- ID:
- ivo://CDS.VizieR/J/AJ/116/2108
- Title:
- AWM 7 radial velocities
- Short Name:
- J/AJ/116/2108
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have measured redshifts and Kron-Cousins R-band magnitudes for a sample of galaxies in the poor cluster AWM 7. We have measured redshifts for 172 galaxies; 106 of these are cluster members. We determine the luminosity function (LF) from a photometric survey of the central 1.2x1.2h^-1^Mpc. The LF has a bump at the bright end and a faint-end slope of {alpha}=-1.37+/-0.16, populated almost exclusively by absorption-line galaxies. The cluster velocity dispersion is lower in the core (~530km/s) than at the outskirts (~680km/s), consistent with the cooling flow seen in the X-ray. The cold core extends ~150h^-1^kpc from the cluster center. The Kron-Cousins R-band mass-to-light ratio of the system is 650+/-170hM_{sun}_/L_{sun}_, substantially lower than previous optical determinations, but consistent with most previous X-ray determinations. We adopt H_0_=100hkm/s/Mpc throughout this paper; at the mean cluster redshift (5247+/-76km/s), 1h^-1^Mpc subtends 65.5'.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/131/2035
- Title:
- B and R magnitudes for spiral galaxies
- Short Name:
- J/AJ/131/2035
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- It is an observational fact that bulges of spiral galaxies contain a high fraction of old and metal-rich stars. Following this observational fact, we have investigated the colors of 21 bulges hosted by a selected sample of high surface brightness spiral galaxies and low surface brightness galaxies observed in the B and R optical bands and the J and Ks near-IR bands.
- ID:
- ivo://CDS.VizieR/J/AJ/159/15
- Title:
- Binary stars in Upper Scorpius
- Short Name:
- J/AJ/159/15
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To address the statistics of binary stars in the 8 Myr old Upper Scorpius (USco) star formation region, we conducted a speckle interferometric survey of 614 association members more massive than 0.4 M_{sun}_ (spectral types earlier than M3V) based on the list of Luhman et al. (2018, J/AJ/156/271). We resolved 187 pairs, 55 of which are new discoveries. Also using the published data and the Gaia DR2 (Cat. I/345), a catalog of 250 physical binaries was produced. We carefully estimated detection limits for each target and studied binary statistics in the separation range from 0.06" to 20" (9-2800 au), as well as clustering at larger separations. The frequency of companions with mass ratios q>0.3 in this separation range is 0.33+/-0.04 and 0.35+/-0.04 for early M- and solar-type stars, respectively, larger by 1.62+/-0.22 and 1.39+/-0.18 times compared to field stars of similar masses. The excess is produced mostly by pairs closer than 100 au. At separations from 100 to 10^4^ au, the separation distribution and companion fraction resemble those of solar-type stars in the field. However, unlike in the field, we see a relative deficit of equal-mass binaries at separations of ~500 au, compared to smaller and larger separations. The distribution of q depends on the separation, with a preference of larger q and a larger fraction of twins with q>0.95 at smaller separations. The binary population of USco differs from binaries in the field in several ways and suggests that binary statistics is not universal.
- ID:
- ivo://CDS.VizieR/J/A+A/587/A61
- Title:
- BlackCAT, stellar-mass BH in X-ray trans.
- Short Name:
- J/A+A/587/A61
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- During the last ~50 years, the population of black hole candidates in X-ray binaries has increased considerably, with 59 Galactic objects being detected in transient low-mass X-ray binaries, as well as a few in persistent systems (including ~5 extragalactic binaries). We collect near-infrared, optical, and X-ray information spread over hundreds of references to study the population of black holes in X-ray transients as a whole. We present the most updated catalogue of black hole transients. This contains X-ray, optical, and near-infrared observations, together with their astrometric and dynamical properties. The catalogue provides new and useful information in both statistical and observational parameters and provides a thorough and complete overview of the black hole population in the Milky Way. Analysing the distances and spatial distribution of the observed systems, we estimate a total population of ~1300 Galactic black hole transients. This means that we have only discovered less than ~5% of the total Galactic distribution. The complete version of this catalogue will be continuously updated online and in the Virtual Observatory, including finding charts and data in other wavelengths.
- ID:
- ivo://CDS.VizieR/I/228
- Title:
- Bordeaux AC Zone Data Reduced to ACRS
- Short Name:
- I/228
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Bordeaux Zone, whose plates are centered between declinations +11 and +17 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 223,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
- ID:
- ivo://CDS.VizieR/J/ApJ/440/28
- Title:
- Brightest Cluster Galaxies velocities
- Short Name:
- J/ApJ/440/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate the use of Brightest Cluster Galaxies (BCGs) as standard candles for measuring galaxy peculiar velocities on large scales. We have obtained precise large-format CCD surface photometry and redshifts for an all-sky, volume-limited (z<=0.05) sample of 119 BCG. We reinvestigate the Hoessel (1980ApJ...241..493H) relationship between the metric luminosity, L_m_, within the central 10h^-1^kpc of the BCGs and the logarithmic slope of the surface brightness profile, {alpha}. The L_m_-{alpha} relationship reduces the cosmic scatter in L_m_ from 0.327mag to 0.244mag, yielding a typical distance accuracy of 17% per BCG. Residuals about the L_m_-{alpha} relationship are independent of BCG luminosity, BCG B-R_c_ color, BCG location within the host cluster, and richness of the host cluster. The metric luminosity is independent of cluster richness even before correcting for its dependence on {alpha}, which provides further evidence for the unique nature of the BCG luminosity function. Indeed, the BCG luminosity function, both before and after application of the {alpha}-correction, is consistent with a single Gaussian distribution. Half the BCGs in the sample show some evidence of small color gradients as a function of radius within their central 50h^-1^kpc regions but with almost equal numbers becoming redder as becoming bluer. However, with the central 10h^-1^kpc the colors are remarkably constant, the mean B-R_c_ color is 1.51 with a dispersion of only 0.06mag. The narrow photometric and color distributions of the BCGs, the lack of "second-parameter" effects, as well as the unique rich cluster environment of BCGs, argue that BCGs are the most homogeneous distance indicators presently available for large-scale structure research.
- ID:
- ivo://CDS.VizieR/II/144
- Title:
- Brightest stars in the field of M31
- Short Name:
- II/144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This Catalogue of 11438 stars in the field of M31 is based on a set of Tautenburg Schmidt plates in U, B, V and R taken by van den Bergh. The range of visual magnitudes of stars is 11.5 < V < 20.
- ID:
- ivo://CDS.VizieR/J/A+AS/124/283
- Title:
- BR magnitude and redshift of A1300
- Short Name:
- J/A+AS/124/283
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first results of an optical follow-up of X-ray bright clusters of galaxies located between 0.15<=z<=0.31: B and R photometry as well as medium resolution spectroscopy of the galaxies. The cluster studied here - A1300 - is found to have a redshift of 0.3072 and a velocity dispersion of 1210km/s, based on 52 cluster members. Structures are observed in the galaxy number counts but the velocity histogram shows no significant departure from a Gaussian distribution.
- ID:
- ivo://CDS.VizieR/J/A+A/177/131
- Title:
- CaII and MgII excess flux density in cool stars
- Short Name:
- J/A+A/177/131
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relation between the CaII H and K line-tore flux density and rotation period is studied for a sample of 313 cool stars of luminosity classes ranging from II-III to V, and compared to similar relations for MgII h and k and soft X-ray.
- ID:
- ivo://CDS.VizieR/J/A+A/476/73
- Title:
- Calibration of Cepheid Period/Luminosity relation
- Short Name:
- J/A+A/476/73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The universality of the Cepheid period-luminosity (PL) relations has been under discussion since metallicity effects were assumed to play a role in the value of the intercept and, more recently, of the slope of these relations. The goal of the present study is to calibrate the Galactic PL relations in various photometric bands (from B to K) and to compare the results to the well-established PL relations in the LMC. We use a set of 59 calibrating stars, the distances of which are measured using five different distance indicators: Hubble Space Telescope and revised Hipparcos parallaxes, infrared surface brightness and interferometric Baade-Wesselink parallaxes, and classical Zero-Age-Main-Sequence-fitting parallaxes for Cepheids belonging to open clusters or OB stars associations. A detailed discussion of absorption corrections and projection factor to be used is given.
