- ID:
- ivo://CDS.VizieR/J/MNRAS/466/1567
- Title:
- Sou323 ICRF reference sample
- Short Name:
- J/MNRAS/466/1567
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We aim to evaluate the possibility of improving the International Celestial Reference System realization starting from the ICRF2 catalogue by investigating the coordinate time series of radio sources observed by the very long baseline interferometry between 1979 and 2016. Sources with long observational history are selected as the candidates and the least-squares fits with special handling of the weights are performed to derive the linear drifts of the source coordinates. Then the sources are sorted, based on the normalized linear drift (i) over the whole sky, and (ii) in four homolographic areas divided by declinations. The axial stability of the reference system and sky distribution defined by the selected sources are evaluated, which are acted as the criterion for the final source lists. With our improved source selection scheme, two groups of sources are proposed and considered suitable for defining a more stable and homogeneous celestial reference system compared to the second version of the current International Celestial Reference Frame (ICRF2). The number of sources in the final lists are 323 and 294, respectively, and the global rotations of the axes derived from apparent motion of the sources are about two times better th
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Search Results
- ID:
- ivo://CDS.VizieR/I/119
- Title:
- Southern Durchmusterung
- Short Name:
- I/119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Southern Durchmusterung (SD) was computerized at the Centre de Donnees Astronomiques de Strasbourg and at the Astronomical Data Center at the National Space Science Data Center, NASA/Goddard Space Flight Center. Corrigenda listed in the original SD volume and published by Kuestner and Sticker have been incorporated into the machine file. In addition, one star indicated to be "missing" in a published list, and later verified, is flagged so that it can be omitted from computer plotted charts if desired. Stars deleted in the various errata lists have been similarly flagged, while those with revised data are flagged and listed in a separate table. This catalog covers the zones -02 to -23 degrees.
- ID:
- ivo://CDS.VizieR/J/A+A/615/A76
- Title:
- Spectroscopic parameters of stars (SPECIES). I.
- Short Name:
- J/A+A/615/A76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The detection and subsequent characterisation of exoplanets are intimately linked to the characteristics of their host star. Therefore, it is necessary to study the star in detail in order to understand the formation history and characteristics of their companion(s). Our aims are to develop a community tool that allows the automated calculation of stellar parameters for a large number of stars, using high resolution echelle spectra and minimal photometric magnitudes, and introduce the first catalogue of these measurements in this work. We measured the equivalent widths of several iron lines and used them to solve the radiative transfer equation assuming local thermodynamic equilibrium in order to obtain the atmospheric parameters (Teff, [Fe/H], logg, and {xi}_t). We then used these values to derive the abundance of 11 chemical elements in the stellar photosphere (Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Ni, Cu, and Zn). Rotation and macroturbulent velocity were obtained using temperature calibrators and synthetic line profiles to match the observed spectra isochrones, we were able to derive the mass, radius, and age for each star using a Bayesian approach. SPECIES obtains bulk parameters that are in good agreement with measured values from different existing catalogues, including when different methods are used to derive them. We find discrepancies in the chemical abundances for some elements with respect to other works, which could be produced by differences in Teff, or in the line list or the atomic line data used to derive them. We also obtained analytic relations to describe the correlations between different parameters, and we implemented new methods to better handle these correlations, which provides a better description of the uncertainties associated with the measurements.
94. SPF1 Catalogue
- ID:
- ivo://CDS.VizieR/I/82
- Title:
- SPF1 Catalogue
- Short Name:
- I/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
95. SPF3 Catalogue
- ID:
- ivo://CDS.VizieR/I/78
- Title:
- SPF3 Catalogue
- Short Name:
- I/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/617/A63
- Title:
- Star formation in the Vela Molecular Ridge
- Short Name:
- J/A+A/617/A63
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Most stars born in clusters and recent results suggest that star formation (SF) preferentially occurs in subclusters. Studying the morphology and SF history of young clusters is crucial to understanding early SF. We identify the embedded clusters of young stellar objects (YSOs) down to M stars, in the HII regions RCW33, RCW32 and RCW27 of the Vela Molecular Ridge. Our aim is to characterise their properties, such as morphology and extent of the clusters in the three HII regions, derive stellar ages and the connection of the SF history with the environment. Through public photometric surveys such as Gaia, VPHAS, 2MASS and Spitzer/GLIMPSE, we identify YSOs with IR, Halpha and UV excesses, as signature of circumstellar disks and accretion. In addition, we implement a method to distinguish M dwarfs and giants, by comparing the reddening derived in several optical/IR color-color diagrams assuming suitable theoretical models. Since this diagnostic is sensitive to stellar gravity, the procedure allows us to identify pre-main sequence stars. We find a large population of YSOs showing signatures of circumstellar disks with or without accretion. In addition, with the new technique of M-type star selection, we find a rich population of young M stars with a spatial distribution strongly correlated to the more massive population. We find evidence of three young clusters, with different morphology. In addition, we identify field stars falling in the same region, by securely classifying them as giants and foreground MS stars. We identify the embedded population of YSOs, down to about 0.1M_{sun}_, associated with the HII regions RCW33, RCW32 and RCW27 and the clusters Vela T2, Cr197 and Vela T1, respectively, showing very different morphologies. Our results suggest a decreasing SF rate in Vela T2 and triggered SF in Cr197 and Vela T1.
- ID:
- ivo://CDS.VizieR/J/AJ/130/2701
- Title:
- Stars in the Sagittarius Rift
- Short Name:
- J/AJ/130/2701
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A magnitude-limited photographic survey of relative proper-motion components and B, V photometry of 1.3x10^6^ stars brighter than apparent B magnitude 14.5+/-0.5 in the fourth Galactic quadrant is converted into a distance-limited survey of 3.26x10^5^ stars up to a distance of 500pc. A streaming motion of 13.5+/-0.5 km/s is detected in 4.1x10^4^ Population I stellar candidates with an orbital perigalactic center located at 6.8<=R<=7.2kpc, with a Sun location Rsol=8.5 kpc. A density perturbation of about 0.1M{sun}/pc^3^ in the Galactic field potential at Ro~6.8kpc is interpreted as resulting from the density wave connected with the Sagittarius-Carina spiral arm. A set of 1.4x10^4^ stars of mass about 1.5+/-0.75 M{sun} identify a pitch angle of 10+/-1{deg} and a migration time from the Sagittarius spiral arm into the greater solar neighborhood of about 35Myr.
- ID:
- ivo://CDS.VizieR/J/A+A/647/A157
- Title:
- Stellar parameters of the EXPRESS sample
- Short Name:
- J/A+A/647/A157
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As part of the search for planets around evolved stars, we can understand planet populations around significantly higher-mass stars than the Sun on the main sequence. This population is difficult to study any other way, particularly with radial-velocities since these stars are too hot and rotate too fast to measure precise velocities. Here we estimate stellar parameters for all of the giant stars from the EXPRESS project, which aims to detect planets orbiting evolved stars, and study their occurrence rate as a function of stellar mass. We analyse high resolution echelle spectra of these stars, and compute the atmospheric parameters by measuring the equivalent widths for a set of iron lines, using an updated method implemented during this work. Physical parameters are computed by interpolating through a grid of stellar evolutionary models, following a procedure that carefully takes into account the post-MS evolutionary phases. Probabilities of the star being in the red giant branch (RBG) or the horizontal branch (HB) are estimated from the derived distributions. Results: We find that, out of 166 evolved stars, 101 of them are most likely in the RGB phase, while 65 of them are in the HB phase. The mean derived mass is 1.41 and 1.87M_{sun}_ for RGB and HB stars, respectively. To validate our method, we compared our results with interferometry and asteroseismology studies. We find a difference in the radius with interferometry of 1.7%. With asteroseismology, we find 2.4% difference in logg, 1.5% in radius, 6.2% in mass, and 11.9% in age. Compared with previous spectroscopic studies, and find a 0.5% difference in Teff, 1% in logg, and 2% in [Fe/H]. We also find a mean mass difference with respect to the EXPRESS original catalogue of 16%. We show that the method presented here can greatly improve the estimates of the stellar parameters for giant stars compared to what was presented previously.
- ID:
- ivo://CDS.VizieR/VII/115
- Title:
- Surface Photometry of ESO-Uppsala Galaxies
- Short Name:
- VII/115
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The 15467 southern galaxies in this catalog were scanned from 407 blue and 407 red original ESO-Schmidt plates using a PDS microdensitometer. The galaxies were selected from the ESO-Uppsala Catalogue (VII/34). The original selection criterion was a minimum visual angular diameter of 1arcmin. The plates were calibrated using a catalog of photo- electric standards of 1700 standard galaxies transformed to a photometric standard system (Cousins) created by the authors. The result is a catalog acquired in a homogeneous fashion for all types of galaxies in various environments. The extracted parameters include radial surface brightness profiles, magnitudes at several isophotal levels, colors, color gradients, effective radius parameters, structural parameters such as axial ratios, position angles, and profile gradients. The full version of the catalog, made of 190 columns, is available as the file "esolv.fit" in FITS table format. The ascii file "esolv1.dat" contains a subset of these columns which includes those parameters listed in the printed book version. Detailed discussion of the catalog creation is given in the published book version (ISBN 3-923524-31-5)
- ID:
- ivo://CDS.VizieR/I/282
- Title:
- The CMT CCD Drift Scan Survey
- Short Name:
- I/282
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is CMC12 (Version 1.0), an astrometric and photometric catalogue of 6.3 million stars in the red magnitude range 9 to 17. The Carlsberg Meridian Telescope (CMT) underwent a major upgrade in March 1999. A 2k by 2k CCD camera was installed with a Sloan r' filter operating in a drift scan mode. With the new system, the magnitude limit is r'_CMT_=17 and the positional accuracy is about 0.035". The main task of the CMT is to map the sky in the declination range -3{deg} to +30{deg} with the aim of providing an astrometric, and photometric, catalogue that can accurately transfer the Hipparcos/Tycho reference frame to Schmidt plates. The current release (Version 1.0) comprises all the observations made between March 1999 and March 2002 with the new CCD in the declination band -3{deg} to +3{deg}. It is intended to release the rest of the catalogue later. A more complete description is available in the documentation at http://www.ast.cam.ac.uk/~dwe/SRF/cmc12/cmc12_documentation.ps or http://www.ast.cam.ac.uk/~dwe/SRF/cmc12/cmc12_documentation.pdf
