In questa pagina pubblichiamo le registrazioni dei seminari scientifici realizzati dai ricercatori INAF-IAPS a scopo di formazione scientifica interna sugli ultimi risultati della ricerca.
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14 Giugno 2023
Federico Tosi – INAF/IAPS
Jupiter Icy Moons Explorer (JUICE): Exploring the emergence of habitable worlds around giant planets.
Abstract: JUpiter ICy moons Explorer (JUICE) was selected in 2012 as the first Large-class mission in the framework of the ESA “Cosmic Vision” programme. JUICE is the first ESA-led mission to the Jupiter system. It successfully launched on 14 April 2023 and will arrive at Jupiter in July 2031.
JUICE will characterize the conditions that may have led to the emergence of habitable environments in ocean-bearing worlds such as the icy Galilean satellites Ganymede, Europa, and Callisto. Ganymede is identified for detailed investigation since it is the largest satellite, it is fully differentiated, and has a unique magnetic environment. For Europa the focus is on the chemistry essential to life and on understanding the formation of surface features. The study of the diversity of the satellite system, important also to shed light on their origins, will be complemented by several targeted flybys of Callisto and additional information gathered remotely on Io and other minor targets. Focused studies of Jupiter’s atmosphere and magnetosphere investigated over a long temporal baseline will further enhance our understanding of the evolution and dynamics of the Jovian system. The Italian and in particular INAF contribution to the payload is significant and here we will place emphasis on these instruments, showing some of the very first data returned in the post-launch, Near-Earth Commissioning Phase.
07 Giugno 2023
Federico Vincentelli – Instituto de Astrofísica de Canarias (IAC)
A shared accretion instability for black holes and neutron stars
Abstract: A fundamental prediction of accretion disk theory is the presence of an unstable phase at high accretion rates: during this phase, the radiation pressure generated by accretion can modify the disk viscosity, leading to the cyclic depletion and refilling of the inner disk on dynamical timescales. Such a scenario, however, has only been quantitatively verified for a single stellar-mass black hole. Although there are hints of these cycles in a few isolated cases, their apparent absence in the variable emission of most bright accreting neutron stars and black holes has been a continuing puzzle. In this talk I will present the results regarding the accreting neutron star Swift J1858.6-0814, showing that an accretion instability can also occur in these systems. Swift J1858.6-0814 is a transient neutron star low-mass X-ray binary discovered in 2018 that displayed remarkably strong flaring on very short timescales from X-ray to radio for more than one year. Due to its remarkable properties we set up an unprecedented multiwavelength (MW) campaign in 2019, using 5 telescopes observing strictly simultaneously with high-time resolution. By analyzing, modeling, and comparing the X-ray/O-IR and radio variability of Swift J1858 and the archetypal black hole GRS 1915+105, we found that the behavior of both objects can be explained consistently if their accretion disks are unstable, producing relativistic ejections during transitions that deplete or refill the inner disk. This new association, allows us to identify the main physical components responsible for the fast multiwavelength variability of highly accreting compact objects and unlocks the possibility of measuring the physical parameters of disks and jets in these sources.
24 Maggio 2023
Marcello Fulchignoni – Université Paris-Cité LESIA – Observatoire de Paris
Dalla casa del prete allo IAPS: 9 lustri di astrofisica romana
Abstract: L’Astrofisica a Roma è arrivata nel 1960/61, all’Università La Sapienza, con la chiamata alla cattedra omonima di Livio Gratton, il Professore. Grazie alla sua lungimiranza l’eccellenza dell’astrofisica romana è mondialmente riconosciuta e da Roma sono partite decine di giovani ricercatori per diffondere e sviluppare le idee maturate a partire da quegli anni, in un rustico malandato situato davanti ai cancelli del CNEN a Via Enrico Fermi a Frascati, una volta abitato dal parroco di Cisternole: « la casa del prete ». Questa fu la prima sede del Laboratorio di Astrofisica, legato alla cattedra universitaria. Il percorso dalla casa del prete allo IAPS è stato lungo, fatto di alti, di bassi, di attese, di entusiasmi e di persone: vogliamo ripercorrerlo nei ricordi per non dimenticare le nostre origini.
26 Aprile 2023
Martina Cardillo – IAPS/INAF
INAF and its One Thousand and One Stories
Abstract: One of the most powerful collaborations in the whole Universe is the one between Art and Science. In the light of this, since 2020, a group of passionate and enthusiastic scientists and non-scientists of the Istituto Nazionale di Astrofisica (INAF) has gathered into a team that aims to unveil and share the beauty of astronomy through art: the “Gruppo Storie”. Our activities include space-adventure podcasts, video making, writing contests and columns for children, comics and also a creation of a portfolio of shows produced by INAF, and a project to engage the public in the discussion about the future of human race, between science and science fiction. Enthusiasm, brainstorming, professionality and creativity are the drivers of this group, to make known all the evocative and beautiful aspects of astronomy through the extraordinary power of art.
22 Marzo 2023
Dr. Yannis Liodakis – Turku University
Supermassive black holes through the lens of multiwavelength polarization
Abstract: Supermassive black holes form the most intriguing astrophysical systems offering countless opportunities to study fundamental physics in regimes not accessible to laboratories on Earth. Their multimessenger emission manifests in the formation of accretion disks, jets, and the acceleration of extremely energetic particles all of which are still poorly understood. Multiwavelength polarization can provide answers to long standing black hole physics questions. However, until recently, the instruments and surveys necessary for such a task were missing. The recently launched Imaging X-ray Polarimetry Explorer — IXPE, the first X-ray polarization mission to target blazars, offers a radically new way of studying high-energy processes in relativistic jets. I will discuss the multiwavelength polarization observations and results from the first year of IXPE observations of radio galaxies and blazars.
29 Febbraio 2023
M. Galaverni & G. Gionti, SJ – Specola Vaticana
From the Astronomical Observatory of the Roman College (Collegio Romano) to the Vatican Observatory (Specola Vaticana)
Abstract: We will describe the transition from the Astronomical Observatory of the Roman College to the Vatican Observatory. Following Fr. Angelo Secchi’s death, in 1879, the Italian State expropriated the Observatory of the Roman College. Ten years later, Fr. Francesco Denza organized a science exhibit with the help of Fr. Giuseppe Lais leading to a formal re-foundation of the Vatican Observatory in 1891 by the Motu Proprio (Papal edict) Ut Mysticam of Pope Leo XIII. We will focus on the contributions of Fr. Lais, deputy director under three Popes and three directors. Fr. Lais, as the last of Secchi’s disciples, cemented the connection between the Roman College Astronomical Observatory and the Vatican Observatory. In the 1906, the Observatory was officially entrusted to the Society of Jesus under the direction of Fr. Johann Hagen. In the Thirties the observatory moved from Vatican City to Castel Gandolfo. A spectrochemical lab was founded to study the meteorites collection. Forty years ago Fr. George Coyne (director 1978-2006) established an agreement with the University of Arizona in Tucson and a new research group of the Specola was established in the USA. In 1993 a new telescope, the Vatican Advanced Technology Telescope, was inaugurated on Mt. Graham. Today the research activity of the Specola continues from planetology to cosmology both in Castel Gandolfo and in Tucson.
17 Febbraio 2023
Fulvia Pucci – Ruhr, Bochum university
The fractal reconnection scenario: energy cascade induced by magnetic reconnection
Abstract: Magnetic reconnection is considered to be the energy source underlying flares and outbursts, from Pulsar wind nebulae, to primordial galaxy clusters energy release. Jets of active galactic nuclei, energy conversion in GRBs and accretion disks, are now believed to be powered by magnetic energy dissipation. The idea that the mechanisms behind the explosive events mentioned previously and explosive events in the solar corona might be the same, stems from the similarity between power-law spectra inferred for these astrophysical environments and solar flares. When magnetic reconnection is at play, primary reconnection sites most often evolve due to current sheet collapse, island merging and secondary modes growth. These dynamics inspired Shibata & Tanuma (2001) to develop the fractal tearing reconnection scenario: the current sheet collapses originating secondary tearing reconnection sites; these thin themselves, transferring energy down to smaller scales, through a self-similar process. In this talk I will discuss the results on self-similar current sheet collapse which suggested introducing the revised fractal reconnection scenario in the context of resistive MHD reconnection. The results from this work prove that understanding the onset of magnetic reconnection is fundamental to provide a universal model for magnetic reconnection and its nonlinear outcome.
1 Febbraio 2023
Santi Cassisi – Osservatorio Astronomico d’Abruzzo (INAF)
The Multiplicity of Stellar Population of Globular Cluster
Abstract: Galactic globular clusters have always been at the crossroad of several investigations in both Stellar and Galactic Astrophysics. For long time, they have been considered the prototypes of Simple Stellar Populations, and hence used for testing and calibrating stellar evolutionary models as well as population synthesis tools. Nowadays, after the discovery of the presence of multiple stellar populations in almost all Galactic GCs, we know that this assumption is no longer valid. The process(es) of formation and early evolution of these star clusters is (are) very far to be understood, and any scenario so far envisaged is severely challenged by the pletora of empirical evidence collected till now. In the same time, thanks to the availability of an impressive observational framework – collected by combining kinematic measurements from Gaia mission, with data provided by large spectroscopic and photometric surveys -, GCs are playing a crucial role for our understanding of the assembly history of the Milky Way. We will review our present knowledge about these important stellar systems, discussing the several, open issues related to their formation/evolution, and discuss how we can use them in our effort to depict the Milky Way assembly history.
18 Gennaio 2023
Hemanth Manikantan – Raman Research Institute, Bangalore, India
The Thompson scattering X-Ray polarimeter POLIX onboard XPoSAT
Abstract: POLIX (Indian X-ray POLarimeter) is the primary scientific payload onboard the upcoming Indian X-ray polarimetry small satellite mission of ISRO (Indian Space Research Organisation) called XPoSat (X-ray Polarimetry Satellite). POLIX is a Thomson scattering X-ray polarimeter operating in the 8-30 keV spectral band designed to detect linear polarisation in astrophysical X-ray sources. POLIX uses the combination of a collimator, a Beryllium scattering block and four surrounding position-sensitive proportional counter detectors. The degree and direction of linear polarisation measurements are achieved by spinning XPoSatalong the viewing axis of POLIX and recording the azimuthal distribution of X-ray photons scattered off the Beryllium scattering block. In this talk, I will discuss the principle of operation and instrument configuration of POLIX, calibration of the position-sensitive proportional counters, and some key scientific prospects of POLIX.
30 Novembre 2022
Angelo Antonelli – Osservatorio Astronomico di Monteporzio
Rome and modern Astronomy
Abstract: Rome’s artistic, architectural, and cultural history is well known and has influenced the whole world for almost 3000 years. Much less known but no less significant is the importance of astronomy in Rome over the centuries. Astronomical studies have been carried out in the city since the time of Ancient Rome, producing important contributions such as the Julian Calendar promulgated by Julius Caesar in 46 B.C.E. Astronomical studies were also carried out in the “Eternal City” during the Medieval Age. But the greatest development began during the Renaissance when mathematicians and other scientists, along with artists and philosophers, arrived at the Court of the Popes. The most important astronomical product has been the calendar reform that took place under Pope Gregory XIII, who gave a great impetus to this project by calling astronomers and mathematicians to Rome to work on it. Gregory XIII also built an observatory in the Vatican called the Torre dei Venti and, in those same years, the Collegio Romano was established in Rome and Christopher Clavius joined it in 1564, teaching mathematics and astronomy. In the seventeenth century, Rome was home to two of the most important lens factories in Europe: one run by Eustachio Divini and the other one by Giuseppe Campani. Between 1600 and 1800, several astronomical observatories were established in Rome, most of them as part of religious institutes devoted to educational activities but also including private observatories built by rich and cultured members of the Roman nobility. The most important observatories were the Astronomical Observatory of the Collegio Romano and the Astronomical Observatory of Campidoglio which reached, with respectively Angelo Secchi and Lorenzo Respighi, the highest level of astronomical research in that period. In particular we remember Angelo Secchi as the father of modern astrophysics and stellar spectroscopy. In the first half of ‘900 the astronomical research in Rome has been carried on at the Astronomical Observatory of Rome (since 1938) and, after the second world war, astrophysics research grew in importance thanks to Livio Gratton who founded the new Laboratories in Frascati. In this seminar I will review the history of astronomy in Rome in the last 450 years.
18 Novembre 2022
L.Giacomini, F.Duras, G.Mantovani – IAPS/INAF
Le attività di didattica e divulgazione in IAPS
Abstract: Verranno illustrate le principali attività di didattica e divulgazione organizzate dall’Ufficio COMET, l’Ufficio di Comunicazione INAF-IAPS sia a livello locale che nazionale, presentando le possibilità di collaborazione per il personale IAPS. Partiremo dalle attività locali, come la Notte Europea dei Ricercatori, i progetti di PCTO per le scuole e il MUVISS, il Museo Virtuale delle Scienze Spaziali, attualmente in fase di riallestimento come green-studio per la realizzazione di contenuti multimediali originali. Analizzeremo poi le attività nazionali portate avanti in collaborazione e per conto dell’Ufficio DD nazionale, presentando EduINAF, il magazine di didattica e divulgazione dell’INAF, le dirette osservative “Il cielo in salotto” e le possibili collaborazioni per partecipare a iniziative e manifestazioni nazionali.
9 Novembre 2022
Mario Guarcello – Osservatorio di Palermo – INAF
EWOCS: The Extended Westerlund One Chandra (and JWST) Survey
Abstract: Star formation in our Galaxy typically occurs in low and intermediate-mass environments counting a few 102, 103 stars. However, a few more extreme star forming environments exist, where hundreds of thousands to millions of stars form in dense regions, often in single events of star formation. Often called “starburst regions”, they are quite rare in our Galaxy today, with a few examples known, while they are common in galaxies experiencing epochs of intense star formation activity (such as interacting galaxies) and in the early Universe. With a distance of 3.87 kpc from the Sun, and an estimated initial mass of 52000 solar masses, Westerlund 1 is the closest starburst cluster to the Sun. It offers the unique possibility to study star and planet formation, the early stellar evolution and the physics of compact objects in a starburst environment. In this talk I will present the EWOCS project (Extended Westerlund One Chandra, and JWST, Survey) which is based on a 1Msec Chandra/ACIS-I Large Project, oncoming JWST observations of Westerlund 1, and other data at high spatial resolution (GEMS/GSAOI, HST, etc…). I will discuss the objectives of the project, present the status of the art of data analysis and some preliminary results.
27 Maggio 2020
Sami Dib – Laboratoire d’Astrophysique de Bordeaux, France
The 1001 modes of Star Formation
Abstract: Star formation is a multi-physics, multi-scale process. the physical scales that are involved vary by 10 orders of magnitude, from the size of entire galaxies down to the size of the Solar system. The physical processes that are involved include gravity, turbulence, magnetic fields, radiation, chemical reactions, and cooling and heating processes. This multiplicity of processes and scales can generate a significant amount of scatter in the outcome of star formation from galaxy to galaxy and from region to region within galaxies, in particular in terms of key quantities such as the stellar initial mass function (IMF), the star formation rate (SFR), and the star formation efficiency (SFE).I will present an overview of the current status of observations for the IMF and the SFR in the Milky Way and in nearby galaxies and discuss theoretical models and numerical simulations that attempt to reproduce these observations. I will also briefly discuss how the morphology of star forming regions can help us understand how these regions have assembled and how the morphology correlates with the SFR.
13 Maggio 2020
Andrea Merloni – MPE (Garching, Germany)
Mapping the hot Universe: the first six months of operations of eROSITA on SRG
Abstract: The emergence of the three-dimensional structure of the cosmic web over the history of the Universe displays very distinctive features when observed in X-rays, where both the most massive collapsed structure (clusters of galaxies) and the most energetic events in the life of galaxies (AGN and Quasars) reveal themselves unambiguously.
The next generation of wide-area, sensitive X-ray surveys designed to map the hot and energetic Universe will be heralded by eROSITA (extended ROentgen Survey with an Imaging Telescope Array), the core instrument on the Russian-German Spektrum-Roentgen-Gamma (SRG) mission, successfully launched in July 2019. On December 13, after completion of its Calibration and Performance Verification phase, SRG/eROSITA has begun its four-years program dedicated to surveying the entire sky eight times in the energy range ~0.2-8 keV.
The high sensitivity, large field of view, high spatial resolution and high survey efficiency of eROSITA is bound to revolutionize X-ray astronomy: within just the first year of operation it will discover more new celestial X-ray objects as have been catalogued from 1962 until today.
I will present an overview of the instrument capabilities, the current status of the mission, the early science results and the expectations for the X-ray all-sky survey program and its planned followup programs.
08 Aprile 2020
Ileana Chinnici – INAF OA Palermo
Alle origini dell’astrofisica: il contributo di Angelo Secchi (1818-1878)
Abstract: Mainly known as trailblazer of the spectral classification of stars and pioneer of solar physics, Angelo Secchi is one of the most brilliant and modern figures in the Italian and international scientific context of the second half of the 19th century. His background was in physics, but he was called in 1849 to became director of the Collegio Romano Observatory, where he applied early techniques of photography and spectroscopy in the field of astronomy. Driven by his wide scientific curiosity, Secchi explored many scientific domains, trying to find correlations between the natural phenomena and giving important contributions in all his fields of interest. This talk will outline his interesting profile of Jesuit scientist and illustrate his main scientific results, that had paved the way to current research topics and methods (not only in astronomy).
25 Marzo 2020
Alessandro Chieffi (INAF/IAPS)
The predicted Masses of stellar black holes as a function of the initial mass, metallicity and initial rotation velocity
Abstract: Massive stars play a major role in driving the physical and chemical evolution of the galaxies because either they are the main responsible for the synthesis of new nuclei (including the long living radioactive ones, as Al26 and Fe60) and they inject enormous amounts of energy in their surroundings, favoring / inhibiting the formation of new stars. They are also the parents of the neutron stars and stellar black holes that populate the universe, and hence they are also strictly connected with spectacular phenomena like the Supernova explosions, GRBs and gravitational waves emission. In this seminar, I will concentrate on the initial mass remnant mass relation, and on its dependence on the metallicity and initial rotational velocity, trying to highlight the major sources of uncertainty that affect the robustness of this connection.
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