- ID:
- ivo://CDS.VizieR/J/A+A/588/A14
- Title:
- Friends-of-friends galaxy group finder
- Short Name:
- J/A+A/588/A14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We improve the widely used friends-of-friends (FoF) group finding algorithm with membership refinement procedures and apply the method to a combined dataset of galaxies in the local Universe. A major aim of the refinement is to detect subgroups within the FoF groups, enabling a more reliable suppression of the fingers-of-God effect. The FoF algorithm is often suspected of leaving subsystems of groups and clusters undetected. We used a galaxy sample built of the 2MRS, CF2, and 2M++ survey data comprising nearly 80000 galaxies within the local volume of 430Mpc radius to detect FoF groups. We conducted a multimodality check on the detected groups in search for subgroups. We furthermore refined group membership using the group virial radius and escape velocity to expose unbound galaxies. We used the virial theorem to estimate group masses. The analysis results in a catalogue of 6282 galaxy groups in the 2MRS sample with two or more members, together with their mass estimates. About half of the initial FoF groups with ten or more members were split into smaller systems with the multimodality check.
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Search Results
- ID:
- ivo://CDS.VizieR/J/other/AstBu/74.62
- Title:
- Fundamental parameters of CP stars
- Short Name:
- J/other/AstBu/74
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The paper presents the results of determination of fundamental parameters (effective temperature, surface gravity, luminosity, mass, radius, rotation velocity, and radial velocity) for 146 stars observed at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences with the Main Stellar Spectrograph during 2009-2011; 124 of the stars are magnetic or potentially magnetic objects. We obtained and analyzed at least 500 pairs of circularly-polarized-emission spectra. Various methods and approaches were used in estimating the fundamental parameters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/397/75
- Title:
- Fundamental Plane analysis in Shapley
- Short Name:
- J/MNRAS/397/75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a Fundamental Plane (FP) analysis of 141 early-type galaxies in the Shapley supercluster at z=0.049 based on spectroscopy from the AAOmega spectrograph at the Anglo-Australian Telescope and photometry from the WFI on the European Southern Observatory/MPI 2.2-m telescope.
- ID:
- ivo://CDS.VizieR/J/A+AS/140/327
- Title:
- Fundamental plane galaxies redshifts
- Short Name:
- J/A+AS/140/327
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial velocities and central velocity dispersions are derived for 238 E/S0 galaxies from medium-resolution spectroscopy. New spectroscopic data have been obtained as part of a study of the Fundamental Plane distances and peculiar motions of early-type galaxies in three selected directions of the South Equatorial Strip, undertaken in order to investigate the reality of large-scale streaming motion; results of this study have been reported in Mueller et al. (1998ApJ...507L.105M). The new APM South Equatorial Strip Catalog (-17.5deg<{delta}<+2.5deg) (Raychaudhury & Lynden-Bell, 2000) was used to select the sample of field galaxies in three directions: (1) 15h10-16h10; (2) 20h30-21h50; (3) 00h10-01h30. The spectra obtained have a median S/N per {AA} of 23, an instrumental resolution (FWHM) of ~4{AA}, and the spectrograph resolution (dispersion) is ~100km/s. The Fourier cross-correlation method was used to derive the radial velocities and velocity dispersions. The velocity dispersions have been corrected for the size of the aperture and for the galaxy effective radius. Comparisons of the derived radial velocities with data from the literature show that our values are accurate to 40km/s. A comparison with results from Jorgensen et al. (1995MNRAS.276.1341J) shows that the derived central velocity dispersion have an rms scatter of 0.036 in log{sigma}. There is no offset relative to the velocity dispersions of Davies et al. (1987ApJS...64..581D).
- ID:
- ivo://astronet.ru/cas/gaiadr2-gaia_source
- Title:
- Gaia DR2 (Gaia Collaboration, 2018)
- Short Name:
- gaiadr2-gaia_sou
- Date:
- 17 Jun 2006 18:44:05
- Publisher:
- Sternberg Astronomical Institute Virtual Observatory Project
- Description:
- </pre><p>Gaia is an ambitious mission to chart a three-dimensional map of our Galaxy, the Milky Way, in the process revealing the composition, formation and evolution of the Galaxy. Gaia will provide unprecedented positional and radial velocity measurements with the accuracies needed to produce a stereoscopic and kinematic census of about one billion stars in our Galaxy and throughout the Local Group. This amounts to about 1 per cent of the Galactic stellar population. <p>The data collected during the first 22 months of the nominal, five-year mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC), resulting into this second data release. A summary of the release properties is provided in Gaia Collaboration et al. (2018b). The overall scientific validation of the data is described in Arenou et al. (2018). Background information on the mission and the spacecraft can be found in Gaia Collaboration et al. (2016), with a more detailed presentation of the Radial Velocity Spectrometer (RVS) in Cropper et al. (2018). In addition, Gaia DR2 is accompanied by various, dedicated papers that describe the processing and validation of the various data products: Lindegren et al. (2018) for the Gaia DR2 astrometry, Riello et al. (2018) and Evans et al. (2018) for the Gaia DR2 photometry, Sartoretti et al. (2018), Soubiran et al. (2018), and Katz et al. (2018) for the Gaia DR2 spectroscopy (radial velocities), Holl et al. (2018) for the Gaia DR2 variability, Andrae et al. (2018) for the Gaia DR2 astrophysical parameters, Gaia Collaboration et al. (2018g) for the Solar-system objects, and Gaia Collaboration et al. (2018f) for the celestial reference frame. Four more papers present a glimpse of the scientific richness of the data in the areas of the Hertzsprung-Russell diagram (Gaia Collaboration et al. 2018a), the mapping of the kinematics and large-scale structure of the Milky Way (Gaia Collaboration et al. 2018e), parallaxes and proper motions of Milky Way satellite galaxies (Gaia Collaboration et al. 2018d), and variable stars in the colour-magnitude diagram (Gaia Collaboration et al. 2018c). In addition to the set of references mentioned above, this documentation provides a detailed, complete overview of the processing and validation of the Gaia DR2 data.
- ID:
- ivo://CDS.VizieR/III/281
- Title:
- Gaia FGK benchmark stars v2.1
- Short Name:
- III/281
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this era of large spectroscopic surveys of stars of the Milky Way, pipelines need to be tested and validated against a set of well-known stars. The Gaia FGK benchmark stars (GBS) are among the preferred samples of reference stars. They consist of a small but carefully selected sample of stars whose parameters are derived consistently and homogeneously. A series of papers has been published that discuss the definition and evolution of the sample of GBS. Here we summarise this work and provide our current list of stars with associated parameters which are recommended for validation and calibration purposes for stellar surveys.
- ID:
- ivo://CDS.VizieR/VI/137
- Title:
- GaiaSimu Universe Model Snapshot
- Short Name:
- VI/137
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Context: This study has been developed in the framework of the computational simulations that are executed for the preparation of the ESA Gaia astrometric mission. Aims: We focus on describing the objects and characteristics that Gaia will potentially observe without taking into consideration instrumental effects (detection efficiency, observing errors). Methods: The theoretical Universe Model prepared for the Gaia simulation has been statistically analysed at a given time. Ingredients of the model are described, with the greatest emphasis on the stellar content, the double and multiple stars, and variability. Results: In this simulation the errors have not yet been included. Hence we estimated the number of objects and their theoretical photometric, astrometric and spectroscopic characteristics if they are perfectly detected.We show that Gaia will be able to potentially observe 1.1 billion of stars (single or part of multiple star systems) of which about 2% are variable stars and 3% have one or two exoplanets. At the extragalactic level, observations will be potentially composed of several millions of galaxies, half a million to 1 million quasars and about 50,000 supernovae that will occur during the five years of the mission.
- ID:
- ivo://CDS.VizieR/VIII/100
- Title:
- GaLactic and Extragalactic All-sky MWA survey
- Short Name:
- VIII/100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the Murchison Widefield Array (MWA), the low-frequency Square Kilometre Array (SKA1 LOW) precursor located in Western Australia, we have completed the GaLactic and Extragalactic All-sky MWA (GLEAM) survey, and present the resulting extragalactic catalogue, utilising the first year of observations. The catalogue covers 24,402 square degrees, over declinations south of +30{deg} and Galactic latitudes outside 10{deg} of the Galactic plane, excluding some areas such as the Magellanic Clouds. It contains 307,456 radio sources with 20 separate flux density measurements across 72-231MHz, selected from a time- and frequency- integrated image centred at 200MHz, with a resolution of ~=2'. Over the catalogued region, we estimate that the catalogue is 90% complete at 170mJy, and 50% complete at 55mJy, and large areas are complete at even lower flux density levels. Its reliability is 99.97% above the detection threshold of 5{sigma}, which itself is typically 50mJy. These observations constitute the widest fractional bandwidth and largest sky area survey at radio frequencies to date, and calibrate the low frequency flux density scale of the southern sky to better than 10%. This paper presents details of the flagging, imaging, mosaicking, and source extraction/characterisation, as well as estimates of the completeness and reliability. All source measurements and images are available online. This is the first in a series of publications describing the GLEAM survey results.
- ID:
- ivo://CDS.VizieR/J/MNRAS/467/3140
- Title:
- Galaxies angular momentum evolution
- Short Name:
- J/MNRAS/467/3140
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a MUSE (Multi-Unit Spectroscopic Explorer) and KMOS (K-band Multi-Object Spectrograph) dynamical study 405 star-forming galaxies at redshift z=0.28-1.65 (median redshift <z>=0.84). Our sample is representative of the star-forming 'main sequence', with star formation rates of SFR=0.1-30M_{sun}_/yr and stellar masses M*=10^8^-10^11^M_{sun}_. For 49+/-4 per cent of our sample, the dynamics suggest rotational support, 24+/-3 per cent are unresolved systems and 5+/-2 per cent appear to be early-stage major mergers with components on 8-30kpc scales. The remaining 22+/-5 per cent appear to be dynamically complex, irregular (or face-on systems). For galaxies whose dynamics suggest rotational support, we derive inclination-corrected rotational velocities and show that these systems lie on a similar scaling between stellar mass and specific angular momentum as local spirals with j*=J/M*{prop.to}M*^2/3^ but with a redshift evolution that scales as j*{prop.to}M*^2/3^(1+z)^-1^. We also identify a correlation between specific angular momentum and disc stability such that galaxies with the highest specific angular momentum (log(j*/M*^2/3^)>2.5) are the most stable, with Toomre Q=1.10+/-0.18, compared to Q=0.53+/-0.22 for galaxies with log(j*/M*^2/3^)<2.5. At a fixed mass, the Hubble Space Telescope morphologies of galaxies with the highest specific angular momentum resemble spiral galaxies, whilst those with low specific angular momentum are morphologically complex and dominated by several bright star-forming regions. This suggests that angular momentum plays a major role in defining the stability of gas discs: at z~1, massive galaxies that have discs with low specific angular momentum are globally unstable, clumpy and turbulent systems. In contrast, galaxies with high specific angular momentum have evolved into stable discs with spiral structure where star formation is a local (rather than global) process.
- ID:
- ivo://CDS.VizieR/VII/209A
- Title:
- Galaxies Behind the Milky Way
- Short Name:
- VII/209A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This catalogue gathers the searches for galaxies of apparent size greater than 0.1mm (6.7") behind the Milky Way from photographic surveys in the near infrared. The five volumes cover the galactic longitude ranges -7 to +68{deg}, and 210 to 250{deg}.