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2021. Cand. young OB stars from GALEX & Gaia DR2
ID:
ivo://CDS.VizieR/J/ApJ/883/8
Title:
Cand. young OB stars from GALEX & Gaia DR2
Short Name:
J/ApJ/883/8
Date:
21 Oct 2021
Publisher:
CDS
Description:
We combine Galaxy Evolution Explorer and Gaia DR2 catalogs to track star formation in the outskirts of our Galaxy. Using photometry, proper motions, and parallaxes we identify a structure of ~300 OB-type candidates located between 12 and 15kpc from the Galactic center that are kinematically cold. The structure is located between l=120{deg} and 200{deg}, above the plane up to ~700pc and below the plane to ~1kpc. The bulk motion is disklike; however, we measure a mean upward vertical motion of 5.7+/-0.4km/s, and a mean outward radial motion of between 8 and 16km/s. The velocity dispersion along the least dispersed of its proper-motion axes (perpendicular to the Galactic disk) is 6.0+/-0.3km/s, confirming the young age of this structure. While spatially encompassing the outer spiral arm of the Galaxy, this structure is not a spiral arm. Its explanation as the Milky Way warp is equally unsatisfactory. The structure's vertical extent, mean kinematics, and asymmetry with respect to the plane indicate that its origin is more akin to a wobble generated by a massive satellite perturbing the Galaxy's disk. The mean stellar ages in this outer structure indicate the event took place some 200Myr ago.
2022. Canes Venatici I images with LOFAR
ID:
ivo://CDS.VizieR/J/MNRAS/496/2663
Title:
Canes Venatici I images with LOFAR
Short Name:
J/MNRAS/496/2663
Date:
21 Oct 2021
Publisher:
CDS
Description:
Dwarf galaxies are dark matter-dominated and therefore promising targets for the search for weakly interacting massive particles (WIMPs), which are well-known candidates for dark matter. Annihilation of WIMPs produce ultra-relativistic cosmic-ray electrons and positrons that emit synchrotron radiation in the presence of magnetic fields. For typical magnetic field strengths (few G) and O(GeV-TeV) WIMP masses (and thus typical electron energies of the same order) this emission peaks at hundreds of MHz. Here, we use the non-detection of 150-MHz radio continuum emission from the dwarf spheroidal galaxy 'Canes Venatici I' with the LOw-Frequency ARray (LO-FAR) to derive constraints on the annihilation cross section of WIMPs into primary electron-positron and other fundamental particle-antiparticle pairs. In this first-of-its-kind LOFAR study, we obtain new constraints on annihilating WIMP dark matter (DM). Using conservative estimates for the magnetic field strengths and diffusion coefficients, we obtain limits that are comparable with those by the Fermi Large Area Telescope (Fermi-LAT) using gamma-ray observations. Assuming s-wave annihilation and WIMPs making up 100% of the DM density, our limits exclude several thermal WIMP realisations in the [2, 20]-GeV mass range. A more ambitious multi-wavelength and multi-target LOFAR study could improve these limits by a few orders of magnitude.
2023. Canis Major R1 X-ray sources
ID:
ivo://CDS.VizieR/J/A+A/506/711
Title:
Canis Major R1 X-ray sources
Short Name:
J/A+A/506/711
Date:
21 Oct 2021
Publisher:
CDS
Description:
The CMa R1 star-forming region contains several compact clusters as well as many young early-B stars. It is associated with a well-known bright rimmed nebula, the nature of which is unclear (fossil HII region or supernova remnant). To help elucidate the nature of the nebula, our goal was to reconstruct the star-formation history of the CMa R1 region, including the previously unknown older, fainter low-mass stellar population, using X-rays. We analyzed images obtained with the ROSAT satellite, covering ~5deg^2^. Complementary VRI photometry was performed with the Gemini South telescope. Colour-magnitude and colour-colour diagrams were used in conjunction with pre-main sequence evolutionary tracks to derive the masses and ages of the X-ray sources.
2024. Cape AC Zone Data Reduced to ACRS
ID:
ivo://CDS.VizieR/I/219
Title:
Cape AC Zone Data Reduced to ACRS
Short Name:
I/219
Date:
21 Oct 2021
Publisher:
CDS
Description:
The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Cape Zone, whose plates are centered between declinations -41 and -51 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 544,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
2025. Cape Catalog of 20554 Faint Stars, -40 to -52{deg}
ID:
ivo://CDS.VizieR/I/6
Title:
Cape Catalog of 20554 Faint Stars, -40 to -52{deg}
Short Name:
I/6
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog contains positions, precessions, proper motions, and photographic magnitudes for 20,554 stars. These were derived from photographs taken at the Royal Observatory, Cape of Good Hope between 1923 and 1928. It covers the astrographic zones -40 degrees to -52 degrees of declination. The positions are given for epoch 1900 (1900.0). It includes spectral types for many of the stars listed. It extends the earlier catalogs derived from the same plates to fainter magnitudes. The computer-readable version consists of a single data table. The stated probable error for the star positions is 0.024 seconds of time (R.A.) and 0.25 seconds of arc (Dec.) for stars with one determination, 0.017 seconds of time, and 0.18 seconds of arc for two determinations, and 0.014 / 0.15 for stars with three determinations. The precession and secular variations were derived from Newcomb's constants. The authors quote probable errors of the proper motions in both coordinates of 0.008 seconds of arc for stars with one determination, 0.0055 seconds for stars with two determinations, and 0.0044 for stars with three. The photographic magnitudes were derived from the measured diameters on the photographic plates and from the magnitudes given in the Cape Photographic Durchmusterung. The spectral classification of the catalogued stars was done with the assistance of Annie Jump Cannon of the Harvard College Observatory. The user should consult the source reference for more details of the measurements and reductions. See also the notes in this document for additional information on the interpretation of the entries.
2026. Cape Photographic Catalog 1950.0 (CPC)
ID:
ivo://CDS.VizieR/I/116
Title:
Cape Photographic Catalog 1950.0 (CPC)
Short Name:
I/116
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog includes most of the stars from the 1900.0 Cordoba Zone Catalogues B and C in the zone -30 deg. -35 deg. at the equinox of 1925.0. Some of the fainter Cordoba stars have been omitted in the rather crowded regions in the Milky Way. The aim was to provide accurate places for an average of 9 to 10 stars per square degree as a reference for a rereduction of the AG positions. Most of the stars have visual magnitudes between 7 and 10. Positions and proper motions have been supplied from the General Catalogue for those stars that were too bright for accurate measurement on photographic plates. The positions are on the FK3 system for the equinox of 1950.0. The probable errors of the positions are nominally +/- 0.15" in both right ascension and declination. That of the proper motions should not exceed +/- 1.4"/century, or +/-14 in the units in which the proper motions expressed in arc are given in the catalog.
2027. Cape Photographic Catalogue 2
ID:
ivo://CDS.VizieR/I/85
Title:
Cape Photographic Catalogue 2
Short Name:
I/85
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog contains the provisional positions for 51018 stars in the Cape zone -40 deg. to -52 deg., on the FK4 system for the equinox 1950.0. The internal mean error of a single coordinate obtained from the mean of r=four plates is estimated to be less than +/- 0.1" at the mean epoch of observation, about 1962. The systematic deviation from the FK4 system in a small area is probably also about +/-0.1". New proper motions have been determined for 22731 stars which are also in the Smithsonian Astrophysical Observatory (SAO) catalogue; the formal mean error of an annual proper motion in each coordinate is about +/-0.004"/a.
2028. Cape Photographic Durchmusterung
ID:
ivo://CDS.VizieR/I/108
Title:
Cape Photographic Durchmusterung
Short Name:
I/108
Date:
21 Oct 2021
Publisher:
CDS
Description:
The "Cape Photographic Durchmusterung" (CPD, Gill and Kapteyn 1895-1900) is a photographic survey of southern stars in the declination range -18 deg to -90 degrees. The original goal of the work was to carry out a southern survey similar to those of the "Bonner Durchmusterung" (BD, Argelander 1859-1862, see also Kuestner 1903) and Schoenfeld (1886) and the "Cordoba Durchmusterung" (CD, Thome 1892-1932) but using photographic plates which would provide a permanent record of the sky at the epoch of observation. The summary of the positional uncertainties quoted in the third volume of the published catalog gives +/- 0.28 sec (R.A.), +/- 0.044 arcmin (Dec.) for zones -18 to -57 degrees, +/- 0.157 sec + 0.0764/cos(delta) sec (R.A.), +/- 0.056 arcmin (Dec.) for zones -58 to -85 degrees, and +/- 0.157 sec + 0.0353/cos(delta) sec (R.A.), +/- 0.0127 arcmin (Dec.) for the polar plate where, as explained in the intro- duction to the third volume, many positions were derived from rectangular coordinates (these are positions reported to 0.1 sec (R.A.) and 0.001 arcmin (Dec.) in the -86 to -89 degree zones in the catalog). The probable error of a photographic magnitude, as determined by combining results for different magnitudes and weighting proportionately according to the numbers of stars in each class of magnitude, is given as +/- 0.055 mag. From an analysis of the faint magnitude limits on the plates discussed in the third volume introduction, the catalog as a whole can be considered complete to photographic magnitude 9.2, but it is stated that it will be found practically complete, in or near the Milky Way, to magnitude 9.5.
2029. Capodimonte Deep Field
ID:
ivo://CDS.VizieR/J/A+A/428/339
Title:
Capodimonte Deep Field
Short Name:
J/A+A/428/339
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the Capodimonte Deep Field (OACDF), a deep field covering an area of 0.5{deg}^2^ in the B, V, R optical bands plus six medium-band filters in the wavelength range 773-913nm. The field reaches the following limiting magnitudes: B_AB_~25.3, V_AB_~24.8 and R_AB_~25.1 and contains ~50000 extended sources in the magnitude range 18<=R_AB_<=25.0. Hence, it is intermediate between deep pencil beam surveys and very wide but shallow surveys.
2030. Carbon abundances in metal-poor stars
ID:
ivo://CDS.VizieR/J/AJ/130/2804
Title:
Carbon abundances in metal-poor stars
Short Name:
J/AJ/130/2804
Date:
21 Oct 2021
Publisher:
CDS
Description:
We develop and test a method for the estimation of metallicities ([Fe/H]) and carbon abundance ratios ([C/Fe]) for carbon-enhanced metal-poor (CEMP) stars based on the application of artificial neural networks, regressions, and synthesis models to medium-resolution (1-2{AA}) spectra and J-K colors. We calibrate this method by comparison with metallicities and carbon abundance determinations for 118 stars with available high-resolution analyses reported in the recent literature.

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