A5020848417- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Scientific Research and Discoveries
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Radio Astronomy Observations and Technology
- Adaptive optics and wavefront sensing
- Cosmology and Gravitation Theories
- Software Engineering Research
- History and Developments in Astronomy
- Spectroscopy and Laser Applications
- Software Engineering Techniques and Practices
- Crystal Structures and Properties
- Bayesian Methods and Mixture Models
- Advanced Statistical Methods and Models
- Astro and Planetary Science
- Advanced Fluorescence Microscopy Techniques
- Pulsars and Gravitational Waves Research
- Open Source Software Innovations
- Blind Source Separation Techniques
- Remote Sensing in Agriculture
University of Trieste
2015-2024
Trieste Astronomical Observatory
2015-2024
National Institute for Astrophysics
2013-2015
SRON Netherlands Institute for Space Research
2007
University of Geneva
1995-2002
Scuola Internazionale Superiore di Studi Avanzati
1990-1998
We evaluate in a homogeneous way the optical masses of 170 nearby clusters (z ≤ 0.15). The sample includes both data from literature and new ESO Nearby Abell Clusters Survey (ENACS) data. On assumption that mass follows galaxy distribution, we compute each cluster by applying virial theorem to member galaxies. constrain very substructured (about 10% our clusters) between two limiting values. After appropriate rescaling X-ray radii, compare estimates those derived analyses, which compiled...
We study the efficiency and reliability of cluster mass estimators that are based on projected phase-space distribution galaxies in a region. To this aim, we analyse data-set 62 clusters extracted from concordance LCDM cosmological hydrodynamical simulation. Galaxies (or Dark Matter particles) first selected cylinders given radius (from 0.5 to 1.5 Mpc/h) ~200 Mpc/h length. Cluster members then identified by applying suitable interloper removal algorithm. Two considered: virial estimator...
We use an unprecedented data-set of about 600 redshifts for cluster members, obtained as part a VLT/VIMOS large programme, to constrain the mass profile z=0.44 MACS J1206.2-0847 over radial range 0-5 Mpc (0-2.5 virial radii) using MAMPOSSt and Caustic methods. then add external constraints from our previous gravitational lensing analysis. invert Jeans equation obtain velocity-anisotropy profiles members. With mass-density we first determination pseudo-phase-space density profile. The...
We perform a comprehensive study of the total mass distribution galaxy cluster RXCJ2248 ($z=0.348$) with set high-precision strong lensing models, which take advantage extensive spectroscopic information on many multiply lensed systems. In effort to understand and quantify inherent systematics in parametric modelling, we explore collection 22 models where use different samples multiple image families, parametrizations cosmological parameters. As input for CLASH HST imaging data follow-up...
We present a detailed mass reconstruction and novel study on the substructure properties in core of Cluster Lensing And Supernova survey with Hubble (CLASH) Frontier Fields galaxy cluster MACS J0416.1−2403. show employ our extensive spectroscopic data set taken VIsible Multi-Object Spectrograph instrument as part CLASH-VLT program, to confirm spectroscopically 10 strong lensing systems select sample 175 plausible members limiting stellar log (M*/M☉) ≃ 8.6. reproduce measured positions 30...
view Abstract Citations (177) References (109) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Velocity Dispersions and X-Ray Temperatures of Galaxy Clusters Girardi, M. ; Fadda, D. Giuricin, G. Mardirossian, F. Mezzetti, Biviano, A. Using a large well-controlled sample clusters galaxies, we investigate the relation between cluster velocity dispersions X-ray temperatures intracluster gas. The selection is based on nonparametric methods. In particular, present...
view Abstract Citations (152) References (107) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Velocity Dispersions in Galaxy Clusters Girardi, M. ; Biviano, A. Giuricin, G. Mardirossian, F. Mezzetti, We analyze the velocity dispersions of 79 galaxy clusters having at least 30 galaxies with available redshifts. show that different estimates dispersion give similar results on cluster samples ~20 each. However. only robust seem to be efficient ~10 A significant...
We present relations between X-ray luminosity and velocity dispersion (L-sigma), gas mass (L-Mgas), cluster radius (r500-sigma) for 62 galaxy clusters in the HIFLUGCS, an flux-limited sample minimizing bias toward any morphology. Our analysis total is based on ~1.3Ms of clean XMM-Newton data 13439 member galaxies with redshifts. Cool cores are among major contributors to scatter L-sigma relation. When cool-core-corrected used intrinsic decreases 0.27 dex. Even after corrected cool core,...
Radio relics are diffuse radio sources observed in galaxy clusters, probably produced by shock acceleration during cluster–cluster mergers. Their large size, of the order 1 Mpc, indicates that emitting electrons need to be (re)accelerated locally. The usually invoked diffusive models have been challenged recent observations and theory. We report discovery complex emission Galaxy cluster PLCKG287.0+32.9, which hosts two relics, a halo, several filamentary emission. Optical suggest is...
Context. The analysis of galaxy properties, such as stellar masses, colors, sizes and morphologies, the relations among them environment, in which galaxies reside, can be used to investigate physical processes driving evolution.
We study the intra-cluster magnetic field in poor galaxy cluster Abell 194 by complementing radio data, at different frequencies, with data optical and X-ray bands. analyze new total intensity polarization observations of obtained Sardinia Radio Telescope (SRT). use SRT combination archival Very Large Array to derive both spectral aging Rotation Measure (RM) images galaxies 3C40A 3C40B embedded 194. The analysis indicates that does not show a major recent merger, but rather agrees scenario...
We present VIMOS-VLT spectroscopy of the Frontier Fields cluster MACS~J0416.1-2403 (z=0.397). Taken as part CLASH-VLT survey, large spectroscopic campaign provided more than 4000 reliable redshifts, including ~800 member galaxies. The unprecedented sample members at this redshift allows us to perform a highly detailed dynamical and structural analysis out ~2.2$r_{200}$ (~4Mpc). Our substructures reveals complex system composed main massive ($M_{200}$~0.9$\times 10^{15} M_{\odot}$) presenting...
We use the public release of ≃100,000 galaxies from Two Degree Field Galaxy Redshift Survey (2dFGRS) to analyze internal dynamics galaxy clusters. select 43 noninteracting clusters that are adequately sampled in 2dFGRS release. Members these selected out ~2 virial radii. build an ensemble cluster by stacking together clusters, after appropriate scaling their velocities and clustercentric distances. solve Jeans equation for hydrostatic equilibrium member within radius cluster, assuming...
We present a new determination of the mass function galaxy clusters, based on optical virial estimates for large sample 152 nearby (z\le0.15) Abell-ACO as provided by Girardi et al. (1998). This includes both data from literature and ENACS data. The resulting is reliably estimated masses larger than M_{lim}\simeq 4\times 10^{14} \msun, while it affected incompleteness at smaller masses. find N(>M_{lim})=(6.3\pm 1.2) 10^{-6} (h^{-1} Mpc)^{-3} cluster within 1.5 h^{-1} radius. Our intermediate...
Aims.Spectral index images can be used to constraint the energy spectrum of relativistic electrons and magnetic field distribution in radio halos relics, providing useful information understand their formation, evolution connection cluster merger processes.
Context. The study of the galaxy stellar mass function (SMF) in relation to environment and density profile, rho(r), is a powerful tool constrain models evolution. Aims. We determine SMF z=0.44 cluster galaxies MACS J1206.2-0847 separately for passive star-forming (SF) galaxies, different regions cluster, from center out approximately 2 virial radii. also rho(r) compare it number total profiles. Methods. use dataset CLASH-VLT survey. Stellar masses are obtained by SED fitting on 5-band...
We present a new strong lensing analysis of the galaxy cluster MACS J1206.2-0847 (MACS 1206), at z=0.44, using deep spectroscopy from CLASH-VLT and VLT/MUSE archival data in combination with imaging Cluster Lensing Supernova survey Hubble. MUSE observations enable spectroscopic identification 23 multiply imaged sources, extending previous compilations by factor approximately five. In total, we use positional measurements 82 multiple images belonging to 27 families z=1.0-6.1 reconstruct...
Aims. In the effort to understand link between structure of galaxy clusters and their populations, we focus on MACS J1206.2-0847 at z ~ 0.44 probe its substructure in projected phase space through spectrophotometric properties a large number galaxies from CLASH-VLT survey.
We present the results of an extensive spectroscopic survey RX J0152.7-1357, one most massive distant clusters galaxies known. Multi-object spectroscopy, carried out with FORS1 and FORS2 on ESO Very Large Telescope (VLT), has allowed us to measure more than 200 redshifts in cluster field confirm 102 as members. The mean redshift is ± 0.001 we estimate velocity dispersion overall galaxy distribution be ~. members clearly irregular, two main clumps that follow X-ray emission mapped by Chandra....
We report the detection of diffuse radio emission which might be connected to a large-scale filament cosmic web covering 8deg x area in sky, likely associated with z~0.1 over-density traced by nine massive galaxy clusters. In this work, we present observations region taken Sardinia Radio Telescope. Two clusters field host powerful halo sustained violent ongoing mergers and provide direct proof intra-cluster magnetic fields. order investigate presence synchrotron beyond complex system,...
Context: The shape of the mass density profiles cosmological halos informs us nature DM and DM-baryons interactions. Previous estimates inner slope clusters galaxies are in opposition to predictions derived from numerical simulations CDM. Aims: We determine profile a massive cluster galaxies, Abell S1063 (RXC J2248.7$-$4431) at $z=0.35$, with dynamical analysis based on an extensive spectroscopic campaign carried out VIMOS MUSE spectrographs ESO VLT. This new data set provides unprecedented...
Using the CLASH-VLT survey, we assembled an unprecedented sample of 1234 spectroscopically confirmed members in Abell~S1063, finding a dynamically complex structure at z_cl=0.3457 with velocity dispersion \sigma_v=1380 -32 +26 km s^-1. We investigate cluster environmental and dynamical effects by analysing projected phase-space diagram orbits as function galaxy spectral properties. classify galaxies according to presence strength [OII] emission line, H$\delta$ absorption colours....
view Abstract Citations (77) References (94) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Velocity Segregation in Galaxy Clusters Biviano, A. ; Girardi, M. Giuricin, G. Mardirossian, F. Mezzetti, We have investigated the velocity field of galaxies clusters. Our sample consists 68 clusters with at least 30 for which redshifts are available literature; 61 these we were also able to collect most galaxy magnitudes. unambiguously found that brighter than...