- ID:
- ivo://CDS.VizieR/J/other/AstBu/70.1
- Title:
- Galaxies in Leo/Cnc region
- Short Name:
- J/other/AstBu/70
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In the region of the sky limited by the coordinates RA=7.0h...12.0h, Dec=0{deg}...+20{deg} and extending from the Virgo Cluster to the South Pole of the Local Supercluster, we consider the data on the galaxies with radial velocities V_LG_<~2000km/s. For 290 among them, we determine individual distances and peculiar velocities. In this region, known as the local velocity anomaly zone, there are 23 groups and 20 pairs of galaxies for which the estimates of virial/orbital masses are obtained. A nearby group around NGC3379 = Leo I and NGC3627 as well as the Local Group show the motion from the Local Void in the direction of Leo cloud with a characteristic velocity of about 400 km/s. Another rich group of galaxies around NGC3607 reveals peculiar velocity of about -420km/s in the frame of reference related with the cosmic background radiation. A peculiar scattered association of dwarf galaxies Gemini Flock at a distance of 8Mpc has the radial velocity dispersion of only 20km/s and the size of approximately 0.7Mpc. The virial mass estimate for it is 300 times greater than the total stellar mass. The ratio of the sum of virial masses of groups and pairs in the Leo/Can region to the sum of stellar masses of the galaxies contained in them equals 26, which is equivalent to the local average density {Omega}_m(local)_=0.074, which is 3-4 times smaller than the global average density of matter.
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Search Results
- ID:
- ivo://CDS.VizieR/J/other/AstBu/69.247
- Title:
- Galaxies in Lynx-Cancer void
- Short Name:
- J/other/AstBu/69
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this work we present the results of photometrical study of 85 objects from the updated sample of galaxies residing in the nearby Lynx-Cancer void. The images in filters u,g,r,i from the Sloan Digital Sky Survey database are used for photometry. The following model-independent parameters are obtained: integrated magnitudes and colours, effective radii and the respective surface brightnesses, optical and Holmberg radii. On results of the radial surface brightness profile analysis, their central values and scalelengths of model discs are derived. The colours of the outer parts of void galaxies are examined and compared to those of the model evolutionary tracks of the PEGASE2 package. This allowed to obtain estimates of the time since the epoch of star formation T_SF_. Among the latter group, the low-luminosity objects with M_B_>-13.2 dominate. The derived integrated absolute magnitudes and colours are used for galaxy stellar mass estimates. All available data on integrated galaxy HI fluxes are used to derive their parameter M(HI)/L_B_ and to estimate their gas mass-fraction. The small ~10% subgroup of the most gas-rich galaxies, with M(HI)/L_B_>2.5, shows gas mass-fractions reaching (94-99)%. Many of these objects also show atypically blue colours of their outer parts. To check possible statistical differences of void galaxy properties and galaxy samples formed with more general criteria, we compared the void sample galaxy parameters with those of 195 galaxies from the Equatorial Survey (ES), formed as a part of the blind HI survey HIPASS. In the common luminosity range (-18.5<M_g_<-13.5) the compared samples show similarity. The lowest luminosity void galaxies differ from the main ES sample. However, there are also ~7% faint so called 'inchoate' galaxies among ES sample with the elevated parameter M(HI)/L_B_, majority of which are situated far from massive neighbours and are probably the analogs of void galaxies.
1163. Galaxies in SGP region
- ID:
- ivo://CDS.VizieR/J/MNRAS/276/689
- Title:
- Galaxies in SGP region
- Short Name:
- J/MNRAS/276/689
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the data from an extensive, moderately deep (b_J_~19.5) spectroscopic survey of ~600 galaxies within four regions of the sky located near the South Galactic Pole. About 75% of the measured galaxies are in an approximately 3x1.5sq.deg region dominated by the rich cluster of galaxies Klemola 44 (Abell 4038). The other three small areas cover about 1sq.deg each. Here, we discuss in detail the observing and data reduction strategies, and the completeness of and errors in the measured redshifts. The data collected are being used for: (i) a study of the large-scale redshift distribution of the galaxies in each field, and (ii) a thorough dynamical investigation of Klemola 44. Results from these analyses will be presented in forthcoming papers.
- ID:
- ivo://CDS.VizieR/J/MNRAS/467/4220
- Title:
- Galaxies inside 120 arcsec of HE 0435-1223
- Short Name:
- J/MNRAS/467/4220
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on spectroscopy and multiband wide-field observations of the gravitationally lensed quasar HE 0435-1223, we determine the probability distribution function of the external convergence {kappa}_ext_ for this system. We measure the under/overdensity of the line of sight towards the lens system and compare it to the average line of sight throughout the Universe, determined by using the CFHTLenS (The Canada France Hawaii Lensing Survey) as a control field. Aiming to constrain {kappa}_ext_ as tightly as possible, we determine under/overdensities using various combinations of relevant informative weighting schemes for the galaxy counts, such as projected distance to the lens, redshift and stellar mass. We then convert the measured under/overdensities into a {kappa}_ext_ distribution, using ray-tracing through the Millennium Simulation. We explore several limiting magnitudes and apertures, and account for systematic and statistical uncertainties relevant to the quality of the observational data, which we further test through simulations. Our most robust estimate of {kappa}_ext_ has a median value {kappa}^med^_ext_=0.004 and a standard deviation {sigma}_{kappa}_=0.025. The measured {sigma}_{kappa}_ corresponds to 2.5 per cent relative uncertainty on the time delay distance, and hence the Hubble constant H_0_ inferred from this system. The median {kappa}^med^_ext_ value varies by ~0.005 with the adopted aperture radius, limiting magnitude and weighting scheme, as long as the latter incorporates galaxy number counts, the projected distance to the main lens and a prior on the external shear obtained from mass modelling. This corresponds to just ~0.5 per cent systematic impact on H_0_. The availability of a well-constrained {kappa}_ext_ makes HE 0435-1223 a valuable system for measuring cosmological parameters using strong gravitational lens time delays.
- ID:
- ivo://CDS.VizieR/J/A+A/406/593
- Title:
- Galaxies in Southern Bright Star Fields I.
- Short Name:
- J/A+A/406/593
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- As a prerequisite for cosmological studies using adaptive optics techniques, we have begun to identify and characterize faint sources in the vicinity of bright stars at high Galactic latitudes. The initial phase of this work has been a program of K_s_ imaging conducted with SOFI at the ESO NTT. From observations of 42 southern fields evenly divided between the spring and autumn skies, we have identified 391 additional stars and 1589 galaxies lying at separations <60" from candidate guide stars in the magnitude range 9.0<R<12.4. When analyzed as a "discrete deep field" with 131-arcmin^2^ area, our dataset gives galaxy number counts that agree with those derived previously over the range 16<K_s_<20.5. This consistency indicates that in the aggregate, our fields should be suitable for future statistical studies. We provide our source catalogue as a resource for users of large telescopes in the southern hemisphere.
- ID:
- ivo://CDS.VizieR/VI/146
- Title:
- Galaxies in the Cosmic Dawn II simulation
- Short Name:
- VI/146
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Cosmic Dawn II (CoDa II) is a new, fully-coupled radiation-hydrodynamics simulation of cosmic reionization and galaxy formation and their mutual impact, to redshift z<6. With 4096^3^ particles and cells in a 94Mpc box, it is large enough to model global reionization and its feedback on galaxy formation while resolving all haloes above 10^8^M_{sun}_. Using the same hybrid CPU-GPU code RAMSES-CUDATON as CoDa I in Ocvirk et al. (2016MNRAS.463.1462O), CoDa II modified and re-calibrated the subgrid star-formation algorithm, making reionization end earlier, at z>~6, thereby better matching the observations of intergalactic Lyman-alpha opacity from quasar spectra and electron-scattering optical depth from cosmic microwave background fluctuations. CoDa II predicts a UV continuum luminosity function in good agreement with observations of high-z galaxies, especially at z=6. As in CoDa I, reionization feedback suppresses star formation in haloes below ~2x10^9^M_{sun}_, though suppression here is less severe, a possible consequence of modifying the star-formation algorithm. Suppression is environment-dependent, occurring earlier (later) in overdense (underdense) regions, in response to their local reionization times. Using a constrained realization of {LAMBDA}CDM constructed from galaxy survey data to reproduce the large-scale structure and major objects of the present-day Local Universe, CoDa II serves to model both global and local reionization. In CoDa II, the Milky Way and M31 appear as individual islands of reionization, i.e. they were not reionized by the progenitor of the Virgo cluster, nor by nearby groups, nor by each other. Description: The galaxy catalogs for redshifts z=10 down to z=6 (the simulation ended at z=5.8) are provided. Galaxies are identified as Friends-of-Friends dark matter haloes with a linking length ll=0.2. Stars are associated to each halo if they are within a sphere of radius r200. Magnitudes are computed using a BPASS stellar population model, as detailed in the article. No dust opacity is considered.
- ID:
- ivo://CDS.VizieR/J/MNRAS/404/749
- Title:
- Galaxies in the field of B2108+213
- Short Name:
- J/MNRAS/404/749
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The gravitational lens system CLASS B2108+213 has two radio-loud lensed images separated by 4.56 arcsec. The relatively large image separation implies that the lensing is caused by a group of galaxies. In this paper, new optical imaging and spectroscopic data for the lensing galaxies of B2108+213 and the surrounding field galaxies are presented. These data are used to investigate the mass and composition of the lensing structure.
- ID:
- ivo://CDS.VizieR/J/MNRAS/395/1213
- Title:
- Galaxies in the field of MACS J1206.2-0847
- Short Name:
- J/MNRAS/395/1213
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We discuss the X-ray and optical properties of the massive galaxy cluster MACSJ1206.2-0847 (z=0.4385), discovered in the Massive Cluster Survey (MACS). Our Chandra observation of the system yields a total X-ray luminosity of 2.4x10^45^erg/s (0.1-2.4keV) and a global gas temperature of 11.6+/-0.7keV, very high values typical of MACS clusters. In both optical and X-ray images, MACSJ1206.2-0847 appears close to relaxed in projection, with a pronounced X-ray peak at the location of the brightest cluster galaxy (BCG); we interpret this feature as the remnant of a cold core. A spectacular giant gravitational arc, 15-arcsec in length, bright (V~21) and unusually red (R-K=4.3), is seen 20-arcsec west of the BCG; we measure a redshift of z=1.036 for the lensed galaxy. From our Hubble Space Telescope image of the cluster, we identify the giant arc and its counter image as a sevenfold imaged system. An excess of X-ray emission in the direction of the arc coincides with a mild galaxy overdensity and could be the remnant of a minor merger with a group of galaxies. We derive estimates of the total cluster mass as well as of the mass of the cluster core using X-ray, dynamical and gravitational-lensing techniques. For the mass enclosed by the giant arc (r<119kpc), our strong-lensing analysis based on Hubble Space Telescope imaging yields a very high value of 1.1x10^14^M_{sun}_, inconsistent with the much lower X-ray estimate of 0.5x10^14^M_{sun}_. Similarly, the virial estimate of 4x10^15^M_{sun}_ for the total cluster mass, derived from multi-object spectroscopy with Canada-France-Hawaii Telescope (CFHT) and the VLT of 38 cluster members, is significantly higher than the corresponding X-ray estimate of 1.7x10^15^M_{sun}_. We take the discrepancy between X-ray and other mass estimates to be indicative of pronounced substructure along the line of sight during an ongoing merger event, an interpretation that is supported by the system's very high velocity dispersion of 1580km/s.
- ID:
- ivo://CDS.VizieR/J/other/RAA/11.245
- Title:
- Galaxies in the field of RX J0054.0-2823
- Short Name:
- J/other/RAA/11.2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present galactic spectroscopic data from a pencil beam of 10.75'x7.5' centered on the X-ray cluster RXJ0054.0-2823 at z=0.29. We study the spectral evolution of galaxies from z=1 down to the cluster redshift in a magnitude-limited sample at R<=23, for which the statistical properties of the sample are well understood. We divide emission-line galaxies into star-forming galaxies, Low Ionization Nuclear Emission line Regions (LINERs), and Seyferts by using emission-line ratios of [OII],H{beta}, and [OIII], and derive stellar fractions from population synthesis models. We focus our analysis on absorption and low-ionization galaxies.
- ID:
- ivo://CDS.VizieR/J/AJ/112/359
- Title:
- Galaxies in the Hubble Deep Field
- Short Name:
- J/AJ/112/359
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of morphological and color data for galaxies with 21<I_814<25mag in the Hubble Deep Field (Williams et al. 1996, in Science with the Hubble Space Telescope II). Galaxies have been inspected and (when possible) independently visually classified on the MDS and DDO systems. Measurements of central concentration and asymmetry are also included in the catalog. The fraction of interacting and merging objects is seen to be significantly higher in the Hubble Deep Field than it is among nearby galaxies. Barred spirals are essentially absent from the deep sample. The fraction of early-type galaxies in the Hubble Deep Field is similar to the fraction of early-types in the Shapley-Ames Catalog, but the fraction of galaxies resembling archetypal grand-design late-type spiral galaxies is dramatically lower in the distant HDF sample.
