We present a database and velocity catalogue towards the region of the Shapley Supercluster based on 18,146 measured velocities for 10,719 galaxies in the approximately 300 square degree area between 12h 43mn 00s < R.A. < 14h 17mn 00s and -23° 30' 00" < Dec < -38° 30' 00". The data catalogue contains velocities from the literature found until 2015. It also includes 5,084 velocities, corresponding to 4,617 galaxies, observed by us at Las Campanas and CTIO observatories and not reported individually until now. Of these, 2,585 correspond to galaxies with no other previously published velocity measurement before 2015. Every galaxy in the velocity database has been identified with a galaxy extracted from the SuperCOSMOS photometric catalogues. We also provide a combined average velocity catalogue for all 10,719 galaxies with measured velocities, adopting the SuperCOSMOS positions as a homogeneous base. A general magnitude cut-off at R2=18.0 mag was adopted (with exceptions only for some of the new reported velocities). In general terms, we confirm the overall structure of the Shapley Supercluster, as found on earlier papers. However, the more extensive velocity data show finer structure, to be discussed in a future publication.
The Shapley Supercluster ($\langle z \rangle\approx0.048$) contains several tens of gravitationally bound clusters and groups, making it it is an ideal subject for radio studies of cluster mergers. We used new high sensitivity radio observations to investigate the less energetic events of mass assembly in the Shapley Supercluster from supercluster down to galactic scales. We created total intensity images of the full region between A 3558 and A 3562, from $\sim 230$ to $\sim 1650$ MHz, using ASKAP, MeerKAT and the GMRT, with sensitivities ranging from $\sim 6$ to $\sim 100$ $μ$Jy beam$^{-1}$. …
We present a 23deg$^2$ weak gravitational lensing survey of the Shapley supercluster core and its surroundings using $gri$ VST images as part of the Shapley Supercluster Survey (ShaSS). This study reveals the overall matter distribution over a region containing 11 clusters at $z{\sim}0.048$ that are all interconnected, as well as several ongoing cluster-cluster interactions. Galaxy shapes have been measured by using the Kaiser-Squires-Broadhurst method for the $g$- and $r$-band images and background galaxies were selected via the $gri$ colour-colour diagram. This technique has allowed us to de…
We present two new examples of galaxies undergoing transformation in the Shapley supercluster core. These low-mass (stellar mass from 0.4E10 to 1E10 Msun) galaxies are members of the two clusters SC-1329-313 (z=0.045) and SC-1327-312 (z=0.049). Integral-field spectroscopy complemented by imaging in ugriK bands and in Halpha narrow-band are used to disentangle the effects of tidal interaction (TI) and ram-pressure stripping (RPS). In both galaxies, SOS-61086 and SOS-90630, we observe one-sided extraplanar ionized gas extending respectively 30kpc and 41kpc in projection from their disks. The gal…
Looking at the region connecting two clusters is a promising way to identify and study the Warm-Hot Intergalactic Medium. Observations show that the spectrum of the bridge between A3556 and A3558 has a stronger soft X-ray emission than the nearby region. Suzaku observations could not discriminate the origin of the extra emission. In this work we analyze a dedicated Chandra observation of the same target to identify point sources and characterize the background emission in the bridge. We find that the count number of the point sources is much higher than average field population (using CDFS~4~M…
We present an overview of a multi-wavelength survey of the Shapley supercluster (SSC; z~0.05) covering a contiguous area of 260 h^-2_70 Mpc^2 including the supercluster core. The project main aim is to quantify the influence of cluster-scale mass assembly on galaxy evolution in one of the most massive structures in the local Universe. The Shapley supercluster survey (ShaSS) includes nine Abell clusters (A3552, A3554, A3556, A3558, A3559, A3560, A3562, AS0724, AS0726) and two poor clusters (SC1327- 312, SC1329-313) showing evidence of cluster-cluster interactions. Optical (ugri) and near-infrar…
We use high signal-to-noise spectroscopy for a sample of 232 quiescent galaxies in the Shapley Supercluster, to investigate how their stellar populations depend on velocity dispersion, luminosity and stellar mass. The sample spans a large range in velocity dispersion (sigma from 30-300 km/s) and in luminosity (M_R from -18.7 to -23.2). Estimates of age, total metallicity (Z/H) and alpha-element abundance ratio (a/Fe) were derived from absorption-line analysis, using single-burst models. Age, Z/H and a/Fe are all correlated positively with velocity dispersion, but we also find significant resid…
The Shapley Supercluster Survey is a multi-wavelength survey covering an area of ~23 deg^2 (~260 Mpc^2 at z=0.048) around the supercluster core, including nine Abell and two poor clusters, having redshifts in the range 0.045-0.050. The survey aims to investigate the role of the cluster-scale mass assembly on the evolution of galaxies, mapping the effects of the environment from the cores of the clusters to their outskirts and along the filaments. The optical (ugri) imaging acquired with OmegaCAM on the VLT Survey Telescope is essential to achieve the project goals providing accurate multi-band…
Neutral Hydrogen in the Shapley Supercluster Core I: Environmental Effects on Gas Content and Galaxy Evolution
Rhodes University（罗德斯大学）；INAF–Istituto di Radioastronomia（意大利国家天体物理研究所射电天文研究所）；INAF–Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）；South African Radio Astronomy Observatory（南非射电天文观测台）
Magnetic Fields in the Shapley Supercluster Core with POSSUM: Challenging Model Predictions
Universidad Complutense de Madrid（马德里康普顿斯大学）；Università degli Studi di Bologna（博洛尼亚大学）；INAF – Istituto di Radioastronomia（意大利国家天体物理研究所射电天文研究所）；The University of Chicago（芝加哥大学）；Dunlap Institute for Astronomy and Astrophysics, University of Toronto（多伦多大学邓普勒天文学与天体物理研究所）；The Australian National University（澳大利亚国立大学）；National Research Council Canada, Herzberg Research Centre for Astronomy and Astrophysics（加拿大国家研究委员会赫茨伯格天文学与天体物理研究中心）
Cosmic dance in the Shapley Concentration Core II. The uGMRT-MeerKAT view of filaments in the brightest cluster galaxies and tailed radio galaxies in the A3528 cluster complex
本文利用 uGMRT 和 MeerKAT 射电观测结合 eROSITA X 射线数据，研究沙普利超星系团核心 A3528 复合体，发现最亮团星系周围存在谱指数极陡的弥散射电纤维，并提出小型并合可重新加速射电星系等离子体。
We trace the cosmic web at redshifts 1.0 <= z <= 1.8 using the quasar data from the SDSS DR7 QSO catalogue (Schneider et al. 2010). We apply a friend-of-friend (FoF) algorithm to the quasar and random catalogues to determine systems at a series of linking lengths, and analyse richness and sizes of these systems. At the linking lengths l <= 30 Mpc/h the number of quasar systems is larger than the number of systems detected in random catalogues, and systems themselves have smaller diameters than random systems. The diameters of quasar systems are comparable to the sizes of poor galaxy superclust…
We present results of a spectroscopic search for Lyman-alpha emitters (LAEs) in the Cl1604 supercluster field using the extensive spectroscopic Keck/DEIMOS database taken as part of the Observations of Redshift Evolution in Large Scale Environments (ORELSE) survey. A total of 12 slitmasks were observed and inspected in the Cl1604 field, spanning a survey volume of 1.365x10^4 co-moving Mpc^3. We find a total of 17 high redshift (4.39 < z < 5.67) LAE candidates down to a limiting flux of 1.9x10^(-18) ergs/s/cm (~0.1L* at z~5), 13 of which we classify as high quality. The resulting LAE number den…
We show how the XXL multiwavelength survey can be used to shed light on radio galaxies and their environment. Two prominent radio galaxies were identified in a visual examination of the mosaic of XXL-North obtained with the Giant Metrewave Radio Telescope at 610MHz. Counterparts were searched for in other bands. Spectroscopic redshifts from the GAMA database were used to identify clusters and/or groups of galaxies, estimate their masses with the caustic method, and quantify anisotropies in the surrounding galaxy distribution via a Fourier analysis. Both radio galaxies are of FR I type and are …
We constructed a Bayesian hyper-parameter statistical method to quantify the difference between predicted velocities derived from the observed galaxy distribution in the \textit{IRAS}-PSC$z$ redshift survey and peculiar velocities measured using different distance indicators. In our analysis we find that the model--data comparison becomes unreliable beyond $70 \hmpc$ because of the inadequate sampling by \textit{IRAS} survey of prominent, distant superclusters, like the Shapley Concentration. On the other hand, the analysis of the velocity residuals show that the PSC$z$ gravity field provides …
We present a new catalogue of distances and peculiar velocities (PVs) of $34,059$ early-type galaxies derived from Fundamental Plane (FP) measurements using data from the Sloan Digital Sky Survey (SDSS). This $7016\,\mathrm{deg}^{2}$ homogeneous sample comprises the largest set of peculiar velocities produced to date and extends the reach of PV surveys up to a redshift limit of $z=0.1$. Our SDSS-based FP distance measurements have a mean uncertainty of 23%. Alongside the data, we produce an ensemble of 2,048 mock galaxy catalogues that reproduce the data selection function, and are used to val…
We use the GALEX data of the GUViCS survey to construct the NUV luminosity function of the Virgo cluster over ~ 300 deg.2, an area covering the cluster and its surrounding regions up to ~ 1.8 virial radii. The NUV luminosity function is also determined for galaxies of different morphological type and NUV-i colour, and for the different substructures within the cluster. These luminosity functions are robust vs. statistical corrections since based on a sample of 833 galaxies mainly identified as cluster members with spectroscopic redshift (808) or high-quality optical scaling relations (10). We …
Theories of modified gravity generically violate the strong equivalence principle, so that the internal dynamics of a self-gravitating system in free fall depends on the strength of the external gravitational field (the external field effect). We fit rotation curves (RCs) from the SPARC database with a model inspired by Milgromian dynamics (MOND), which relates the outer shape of a RC to the external Newtonian field from the large-scale baryonic matter distribution through a dimensionless parameter $e_{\rm N}$. We obtain a $>4σ$ statistical detection of the external field effect (i.e. $e_{\rm …
