A5011962744- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Cosmology and Gravitation Theories
- Astrophysics and Star Formation Studies
- Scientific Research and Discoveries
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Dark Matter and Cosmic Phenomena
- Adaptive optics and wavefront sensing
- Radio Astronomy Observations and Technology
- History and Developments in Astronomy
- Particle physics theoretical and experimental studies
- Computational Physics and Python Applications
- Remote Sensing in Agriculture
- Geophysics and Gravity Measurements
- Plant Water Relations and Carbon Dynamics
- Particle Accelerators and Free-Electron Lasers
- Complex Systems and Time Series Analysis
- Relativity and Gravitational Theory
- Black Holes and Theoretical Physics
- Particle Detector Development and Performance
- Advanced X-ray Imaging Techniques
University of Trieste
2016-2025
Istituto Nazionale di Fisica Nucleare, Sezione di Trieste
2016-2025
Institute for Fundamental Physics of the Universe
2019-2025
Trieste Astronomical Observatory
2016-2025
Institute for High Performance Computing and Networking
2023-2024
University College London
2024
University of Copenhagen
2024
Flatiron Health (United States)
2024
Flatiron Institute
2024
Royal Holloway University of London
2024
The abundance and structure of dark matter subhalos has been analyzed extensively in recent studies matter-only simulations, but comparatively little is known about the impact baryonic physics on halo substructures. We here extend SUBFIND algorithm for substructure identification such that it can be reliably applied to dissipative hydrodynamical simulations include star formation. This allows, particular, galaxies as substructures clusters galaxies, a determination their content...
In this paper we present the source catalog obtained from a 942 ks exposure of Chandra Deep Field South (CDFS), using Advanced CCD Imaging Spectrometer (ACIS-I) on X-ray Observatory. Eleven individual pointings made between 1999 October and 2000 December were combined to generate final image used for object detection. Catalog generation proceeded simultaneously two different methods; method our own design modified version SExtractor algorithm, wavelet transform technique developed...
We present our first results from 120 ks of X-ray observations obtained with the Advanced CCD Imaging Spectrometer on Chandra X-Ray Observatory. The field two combined exposures is 0.096 deg2 and detection limit to a S/N 2 (corresponding ~7 net counts). reach flux × 10-16 erg s-1 cm-2 in 0.5-2 keV soft band 10-15 2-10 hard band. Our sample has 144 sources 91 sources, for total 159 sources. Fifteen are detected only band, 68 For optical identification, we carried out survey VRI FORS-1 imaging...
This White Paper, submitted to the recent ESA call for science themes define its future large missions, advocates need a transformational leap in our understanding of two key questions astrophysics: 1) How does ordinary matter assemble into scale structures that we see today? 2) do black holes grow and shape Universe? Hot gas clusters, groups intergalactic medium dominates baryonic content local Universe. To understand astrophysical processes responsible formation assembly these structures,...
In this review, we describe our current understanding of cluster formation: from the general picture collapse initial density fluctuations in an expanding Universe to detailed simulations formation including effects galaxy formation. We outline both areas which highly accurate predictions theoretical models can be obtained and where are uncertain due physics feedback. The former includes description structural properties dark matter halos hosting cluster, their mass function clustering...
▪ Abstract Considerable progress has been made over the past decade in study of evolutionary trends population galaxy clusters Universe. In this review we focus on observations X-ray band. surveys with ROSAT satellite, supplemented by follow-up studies ASCA and Beppo-SAX, have allowed an assessment evolution space density out to z ≈ 1 physical properties intracluster medium 0.5. With advent Chandra Newton-XMM their unprecedented sensitivity angular resolution, these extended beyond redshift...
In this study, we present a detailed, statistical analysis of black hole growth and the evolution active galactic nuclei (AGN) using cosmological hydrodynamic simulations run down to $z=0$. The self-consistently follow radiative cooling, star formation, metal enrichment, associated feedback processes from both supernovae typeII/Ia AGN. We consider two simulation runs, one with large co-moving volume $(500\ \mathrm{Mpc})^3$ smaller $(68\ but by factor almost 20 higher mass resolution....
We present a detailed X-ray spectral analysis of the sources in 1Ms catalog Chandra Deep Field South (CDFS) taking advantage optical spectroscopy and photometric redshifts for 321 extragalactic out total sample 347 sources. As default model, we adopt power law with slope Γ an intrinsic redshifted absorption NH, fixed Galactic unresolved Fe emission line. For 82 bright sources, are able to perform leaving both NH free. The weighted mean value is , distribution best fit values shows dispersion...
(Abridged) We examine the radial entropy distribution and its scaling using 31 nearby galaxy clusters from Representative XMM-Newton Cluster Structure Survey (REXCESS). The profiles are robustly measured at least out to R_1000 in all systems R_500 13 systems. Compared theoretical expectations, observed distributions show a mass-dependent excess that is greater extends larger radii lower mass At R_500, dependence both negligible within uncertainties. Mirroring this behaviour, of gas shallower...
Taking advantage of the all-sky coverage and broadfrequency range Planck satellite, we study Sunyaev-Zeldovich (SZ) pressure profiles 62 nearby massive clusters detected at high significance in 14-month nominal survey. Careful reconstruction SZ signal indicates that most are individually least out to R500. By stacking radial profiles, have statistically 3 × R500, i.e., a density contrast about 50–100, though dispersion mean profile dominates statistical errors across whole range. Our...
We present an implementation of smoothed particle hydrodynamics (SPH) with improved accuracy for simulations galaxies and the large-scale structure. In particular, we combine, implement, modify test a vast majority SPH improvement techniques in latest instalment GADGET code. use Wendland kernel functions, wake-up time-step limiting mechanism time-dependent scheme artificial viscosity, which includes high-order gradient computation shear flow limiter. Additionally, include novel prescription...
We present an analysis of the relation between masses cluster- and group-sized haloes, extracted from Λ cold dark matter (ΛCDM) cosmological N-body hydrodynamic simulations, their velocity dispersion at different redshifts z = 2 to 0. The main aim this is understand how implementation baryonic physics in simulations affects such relations, i.e. what extent use as a proxy for cluster mass determination hampered by imperfect knowledge physics. In our analysis, we several sets with implemented:...
Gravitational lensing by clusters of galaxies offers a powerful probe their structure and mass distribution. Deriving lens magnification map for galaxy cluster is classic inversion problem many methods have been developed over the past two decades to solve it. Several research groups techniques independently predominantly dark matter distribution in lenses. While these all provided remarkably high precision maps, particularly with exquisite imaging data from Hubble Space Telescope (HST),...
We present results obtained from a set of cosmological hydrodynamic simulations galaxy clusters, aimed at comparing predictions with observational data on the diversity between cool-core (CC) and non-cool-core (NCC) clusters. Our include effects stellar AGN feedback are based an improved version smoothed particle hydrodynamics code GADGET-3, which ameliorates gas mixing better captures gas-dynamical instabilities by including suitable artificial thermal diffusion. In this Letter, we focus...
We introduce the THE THREE HUNDRED project, an endeavour to model 324 large galaxy clusters with full-physics hydrodynamical re-simulations. Here we present data set and study differences observations for fundamental cluster properties scaling relations. find that modelled are generally in reasonable agreement respect baryonic fractions gas relations at redshift z = 0. However, there still some (model-dependent) differences, such as central galaxies being too massive, colours (g - r) bluer...
Galaxy clusters contain more small-scale gravitational lenses than expected from cosmological simulations.
We present results on the X-ray properties of clusters and groups galaxies, extracted from a large hydrodynamical simulation. used GADGET code to simulate LambdaCDM model within box 192 Mpc/h side, with 480^3 dark matter particles as many gas particles. The simulation includes radiative cooling, star formation supernova feedback. simulated M-T relation is consistent observations once we mimic procedure for mass estimates applied real clusters. Also, adopted choices Omega_m=0.3 sigma_8=0.8...
We present the main results from our 940 ks observation of Chandra Deep Field-South using source catalog described in an accompanying paper by Giacconi et al. extend measurement number counts to 5.5 × 10-17 ergs cm-2 s-1 soft 0.5-2 keV band and 4.5 10-16 hard 2-10 band. The hard-band log N-log S shows a significant flattening (slope ≃0.6) below ≈10-14 s-1, leaving at most 10%-15% X-ray background be resolved, uncertainty lying total flux (XRB). On other hand, analysis very 5-10 reveals...
We analyze the ROSAT Deep Cluster Survey (RDCS) to derive cosmological constraints from evolution of cluster X-ray luminosity distribution. The sample contains 103 galaxy clusters out z ≃ 0.85 and flux limit Flim = 3 × 10-14 ergs s-1 cm-2 (RDCS-3) in [0.5-2.0] keV energy band, with a high-redshift extension containing four at 0.90 ≤ 1.26 brighter than 1 (RDCS-1). assume models be specified by matter density parameter Ωm, rms fluctuation amplitude 8 h-1 Mpc scale σ8, shape for cold dark...
Context.The largest uncertainty for cosmological studies using clusters of galaxies is introduced by our limited knowledge the statistics galaxy cluster structure, and scaling relations between observables mass.