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131. CANDELS galaxy structure classification
ID:
ivo://CDS.VizieR/J/MNRAS/458/963
Title:
CANDELS galaxy structure classification
Short Name:
J/MNRAS/458/963
Date:
21 Oct 2021
Publisher:
CDS
Description:
Important but rare and subtle processes driving galaxy morphology and star formation may be missed by traditional spiral, elliptical, irregular or Sersic bulge/disc classifications. To overcome this limitation, we use a principal component analysis (PCA) of non-parametric morphological indicators (concentration, asymmetry, Gini coefficient, M_20_, multimode, intensity and deviation) measured at rest-frame B band (corresponding to HST/WFC3 F125W at 1.4<z<2) to trace the natural distribution of massive (>10^10^M_{sun}_) galaxy morphologies. PCA quantifies the correlations between these morphological indicators and determines the relative importance of each. The first three principal components (PCs) capture ~75 per cent of the variance inherent to our sample. We interpret the first PC as bulge strength, the second PC as dominated by concentration and the third PC as dominated by asymmetry. Both PC1 and PC2 correlate with the visual appearance of a central bulge and predict galaxy quiescence. PC1 is a better predictor of quenching than stellar mass, as good as other structural indicators (Sersic-n or compactness). We divide the PCA results into groups using an agglomerative hierarchical clustering method. Unlike Sersic, this classification scheme separates compact galaxies from larger, smooth protoelliptical systems, and star-forming disc-dominated clumpy galaxies from star-forming bulge-dominated asymmetric galaxies. Distinguishing between these galaxy structural types in a quantitative manner is an important step towards understanding the connections between morphology, galaxy assembly and star formation.
132. CANDELS visual classifications for GOODS-S
ID:
ivo://CDS.VizieR/J/ApJS/221/11
Title:
CANDELS visual classifications for GOODS-S
Short Name:
J/ApJS/221/11
Date:
21 Oct 2021
Publisher:
CDS
Description:
We have undertaken an ambitious program to visually classify all galaxies in the five CANDELS fields down to H<24.5 involving the dedicated efforts of over 65 individual classifiers. Once completed, we expect to have detailed morphological classifications for over 50000 galaxies spanning 0<z<4 over all the fields, with classifications from 3 to 5 independent classifiers for each galaxy. Here, we present our detailed visual classification scheme, which was designed to cover a wide range of CANDELS science goals. This scheme includes the basic Hubble sequence types, but also includes a detailed look at mergers and interactions, the clumpiness of galaxies, k-corrections, and a variety of other structural properties. In this paper, we focus on the first field to be completed --GOODS-S, which has been classified at various depths. The wide area coverage spanning the full field (wide+deep+ERS) includes 7634 galaxies that have been classified by at least three different people. In the deep area of the field, 2534 galaxies have been classified by at least five different people at three different depths. With this paper, we release to the public all of the visual classifications in GOODS-S along with the Perl/Tk GUI that we developed to classify galaxies. We present our initial results here, including an analysis of our internal consistency and comparisons among multiple classifiers as well as a comparison to the Sersic index. We find that the level of agreement among classifiers is quite good (>70% across the full magnitude range) and depends on both the galaxy magnitude and the galaxy type, with disks showing the highest level of agreement (>50%) and irregulars the lowest (<10%). A comparison of our classifications with the Sersic index and rest-frame colors shows a clear separation between disk and spheroid populations. Finally, we explore morphological k-corrections between the V-band and H-band observations and find that a small fraction (84 galaxies in total) are classified as being very different between these two bands. These galaxies typically have very clumpy and extended morphology or are very faint in the V-band.
133. CANDELS z~2 galaxy properties
ID:
ivo://CDS.VizieR/J/ApJ/793/101
Title:
CANDELS z~2 galaxy properties
Short Name:
J/ApJ/793/101
Date:
21 Oct 2021
Publisher:
CDS
Description:
We use CANDELS imaging, 3D-HST spectroscopy, and Chandra X-ray data to investigate if active galactic nuclei (AGNs) are preferentially fueled by violent disk instabilities funneling gas into galaxy centers at 1.3<z<2.4. We select galaxies undergoing gravitational instabilities using the number of clumps and degree of patchiness as proxies. The CANDELS visual classification system is used to identify 44 clumpy disk galaxies, along with mass-matched comparison samples of smooth and intermediate morphology galaxies. We note that despite being mass-matched and having similar star formation rates, the smoother galaxies tend to be smaller disks with more prominent bulges compared to the clumpy galaxies. The lack of smooth extended disks is probably a general feature of the z~2 galaxy population, and means we cannot directly compare with the clumpy and smooth extended disks observed at lower redshift. We find that z~2 clumpy galaxies have slightly enhanced AGN fractions selected by integrated line ratios (in the mass-excitation method), but the spatially resolved line ratios indicate this is likely due to extended phenomena rather than nuclear AGNs. Meanwhile, the X-ray data show that clumpy, smooth, and intermediate galaxies have nearly indistinguishable AGN fractions derived from both individual detections and stacked non-detections. The data demonstrate that AGN fueling modes at z~1.85 - whether violent disk instabilities or secular processes - are as efficient in smooth galaxies as they are in clumpy galaxies.
134. Candidates for astrometric microlensing
ID:
ivo://org.gavo.dc/amlensing/q/q
Title:
Candidates for astrometric microlensing
Short Name:
am lensing cands
Date:
27 Dec 2024 08:31:05
Publisher:
The GAVO DC team
Description:
A catalogue of candidate stars for observing astrometric microlensing using Gaia.
135. 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.
136. 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.
137. 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.
138. 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.
139. CARMENES input catalogue of M dwarfs. V.
ID:
ivo://CDS.VizieR/J/A+A/642/A115
Title:
CARMENES input catalogue of M dwarfs. V.
Short Name:
J/A+A/642/A115
Date:
02 Mar 2022 00:04:08
Publisher:
CDS
Description:
The relevance of M dwarfs in the search for potentially habitable Earth-size planets has grown significantly in the last years. In our on-going effort of comprehensively and accurately characterising confirmed and potential planet-hosting M dwarfs, in particular for the CARMENES survey, we have carried out a comprehensive multi-band photometric analysis involving spectral energy distributions, luminosities, absolute magnitudes, colours, and spectral types, from which we have derived basic astrophysical parameters. We have carefully compiled photometry in 20 passbands from the far-ultraviolet to the mi-infrared, and combined it with the latest parallactic distances and close-multiplicity information, mostly from Gaia DR2, of a sample of 2479 K5 V to L8 stars and ultracool dwarfs, including 2210 nearby, bright, M dwarfs. For that, we have made extensive use of Virtual Observatory tools. We have homogeneously computed accurate bolometric luminosities, effective temperatures of 1843 single stars, derived their radii and masses, studied the impact of metallicity, and compared our results with the literature. The over 40 000 individually-inspected magnitudes, together with the basic data and derived parameters of the stars, one by one and averaged by spectral type, have been made public to the astronomical community. In addition, we have reported 40 new close multiple systems and candidates (rho<3.3-arcsec) and 36 overluminous stars that are assigned to young Galactic populations. In the new era of exoplanet searches around M dwarfs via transit (e.g., TESS, PLATO) and radial velocity (e.g., CARMENES, NIRPS+HARPS), this work is of fundamental importance for stellar and, thus, planetary parameter determination.
140. CARS image cutouts
ID:
ivo://org.gavo.dc/cars/q/cutout
Title:
CARS image cutouts
Short Name:
CARS_cutout
Date:
27 Dec 2024 08:31:13
Publisher:
The GAVO DC team
Description:
Images and data from from the CFHTLS archive research survey, a multi-band dataset spanning 37 square degrees of sky in high galactic latitudes.

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