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91. Candidate Cluster Members with Deep learning
ID:
ivo://CDS.VizieR/J/A+A/643/A177
Title:
Candidate Cluster Members with Deep learning
Short Name:
J/A+A/643/A177
Date:
21 Oct 2021
Publisher:
CDS
Description:
The next generation of extensive and data-intensive surveys are bound to produce a vast amount of data, which can be efficiently dealt with using machine-learning and deep-learning methods to explore possible correlations within the multi-dimensional parameter space. We explore the classification capabilities of convolution neural networks (CNNs) to identify galaxy cluster members (CLMs) by using Hubble Space Telescope (HST) images of fifteen galaxy clusters at redshift 0.19<~z<~0.60, observed as part of the CLASH and Hubble Frontier Field programmes. We used extensive spectroscopic information, based on the CLASH-VLT VIMOS programme combined with MUSE observations, to define the knowledge base. We performed various tests to quantify how well CNNs can identify cluster members on ht basis of imaging information only. Furthermore, we investigated the CNN capability to predict source memberships outside the training coverage, in particular, by identifying CLMs at the faint end of the magnitude distributions. We find that the CNNs achieve a purity-completeness rate >~90%, demonstrating stable behaviour across the luminosity and colour of cluster galaxies, along with a remarkable generalisation capability with respect to cluster redshifts. We concluded that if extensive spectroscopic information is available as a training base, the proposed approach is a valid alternative to catalogue-based methods because it has the advantage of avoiding photometric measurements, which are particularly challenging and time-consuming in crowded cluster cores. As a byproduct, we identified 372 photometric cluster members, with mag(F814)<25, to complete the sample of 812 spectroscopic members in four galaxy clusters RX J2248-4431, MACS J0416-2403, MACS J1206-0847 and MACS J1149+2223. When this technique is applied to the data that are expected to become available from forthcoming surveys, it will be an efficient tool for a variety of studies requiring CLM selection, such as galaxy number densities, luminosity functions, and lensing mass reconstruction.
92. Candidate field horizontal-branch stars catalog
ID:
ivo://CDS.VizieR/J/ApJS/67/461
Title:
Candidate field horizontal-branch stars catalog
Short Name:
J/ApJS/67/461
Date:
21 Oct 2021
Publisher:
CDS
Description:
Coordinates and brightness estimates are presented for 4408 candidate field horizontal-branch stars selected using an objective-prism, interference-filter survey technique. The candidates lie primarily in the southern Galactic hemisphere, and are distributed in color over the range B-V from -0.2 to 0.40. Previous spectroscopic observation of a subset of these candidates indicates that roughly 85 percent of the catalog objects are bona fide members of the field blue horizontal branch. The remaining candidates include, in order of frequency, stars with main-sequence gravity which are likely to be a mix of metal-deficient turnoff stars and field blue stragglers, metallic line (Am) stars, A stars of near-solar metallicity, and high-luminosity or binary stars.
93. Candidate halo dark matter
ID:
ivo://CDS.VizieR/J/other/Sci/292.698
Title:
Candidate halo dark matter
Short Name:
J/other/Sci/292.
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Milky Way galaxy contains a large, spherical component which is believed to harbor a substantial amount of unseen matter. Recent observations indirectly suggest that as much as half of this "dark matter" may be in the form of old, very cool white dwarfs, the remnants of an ancient population of stars as old as the galaxy itself. We conducted a survey to find faint, cool white dwarfs with large space velocities, indicative of their membership in the galaxy's spherical halo component. The survey reveals a substantial, directly observed population of old white dwarfs, too faint to be seen in previous surveys. This newly discovered population accounts for at least 2 percent of the halo dark matter. It provides a natural explanation for the indirect observations, and represents a direct detection of galactic halo dark matter.
94. Candidate member stars of the Sagittarius stream
ID:
ivo://CDS.VizieR/J/A+A/635/L3
Title:
Candidate member stars of the Sagittarius stream
Short Name:
J/A+A/635/L3
Date:
21 Oct 2021
Publisher:
CDS
Description:
We aim to measure the proper motion along the Sagittarius stream, which is the missing piece in determining its full 6D phase space coordinates. We conduct a blind search of over-densities in proper motion from the Gaia second data release (DR2) in a broad region around the Sagittarius stream by applying wavelet transform techniques. We find that for most of the sky patches, the highest intensity peaks delineate the path of the Sagittarius stream. The 1500 peaks identified depict a continuous sequence spanning almost 2pi in the sky, only obscured when the stream crosses the Galactic disk. Altogether, around 100000 stars potentially belong to the stream as indicated by a coarse inspection of the color-magnitude diagrams. From these stars, we determine the proper motion along the Sagittarius stream, making it the proper-motion sequence with the largest span and continuity ever measured for a stream. A first comparison with existing N-body models of the stream reveals some discrepancies, especially near the pericenter of the trailing arm and an underestimation of the total proper motion for the leading arm. Our study provides a starting point for determining the variation of the population of stars along the stream, the distance to the stream from the red clump stars, and the solar motion. It also permits much more accurate measurement of the Milky Way potential.
95. 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.
96. 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.
97. 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.
98. 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.
99. Carbon stars from the Hamburg/ESO survey
ID:
ivo://CDS.VizieR/J/A+A/375/366
Title:
Carbon stars from the Hamburg/ESO survey
Short Name:
J/A+A/375/366
Date:
21 Oct 2021
Publisher:
CDS
Description:
This catalog contains 403 Faint High Latitude Carbon (FHLC) stars selected from the digitized objective prism plates of the Hamburg/ESO Survey (HES). Because of the ~15{AA} spectral resolution and high signal-to-noise ratio of the HES prism spectra, our automated procedure based on the detection of C_2_ and CN molecular bands permits high-confidence identification of carbon stars without the need for follow-up spectroscopy. 329 plates (87% of the survey) were examined, covering 6400deg^2^ to a magnitude limit of V~16.5. The catalog lists coordinates, photometry, and carbon band indices for 403 FHLC stars found in the Hamburg/ESO survey. B_J_ magnitudes are accurate to better than +/-0.2mag, including zero point errors. V magnitudes, B-V and U-B colors were derived by the procedure described in Christlieb et al. (2001A&A...366..898C). We also list an object classification for the sources, where "stars", "bright" and "ext" refer to point sources, sources above a saturation threshold, and sources detected as extended in DSS I images, respectively. We do not list V, B-V and U-B for saturated objects, because our color calibrations are not valid for them. Finally, we list two selection flags.
100. Carlsberg Meridian Catalog 14 (CMC14)
ID:
ivo://CDS.VizieR/I/304
Title:
Carlsberg Meridian Catalog 14 (CMC14)
Short Name:
I/304
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Carlsberg Meridian Telescope (formerly the Carlsberg Automatic Meridian Circle) is dedicated to carrying out high-precision optical astrometry. It underwent a major upgrade in March 1999, with the installation of a 2kx2k CCD camera was installed with a Sloan r' filter operating in a drift scan mode. With the new system, the magnitude limit is 17 (r'mag) and the positional accuracy is in the range 35 to 100 mas. The resulting survey is aimed to provide an astrometric and photometric catalogue in the declination range -30 to +50 degrees. This catalogue is the result of all the observations made between March 1999 and October 2005 in the declination band -30 to +50 -- minus a gap between 5h30m and 10h30m for declinations south of -15. It contains 95,858,475 stars, plus 8,046,291 in the rejected files. Further information can be found in the documentation (cmc14doc.pdf) or at the web site http://www.ast.cam.ac.uk/~dwe/SRF/camc.html . It supersedes the previous versions (Cat. I/282) A dedicated remote query program (findcmc14) can be downloaded from http://cdsweb.u-strasbg.fr/doc/cdsclient.html

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