification of multiple populations to those based on the Na-O anticorrelation and pseudo-color indices in Hubble Space Telescope UV photometry, and find general agreement between all three methods. Our large sample size also allows us to study the radial distribution of each population, and we find that the CN-enhanced population is more centrally concentrated. We use our C and N measurements to compare the evolutionary changes in these elements as a function of magnitude between the two populations, and show that both populations experience similar evolutionary changes to the surface abundances of C and N. Finally, we calculate C+N+O abundances for each population and compare them to similar measurements made in M10; we find that in both clusters, CN-enhanced stars have a slightly enhanced C+N+O ({Delta}(C+N+O)~0.2dex).
- ID:
- ivo://CDS.VizieR/J/AJ/158/14
- Title:
- Stellar populations of globular clusters using APOGEE
- Short Name:
- J/AJ/158/14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate aluminum abundance variations in the stellar populations of globular clusters using both literature measurements of sodium and aluminum and APOGEE measurements of nitrogen and aluminum abundances. For the latter, we show that the Payne is the most suitable of the five available abundance pipelines for our purposes. Our combined sample of 42 globular clusters spans approximately 2 dex in [Fe/H] and 1.5 dex in logM_GC_/M_{sun}_. We find no fewer than five globular clusters with significant internal variations in nitrogen and/or sodium with little to no corresponding variation in aluminum, and that the minimum present-day cluster mass for aluminum enrichment in metal-rich systems is logM_GC_/M_{sun}_~4.50+2.17([Fe/H]+1.30). We demonstrate that the slopes of the [Al/Fe] versus [Na/Fe] and [Al/Fe] versus [N/Fe] relations for stars without field-like abundances are approximately log-linearly dependent on both the metallicity and the stellar mass of the globular clusters. In contrast, the relationship between [Na/Fe] and [N/Fe] shows no evidence of such dependencies. This suggests that there were (at least) two classes of non-supernova chemical polluters that were common in the early universe, and that their relative contributions within globular clusters somehow scaled with the metallicity and mass of globular clusters. The first of these classes is predominantly responsible for the CNO and NeNa abundance variations, and likewise the second for the MgAl abundance variations. Particularly striking examples of this dichotomy include 47 Tuc and M4. As an auxiliary finding, we argue that abundance variations among Terzan 5 stars are consistent with it being a normal globular cluster.
- ID:
- ivo://CDS.VizieR/J/AJ/156/217
- Title:
- Stellar properties for M dwarfs in MEarth-South
- Short Name:
- J/AJ/156/217
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Stellar rotation periods are valuable both for constraining models of angular momentum loss and for understanding how magnetic features impact inferences of exoplanet parameters. Building on our previous work in the northern hemisphere, we have used long-term, ground-based photometric monitoring from the MEarth Observatory to measure 234 rotation periods for nearby, southern hemisphere M dwarfs. Notable examples include the exoplanet hosts GJ 1132, LHS 1140, and Proxima Centauri. We find excellent agreement between our data and K2 photometry for the overlapping subset. Among the sample of stars with the highest quality data sets, we recover periods in 66%; as the length of the data set increases, our recovery rate approaches 100%. The longest rotation periods we detect are around 140 days, which we suggest represent the periods that are reached when M dwarfs are as old as the local thick disk (about 9 Gyr).
- ID:
- ivo://CDS.VizieR/III/216
- Title:
- Stellar Radial Velocities 1991-1998
- Short Name:
- III/216
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The present catalogue is the third version and supersedes the first one (1991-1994) published by Malaroda et al. (2000A&AS..144....1M, Cat. <III/204>). We have revised the issues of the journals listed in Table 1, for the period 1991-1998. It is not a complete list of all journals devoted to astronomical literature, but they are the most important ones and those available at our libraries. We prepared a plain ASCII file with the object identifications as provided by the authors. This file was transferred to the SIMBAD database, and, using the proper formats and filters, we have retrieved the identification for each object according to the rules of SIMBAD. In the same way we have also retrieved: the J2000 coordinates, the V magnitude, and the spectral classification for each object.
- ID:
- ivo://CDS.VizieR/III/249
- Title:
- Stellar radial velocities bibliographic catalog
- Short Name:
- III/249
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- The present catalogue is the twelfth version and the continuation of the first one (1991-1994) published by Malaroda et al. (2000A&AS..144....1M). Since the 2005 version, we present the catalogue in a database for helping the search. We have revised the issues of the journals listed in Table 1, for the period 1991-2006June. It is not a complete list of all journals devoted to astronomical literature, but they are the most important ones and those available at our libraries. We prepared a plain ASCII file with the object identifications as provided by the authors. This file was transferred to the SIMBAD database, and, using the proper for mats and filters, we have retrieved the identification for each object according to the rules of SIMBAD. In the same way we have also retrieved: the J2000 coordinates, the V magnitude, and the spectral classification for each object.