A5114374654- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Calibration and Measurement Techniques
- Astronomical Observations and Instrumentation
- Relativity and Gravitational Theory
- Solar and Space Plasma Dynamics
- Superconducting and THz Device Technology
- Atomic and Molecular Physics
- Particle Detector Development and Performance
- X-ray Spectroscopy and Fluorescence Analysis
- Laser-induced spectroscopy and plasma
- Radioactive Decay and Measurement Techniques
- Astro and Planetary Science
- Spectroscopy and Laser Applications
- Statistical and numerical algorithms
- Pulsars and Gravitational Waves Research
University of Rome Tor Vergata
2015-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2007-2024
Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata
2023
Center for Astrophysics Harvard & Smithsonian
2010-2021
Istituto Centrale per la Ricerca Scientifica e Tecnologica Applicata al Mare
2020
Istituto Nazionale di Fisica Nucleare, Sezione di Lecce
2014
Agenzia Spaziale Italiana
2012
Aalto University
2012
European Space Research Institute
2012
Istituto Nazionale di Fisica Nucleare
2011
We present in this paper new and updated calculations of the ionization equilibrium for all elements from H to Ni. collected these data available literature radiative plus dielectronic recombination rates. In particular, rates have been fitted with a single formula related coefficients are tabulated. Our results compared previous works.
We use Chandra data to map the gas temperature in central region of merging cluster A2142. The is markedly nonisothermal; it appears that cooling flow has been disturbed but not destroyed by a merger. X-ray image exhibits two sharp, bow-shaped, shock-like surface brightness edges or density discontinuities. However, and pressure profiles across these indicate are shock fronts. reasonably continuous edges, while entropy jumps opposite sense (i.e. denser side edge lower temperature, hence...
Theoretical studies of the physical processes guiding formation and evolution galaxies galaxy clusters in X-ray are mainly based on results numerical hydrodynamical N-body simulations, which turn often directly compared to observations. Although trivial principle, these comparisons not always simple. We demonstrate that projected spectroscopic temperature thermally complex obtained from observations is lower than emission-weighed temperature, widely used analysis simulations. show this bias...
<i>Context. <i/>Among the methods employed to measure mass of galaxy clusters, techniques based on lensing and X-ray analyses are perhaps most widely used; however, comparison between these estimates is often difficult and, in several results apparently inconsistent.<i>Aims. <i/>We aim at investigating potential biases cluster profiles.<i>Methods. performed realistic simulations observations that were subsequently analyzed using observational techniques. The resulting compared with input...
We present the Planck Sky Model (PSM), a parametric model for generation of all-sky, few arcminute resolution maps sky emission at submillimetre to centimetre wavelengths, in both intensity and polarisation. Several options are implemented cosmic microwave background, Galactic diffuse (synchrotron, free-free, thermal spinning dust, CO lines), H-II regions, extragalactic radio sources, dusty galaxies, kinetic Sunyaev-Zeldovich signals from clusters galaxies. Each component is simulated by...
The X-ray Integral Field Unit (X-IFU) is the high resolution spectrometer of ESA Athena observatory. Over a field view 5' equivalent diameter, it will deliver spectra from 0.2 to 12 keV with spectral 2.5 eV up 7 on ∼ 5" pixels. X-IFU based large format array super-conducting molybdenum-gold Transition Edge Sensors cooled at 90 mK, each coupled an absorber made gold and bismuth pitch 249 μm. A cryogenic anti-coincidence detector located underneath prime TES enables non background be reduced....
The hot plasma in galaxy clusters is expected to be heated high temperatures through shocks and adiabatic compression. thermodynamical properties of the gas encode information on processes leading thermalization cluster's potential well as non-gravitational such cooling, AGN feedback kinetic energy. In this work we present radial profiles thermodynamic intracluster medium (ICM) out virial radius for a sample 12 selected from Planck all-sky survey. We determine universal density, temperature,...
We present a comprehensive space-based study of ten X-ray luminous galaxy clusters (L_X>=8e44erg/s[0.1-2.4keV]) at z=0.2. Hubble Space Telescope observations reveal numerous gravitationally-lensed arcs for which we four new spectroscopic redshifts, bringing the total to thirteen confirmed in this cluster sample. combine multiple-image systems with weakly-sheared background galaxies model mass distribution cores (R<=500kpc). These models are complemented by high-resolution data from...
We present detailed predictions of the contributions various source populations to counts at frequencies tens GHz. New evolutionary models are worked out for flat-spectrum radio quasars, BL Lac objects, and steep-spectrum sources. Source characterized by spectra peaking high frequencies, such as extreme GPS sources, ADAF/ADIOS sources early phases γ-ray burst afterglows also dealt with. The different star-forming galaxies (normal spirals, starbursts, high-z detected SCUBA MAMBO surveys,...
We examine the systematics affecting X-ray mass estimators applied to a set of five galaxy clusters resolved at high resolution in hydrodynamic simulations, including cooling, star formation and feedback processes. These simulated objects are processed through Map Simulator, X-MAS, provide Chandra-like long exposures that analysed reconstruct gas temperature, density profiles used as input. have different dynamic state: we consider hot cluster with temperature T= 11.4 keV, perturbed 3.9...
Chandra data on A1795 reveal a mild edge-shaped discontinuity in the gas density and temperature southern sector of cluster at r = 60 h-1 kpc. The inside edge is 1.3-1.5 times denser cooler than outside, while pressure continuous, indicating that this "cold front," surface contact between two moving gases. continuity indicates current relative velocity gases near zero, making appear to be hydrostatic equilibrium. However, total mass profile, derived from under equilibrium assumption,...
[Abridged] We present a comparison between weak-lensing (WL) and X-ray mass estimates of sample numerically simulated clusters. The consists on the 20 most massive objects at redshift z=0.25 Mvir > 5 x 10^{14} Msun h^{-1}. They were found in cosmological simulation volume 1 h^{-3} Gpc^3, evolved framework WMAP-7 normalized cosmology. Each cluster has been resimulated higher resolution with more complex gas physics. processed it thought Skylens X-MAS to generate optical mock observations...
We present a statistical analysis of sample 20 strong lensing clusters drawn from the Local Cluster Substructure Survey (LoCuSS), based on high resolution Hubble Space Telescope imaging cluster cores and follow-up spectroscopic observations using Keck-I telescope. use detailed parameterized models mass distribution in cores, to measure total fraction that associated with substructures within R<250kpc.These measurements are compared baryons as traced by old stellar populations X-ray emitting...
We compare X-ray hydrostatic and weak-lensing mass estimates for a sample of 12 clusters that have been observed with both XMM-Newton Subaru. At an over-density \Delta=500, we obtain 1-M^{X}/M^{WL}=0.01+/-0.07 the whole sample. also divided into undisturbed disturbed sub-samples based on quantitative morphologies using asymmetry fluctuation parameters, obtaining 1-M^{X}/M^{WL}=0.09+/-0.06 -0.06+/-0.12 clusters, respectively. In addition to non-thermal pressure support, there may be competing...
Abstract We derive and compare the fractions of cool-core clusters in Planck Early Sunyaev–Zel’dovich sample 164 with <?CDATA $z\leqslant 0.35$?> a flux-limited X-ray 100 0.30$?> , using Chandra observations. use four metrics to identify clusters: (1) concentration parameter, which is ratio integrated emissivity profile within 0.15 r 500 that ; (2) 40 kpc 400 kpc; (3) cuspiness gas density profile, negative logarithmic derivative respect radius, measured at 0.04 (4) central density, 0.01 ....
Abstract We test the assumption of hydrostatic equilibrium in an X-ray luminosity selected sample 50 galaxy clusters at 0.15 &lt; z 0.3 from Local Cluster Substructure Survey (LoCuSS). Our weak-lensing measurements M500 control systematic biases to sub-4 per cent, and our same achieve excellent agreement between XMM–Newton Chandra. The mean ratio lensing mass for these is $\mathrel {\beta _{\rm X}}\;= 0.95\pm 0.05$, 44 also detected by Planck, Planck estimate LoCuSS P}}\;= 0.04$. Based...
Any variation of the fundamental physical constants, and more particularly fine structure constant, $\alpha$, or mass electron, $m_e$, would affect recombination history Universe cause an imprint on cosmic microwave background angular power spectra. We show that Planck data allow one to improve constraint time constant at redshift $z\sim 10^3$ by about a factor 5 compared WMAP data, as well break degeneracy with Hubble $H_0$. In addition we can set $m_{\rm e}$, simultaneous two constants....
The Cluster HEritage project with XMM-Newton - Mass Assembly and Thermodynamics at the Endpoint of structure formation (CHEX-MATE) is a three mega-second Multi-Year Heritage Programme to obtain X-ray observations minimally-biased, signal-to-noise limited sample 118 galaxy clusters detected by Planck through Sunyaev-Zeldovich effect. programme, described in detail this paper, aims study ultimate products time mass. It composed census most recent objects have formed (Tier-1: 0.05 < z 0.2; 2 x...
Abstract We present LOw Frequency ARray observations of the Coma Cluster field at 144 MHz. The cluster hosts one most famous radio halos, a relic, and low surface brightness bridge. detect new features that allow us to make step forward in understanding particle acceleration clusters. halo extends for more than 2 Mpc, which is largest extent ever reported. To northeast cluster, beyond virial radius, we discover an arc-like source could trace particles accelerated by accretion shock. west...
We show an interesting correlation between the surface brightness and temperature structure of relaxed clusters RX J1720.1+2638 MS 1455.0+2232, hosting a pair cold fronts, their central core-halo radio source. discuss possibility that origin this diffuse emission may be strictly connected with gas sloshing mechanism suggested to explain formation fronts in non-major-merging clusters. radiative lifetime relativistic electrons is much shorter than timescale on which they can transported from...
We present the first weak-lensing-based scaling relation between galaxy cluster mass, M_wl, and integrated Compton parameter Y_sph. Observations of 18 clusters at z~0.2 were obtained with Subaru 8.2-m telescope Sunyaev-Zel'dovich Array. The M_wl-Y_sph relations, measured Delta=500, 1000, 2500 rho_c, are consistent in slope normalization previous results derived under assumption hydrostatic equilibrium (HSE). find an intrinsic scatter M_wl fixed Y_sph 20%, larger than both measurements...
A521 is an interacting galaxy cluster located at z = 0.247, hosting a low-frequency radio halo connected to eastern relic. Previous Chandra observations hinted the presence of X-ray brightness edge position relic, which may be shock front. We analyze deep observation recently performed with XMM-Newton in order probe structure up outermost regions covered by emission. The atmosphere exhibits various and temperature anisotropies. In particular, two cores appear separated cold fronts. find...
We analyse cosmological hydrodynamical simulations of galaxy clusters to study the X-ray scaling relations between total masses and observable quantities such as luminosity, gas mass, temperature, $Y_{X}$. Three sets are performed with an improved version smoothed particle hydrodynamics GADGET-3 code. These consider following: non-radiative gas, star formation stellar feedback, addition feedback by active galactic nuclei (AGN). select $M_{500} > 10^{14} M_{\odot} E(z)^{-1}$, mimicking...