- ID:
- ivo://CDS.VizieR/J/A+A/385/39
- Title:
- 13 and 22cm radio flux from A3571
- Short Name:
- J/A+A/385/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this paper we report and discuss the results of a radio survey in the A3571 cluster complex, a structure located in the Shapley Concentration core, and formed by the three clusters A3571, A3572 and A3575. The survey was carried out simultaneously at 22cm and 13cm with the Australia Telescope Compact Array, and led to the detection of 124 radio sources at 22cm. The radio source counts in this region are in agreement with the background counts. Among the 36 radio sources with optical counterpart, six have a measured redshift that places them at the distance of the A3571 cluster complex, and nine radio sources have optical counterparts most likely members of this cluster complex. All of the radio galaxies emit at low power level, i.e. P_22cm_<=10^22.6^ W/Hz. A number of them are likely to be starburst galaxies.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/390/1133
- Title:
- Anisotropic distribution of satellite galaxies
- Short Name:
- J/MNRAS/390/1133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We identify satellites of isolated galaxies in the Sloan Digital Sky Survey and examine their angular distribution. Using mock catalogues generated from cosmological N-body simulations, we demonstrate that the selection criteria used to select isolated galaxies and their satellites in large galaxy redshift surveys must be very strict in order to correctly identify systems in which the primary galaxy dominates its environment. We demonstrate that the criteria used in many previous studies instead select predominantly group members. We refine a set of selection criteria for which the group contamination is estimated to be less than 7 per cent and present a catalogue of the resulting sample.
- ID:
- ivo://CDS.VizieR/J/A+A/592/A48
- Title:
- Annotations to the second Planck cluster catalog
- Short Name:
- J/A+A/592/A48
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an all sky map of the y-type distortion calculated from the full mission Planck HFI (High Frequency Instrument) data using the recently proposed approach to component separation based on parametric model fitting and model selection. This simple model selection approach allows us to distinguish between carbon monoxide (CO) line emission and y-type distortion, something that is not possible using the internal linear combination based methods. We create a mask to cover the regions of significant CO emission relying on the information in the {chi}^2^ map obtained when fitting for the y-distortion and CO emission to the lowest four HFI channels. We revisit the second Planck cluster catalog and try to quantify the quality of the cluster candidates in an approach that is similar in spirit to Aghanim et al. (2015A&A...580A.138A). We find that at least 93% of the clusters in the cosmology sample are free of CO contamination. We also find that 59% of unconfirmed candidates may have significant contamination from molecular clouds. We agree with Planck Collaboration et al. (2016, A&A, in press., arXiv:1502.01598) for the worst offenders. We suggest an alternative validation strategy of measuring and subtracting the CO emission from the Planck cluster candidates using radio telescopes thus improving the reliability of the catalog. Our CO mask and annotations to the Planck cluster catalog identifying cluster candidates with possible CO contamination are made publicly available.
- ID:
- ivo://CDS.VizieR/J/MNRAS/477/1760
- Title:
- Antlia galaxies geometric parameters
- Short Name:
- J/MNRAS/477/1760
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a statistical isophotal analysis of 138 early-type galaxies in the Antlia cluster, located at a distance of ~35Mpc. The observational material consists of CCD images of four 36x36arcmin^2^ fields obtained with the MOSAIC II camera at the Blanco 4-m telescope at Cerro Tololo Interamerican Observatory. Our present work supersedes previous Antlia studies in the sense that the covered area is four times larger, the limiting magnitude is M_B_~-9.6mag, and the surface photometry parameters of each galaxy are derived from Sersic model fits extrapolated to infinity. In a companion previous study we focused on the scaling relations obtained by means of surface photometry, and now we present the data, on which the previous paper is based, the parameters of the isophotal fits as well as an isophotal analysis. For each galaxy, we derive isophotal shape parameters along the semimajor axis and search for correlations within different radial bins. Through extensive statistical tests, we also analyse the behaviour of these values against photometric and global parameters of the galaxies themselves. While some galaxies do display radial gradients in their ellipticity ({epsilon}) and/or their Fourier coefficients, differences in mean values between adjacent regions are not statistically significant. Regarding Fourier coefficients, dwarf galaxies usually display gradients between all adjacent regions, while non-dwarfs tend to show this behaviour just between the two outermost regions. Globally, there is no obvious correlation between Fourier coefficients and luminosity for the whole magnitude range (-12>=M_V_>=-22); however, dwarfs display much higher dispersions at all radii.
- ID:
- ivo://CDS.VizieR/J/ApJ/511/595
- Title:
- An X-Ray Survey of Galaxies in Pairs
- Short Name:
- J/ApJ/511/595
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Results are reported from the first survey of X-ray emission from galaxies in pairs. The sample consists of 52 pairs of galaxies from the Catalog of Paired Galaxies (Cat. <VII/77>) whose coordinates overlap the ROSAT Position Sensitive Proportional Counter pointed observations. The mean observed log(L_x_) for early-type pairs is 41.35+/-0.21, while the mean log(L_x_) predicted using the (L_X_-L_b_) relationship for isolated early-type galaxies is 42.10+/-0.19. With 95% confidence, the galaxies in pairs are underluminous in the X-ray, compared with isolated galaxies, for the same L_b_. A significant fraction of the mixed pair sample also appears similarly underluminous. A spatial analysis shows that the X-ray emission from pairs of both types typically has an extent of 10 - 50 kpc, much smaller than the group intergalactic medium, and thus likely originates from the galaxies. CPG 564, the most X-ray luminous early-type pair, 4.7x10^42^ergs/s, is an exception. The extent of its X-ray emission, greater than 169 kpc, and HWHM, {~}80 kpc, is comparable to that expected from an intergalactic medium. The sample shows only a weak correlation, {~}81% confidence, between L_X_ and L_b_, presumably due to variations in gas content within the galaxies. No correlation between L_X_ and the pair velocity difference ({delta}v), separation ({delta}r), or far-infrared luminosity (L_fir_) is found, although the detection rate is low, 22%.
- ID:
- ivo://CDS.VizieR/J/MNRAS/269/151
- Title:
- APM cluster redshift survey
- Short Name:
- J/MNRAS/269/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present redshifts for a sample of 228 clusters selected from the APM Galaxy Survey, 188 of which are new redshift determinations. Redshifts are listed for 365 galaxies, and non-cluster galaxy redshifts have been rejected from this sample using a likelihood ratio test based on the projected and apparent magnitude distributions of each cluster region. We test this technique using clusters for which redshifts have been measured for more than 10 galaxies. Our redshift sample is nearly complete and has been used in previous papers to study the three-dimensional distribution of rich clusters of galaxies. 156 of the clusters in our sample are listed in the Abell catalogue or supplement, and the remainder are new cluster identifications.
- ID:
- ivo://CDS.VizieR/J/A+A/581/A126
- Title:
- Application of the D^3^PO algorithm
- Short Name:
- J/A+A/581/A126
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze the 6.5yr all-sky data from the Fermi LAT restricted to gamma-ray photons with energies between 0.6-307.2GeV. We present a non-parametric reconstruction of the diffuse photon flux up to several hundred GeV, its all-sky spectral index map, and its angular power spectrum. We decompose the diffuse emission into a cloud-like abd a bubble-like component and analyze their spectra. Additionally, we wrote up a catalog of source candidates that includes 3106 sources. For each source we report the location in the sky, flux, spectral index, and possible associations with sources from the second and third Fermi source catalog.
- ID:
- ivo://CDS.VizieR/J/AJ/123/1200
- Title:
- Aquarius superclusters. I.
- Short Name:
- J/AJ/123/1200
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We study the distribution of galaxies and galaxy clusters in a 10{deg}x6{deg} field in the Aquarius region. In addition to 63 clusters in the literature, we have found 39 new candidate clusters using a matched-filter technique and a counts-in-cells analysis. From redshift measurements of galaxies in the direction of these cluster candidates, we present new mean redshifts for 31 previously unobserved clusters, while improved mean redshifts are presented for 35 other systems.
- ID:
- ivo://CDS.VizieR/J/AJ/128/2642
- Title:
- Aquarius superclusters. II.
- Short Name:
- J/AJ/128/2642
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present spectroscopic and photometric data for 920 galaxies selected in 68 fields of the Aquarius Cluster Catalog. Typically, the 15 brightest candidate members with magnitudes in the range 16<b_J_<21 were selected for observations, and ~71% turn out to be cluster members. Using the new redshift determinations, we assign galaxies to groups and clusters, and by including data from the literature we calculate systemic velocities and velocity dispersions for 74 clusters, each with redshifts measured for at least six individual galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/285/898
- Title:
- A3556 radio properties
- Short Name:
- J/MNRAS/285/898
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have imaged the portion of the Shapley Concentration core surrounding the cluster A3556 at wavelengths of 36cm with the Molonglo Observatory Synthesis Telescope (MOST), and at 22 and 13cm with the Australia Telescope Compact Array (ATCA). We have defined a radio sample of 112 radio sources at 22cm. Cross-correlation with optical catalogues allowed the identification of 29 radio sources, nine of which belong to A3556. The radio and optical properties of A3556 have been studied in detail. Two extended radio sources are associated with cluster members, i.e. a narrow-angle-tail source located at a projected distance of 0.06R_A_ from the centre, possibly in the late stages of its existence, and a wide-angle-tail source at the periphery of the cluster. We also performed a statistical analysis of the cluster properties. The optical luminosity function shows that the cluster has an excess of bright optical galaxies. In agreement with well-established results, we found that the probability of radio emission increases for brighter galaxies. Furthermore, our radio luminosity function and those obtained for elliptical galaxies located in different environments (poor groups and rich clusters) are very similar, implying that the peculiar dynamical state of A3556 has no influence on the radio emission properties of the cluster galaxies.
