Seminari


Il Dottorato in Astronomy, Astrophysics and Space Science incoraggia gli studenti a seguire in grande numero di seminari organizzati dagli istituti che organizzano il corso:
- Sapienza Università di Roma, dipartimento di Fisica
- Università degli studi di Roma "Tor Vergata", dipartimento di Fisica
- INAF, Istituto Nazionale di AstroFisica

Segue lista di seminari

2022


Annalisa Pillepich, Max Planck Institute for Astronomy, Heidelberg: The many diverse manifestations of supermassive black-hole feedback: from simulations to observations, and back
26 ottobre 2022
Abstract to be updated
Carole Haswell, The Open University: Towards the geology of exoplanets
22 settembre 2022
Abstract to be updated
Pascal Oesch, University of Geneva: Galaxy Build-up During the Cosmic Reionization Epoch
4 luglio 2022
To be updated
Elena Maria Rossi, Leiden Observatory: A multi-tracer study of the Local Group of galaxies
8 giugno 2022
The Local Group, and the Milky Way in particular is a unique laboratory to study the process of galaxy assembly because of our vantage point. This is especially true in this era of current and up-coming (all sky) surveys like e.g. Gaia, WEAVE, 4MOST, DASI, LSST, and Euclid, that are delivering an unprecedented astrometric, spectroscopic and photometric view of the Galactic stellar population. In this talk, I will review my group's work --both theoretical and observational -- towards the understanding of the mass distribution and other properties of the Milky Way using different dynamical tracers such as stellar streams and hypervelocity stars. Looking at the future, I will also show my vision for Galactic studies in the LISA era, when gravitational waves will deliver complementary information with respect to electromagnetic waves.
Samaya Nissanke, University of Amsterdam: Gravitational waves and multi-messenger astrophysics
26 maggio 2022
To be updated
Rachel Somerville, Center for Computational Astrophysics Flatiron Institute: Developing new galaxy formation models that will help us Learn the Universe
5 maggio 2022
Understanding and simulating galaxy formation from first principles is a huge computational challenge because of the vast range of scales and rich array of physics involved. Upcoming experiments will map galaxies and gas across unprecedented volumes and probe further back into cosmic time than ever before. These experiments have the potential to probe fundamental physics questions such as the nature of dark matter and dark energy, and the initial conditions of the Universe. But in order to extract the full scientific potential from these data, we need to understand how luminous tracers (stars and gas) are related to the underlying matter density field, and we must develop techniques that can accurately forward model the galaxy formation process with a computational efficiency that is orders of magnitude higher than standard numerical hydro/N-body techniques. I will describe the philosophy and status of the SMAUG (Simulating Multiscale Astrophysics to Understand Galaxies) project, and how it will form a pillar in the new Simons Collaboration "Learning the Universe", which will combine new galaxy formation models, new machine learning techniques, and simulation based inference to obtain constraints on cosmology and astrophysics.
Georges Meynet, University of Geneva: Stars at the Extreme: First Stars, Spinstars and Supermassive Stars
6 aprile 2022
The presentation will focus on stars at some extreme either from the point of view of their mass (supermassive stars), rotation (spinstars) or initial composition (Pop III stars). The talk will begin by a general overview of the main challenges faced by the modeling of massive stars with a special focus on the transport processes in convective and radiative zones. Then the presentation will continue discussing recent results about the binary statistics of Pop III populations, the chemical and radiative feedback of Pop III stars, the evolution of very massive stars i.e. stars with masses between 150 and 300 solar masses at different metallicities addressing the question of the progenitor of Pair Instability supernovae and the limits of the mass domain for the black hole mass gap. Finally, new models for the formation of supermassive stars that are candidates as seeds for the formation of supermassive black holes at high redshift will be presented
Felix Aharonian, Dublin Institute for Advanced Studies and Max-Planck-Institute for Nuclear Physics (MPIK), Heidelberg, Germany: PeVatrons and the "Century-old-Mistery" of Galactic Cosmic Rays
2 marzo 2022
Despite the recent advances in Cosmic Ray studies, the origin of Galactic Cosmic Rays (CRs) is still considered a "century-old mystery" - we do not know yet which sources contribute to CR fluxes measured in the Earth's vicinity. Identifying the major CR contributors with astronomical source populations is one of the highest priorities of the field. The best carriers of information about CR factories are gamma-rays and neutrinos - the only stable and neutral secondary products of CR interactions pointing to the CR production sites. The recent years' outstanding achievement of gamma-ray astronomy was the discovery of TeV gamma-radiation from SNRs generally supporting the SNR paradigm of the origin of Galactic CRs. On the other hand, the lack of the extension of gamma-ray spectra of young SNRs well beyond 10 TeV raises doubts about their ability to contribute to the highest energy galactic CR spectrum in the so-called "knee" region above 1 PeV. Meanwhile, the ultra-high-energy (UHE; E> 100 TeV) gamma-ray observations of the clusters of young massive stars demonstrate mounting evidence of these objects (and related superbubbles) being prime contributors to Galactic CRs at PeV energies. I will discuss these observations in the context of the concept of "Young Stars versus Dead Stars". The hunt for CR PeVatrons cannot be reduced merely to the identification of the sources contributing to the local "CR fog". The term 'cosmic rays' has broader implications; after matter, radiation and magnetic fields, the relativistic nonthermal plasma constitutes the fourth substance of the observable Universe. The localisation and exploration of physical conditions and processes in these extreme CR factories, independent of their relative contributions to the 'CR fog', is a fundamental issue in its own right. I will highlight the recent exciting achievements of UHE gamma-ray astronomy in elucidating the cites of extreme CR accelerators in the Milky Way and discuss the implications of the discovery of a large number of CR PeVatrons by the LHAASO collaboration.
Volker Bromm, University of Texas at Austin: What do we know about the first stars and galaxies?
8 febbraio 2022
I will review the emerging theoretical framework for how stars, galaxies, and black holes transformed the early universe. Predictions for the enrichment of the intergalactic medium with heavy chemical elements, the rate of supernova explosions and gamma-ray bursts, as well as the number density and properties of the first galaxies, sensitively depend on the particle-physics nature of dark matter. To constrain the elusive first generation of stars, we can bring to bear a powerful combination of probes at high redshifts and in our local neighborhood. The latter approach, known as “stellar archaeology” holds particular promise in light of ongoing and planned large surveys of metal-poor stars, both in the Milky Way and its dwarf satellites. It is exciting to contemplate the decade ahead, when the James Webb Space Telescope (JWST) will allow us to confront theory with observations at the edge of time.

2021


Licia Verde, ICREA and Institute of Cosmological Sciences, University of Barcelona: "The future beyond precision cosmology"
14/12/2021

Samaya Nissanke, University of Amsterdam: "Gravitational waves and multi-messenger astrophysics"
30/11/2021

Giovanna Tinetti, Department of Physics and Astronomy, University College London: "Decoding the light from other worlds"
09/11/2021

Pavel Kroupa, University of Bonn and Charles University of Prague: How observations of stellar populations constrain cosmological models
19/10/2021

Ralf Klessen, Institute for Theoretical Astrophysics, University of Heidelberg: Star formation through space and time
23/09/2021

Piero Madau, Department of Astronomy and Astrophysics, University of California Santa Cruz: The dark and luminous side of structure formation
22/06/2021

Debora Sijacki, Institute of Astronomy, University of Cambridge, UK: The evolution of massive black holes through cosmic times
01/06/2021

Roberto Maiolino, Cavendish Laboratory, University of Cambridge, UK: Quenching star formation in galaxies
18/05/2021

Joseph Silk, Institut d’Astrophysique de Paris, The Johns Hopkins University, University of Oxford: The future of cosmology
16/04/2021
One of the greatest challenges in cosmology is understanding the origin of the structure of the universe. The cosmic microwave background and large-scale surveys of galaxies have provided unique windows for probing cosmology and its inflationary origin. But where do we go next? Future experiments are planned with the next generation of observatories that will increase the current precision of cosmological measurements by an order of magnitude. However we need to do far better if there is to be a guaranteed science return that will definitively probe our cosmic origins. I shall argue that the ultimate goal for our future strategy must be astronomy from lunar-based telescopes.
Benedetta Ciardi, Max Planck Institute for Astrophysics: Exploring cosmic reionization with 21cm telescopes
09/03/2021
Cosmic reionization is the last major phase transition undergone by our Universe. Although most studies agree on the general characteristics of H reionization (for example that is driven by stars and it is mostly if not fully complete by z ≈ 6), its details are still largely unknown, among which the contribution from and role played by more energetic sources. In this talk, I will discuss the ingredients needed for a correct modeling of cosmic reionization and present results from recent radiative transfer simulations accounting for a variety of source types (such as stars, quasars, X-ray binaries). I will then discuss the observability of reionization in terms of various diagnostics associated to the 21cm signal from neutral hydrogen and present the latest results from the LOFAR radio telescope. Join Zoom Meeting https://uniroma1.zoom.us/j/89931306878?pwd=WG5RYlYyZzRSMzJsOFpSRHczWEFCZz09
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