- ID:
- ivo://CDS.VizieR/J/A+A/602/A100
- Title:
- Merging groups and clusters from the SDSS data
- Short Name:
- J/A+A/602/A100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Galaxy groups and clusters are the main tools to test cosmological models and to study the environmental effect of galaxy formation. This work aims to provide a catalogue of galaxy groups/clusters and potentially merging systems based on the SDSS main galaxy survey. We identify galaxy groups and clusters using the modified friends-of-friends (FoF) group finder that is designed specifically for flux-limited galaxy surveys. FoF group membership is refined by multimodality analysis to find subgroups and by using the group virial radius and escape velocity to expose unbound galaxies. We look for merging systems by comparing distances between group centres with group radii. The analysis results in a catalogue of 88 662 galaxy groups with at least two members. Among them are 6873 systems with at least 6 members which we consider as more reliable groups. We find 498 group mergers with up to six groups.
Number of results to display per page
Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/140/2052
- Title:
- MESS: Multi-wavelength Extreme Starburst Sample
- Short Name:
- J/AJ/140/2052
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This paper introduces the Multi-wavelength Extreme Starburst Sample (MESS), a new catalog of 138 star-forming galaxies (0.1<z<0.3) optically selected from the Sloan Digital Sky Survey using emission line strength diagnostics to have a high absolute star formation rate (SFR; minimum 11M_{sun}_/yr with median SFR~61M_{sun}_/yr based on a Kroupa initial mass function). The MESS was designed to complement samples of nearby star-forming galaxies such as the luminous infrared galaxies (LIRGs) and ultraviolet luminous galaxies (UVLGs). Observations using the Multi-band Imaging Photometer (24, 70, and 160um channels) on the Spitzer Space Telescope indicate that the MESS galaxies have IR luminosities similar to those of LIRGs, with an estimated median total IR luminosity L_IR_=~3x10^11^L_{sun}_.
- ID:
- ivo://CDS.VizieR/J/A+A/589/A109
- Title:
- Metal enrichment in semi-analytical model
- Short Name:
- J/A+A/589/A109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gas flows play a fundamental role in galaxy formation and evolution, providing the fuel for the star formation process. These mechanisms leave an imprint in the amount of heavy elements that enrich the interstellar medium (ISM). Thus, the analysis of this metallicity signature provides additional constraint on the galaxy formation scenario. We aim to discriminate between four different galaxy formation models based on two accretion scenarios and two different star formation recipes. We address the impact of a bimodal accretion scenario and a strongly regulated star formation recipe on the metal enrichment process of galaxies. We present a new extension of the eGalICS model, which allows us to track the metal enrichment process in both stellar populations and in the gas phase. Based on stellar metallicity bins from 0 to 2.5Z_{sun}_, our new chemodynamical model is applicable for situations ranging from metal-free primordial accretion to very enriched interstellar gas contents. We use this new tool to predict the metallicity evolution of both the stellar populations and gas phase. We compare these predictions with recent observational measurements. We also address the evolution of the gas metallicity with the star formation rate (SFR). We then focus on a sub-sample of Milky Way-like galaxies. We compare both the cosmic stellar mass assembly and the metal enrichment process of such galaxies with observations and detailed chemical evolution models.
- ID:
- ivo://CDS.VizieR/J/MNRAS/403/1625
- Title:
- Method for orientation angles of galaxies
- Short Name:
- J/MNRAS/403/1625
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A method is proposed for the determination of the position and inclination angles of the plane of a spiral galaxy based on the assumption that every spiral arm is a monotonic function of the radius against azimuthal angle. This method may yield more accurate results than the more commonly employed isophote method, which is subject to a number of drawbacks. Analytical study, calibration against other methods and examples of application of the proposed method to real galaxies are presented.
- ID:
- ivo://CDS.VizieR/J/A+AS/136/519
- Title:
- Mg2 indices for early-type galaxies
- Short Name:
- J/A+AS/136/519
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 210 new measurements of the central absorption line-strength Mg_2_ index for 87 early-type galaxies drawn from the Prugniel & Simien (1996, Cat. <J/A+A/309/749>) sample. 28 galaxies were not observed before. The results are compared to measurements published previously as available in HYPERCAT, and rescaled to the Lick system. The mean individual internal error on these measurements is 0.009mag+/-0.003mag and the mean external error is 0.012mag+/-0.002mag for this series of measurements. These data are also available from HYPERCAT.
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/1644
- Title:
- 843MHz MOST ATLAS catalogue
- Short Name:
- J/MNRAS/421/1644
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- At the faintest radio flux densities (S1.4<10mJy), conflicting results have arisen regarding whether there is a flattening of the average spectral index between a low radio frequency (325 or 610MHz) and, for example, 1.4GHz. We present a new catalogue of 843-MHz radio sources in the European Large Area ISO Survey-South 1 field, which contains the sources, their Australia Telescope Large Area Survey (ATLAS) counterparts and the spectral index distribution of the sources as a function of flux density.
- ID:
- ivo://CDS.VizieR/VII/240
- Title:
- Millennium Galaxy Catalogue
- Short Name:
- VII/240
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Millennium Galaxy Catalogue (MGC) is a 37.5deg^2^, medium-deep, B-band imaging survey along the celestial equator, taken with the Wide Field Camera on the Isaac Newton Telescope. The survey region is contained within the regions of both the Two Degree Field Galaxy Redshift Survey (2dFGRS) and the Sloan Digital Sky Survey Early Data Release (SDSS-EDR). The survey has a uniform isophotal detection limit of 26mag.arcsec^-2^ and it provides a robust, well-defined catalogue of stars and galaxies in the range 16<=B_MGC_<24 mag. Here we describe the survey strategy, the photometric and astrometric calibration, source detection and analysis, and present the galaxy number counts that connect the bright and faint galaxy populations within a single survey. We argue that these counts represent the state of the art and use them to constrain the normalizations ({phi}*) of a number of recent estimates of the local galaxy luminosity function. We find that the 2dFGRS, SDSS Commissioning Data (CD), ESO Slice Project, Century Survey, Durham/UKST, Mt Stromlo/APM, SSRS2 and NOG luminosity functions require a revision of their published {phi}* values by factors of 1.05+/-0.05, 0.76+/-0.10, 1.02+/-0.22, 1.02+/-0.16, 1.16+/-0.28, 1.75+/-0.37, 1.40+/-0.26 and 1.01+/-0.39, respectively. After renormalizing the galaxy luminosity functions we find a mean local b_J_ luminosity density of 1.986+/-0.031x10^8^h L_{sun}_.Mpc^-3^
- ID:
- ivo://CDS.VizieR/J/MNRAS/459/140
- Title:
- M81, LMC and 3C 273/Coma 17-60keV obs.
- Short Name:
- J/MNRAS/459/140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results of a deep survey of three extragalactic fields, M81 (exposure of 9.7Ms), Large Magellanic Cloud (6.8 Ms) and 3C 273/Coma (9.3Ms), in the hard X-ray (17-60keV) energy band with the IBIS telescope onboard the INTEGRAL observatory, based on 12 years of observations (2003-2015). The combined survey reaches a 4{sigma} peak sensitivity of 0.18mCrab (2.6x10^-12^erg/s/cm^2^) and sensitivity better than 0.25 and 0.87mCrab over 10 per cent and 90 per cent of its full area of 4900 deg^2^, respectively. We have detected in total 147 sources at S/N>4{sigma}, including 37 sources observed in hard X-rays for the first time. The survey is dominated by extragalactic sources, mostly active galactic nuclei (AGN). The sample of identified sources contains 98 AGN (including 64 Seyfert galaxies, seven low-ionization nuclear emission-line region galaxies, three X-ray bright optically normal galaxies, 16 blazars and eight AGN of unclear optical class), two galaxy clusters (Coma and Abell 3266), 17 objects located in the Large and Small Magellanic Clouds (13 high- and two low-mass X-ray binaries and two X-ray pulsars), three Galactic cataclysmic variables, one ultraluminous X-ray source (M82 X-1) and one blended source (SWIFT J1105.7+5854). The nature of 25 sources remains unknown, so that the survey's identification is currently complete at 83 per cent. We have constructed AGN number-flux relations (log N-log S) and calculated AGN number densities in the local Universe for the entire survey and for each of the three extragalactic fields.
- 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/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.
