- ID:
- ivo://CDS.VizieR/J/A+AS/103/67
- Title:
- Evolutionary sequences with MC metallicities
- Short Name:
- J/A+AS/103/67
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Tables of evolutionary sequences for massive stars with metallicities Z=0.002 and Z=0.01 in the mass range 9 to 40 M_{sun}_ and mass ratios 0.9 and 0.6 are presented. The orbital periods are chosen such that mass transfer according to case B occurs, i.e. mass exchange after core hydrogen exhaustion, during semi-detached and contact phases. The evolutionary code used by de Loore & De Greve (1992A&AS...94..453D) for galactic massive close binaries was updated, i.e. new thermodynamic quantities and new opacities were installed. The evolution of both components is followed simultaneously. Stellar wind mass loss rates during the OB phase are scaled according to the radiatively driven wind theory. Wolf-Rayet mass loss rates are assumed to be independent of metallicity. The models presented here may be used to interpret and evaluate the observations of Wolf-Rayet stars and massive binary X-ray sources in the Small and Large Magellanic Clouds.
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- ID:
- ivo://CDS.VizieR/J/A+A/573/A71
- Title:
- Evolution of rotating very massive LC stars
- Short Name:
- J/A+A/573/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With growing evidence for the existence of very massive stars at subsolar metallicity, there is an increased need for corresponding stellar evolution models. We present a dense model grid with a tailored input chemical composition appropriate for the Large Magellanic Cloud (LMC).
- ID:
- ivo://CDS.VizieR/J/ApJ/417/209
- Title:
- Faint planetary nebulae in Magellanic Clouds
- Short Name:
- J/ApJ/417/209
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The accuracy of spectrophotometry for Magellanic Cloud planetary nebulae is limited by a number of physical effects and operational difficulties: atmospheric dispersion, wavelength-dependent seeing, pointing and guiding errors, and a background of numerous stars and diffuse emission. We describe procedures to minimize the impact of some of these. We then compare our results for both bright and faint objects with published values. There are a few exceptional cases (e.g., LMC 89), but generally we find that bright planetary nebulae in the Clouds have been observed with high accuracy. On the other hand, observations of the faint sample from Jacoby (1980ApJS...42....1J) suffer seriously from many of these effects. We also compare published {lambda}5007 photometry with new CCD photometry for nine faint planetary nebulae. We find the photographic photometry presented by Jacoby (1980ApJS...42....1J) to be accurate to 0.26mag. Fluxes for the fainter objects that are derived from spectrophotometry (Boroson & Liebert, 1989ApJ...339..844B) are found to be less reliable. In comparison, spectrophotometry using the observational techniques presented in this paper provides reliable absolute fluxes. With these improved observations, we review the correlations presented by Kaler & Jacoby (1990ApJ...362..491K, 1991ApJ...382..134K) between abundance ratios and central star mass. The new results fit our earlier correlation for N/O, strengthen that for He/H, and change little about those for C/O and O/H.
- ID:
- ivo://CDS.VizieR/J/MNRAS/467/1776
- Title:
- Faraday rotation in Magellanic Bridge
- Short Name:
- J/MNRAS/467/1776
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an investigation into the magnetism of the Magellanic Bridge, carried out through the observation of Faraday rotation towards 167 polarized extragalactic radio sources spanning the continuous frequency range of 1.3-3.1GHz with the Australia Telescope Compact Array. Comparing measured Faraday depth values of sources 'on' and 'off' the Bridge, we find that the two populations are implicitly different. Assuming that this difference in populations is due to a coherent field in the Magellanic Bridge, the observed Faraday depths indicate a median line-of-sight coherent magnetic-field strength of B||~=0.3uG directed uniformly away from us. Motivated by the varying magnitude of Faraday depths of sources on the Bridge, we speculate that the coherent field observed in the Bridge is a consequence of the coherent magnetic fields from the Large and Small Magellanic Clouds being pulled into the tidal feature. This is the first observation of a coherent magnetic field spanning the entirety of the Magellanic Bridge and we argue that this is a direct probe of a 'pan-Magellanic' field.
- ID:
- ivo://CDS.VizieR/J/A+A/454/257
- Title:
- First overtone RR Lyrae in LMC
- Short Name:
- J/A+A/454/257
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- By using the full span of multicolor data on a representative sample of first overtone RR Lyrae stars in the Large Magellanic Cloud (LMC), we revisit the problem of the incidence rate of the amplitude/phase-modulated (Blazhko) stars. Methods. Multicolor data, obtained by the MAssive Compact Halo Objects (MACHO) project, are utilized through a periodogram averaging method. Multicolor data, obtained by the MAssive Compact Halo Objects (MACHO) project, are utilized through a periodogram averaging method.
- ID:
- ivo://CDS.VizieR/J/MNRAS/438/2440
- Title:
- Fourier analysis of 13095 LMC RR Lyr stars
- Short Name:
- J/MNRAS/438/2440
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a careful and detailed light-curve analysis of publicly available I-band data on fundamental mode RR Lyrae (RRab) stars of the Large Magellanic Cloud (LMC) obtained by the Optical Gravitational Lensing Experiment phase-III project. Using the Fourier parameters of 13095 RRab stars, metallicities and absolute magnitudes of individual stars are obtained. The representation of stars on the P-{phi}_31_^V^ plane shows the existence of three significant metallicity groups with mean metallicities as -1.20+/-0.12, -1.57+/-0.10 and -1.89+/-0.09dex. The corresponding absolute magnitudes of these three groups are obtained as 0.70+/-0.08, 0.59+/-0.06 and 0.49+/-0.08mag, respectively. Distribution of these three groups as a function of vertical |z| distance indicates that the formation of the LMC disc predates the formation of the inner halo. Issue of the existence of a metallicity gradient as a function of galactocentric distances has also been addressed. Approximating the structure of the LMC disc as a triaxial ellipsoid, the inclination angle (i) relative to the plane of the sky and the position angle of the line of nodes ({theta}_lon_) were estimated as 24.20{deg} and 176.01{deg}, respectively. The axes ratios and the eccentricity were also determined using the principal axis transformation method.
- ID:
- ivo://CDS.VizieR/J/A+A/555/A131
- Title:
- Fundamental parameters of star clusters in the LMC
- Short Name:
- J/A+A/555/A131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To enlarge our growing sample of well-studied star clusters in the Large Magellanic Cloud (LMC), we present CCD Washington CT1 photometry to T1~23 in the fields of twenty-three mostly unstudied clusters located in the inner disc and outer regions of the LMC. We estimated cluster radii from star counts. Using the cluster Washington (T1,C-T1) colour-magnitude diagrams, statistically cleaned from field star contamination, we derived cluster ages and metallicities from a comparison with theoretical isochrones of the Padova group. Whenever possible, we also derived ages using delta T1 - the magnitude difference between the red giant clump and the main sequence turn off - and estimated metallicities from the standard giant branch procedure. We enlarged our sample by adding clusters with published ages and metallicities determined on a similar scale by applying the same methods. We examined relationships between their positions in the LMC, ages and metallicities. We find that the two methods for age and metallicity determination agree well with each other. Fourteen clusters are found to be intermediate-age clusters (1-2Gyr), with [Fe/H] values ranging from -0.4 to -0.7. The remaining nine clusters turn out to be younger than 1Gyr, with metallicities between 0.0 and -0.4. Our 23 clusters represent an increase of ~30% in the current total amount number of well-studied LMC clusters using Washington photometry. In agreement with previous studies, we find no evidence for a metallicity gradient. We also find that the younger clusters were formed closer to the LMC centre than the older ones.
- ID:
- ivo://CDS.VizieR/J/PASP/121/634
- Title:
- FUSE observations in Magellanic Clouds
- Short Name:
- J/PASP/121/634
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an atlas of stellar sight line data from the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite for 287 stars in the Magellanic Clouds, obtained from eight years of satellite operations. The intent of our project is to make this rich ensemble data set accessible to a broad community of researchers in a standardized format that will enable easy identification of subsets of these data that are appropriate for pursuing specific science programs. We present the data in a standardized manner, showing key interstellar lines on a velocity scale, optical (MCELS) and infrared (Spitzer) sight line context images, and overview plots of the spectral region containing the OVI {lambda}{lambda}1032, 1038 doublet, and the entire 905-1187{AA} spectral range observed with FUSE. Objects with multiple observations have had their data summed to directly provide the highest signal-to-noise ratio available. These data are accessible online as a High Level Science Product through the Multimission Archive at Space Telescope (MAST). In this article, we describe the data sets and processing, the atlas materials, and the MAST interface in detail, and also provide examples of how to use these materials.
- ID:
- ivo://CDS.VizieR/J/ApJ/718/L141
- Title:
- FUV diffuse emission from the LMC
- Short Name:
- J/ApJ/718/L141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first observations of diffuse radiation in the far-ultraviolet (FUV; 1000-1150{AA}) from the Large Magellanic Cloud based on observations made with the Far Ultraviolet Spectroscopic Explorer. The fraction of the total radiation in the field emitted as diffuse radiation is typically 5%-20% with a high of 45% near N70 where there are few exciting stars, indicating that much of the emission is not due to nearby stars. Much less light is scattered in the FUV than at longer wavelengths, with the stellar radiation going into heating the interstellar dust.
- ID:
- ivo://CDS.VizieR/J/AcA/66/433
- Title:
- Gaia DR1 and OGLE variable stars
- Short Name:
- J/AcA/66/433
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comparison of the Gaia DR1 samples of pulsating variable stars - Cepheids and RR Lyr type - with the OGLE Collection of Variable Stars aiming at the characterization of the Gaia mission performance in the stellar variability domain. Out of 575 Cepheids and 2322 RR Lyr candidates from the Gaia DR1 samples located in the OGLE footprint in the sky, 559 Cepheids and 2302 RR Lyr stars are genuine pulsators of these types. The number of misclassified stars is low indicating reliable performance of the Gaia data pipeline. The completeness of the Gaia DR1 samples of Cepheids and RR Lyr stars is at the level of 60-75% as compared to the OGLE Collection dataset. This level of completeness is moderate and may limit the applicability of the Gaia data in many projects.
