A5025255841- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Cosmology and Gravitation Theories
- Plant Water Relations and Carbon Dynamics
- Radio Astronomy Observations and Technology
- Adaptive optics and wavefront sensing
- Relativity and Gravitational Theory
- Heat Transfer Mechanisms
- Mechanics and Biomechanics Studies
- Advanced Measurement and Metrology Techniques
- Remote Sensing in Agriculture
- Black Holes and Theoretical Physics
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Advanced Vision and Imaging
- Geophysics and Sensor Technology
- High-pressure geophysics and materials
- Advanced Thermodynamics and Statistical Mechanics
- Superconducting and THz Device Technology
University of Milano-Bicocca
2015-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca
2015-2024
ASTRO-3D
2024
Brera Astronomical Observatory
2020-2024
ARC Centre of Excellence for All-sky Astrophysics
2024
University of Milan
2013-2019
Max Planck Society
2010-2011
University of Michigan–Ann Arbor
2008-2011
University of Insubria
2006-2011
Max Planck Institute for Astrophysics
2010-2011
Abstract The Laser Interferometer Space Antenna (LISA) will be a transformative experiment for gravitational wave astronomy, and, as such, it offer unique opportunities to address many key astrophysical questions in completely novel way. synergy with ground-based and space-born instruments the electromagnetic domain, by enabling multi-messenger observations, add further discovery potential of LISA. next decade is crucial prepare community LISA’s first observations. This review outlines...
The grand challenges of contemporary fundamental physics---dark matter, dark energy, vacuum inflation and early universe cosmology, singularities the hierarchy problem---all involve gravity as a key component. And all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some most remarkable predictions General Relativity: event horizons, ergoregions. hitherto invisible landscape Universe is being unveiled before our eyes: historical direct detection...
X-ray quasi-periodic eruptions (QPEs) represent a recently discovered example of extreme variability associated with supermassive black holes. These are high-amplitude bursts recurring every few hours that detected in the soft band from nuclei nearby galaxies whose optical spectra lack broad emission lines typically observed unobscured active galaxies. The physical origin this new phenomenon is still unknown and several theoretical models have been presented. However, no attempt has made so...
The dynamics of two massive black holes in a rotationally supported nuclear disc 10^8 solar masses is explored using N-Body/SPH simulations. Gas and star particles are co-present the disc. Described by Mestel profile, has vertical support provided turbulence gas, stellar velocity dispersion. A primary hole 4 million placed at centre disc, while secondary set initially on an eccentric co-rotating orbit plane. Its mass 1 to 1, 4, 10 ratio, relative primary. With this choice, we mimic pairs...
We present the results of a semianalytical model that evolves masses and spins massive black holes together with properties their host galaxies along cosmic history. As consistency check, our broadly reproduces number observations, e.g. star formation history, hole mass luminosity function galaxy at low redshift, to bulge relation, morphological distribution redshift. For first time in investigation, we relax simplifying assumptions perfect coherency or isotropy gas fueling holes. The...
The last century has seen enormous progress in our understanding of the Universe. We know life cycles stars, structure galaxies, remnants big bang, and have a general how Universe evolved. come remarkably far using electromagnetic radiation as tool for observing However, gravity is engine behind many processes Universe, much its action dark. Opening gravitational window on will let us go further than any alternative. Gravity own messenger: Gravitational waves, ripples fabric spacetime. They...
We study the dynamics of supermassive black hole binaries embedded in circumbinary gaseous discs, with SPH code Gadget-2. The sub-parsec binary (of total mass M and ratio q=1/3) has excavated a gap transfers its angular momentum to self--gravitating disc (M_disc=0.2 M). explore changes eccentricity e, by simulating sequence models that differ initial e_0, only. In initially low-eccentric binaries, increases time, while high-eccentric e declines, indicating existence limiting e_crit is found...
We study supermassive black holes (BHs) in merging galaxies, using a suite of hydrodynamical simulations with very high spatial (~10 pc) and temporal (~1 Myr) resolution, where we vary the initial mass ratio, orbital configuration, gas fraction. (i) address question when why, during merger, increased BH accretion occurs, quantifying inflows rates. (ii) also quantify relative effectiveness inducing AGN activity merger-related versus secular-related causes, by studying different stages...
We explore the newly discovered ``hangup-kick'' effect, which greatly amplifies recoil for configurations with partial spin-/orbital angular momentum alignment, by studying a set of 48 new simulations equal-mass, spinning black-hole binaries. propose phenomenological model that takes this effect into account and then use model, in conjunction statistical distributions spin magnitude orientations, based on accretion simulations, to find probabilities observing recoils several thousand...
We discuss the relationship between a standard Shakura & Sunyaev (1973) accretion disk model and Big Blue Bump (BBB) observed in Type 1 AGN, propose new method to estimate black hole masses. apply this sample of 23 radio-loud narrow-line Seyfert (RL-NLS1) galaxies, using data from WISE (Wide-field Infrared Survey Explorer), SDSS (Sloan Digital Sky Survey) GALEX. Our mass estimates are at least factor $\sim$6 above previous results based on single epoch virial methods, while Eddington ratios...
We consider super-critical accretion with angular momentum onto stellar-mass black holes as a possible mechanism for growing billion-solar-mass from light seeds at early times. use the radiatively inefficient "slim disk" solution—advective, optically thick flows that generalize standard geometrically thin disk model—to show how mildly super-Eddington intermittent may significantly ease problem of assembling first massive when universe was less than 0.8 Gyr old. Because low radiative...
Using high-resolution hydrodynamical simulations, we explore the spin evolution of massive dual black holes orbiting inside a circumnuclear disc, relic gas-rich galaxy merger. The spiral inwards from initially eccentric co- or counter-rotating coplanar orbits relative to disc's rotation, and accrete gas that is carrying net angular momentum. As hole mass grows, its changes in strength direction due gravito-magnetic coupling with small-scale accretion disc. We find spins loose memory their...
We present the results of a systematic search for massive black hole binaries in Sloan Digital Sky Survey spectroscopic database. focus on bound binaries, under assumption that one holes is active. In this framework, broad lines associated to accreting are expected show velocity shifts with respect narrow lines, which trace rest-frame galaxy. For sample 54586 quasars and 3929 galaxies at redshifts 0.1<z<1.5 we brute-force model each spectrum as mixture two different redshifts. The spectral...
A growing body of evidence indicates that the star formation rate per unit stellar mass (sSFR) decreases with increasing in normal "main-sequence" forming galaxies. Many processes have been advocated as responsible for such a trend (also known quenching), e.g., feedback from active galactic nuclei (AGNs), and classical bulges. We determine refined versus relation local Universe. To this aim we use Halpha narrow-band imaging follow-up survey (Halpha3) field galaxies selected HI Arecibo Legacy...
Supermassive black holes (SMBHs) have been detected in the centers of most nearby massive galaxies. Galaxies today are not only products billions years galaxy mergers, but also SMBH activity as active galactic nuclei (AGNs) that is connected to mergers. In this context, detection AGN pairs should be relatively common. Observationally, however, dual AGNs scant, being just a few percent all AGNs. Letter, we investigate triggering merging galaxies via suite high-resolution hydrodynamical...
We searched for quasi-periodicities on year-like timescales in the light curves of 6 blazars optical - near infrared bands and we made a comparison with high energy emission. obtained optical/NIR from REM photometry plus archival SMARTS data accessed Fermi $\gamma$-ray data. The periodograms often show strong peaks gamma-ray bands, which some cases may be inter-related. significance revealed is then discussed, taking into account that noise frequency dependent. Quasi-periodicities timescale...
We study the interplay between gas accretion and gravity torques in changing a binary elements its total angular momentum (L) budget. Especially, we analyse physical origin of (T_g) their location within disc. 3D SPH simulations evolution initially quasi-circular massive black hole binaries (BHBs) residing central hollow self-gravitating circumbinary discs. use different thermodynamics cavity for numerical size holes to show that (i) BHB eccentricity growth found previously is general...
The rapid assembly of the massive black holes that power luminous quasars observed at $z \sim 6-7$ remains a puzzle. Various direct collapse models have been proposed to head-start hole growth from initial seeds with masses $\sim 10^5\,\rm M_\odot$, which can then reach billion solar mass while accreting Eddington limit. Here we propose an alternative scenario based on radiatively inefficient super-critical accretion stellar-mass embedded in gaseous circum-nuclear discs (CNDs) expected exist...
The dynamics of black hole seeds in high redshift galaxies is key to understand their ability grow via accretion and pair close binaries during galactic mergers. To properly follow the holes we develop a physically motivated model capture unresolved dynamical friction from stars, dark matter gas. We first validate then use it investigate seed born at $z\sim9$ dwarf proto-galaxies. perform suite zoom cosmological simulations with spatial resolution as 10 pc stellar mass $2\times10^3 \,...
Massive black hole (MBH) coalescences are powerful sources of low-frequency gravitational waves. To study these events in the cosmological context we need to trace large-scale structure and cosmic evolution a statistical population galaxies, from dim dwarfs bright galaxies. cover such large range galaxy masses, analyse two complementary simulations: Horizon-AGN with volume low resolution which tracks high-mass (> 1e7 Msun) MBH population, NewHorizon smaller but higher that traces low-mass (<...
ABSTRACT We use the magnetic-hydrodynamical simulation TNG50 to study evolution of barred massive disc galaxies. Massive spiral galaxies are already present as early z = 4, and bar formation takes place at those times. The bars grow longer stronger host evolve, with sizes increasing a pace similar that scalelengths. fraction mildly evolves redshift for $M_{*}\ge 10^{10}\rm M_{\odot }$, being greater than $\sim 40{{\ \rm per\ cent}}$ 0.5 &lt; 3 30{{\ 0. When larger given physical size...
We present JWST/NIRSpec integral field data of the quasar PJ308-21 at $z=6.2342$. As shown by previous ALMA and HST imaging, has two companion sources, interacting with host galaxy. The high-resolution G395H/290LP NIRSpec spectrum covers $2.87-5.27\ \rm \mu m$ wavelength range shows rest-frame optical emission exquisite quality ($S/N\sim 100-400$ per spectral element). Based on H$\beta$ line from broad region, we obtain an estimate black hole mass $M_{\rm BH,H\beta}\sim 2.7\times 10^{9}\...