We present deep 1.4GHz Very Large Array radio continuum observations of two ~0.5{deg}^2^ fields in the Coma cluster of galaxies. The two fields, "Coma 1" and "Coma 3", correspond to the cluster core and southwest infall region and were selected on account of abundant preexisting multiwavelength data. In their most sensitive regions the radio data reach 22uJy rms per 4.4" beam, sufficient to detect (at 5{sigma}) Coma member galaxies with L_1.4GHz_=1.3x10^20^W/Hz. The full catalog of radio detections is presented herein and consists of 1030 sources detected at >=5{sigma}, 628 of which are within the combined Coma 1 and Coma 3 area. We also provide optical identifications of the radio sources using data from the Sloan Digital Sky Survey. The depth of the radio observations allows us to detect active galactic nucleus in cluster elliptical galaxies with M_r_<-20.5 (AB magnitudes), including radio detections for all cluster ellipticals with M_r_<-21.8. At fainter optical magnitudes (-20.5<M_r_~<-19), the radio sources are associated with star-forming galaxies with star formation rates as low as 0.1M_{sun}_/yr.
We present extensive and accurate photometry in the near-infrared H band (about 1.62{mu}m) of a complete sample of objects in an area of about 400arcmin^2^ toward the Coma cluster of galaxies. The sample, including about 300 objects, is complete down to H~17mag, the exact value depending on the type of magnitude (isophotal, aperture, Kron) and the particular region studied. This is six magnitudes below the characteristic magnitude of galaxies, well into the dwarfs' regime at the distance of the Coma cluster. For each object (star or galaxy) we provide aperture magnitudes computed within five different apertures, the magnitude within the 22mag/arcsec^2^ isophote, the Kron magnitude and radius, magnitude errors, as well as the coordinates, the isophotal area, and a stellarity index. Photometric errors are 0.2mag at the completness limit. This sample is meant to be the zero-redshift reference for evolutionary studies of galaxies.
The Coma supercluster (100h^-1^Mpc) offers an unprecedented contiguous range of environments in the nearby Universe. In this paper, we present a catalogue of spectroscopically confirmed galaxies in the Coma supercluster detected in the ultraviolet (UV) wavebands. We use the arsenal of UV and optical data for galaxies in the Coma supercluster covering ~500deg^2^ on the sky to study their photometric and spectroscopic properties as a function of environment at various scales. We identify the different components of the cosmic-web: large-scale filaments and voids using Discrete Persistent Structures Extractor, and groups and clusters using Hierarchical Density-based spatial clustering of applications with noise, respectively. We find that in the Coma supercluster the median emission in H{alpha} inclines, while the g-r and FUV-NUV colours of galaxies become bluer moving further away from the spine of the filaments out to a radius of ~1Mpc. On the other hand, an opposite trend is observed as the distance between the galaxy and centre of the nearest cluster or group decreases. Our analysis supports the hypothesis that properties of galaxies are not just defined by its stellar mass and large-scale density, but also by the environmental processes resulting due to the intrafilament medium whose role in accelerating galaxy transformations needs to be investigated thoroughly using multiwavelength data.
The measurement of the mass of clusters of galaxies is crucial for their use in cosmology and astrophysics. Masses can be efficiently determined with weak lensing (WL) analyses. I compiled literature catalogues of WL clusters (LC2). Cluster identifiers, coordinates, and redshifts have been standardized. WL masses were reported to over-densities of 2500, 500, 200, and to the virial one in the reference {Lambda}CDM model. Duplicate entries were carefully handled. I produced three catalogues: LC2-single, with 485 unique groups and clusters analysed with the single-halo model; LC2-substructure, listing substructures in complex systems; LC2-all, listing all the 822 WL masses found in the literature. The catalogues and future updates are publicly available at http://pico.bo.astro.it/~sereno/CoMaLit/LC2/ .
The scaling of observable properties of galaxy clusters with mass evolves with time. Assessing the role of the evolution is crucial to study the formation and evolution of massive haloes and to avoid biases in the calibration. We present a general method to infer the mass and the redshift dependence, and the time-evolving intrinsic scatter of the mass-observable relations. The procedure self-calibrates the redshift-dependent completeness function of the sample. The intrinsic scatter in the mass estimates used to calibrate the relation is considered too. We apply the method to the scaling of mass M_Delta_ versus line-of-sight galaxy velocity dispersion {sigma}v, optical richness, X-ray luminosity, L_X_, and Sunyaev-Zel'dovich signal. Masses were calibrated with weak lensing measurements. The measured relations are in good agreement with time and mass dependences predicted in the self-similar scenario of structure formation. The lone exception is the L_X_-M_Delta_ relation, whose time evolution is negative in agreement with formation scenarios with additional radiative cooling and uniform preheating at high redshift. The intrinsic scatter in the sigma_v_-M_Delta_ relation is notably small, of the order of 14 per cent. Robust predictions on the observed properties of the galaxy clusters in the Cluster Lensing And Supernova survey with Hubble sample are provided as cases of study. Catalogues and scripts are publicly available at http://pico.bo.astro.it/~sereno/CoMaLit/ .
Mass measurements of astronomical objects are most wanted but still elusive. We need them to trace the formation and evolution of cosmic structure but we can get direct measurements only for a minority. This lack can be circumvented with a proxy and a scaling relation. The twofold goal of estimating the unbiased relation and finding the right proxy value to plug in can be hampered by systematics, selection effects, Eddington/Malmquist biases and time evolution. We present a Bayesian hierarchical method that deals with these issues. Masses to be predicted are treated as missing data in the regression and are estimated together with the scaling parameters. The calibration subsample with measured masses does not need to be representative of the full sample as far as it follows the same scaling relation. We apply the method to forecast weak lensing calibrated masses of the Planck, redMaPPer and MCXC clusters. Planck masses are biased low with respect to weak lensing calibrated masses, with a bias more pronounced for high-redshift clusters. MCXC masses are under-estimated by ~20 per cent, which may be ascribed to hydrostatic bias. Packages and catalogues are made available with the paper.
The role played by protostellar feedback in clustered star formation is still a matter of debate. In particular, protostellar outflows have been proposed as a source of turbulence in cluster-forming clumps, which may provide support against global collapse for several free-fall times. Here, we seek to test the above hypothesis in the case of the well-documented NGC 2264-C protocluster, by quantifying the amount of turbulence and support injected in the surrounding medium by protostellar outflows. Using the HERA heterodyne array on the IRAM 30m telescope, we carried out an extensive mapping of NGC 2264-C in the three molecular line transitions ^12^CO(2-1), ^13^CO(2-1), and C^18^O(2-1). We found widespread high-velocity 12 CO emission, testifying to the presence of eleven outflow lobes, closely linked to the compact millimeter continuum sources previously detected in the protocluster. We carried out a detailed analysis of the dynamical parameters of these outflows, including a quantitative evaluation of the overall momentum flux injected in the cluster-forming clump. These dynamical parameters were compared to the gravitational and turbulent properties of the clump. We show that the population of protostellar outflows identified in NGC 2264-C is likely to contribute a significant fraction of the observed turbulence but cannot efficiently support the protocluster against global collapse. Gravity appears to largely dominate the dynamics of the NGC 2264-C clump at the present time ; however it is possible that an increase in the star formation rate during the later evolution of the protocluster will trigger enough outflows to finally halt the contraction of the cloud.
The large submillimetre map of rho Oph A in the ^12^C^18^O(3-2) line, obtained with the APEX 12m telescope, covers 10' in RA by 5' in DE, sampled on a rectangular grid, aligned with the equatorial coordinate system and with regular 20" spacings (548 spectra). An inner ^12^C^18^O(3-2) map, extending over 200" by 200" (462 spectra) is sampled at the Nyqvist frequency.
The Serpens North cluster is a nearby low mass star forming region which is part of the Gould belt. It contains a range of young stars thought to correspond to two different bursts of star formation and provides the opportunity to study different stages of cluster formation. This work aims to study the molecular gas in the Serpens North cluster to probe the origin of the most recent burst of star formation in Serpens. Transitions of the C^17^O and C^18^O observed with the IRAM 30m telescope and JCMT are used to study the mass and velocity structure of the region while the physical properties of the gas are derived using LTE and non-LTE analyses of the three lowest transitions of C^18^O.
To understand the environment and extended structure of the host galactic gas whose molecular absorption line chemistry, we previously observed along the microscopic line of sight to the blazar/radio-continuum source NRAO 150 (aka B0355+508). We used the IRAM 30m Telescope and Plateau de Bure Interferometer to make two series of images of the host gas: i) 22.5" resolution single-dish maps of ^12^CO J=1-0 and 2-1 emission over a 220" by 220" field; ii) a hybrid (interferometer+singledish) aperture synthesis mosaic of ^12^CO J=1-0 emission at 5.8" resolution over a 90"-diameter region. At 22.5" resolution, the CO J=1-0 emission toward NRAO 150 is 30-100% brighter at some velocities than seen previously with 1' resolution, and there are some modest systematic velocity gradients over the 220" field. Of the five CO components seen in the absorption spectra, the weakest ones are absent in emission toward NRAO 150 but appear more strongly at the edges of the region mapped in emission. The overall spatial variations in the strongly emitting gas have Poisson statistics with rms fluctuations about equal to the mean emission level in the line wings and much of the line cores. The J=2-1/J=1-0 line ratios calculated pixel-by-pixel cluster around 0.7. At 6" resolution, disparity between the absorption and emission profiles of the stronger components has been largely ameliorated. The ^12^CO J=1-0 emission exhibits i) remarkably bright peaks, Tmb=12-13K, even as 4" from NRAO 150; ii) smaller relative levels of spatial fluctuation in the line cores, but a very broad range of possible intensities at every velocity; and iii) striking kinematics whereby the monotonic velocity shifts and supersonically broadened lines in 22.5" spectra are decomposed into much stronger velocity gradients and abrupt velocity reversals of intense but narrow, probably subsonic, line cores. CO components that are observed in absorption at a moderate optical depth (0.5) and are undetected in emission at 1' resolution toward NRAO 150 remain undetected at 6" resolution. This implies that they are not a previously-hidden large-scale molecular component revealed in absorption, but they do highlight the robustness of the chemistry into regions where the density and column density are too low to produce much rotational excitation, even in CO. Bright CO lines around NRAO 150 most probably reflect the variation of a chemical process, i.e. the C+-CO conversion. However, the ultimate cause of the variations of this chemical process in such a limited field of view remains uncertain.