- ID:
- ivo://CDS.VizieR/J/MNRAS/473/849
- Title:
- Mass segregation in Galactic stellar clusters
- Short Name:
- J/MNRAS/473/849
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We quantify the structure of a very large number of Galactic open clusters and look for evidence of mass segregation for the most massive stars in the clusters. We characterize the structure and mass segregation ratios of 1276 clusters in the Milky Way Stellar Cluster (MWSC) catalogue containing each at least 40 stars and that are located at a distance of up to ~2kpc from the Sun. We use an approach based on the calculation of the minimum spanning tree of the clusters, and for each one of them, we calculate the structure parameter Q and the mass segregation ratio {LAMBDA}_MSR_. Our findings indicate that most clusters possess a Q parameter that falls in the range 0.7-0.8 and are thus neither strongly concentrated nor do they show significant substructure. Only 27 per cent can be considered centrally concentrated with Q values >0.8. Of the 1276 clusters, only 14 per cent show indication of significant mass segregation ({LAMBDA}_MSR_>1.5). Furthermore, no correlation is found between the structure of the clusters or the degree of mass segregation with their position in the Galaxy. A comparison of the measured Q values for the young open clusters in the MWSC to N-body numerical simulations that follow the evolution of the Q parameter over the first 10Myr of the clusters life suggests that the young clusters found in the MWSC catalogue initially possessed local mean volume densities of {rho}*~=10-100M_{sun}_/pc^3^.
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Search Results
- ID:
- ivo://CDS.VizieR/J/other/BSAO/57.5
- Title:
- 2MASS-selected Flat Galaxy Catalog (2MFGC)
- Short Name:
- J/other/BSAO/57.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- An all-sky catalog of 18020 disc-like galaxies is presented. The galaxies are selected from the Extended Source Catalog of the Two Micron All-Sky Survey (XSC 2MASS) basing on their 2MASS axial ratio a/b>=3. The Catalog contains data on magnitudes of a galaxy in the J, H, Ks bands, its axial ratio, positional angle, index of luminosity concentration, as well as identification of the galaxy with the LEDA and the NED databases. Unlike the available optical catalogs, the new 2MFGC catalog seems to be more suitable to study cosmic streaming on a scale of z~0.1. The dipole moment of distribution of the bright (K<11mag) 2MFGC objects (l=227{deg}, b=41{deg} or SGL=90{deg}, SGB=-43{deg}) lies within statistical errors (+/-15{deg}) in the direction of the IRAS dipole and the optical RFGC dipole.
- ID:
- ivo://CDS.VizieR/VII/257
- Title:
- 2MASS-selected Isolated Galaxies (2MIG)
- Short Name:
- VII/257
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We undertook searches for isolated galaxies based on automatic selection of infrared sources from the Two Micron All-Sky Survey (2MASS, Cat. II/246) followed by a visual inspection of their surrounding. Using a modified criterion by Karachentseva (1973SoSAO...8....3K), we compiled a catalog of 3227 isolated galaxies (2MIG) containing 6% of 2MASS Extended Sources (2MASX, Cat. VII/233) brighter than K_s_=12mag with angular diameters a_K_<=30". The most isolated 2493 galaxies among them enter in the 2MASS Very Isolated Galaxy Catalog, 2MVIG. Being situated in the regions of extremely low mass density, the 2MVIG galaxies can serve as a reference sample for investigation the influence of environment on structure and evolution of galaxies.
364. MCG Vol.5
- ID:
- ivo://CDS.VizieR/VII/100
- Title:
- MCG Vol.5
- Short Name:
- VII/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Morphological Catalogue of Galaxies, Volume 5 (Vorontsov-Velyaminov et al. 1974) includes 1637 galaxies, probably no fainter than the fourteenth magnitude. The catalog was based on Palomar Sky Atlas prints and comprises areas from -30 to -45 degrees in declination. In contrast to the earlier four volumes of the catalog, the fifth was based on the red prints of the Sky Survey only. Visual magnitude estimates are thus in the red. Note that in all cases when in other sources the photoelectric B or photographic magnitude of galaxies are encountered, preference to those values has been given over those of Vorontsov-Velyaminov's estimates. All notes to galaxies published in the earlier volume are included here as well (Kogoshvili 1983). In addition, the following data were used from the ESO/Uppsala survey (Lauberts 1982): magnitudes, colors, radial velocities, Hubble types, and galaxy diameters as measured on the ESO(B) atlas plates up to the surface brightness slightly fainter than 25 magnitudes per square arcsec. These maximum major and minor galaxy diameters are provided in the fifth volume in place of the values taken from the UGC catalog in the earlier four volumes. Various data from both the reference Catalog of Bright Galaxies (de Vaucouleurs et al. 1964) and B-V and U-B colors from the General Catalogue of Photoelectric Magnitudes and Colours (Longo et al. 1983) were included. Fields included in the catalog are identification number; zone sign, number, and field number; galaxy number in the field; component or symbolic designation; NGC or IC identification; B1950.0 position, magnitude, magnitude accuracy, and magnitude reference; angular diameters, surface brightness, symbolic description galaxy, morphological type, galaxy type, heliocentric radial velocity; radial velocity corrected for solar motion; rotational velocity, dates of first two supernovae, number of supernovae, number of H II regions, U-B and B-V colors and references, radio flux densities at 178, 780, 1400, 2700, and 5000 MHz; number of nearby cluster; and coded information on membership of the galaxy to double or multiple systems, interaction features, and faint components.
- ID:
- ivo://CDS.VizieR/J/ApJS/237/36
- Title:
- Merging dwarf galaxies in the local universe
- Short Name:
- J/ApJS/237/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the largest publicly available catalog of interacting dwarf galaxies. It includes 177 nearby merging dwarf galaxies of stellar mass M*<10^10^M_{sun}_ and redshifts z<0.02. These galaxies are selected by visual inspection of publicly available archival imaging from two wide-field optical surveys (SDSS-III and the Legacy Survey), and they possess low-surface-brightness features that are likely the result of an interaction between dwarf galaxies. We list UV and optical photometric data that we use to estimate stellar masses and star formation rates. So far, the study of interacting dwarf galaxies has largely been done on an individual basis, and lacks a sufficiently large catalog to give statistics on the properties of interacting dwarf galaxies, and their role in the evolution of low-mass galaxies. We expect that this public catalog can be used as a reference sample to investigate the effects of the tidal interaction on the evolution of star formation, and the morphology/structure of dwarf galaxies. Our sample is overwhelmingly dominated by star-forming galaxies, and they are generally found significantly below the red sequence in the color-magnitude relation. The number of early-type galaxies is only 3 out of 177. We classify them, according to observed low-surface-brightness features, into various categories including shells, stellar streams, loops, antennae, or simply interacting. We find that dwarf-dwarf interactions tend to prefer the low-density environment. Only 41 out of the 177 candidate dwarf-dwarf interaction systems have giant neighbors within a sky-projected distance of 700kpc and a line-of-sight radial velocity range +/-700km/s, and compared to the LMC-SMC, they are generally located at much larger sky-projected distances from their nearest giant neighbors.
- ID:
- ivo://CDS.VizieR/J/MNRAS/458/226
- Title:
- MeSsI low-redshift merging cluster sample
- Short Name:
- J/MNRAS/458/226
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Merging galaxy systems provide observational evidence of the existence of dark matter and constraints on its properties. Therefore, statistically uniform samples of merging systems would be a powerful tool for several studies. In this paper, we present a new methodology for the identification of merging systems and the results of its application to galaxy redshift surveys. We use as a starting point a mock catalogue of galaxy systems, identified using friends-of-friends algorithms, that have experienced a major merger, as indicated by its merger tree. By applying machine learning techniques in this training sample, and using several features computed from the observable properties of galaxy members, it is possible to select galaxy groups that have a high probability of having experienced a major merger. Next, we apply a mixture of Gaussian techniques on galaxy members in order to reconstruct the properties of the haloes involved in such mergers. This methodology provides a highly reliable sample of merging systems with low contamination and precisely recovered properties. We apply our techniques to samples of galaxy systems obtained from the Sloan Digital Sky Survey Data Release 7, the Wide-Field Nearby Galaxy-Cluster Survey (WINGS) and the Hectospec Cluster Survey (HeCS). Our results recover previously known merging systems and provide several new candidates. We present their measured properties and discuss future analysis on current and forthcoming samples.
- ID:
- ivo://CDS.VizieR/J/AJ/133/2764
- Title:
- M31 globular clusters structural parameters
- Short Name:
- J/AJ/133/2764
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The structures of globular clusters (GCs) reflect their dynamical states and past histories. High-resolution imaging allows the exploration of morphologies of clusters in other galaxies. Surface brightness profiles from new Hubble Space Telescope observations of 34 GCs in M31 are presented, together with fits of several different structural models to each cluster. M31 clusters appear to be adequately fit by standard King models and do not obviously require alternate descriptions with relatively stronger halos, such as are needed to fit many GCs in other nearby galaxies. The derived structural parameters are combined with corrected versions of those measured in an earlier survey in order to construct a comprehensive catalog of structural and dynamical parameters for M31 GCs with a sample size similar to that for the Milky Way. Clusters in M31, the Milky Way, Magellanic Clouds, the Fornax dwarf spheroidal, and NGC 5128 define a very tight fundamental plane with identical slopes. The combined evidence for these widely different galaxies strongly reinforces the view that old GCs have near-universal structural properties, regardless of host environment.
- ID:
- ivo://CDS.VizieR/J/MNRAS/435/650
- Title:
- 325MHz GMRT survey of Herschel-ATLAS/GAMA fields
- Short Name:
- J/MNRAS/435/650
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a 325MHz survey, undertaken with the Giant Metrewave Radio Telescope (GMRT), which covers a large part of the three equatorial fields at 9, 12 and 14.5h of right ascension from the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) in the area also covered by the Galaxy And Mass Assembly (GAMA) survey. The full data set, after some observed pointings were removed during the data reduction process, comprises 212 GMRT pointings covering ~90deg^2^ of sky. We have imaged and catalogued the data using a pipeline that automates the process of flagging, calibration, self-calibration and source detection for each of the survey pointings. The resulting images have resolutions of between 14 and 24-arcsec and minimum rms noise (away from bright sources) of ~1mJy/beam, and the catalogue contains 5263 sources brighter than 5{sigma}. We investigate the spectral indices of GMRT sources which are also detected at 1.4GHz and find them to agree broadly with previously published results; there is no evidence for any flattening of the radio spectral index below S_1.4_=10mJy. This work adds to the large amount of available optical and infrared data in the H-ATLAS equatorial fields and will facilitate further study of the low-frequency radio properties of star formation and AGN activity in galaxies out to z~1.
- ID:
- ivo://CDS.VizieR/J/A+A/406/867
- Title:
- Mid-IR galaxies in Virgo cluster. III.
- Short Name:
- J/A+A/406/867
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ISOCAM imaging data at 6.75 and 15{mu}m for 145 galaxies in the Virgo cluster and in the Coma/A1367 supercluster. Of these, 99 form a complete, optically-selected, volume-limited sample including galaxies in the core and in the periphery of the Virgo cluster, suitable for statistical analysis. 34 of the Virgo galaxies were resolved by ISOCAM: for these objects we present mid-IR images, radial light and colour profiles, as well as effective and isophotal radii, surface brightness and light concentration indices.
- ID:
- ivo://CDS.VizieR/J/ApJS/190/147
- Title:
- Mid-IR galaxy morphology from S^4^G
- Short Name:
- J/ApJS/190/147
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Spitzer Space Telescope Infrared Array Camera imaging provides an opportunity to study all known morphological types of galaxies in the mid-IR at a depth significantly better than ground-based near-infrared and optical images. The goal of this study is to examine the imprint of the de Vaucouleurs classification volume in the 3.6um band, which is the best Spitzer waveband for galactic stellar mass morphology owing to its depth and its reddening-free sensitivity mainly to older stars. For this purpose, we have prepared classification images for 207 galaxies from the Spitzer archive, most of which are formally part of the Spitzer Survey of Stellar Structure in Galaxies (S^4^G), a Spitzer post-cryogenic ("warm") mission Exploration Science Legacy Program survey of 2331 galaxies closer than 40Mpc. For the purposes of morphology, the galaxies are interpreted as if the images are blue light, the historical waveband for classical galaxy classification studies. We find that 3.6um classifications are well correlated with blue-light classifications, to the point where the essential features of many galaxies look very similar in the two very different wavelength regimes. We present an atlas of all of the 207 galaxies analyzed here and bring attention to special features or galaxy types, such as nuclear rings, pseudobulges, flocculent spiral galaxies, I0 galaxies, double-stage and double-variety galaxies, and outer rings, that are particularly distinctive in the mid-IR.
