- ID:
- ivo://CDS.VizieR/J/MNRAS/348/866
- Title:
- 2dFGRS Percolation-Inferred Galaxy Group (2PIGG)
- Short Name:
- J/MNRAS/348/866
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The construction of a catalogue of galaxy groups from the Two-degree Field Galaxy Redshift Survey (2dFGRS) is described. Groups are identified by means of a friends-of-friends percolation algorithm which has been thoroughly tested on mock versions of the 2dFGRS generated from cosmological N-body simulations. The tests suggest that the algorithm groups all galaxies that it should be grouping, with an additional 40 per cent of interlopers. About 55 per cent of the ~190000 galaxies considered are placed into groups containing at least two members of which ~29000 are found. Of these, ~7000 contain at least four galaxies, and these groups have a median redshift of 0.11 and a median velocity dispersion of 260km/s. This 2dFGRS Percolation-Inferred Galaxy Group (2PIGG) catalogue represents the largest available homogeneous sample of galaxy groups.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/350/1485
- Title:
- 2dFGRS: Radio galaxies properties
- Short Name:
- J/MNRAS/350/1485
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The clustering properties of local, S_1.4GHz_>=1mJy, radio sources are investigated for a sample of 820 objects drawn from the joint use of the Faint Images of the Radio Sky at 20cm (FIRST, <VIII/71>) and 2dF Galaxy Redshift surveys (<VII/223>, <VII/226>). To this aim, we present 271 new b_J_<=19.45mag spectroscopic counterparts of FIRST radio sources to be added to those already introduced in our previous paper.
- ID:
- ivo://CDS.VizieR/J/MNRAS/352/939
- Title:
- 2dFGRS Wiener reconstruction of cosmic web
- Short Name:
- J/MNRAS/352/939
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We reconstruct the underlying density field of the Two-degree Field Galaxy Redshift Survey (2dFGRS, <VII/226>) for the redshift range 0.035<z<0.200 using the Wiener filtering method. The Wiener filter suppresses shot noise and accounts for selection and incompleteness effects. The method relies on prior knowledge of the 2dF power spectrum of fluctuations and the combination of matter density and bias parameters, however the results are only slightly affected by changes to these parameters. We present maps of the density field. We use a variable smoothing technique with two different effective resolutions: 5 and 10h^-1^Mpc at the median redshift of the survey. We identify all major superclusters and voids in the survey. In particular, we find two large superclusters and two large local voids. The full set of colour maps can be viewed on the World Wide Web at http://www.ast.cam.ac.uk/~pirin .
- ID:
- ivo://nasa.heasarc/sixdfgs
- Title:
- 6dFGS Galaxy Survey Final Redshift Release Catalog
- Short Name:
- SIXDFGS
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The final redshift release of the 6dF Galaxy Survey (6dFGS) is a combined redshift and peculiar velocity survey over the southern sky (|b| > 10 degrees). Its 136,304 spectra have yielded 110,256 new extragalactic redshifts and a new catalogue of 125,071 galaxies making near-complete samples with limits in (K, H, J, r<sub>F</sub>, b<sub>J</sub>) (12.65, 12.95, 13.75, 15.60, 16.75). The median redshift of the survey is 0.053. The catalog includes basic data for the galaxies in the 6dFGS with redshifts, using the best 6dFGS redshifts (radial velocity quality flag Q =3 or 4) plus available redshifts from SDSS, 2dFGRS and ZCAT (124,647 entries in all). It supersedes the previous DR2 version (<a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/249">CDS Cat. VII/249</a>). The home page of of the 6dFGS database is <a href="http://www-wfau.roe.ac.uk/6dFGS">http://www-wfau.roe.ac.uk/6dFGS</a>. Any use of these data should explicitly state that they come from the Final Release of 6dFGS and cite both the 6dGS DR3 paper (Jones et al. 2009, MNRAS, 399, 683) as well as the original 6dFGS survey paper (Jones et al. 2004, MNRAS, 355, 747). This table was created by the HEASARC in March 2011 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/259">CDS Catalog VII/259</a> file 6dfgs.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/twodfqsoz
- Title:
- 2dF QSO Redshift (2QZ) Survey
- Short Name:
- TWODFQSOZ
- Date:
- 27 Sep 2024
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The final catalog of the 2dF QSO Redshift Survey (2QZ) is based on Anglo-Australian Telescope 2dF spectroscopic observations of 44,576 color-selected (u, b<sub>J</sub>, r) objects with 18.25 < b<sub>J</sub> < 20.85 selected from automated plate measurement scans of UK Schmidt Telescope (UKST) photographic plates. The 2QZ comprises 23,338 quasi-stellar objects (QSOs), 12,292 galactic stars (including 2,071 white dwarfs) and 4,558 compact narrow emission-line galaxies. The authors obtained a reliable spectroscopic identification for 86 per cent of objects observed with 2dF. They also report on the 6dF QSO Redshift Survey (6QZ), based on UKST 6dF observations of 1,564 brighter (16 < b<sub>J</sub> < 18.25) sources selected from the same photographic input catalog. In total, the authors identified 322 QSOs spectroscopically in the 6QZ. The completed 2QZ is, by more than a factor of 50, the largest homogeneous QSO catalog ever constructed at these faint limits (b<sub>J</sub> < 20.85) and high QSO surface densities (35 QSOs/deg<sup>2</sup>). As such, it represents an important resource in the study of the Universe at moderate-to-high redshifts. The survey area comprised 30 UKST fields, arranged in two 75 degrees by 5 degrees declination strips, one passing across the South Galactic Gap centered on Dec = -30 degrees (the SGP strip), and the other across the North Galactic Gap centered on Dec = 0 degrees (referred to in the reference paper as the equatorial strip, but also known as the NGP strip. The total survey area is 721.6 deg<sup>2</sup>, when allowance is made for regions of sky excised around bright stars. Spectroscopic observations of the input catalogue were made with the 2dF instrument at the Anglo-Australian Telescope (AAT; the 2QZ sample) and the 6dF instrument at the UKST (the 6QZ sample). 2dF spectroscopic observations began in January 1997 and were completed in April 2002. Six-degree Field observations were performed over the period 2001 March-2002 September. This online catalog was created by the HEASARC in October 2010 based on the machine-readable table 2qz.dat obtained from the CDS (their catalog VII/241). This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/MNRAS/372/425
- Title:
- 2dF-SDSS Luminous Red Galaxy Survey, 2SLAQ
- Short Name:
- J/MNRAS/372/425
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a spectroscopic survey of almost 15000 candidate intermediate-redshift luminous red galaxies (LRGs) brighter than i=19.8, observed with 2dF on the Anglo-Australian Telescope. The targets were selected photometrically from the Sloan Digital Sky Survey (SDSS) and lie along two narrow equatorial strips covering 180deg^2^. Reliable redshifts were obtained for 92 per cent of the targets and the selection is very efficient: over 90 per cent have 0.45<z<0.8. More than 80 per cent of the ~11000 red galaxies have pure absorption-line spectra consistent with a passively evolving old stellar population. The redshift, photometric and spatial distributions of the LRGs are described. The 2SLAQ data will be released publicly from mid-2006, providing a powerful resource for observational cosmology and the study of galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/MNRAS/386/1443
- Title:
- 2dF study of globular clusters in NGC 5128
- Short Name:
- J/MNRAS/386/1443
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed a spectroscopic study of globular clusters (GCs) in the nearest giant elliptical NGC 5128 using the 2dF facility at the Anglo-Australian Telescope. We obtained integrated optical spectra for a total of 254 GCs, 79 of which are newly confirmed on the basis of their radial velocities and spectra. In addition, we obtained an integrated spectrum of the galaxy starlight along the southern major axis.
- ID:
- ivo://CDS.VizieR/J/MNRAS/353/601
- Title:
- 2dF survey of the Small Magellanic Cloud
- Short Name:
- J/MNRAS/353/601
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of new spectral types for hot, luminous stars in the Small Magellanic Cloud. The catalogue contains 4161 objects, giving an order of magnitude increase in the number of SMC stars with published spectroscopic classifications. The targets are primarily B- and A-type stars (2862 and 853 objects respectively), with 1 Wolf-Rayet, 139 O-type, and 306 FG stars, sampling the main sequence to ~mid-B. The selection and classification criteria are described, and objects of particular interest are discussed, including UV-selected targets from the Ultraviolet Imaging Telescope (UIT) experiment, Be and B[e] stars, `anomalous A supergiants', and composite-spectrum systems. We examine the incidence of Balmer-line emission, and the relationship between H-gamma equivalent width and absolute magnitude for BA stars.
- ID:
- ivo://CDS.VizieR/J/A+A/438/201
- Title:
- DG Leo uvby differential photometry
- Short Name:
- J/A+A/438/201
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Multi-site and multi-year differential photometry of the triple star DG Leo reveals a complex frequency spectrum that can be modelled as the combination of at least three {delta} Scuti type frequencies in the range 11.5-13c/d (with semi-amplitudes of 2-7mmag) and a superimposed slow variability of larger amplitude. The period of the slow variation fits very well with half the orbital period of the inner spectroscopic binary indicating the presence of ellipsoidal variations caused by the tidally deformed components in a close configuration. These findings, together with the results of a recent spectroscopic analysis (showing that the system consists of a pair of mild Am stars and one A-type component of normal solar composition), infer that DG Leo is an extremely interesting asteroseismic target. Identification of which component(s) of this multiple system is (or are) pulsating and determination of the excited pulsation modes will both contribute to a much better understanding of the non-trivial link between multiplicity, chemical composition, rotation, and pulsation in the lower part of the classical Cepheid instability strip.
- ID:
- ivo://CDS.VizieR/J/ApJ/771/L45
- Title:
- 3D global climate models for exoplanet around M-star
- Short Name:
- J/ApJ/771/L45
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The habitable zone (HZ) is the circumstellar region where a planet can sustain surface liquid water. Searching for terrestrial planets in the HZ of nearby stars is the stated goal of ongoing and planned extrasolar planet surveys. Previous estimates of the inner edge of the HZ were based on one-dimensional radiative-convective models. The most serious limitation of these models is the inability to predict cloud behavior. Here we use global climate models with sophisticated cloud schemes to show that due to a stabilizing cloud feedback, tidally locked planets can be habitable at twice the stellar flux found by previous studies. This dramatically expands the HZ and roughly doubles the frequency of habitable planets orbiting red dwarf stars. At high stellar flux, strong convection produces thick water clouds near the substellar location that greatly increase the planetary albedo and reduce surface temperatures. Higher insolation produces stronger substellar convection and therefore higher albedo, making this phenomenon a stabilizing climate feedback. Substellar clouds also effectively block outgoing radiation from the surface, reducing or even completely reversing the thermal emission contrast between dayside and nightside. The presence of substellar water clouds and the resulting clement surface conditions will therefore be detectable with the James Webb Space Telescope.