- ID:
- ivo://CDS.VizieR/J/ApJS/103/331
- Title:
- mJy radio sources at 1.4 GHz
- Short Name:
- J/ApJS/103/331
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- From the 1.4GHz radio survey of Condon, Dickey, & Salpeter (Cat. <J/AJ/99/1071>) in a region much devoid of rich galaxy clusters at redshifts z<0.43 we selected a "distant" sample of 57 radio sources complete to a 1.4GHz flux density of 35mJy and a "nearby" sample of 36 mostly weaker radio sources which are optically brighter than B~19mag. Our ultimate goals are (1) to study the radio, optical, and near-IR properties of those high-redshift (z~1), moderate-power radio sources in the distant sample and to compare them with that of more powerful radio sources, and (2) to make a comparison of primarily noncluster radio sources in the nearby sample with a companion survey of radio sources in a pair of rich superclusters at z~0.1. In this first paper of a series, we report our new C-array VLA continuum snapshots at 4.86GHz and optical R-band CCD imaging photometry for these two samples and tabulate the observational results on individual sources. Some direct sample statistical properties are also discussed in the paper and summarized as follows: (1) The distant sample: (a) The sample median flux density at 1.4GHz is about 65mJy. (b) The majority (80%) of the sample sources have a steep spectrum between 1.4 and 4.86GHz with a spectral index around 0.9. Nineteen (90%) of the 21 sources that are fully resolved at 4.86 GHz (i.e., angular sizes {theta}>11") have a radio morphology of Fanaroff-Riley (FR) II type. (c) Thirty-seven (88%) of the 42 optically imaged sample sources were optically identified to a limiting R-band magnitude of R~23.5mag. About 15% of the identified radio sources appear to be point sources, and the others are extended galaxies with an appearance similar to nearby elliptical galaxies. (d) Twenty-eight (76%) of the optically identified sources have R>20mag, suggesting that these are probably distant (z>0.8), with a redshift distribution peaking at z~1, where their radio luminosities are about 10 times the break power between the FR I and II classes. (e) We found no strong evidence for the radio and optical axes of the resolved radio sources (i.e., {theta}>5") to be correlated or anticorrelated, nor any evidence for strong clustering around sample radio sources on average. (2) The nearby sample: except for R<15, the sample is dominated by elliptical galaxies with 16<R<18.5mag and a spectral index distribution similar to that of the distant sample. Based on the radial distribution of optical objects around each radio source, we found that the average radio source environment becomes richer from that characteristic of galaxy groups for R<17mag (z<0.2) to that of galaxy groups to clusters at R>18mag (z>0.3) .
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Search Results
- ID:
- ivo://CDS.VizieR/J/PASJ/63/S363
- Title:
- MOIRCS Deep Survey. VII.
- Short Name:
- J/PASJ/63/S363
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigated rest-frame near-infrared (NIR) morphologies of a sample of 139 galaxies with Ms>=1x10^109M_{sun}_ at z=0.8-1.2 in the GOODS-North field using our deep NIR imaging data (MOIRCS Deep Survey, MODS). We focused on Luminous Infrared Galaxies (LIRGs), which dominate a high star formation rate (SFR) density at z~1, in a sample identified by cross-correlating with the Spitzer/MIPS 24mum source catalog. We performed two-dimensional light profile fittings of z~1 galaxies in the Ks-band (rest-frame J-band) with a single-component Sersic model.
- ID:
- ivo://CDS.VizieR/J/ApJS/171/376
- Title:
- MOJAVE. III. VLA 1.4GHz images
- Short Name:
- J/ApJS/171/376
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The MOJAVE blazar sample consists of the 133 brightest, most compact radio-loud AGNs in the northern sky, and it is selected on the basis of VLBA 2cm correlated flux density exceeding 1.5Jy (2Jy for declinations south of 0) at any epoch between 1994 and 2003. Since 1994 we have been gathering VLBA data on the sample to measure superluminal jet speeds and to better understand the parsec-scale kinematics of AGN jets. We have obtained 1.4GHz VLA A configuration data on 57 of these sources to investigate whether the extended luminosity of blazars is correlated with parsec-scale jet speed and also to determine what other parsec-scale properties are related to extended morphology, such as optical emission line strength and gamma-ray emission. We present images and measurements of the kiloparsec scale emission from the VLA data, which will be used in subsequent statistical studies of the MOJAVE sample.
- ID:
- ivo://CDS.VizieR/J/A+A/581/A74
- Title:
- Molecular clouds as viewed by ATLASGAL
- Short Name:
- J/A+A/581/A74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first study of the relationship between the column density distribution of molecular clouds within nearby Galactic spiral arms and their evolutionary status as measured from their stellar content. We analyze a sample of 195 molecular clouds located at distances below 5.5kpc, identified from the ATLASGAL 870{mu}m data. We define three evolutionary classes within this sample: starless clumps, star-forming clouds with associated young stellar objects, and clouds associated with HII regions. We find that the N(H_2_) probability density functions (N-PDFs) of these three classes of objects are clearly different: the N-PDFs of starless clumps are narrowest and close to log-normal in shape, while star-forming clouds and HII regions exhibit a power-law shape over a wide range of column densities and log-normal-like components only at low column densities. We use the N-PDFs to estimate the evolutionary time-scales of the three classes of objects based on a simple analytic model from literature. Finally, we show that the integral of the N-PDFs, the dense gas mass fraction, depends on the total mass of the regions as measured by ATLASGAL: more massive clouds contain greater relative amounts of dense gas across all evolutionary classes.
- ID:
- ivo://CDS.VizieR/J/MNRAS/355/82
- Title:
- Morphological analysis of HDF-N and HDF-S
- Short Name:
- J/MNRAS/355/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on drizzled F606W and F814W images, we present quantitative structural parameters in the V-band rest-frame for all galaxies with z<1 and I_814_(AB)<24.5mag in the Hubble Deep Fields North and South. Our structural parameters are based on a two-component surface brightness distribution using a Sersic bulge and an exponential disc. Detailed simulations and comparisons with previous work are presented.
- ID:
- ivo://CDS.VizieR/VII/62A
- Title:
- Morphological Cat. of Gal. (MCG)
- Short Name:
- VII/62A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The catalog is a compilation of information for approximately 34000 galaxies found and examined on the Palomar Observatory Sky Survey (POSS). Individual identifiers are assigned for about 29000 galaxies and information on the remaining 5000 is present in the extensive notes of the published catalogs (Vorontsov-Velyaminov et al. 1962-1968). The catalog is structured according to the POSS zones, counting from the equator, and is numbered from +15 (corresponding to +90 deg) to +01 (+06 zone) and +00 (equatorial zone) to -05 (-30 zone); the fields are numbered with increasing right ascension. The catalog includes cross-identifications to the NGC (Dreyer 1888) and IC (Dreyer 1895, 1908) catalogs, equatorial coordinates for B1950.0, magnitudes, estimated sizes and intensities of the brighter inner region and the entire object, and estimated inclinations.
- ID:
- ivo://CDS.VizieR/J/MNRAS/432/3141
- Title:
- Morphological classification of PM2GC galaxies
- Short Name:
- J/MNRAS/432/3141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the galaxy stellar mass function in different environments in the local Universe, considering both the total mass function and that of individual galaxy morphological types. We compare the mass functions of galaxies with log_10_M*/M_{sun}_>=10.25 in the general field and in galaxy groups, binary and single galaxy systems from the Padova-Millennium Galaxy and Group Catalogue at z=0.04-0.1 with the mass function of galaxy clusters of the WIde-field Nearby Galaxy-Cluster Survey at z=0.04-0.07. Strikingly, the variations of the mass function with global environment, overall, are small and subtle. The shapes of the mass functions of the general field and clusters are indistinguishable, and only small, statistically insignificant variations are allowed in groups. Only the mass function of our single galaxies, representing the least massive haloes and comprising less than a third of the general field population, is proportionally richer in low-mass galaxies than other environments. The most notable environmental effect is a progressive change in the upper galaxy mass, with very massive galaxies found only in the most massive environments. This environment-dependent mass cut-off is unable to affect the Schechter parameters and the Kolmogorov-Smirnov test, and can only be revealed by an ad hoc analysis. Finally, we show how, in each given environment, the mass function changes with morphological type, and that galaxies of the same morphological type can have different mass functions in different environments.
- ID:
- ivo://CDS.VizieR/J/MNRAS/274/1107
- Title:
- Morphological classifications of APM galaxies
- Short Name:
- J/MNRAS/274/1107
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the consistency of visual morphological classifications of galaxies by comparing classifications for 831 galaxies from six independent observers. The galaxies were classified on laser print copy images or on computer screen using scans made with the Automated Plate Measuring (APM) machine. Classifications are compared using the Revised Hubble numerical type index T. We find that individual observers agree with one another with rms combined dispersions of between 1.3 and 2.3 type units, typically about 1.8 units. The dispersions tend to decrease slightly with increasing angular diameter and, in some cases, with increasing axial ratio (b/a). The agreement between independent observers is reasonably good but the scatter is non-negligible. In spite of the scatter, the Revised Hubble T system can be used to train an automated galaxy classifier, e.g. an artificial neural network, to handle the large number of galaxy images that are being compiled in the APM and other surveys.
- ID:
- ivo://CDS.VizieR/J/AJ/134/579
- Title:
- Morphologically classified galaxies from SDSS DR3
- Short Name:
- J/AJ/134/579
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of morphologically classified bright galaxies in the north equatorial stripe (230deg^2^) derived from the Third Data Release of the Sloan Digital Sky Survey (SDSS). Morphological classification is performed by visual inspection of images in the g band. The catalog contains 2253 galaxies complete to a magnitude limit of r=16 after Galactic extinction correction, selected from 2658 objects that are judged to be extended in the photometric catalog in the same magnitude limit. A total of 1866 galaxies in our catalog have spectroscopic information. A brief statistical analysis is presented for the frequency of morphological types and mean colors in the catalog. A visual inspection of the images reveals that the rate of interacting galaxies in the local universe is approximately 1.5% in the r<=16 sample. A verification is made for the photometric catalog generated by the SDSS, especially as to its bright-end completeness.
- ID:
- ivo://CDS.VizieR/J/ApJ/781/12
- Title:
- Morphological parameters of galaxies from Spitzer
- Short Name:
- J/ApJ/781/12
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The morphology of galaxies can be quantified to some degree using a set of scale-invariant parameters. Concentration (C), asymmetry (A), smoothness (S), the Gini index (G), the relative contribution of the brightest pixels to the second-order moment of the flux (M_20_), ellipticity (E), and the Gini index of the second-order moment (G_M_) have all been applied to morphologically classify galaxies at various wavelengths. Here, we present a catalog of these parameters for the Spitzer Survey of stellar structure in Galaxies, a volume-limited, near-infrared (NIR) imaging survey of nearby galaxies using the 3.6 and 4.5{mu}m channels of the Infrared Array Camera on board the Spitzer Space Telescope. Our goal is to provide a reference catalog of NIR quantified morphology for high-redshift studies and galaxy evolution models with enough detail to resolve stellar mass morphology. We explore where normal, non-interacting galaxies--those typically found on the Hubble tuning fork--lie in this parameter space and show that there is a tight relation between concentration (C_82_) and M_20_ for normal galaxies. M_20_ can be used to classify galaxies into earlier and later types (i.e., to separate spirals from irregulars). Several criteria using these parameters exist to select systems with a disturbed morphology, i.e., those that appear to be undergoing a tidal interaction. We examine the applicability of these criteria to Spitzer NIR imaging. We find that four relations, based on the parameters A and S, G and M_20_, G_M_, C, and M_20_, respectively, select outliers in morphological parameter space, but each selects different subsets of galaxies. Two criteria (G_M_>0.6,G>-0.115xM_20_+0.384) seem most appropriate to identify possible mergers and the merger fraction in NIR surveys. We find no strong relation between lopsidedness and most of these morphological parameters, except for a weak dependence of lopsidedness on concentration and M_20_.
