———————– YEAR 2018 ———————–
12-12-2018, 14:30, Aula IB09, ARTOV – IAPS – Via Fosso Del Cavaliere, 100
Stellar Activity and exoplanets: the Sun’s lesson
Francesco Berrilli (Università degli Studi di Roma Tor Vergata)
The solar atmosphere, acting as a nonlinear dissipative system subjected to an external forcing (i.e. non zero energy flow), presents a state of reduced symmetry with the consequent formation of convective and magnetic structures and evolution of associated patterns. These magneto-convective structures, modulated by the global dynamo, interact with the hosted planets and impact the climate and habitability of terrestrial (exo)planets. Innovative spectral proxies of solar activity and planetary climatic response may be useful for application to observational surveys of UV activity in Sun-like stars and IR signal in exoplanetary systems.
28-11-2018, 14:00-14:50, Aula IB09, ARTOV – IAPS – Via Fosso Del Cavaliere, 100
Che cosa è e come funziona l’Ufficio Comunicazione INAF per la Didattica e la Divulgazione
Stefano Sandrelli (INAF, Osservatorio di Brera)
Dal maggio 2016, la Presidenza INAF si e’ dotata di una struttura per la Comunicazione che coordina le azioni di Didattica e Divulgazione dell’ente, cercando di valorizzare sempre di piu’ le strutture sul territorio e la componente di ricerca. Vediamo insieme con quali strumenti, quali strategie, quale visione e quali prospettive per il futuro.
28-11-2018, 14:50-15:15, Aula IB09, ARTOV – IAPS – Via Fosso Del Cavaliere, 100
Presentazione attività di Didattica e Divulgazione IAPS
Livia Giacomini (INAF – IAPS)
Verranno illustrate le principali attività di didattica e divulgazione organizzate dall’Ufficio di Comunicazione INAF-IAPS e le possibilità di collaborare con noi. Partendo dal nostro nuovo sito (www.iaps.inaf.it/ufficio.comunicazione), verranno presentati i progetti dedicati alle scuole e le possibili partecipazioni a eventi e manifestazioni divulgative. Saranno infine illustrati i due nuovi progetti Pianeti in una stanza e il MUVISS, il Museo Virtuale delle Scienze Spaziali.
28-11-2018, 15:15-15:30, Aula IB09, ARTOV – IAPS – Via Fosso Del Cavaliere, 100
Presentazione Olimpiadi di Astronomia
Fiamma Capitanio (INAF – IAPS)
Le Olimpiadi Italiane di Astronomia, con il pretesto della competizione, offrono agli studenti delle scuole italiane un’occasione di confronto con altri ragazzi e la possibilità di coltivare l’interesse e la passione per l’astronomia (materia poco studiata nelle scuole superiori). Inoltre i ragazzi che vi partecipano hanno l’occasione di incontrare e conoscere il mondo della ricerca scientifica. Illustrerò brevemente l’organizzazione delle Olimpiadi Italiane di Astronomia e il coinvolgimento del nostro istituto sia a livello locale che nazionale.
21-11-2018, 11:00, aula Convegni, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
The quest for single and dual active galactic nuclei: a numerical perspective
Pedro Capelo (University of Zurich)
Supermassive black holes (SMBHs) are believed to lie at the centre of most galaxies and to coevolve with them, growing through both mergers and accretion, shining as active galactic nuclei (AGN), and feeding part of the accretion energy back to their hosts. When galaxies merge, SMBHs may reveal themselves as dual AGN and, much later in the merging process, as gravitational-wave sources. I address a variety of questions, related to both dynamics and growth of SMBHs, by using high-resolution, N-body, hydrodynamical simulations of mergers between late-type galaxies, in which I vary mass ratios, gas fractions, orbital configurations, and SMBH masses, and where I include realistic descriptions of cooling, stellar and SMBH feedback, and star formation. In this talk, I will mostly focus on examining which mergers preferentially trigger AGN activity, distinguishing between merger-related and secular-related accretion, tracing the resultant evolution of the SMBH mass ratios in the pairing process, describing different gas feeding paths, and connecting theory with observations in the search for dual AGN.
07-11-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
High-contrast imaging observations of exoplanetary systems: current status and future perspectives
Valentina D’Orazi (INAF/OAPadova, Padova)
Thanks to notable advancements in adaptive optics combined with coronagraphic observational strategies, high-contrast imaging techniques are rapidly progressing in the current years. The exploration of the sub-stellar regime via direct imaging, hampered so far by technical limitations, is starting to provide us with a powerful tool. SPHERE at VLT, combining extreme adaptive optics with coronagraphy, dual-band imaging and integral field spectroscopy, has started its operations: relatively massive exoplanets at few tenths of arcsecond separations and contrasts better than 106 can be reached. In this contribution I will present recent results obtained with SPHERE in the framework of the SHINE survey. Moreover, I will present a new system for coronagraphy with high-order adaptive optics that will be operating at LBT by the end of 2019: SHARKs. This system will provide coronagraphic observations from visual to NIR bands, allowing a spectral coverage that is not currently available for any other instrument in the world. Finally, I will discuss the employment of a brand-new technique that combines highcontrast imaging with high-dispersion spectroscopy, allowing in principle to reach contrasts down to 1010. In the era of E-ELT, this will open the way to investigating earth-like planets in the habitable zones of their parent stars.
31-10-2018, 11:00, aula Convegni, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Unveiling the Obscured Universe with SPICA observations
Luigi Spinoglio (INAF/IAPS Roma)
A most exciting but still unknown process in modern astrophysics is how galaxy evolution develops from the last ten billion years. Star formation (SF) and accretion onto supermassive black holes (BHA) play this game. Around the peak of the SF and BHA rate histories (z=1-4), galaxies and stars develop in dusty heavily obscured environments, preventing optical/UV observations to reveal their nature. As opposite, IR spectroscopy (and photometry at higher redshift) will reveal physically galaxy evolution, allowing to measure through lines the main physical properties (e.g., ionization field, density, metallicity, gas velocities, etc.). I will show how the ESAJAXA (preselected in M5) mission SPICA will do this.
Also unknown, because deeply obscured by interstellar dust, is the early evolution of stars and planets, which will strongly benefit from key observations that only SPICA will be able to do. I will also outline the IR spectroscopy of proto-planetary disks and protostellar objects and FIR polarimetric images of interstellar filaments, to give a few examples.
24-10-2018, 11:00, Aula Convegni, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
The search for life elsewhere
Daniela Billi (Università di Tor Vergata, Roma)
Are we alone in the Universe? Clues to address this question derive from disparate disciplines, from the most hostile places on Earth, from the experiments carried out in research laboratories and outside the International Space Station, as well as from the space missions that study comets and asteroids.
10-10-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Supermassive black holes and planetary habitability
Amedeo Balbi (Università di Tor Vergata, Roma)
It is generally thought that the habitability of a planet is strongly influenced by the amount of ionizing radiation incident on its atmosphere and surface. While the host star is usually the prevalent origin of such high-energy radiation, previous studies have also considered the effect on a hypothetic biosphere of other possible sources, in particular with regard to potentially catastrophic transient events such as nearby gamma ray bursts or supernova explosions. Here we consider a phenomenon whose astrobiological consequences are much less explored, i.e. the production of X-ray and extreme ultraviolet (XUV) radiation during the peak of the active phase of supermassive black holes. In particular, we investigated how the activity of the supermassive black hole at the center of the Milky Way, known as Sagittarius A* (Sgr A*), may have affected the habitability of Earthlike planets in our Galaxy. Our results show for the first time that the combined effect of atmospheric loss and of the direct biological damage to surface life was probably significant during the AGN phase of Sgr A*, possibly hindering the development of complex life within a few kiloparsecs from the galactic center.
04-10-2018, 14:30, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Turbulence: the last unsolved problem of classical physics
Vincenzo Carbone (Università della Calabria, Cosenza)
Since the early ‘500, the problem of turbulence in fluid flows has been posed to the attention of scientists. Although a lot of efforts have been devoted to solve the problem, both from a mathematical and physical point of view, some basic aspect of turbulent fluid flows yet remains somewhat wrapped in mystery. The advent of space flights and high performance computers provided a lot of new experimental evidences and, in some sense, further complications in the theory. The talk provides an up to date short review of this last
unsolved problem of classical physics.
26-09-2018, 11:00, Aula Convegni, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Radar evidence of subglacial liquid water on Mars
Roberto Orosei (INAF – Istituto di Radioastronomia)
The presence of liquid water at the base of the Martian polar caps has long been suspected but not observed. We surveyed the Planum Australe region using the Mars Advanced Radar for Subsurface and Ionosphere Sounding, a low-frequency radar on the Mars Express spacecraft. Radar profiles collected between May 2012 and December 2015, contain evidence of liquid water trapped below the ice of the South Polar Layered Deposits. Anomalously bright subsurface reflections were found within a well-defined, 20km wide zone centered at 193°E, 81°S, surrounded by much less reflective areas. Quantitative analysis of the radar signals shows that this bright feature has high dielectric permittivity >15, matching water-bearing materials. We interpret this feature as a stable body of liquid water on Mars.
19-09-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Detection of the Missing Baryons in the Warm-Hot Intergalactic Medium
Fabrizio Nicastro (INAF – Ossrvatorio Astronomico di Roma)
It has been known for decades that the observed number of baryons in the local Universe falls about 30-40% short of the total number of baryons predicted by Big-Bang Nucleosynthesis, inferred by density fluctuations of the Cosmic Microwave Background and seen during the first 2-3 billion years of the universe (redshift z>2-3) in the so called “Lyman-α Forest”. While theory provides a reasonable solution to this paradox, by locating the missing baryons in hot and tenuous filamentary gas connecting galaxies, it also sanctions the difficulty of detecting them because their by far largest constituent, hydrogen, is mostly ionized and therefore virtually invisible in ordinary signal-to-noise Far-Ultraviolet spectra. Indeed, despite the large observational efforts, only a few marginal claims of detection have been made so far.
Here I will first review the observational efforts pursued over the past 15 years by several groups and will then present our recent results that show that the missing baryons are indeed found in a tenuous warm-hot and moderately enriched medium that traces large concentrations of galaxies and permeates the space between and around them. I will show that the number of OVII systems detected down to the sensitivity threshold of our data, agrees well with numerical simulation predictions for the long-sought hot intergalactic medium, and its detection adds a fundamental tile to the long-standing missing baryon puzzle. Finally, I will comment on the implications of these new results for future high resolution X-ray missions (e.g. Athena).
17-09-2018, 11:00, Aula Gratton, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
The peculiar case of the active galactic nucleus in PBC J2333.9-2343
Lorena Hernandez (Euniversity of VALPARAISO – CHILE)
Under unification schemes, active galactic nuclei (AGN) can be explained by orientation effects. However, some sources show properties at different frequencies that led to incongruent classifications and cannot be explained by such unification scheme. This is the case of PBC J2333.9-2343; its optical spectrum is of a type 2 AGN but its X-ray spectrum does not show signs of absorption, and in the radio it has many features typical of a blazar but it is a giant radio galaxy. Using multiwavelength simultaneous data from XMM-Newton, San Pedro Mártir telescope and VLBA, we find that these classifications cannot be attributed to variability. We propose that PBC J2333.2343 is a blazar that has undergone a restarting activity episode in its nucleus. Interestingly, it has changed from being a radio galaxy to become a blazar, showing an exceptional change in the direction of the jet that, by chance, occurred in the plane of the sky.
Moreover, we have analyzed Swift and New Technology Telescope (NTT) data to study the variability of the source, revealing a change in the broad line region BLR) clouds and increasing variability at all observed wavelengths and we have detected an outflow in its optical spectra.
12-09-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
The Milky Way in motion
Ronald Drimmel (INAF – Ossrvatorio Astrofisico di Torino)
Thanks to the most recent data release from ESA’s Gaia satellite, the astronomical community now has at its finger tips the parallaxes and proper motions of over a billion stars. While this represents only a tiny fraction of the total number of stars in our galaxy, it samples a significant fraction of the volumn of the Milky Way. Gaia is not only a galactic cartographers dream machine: thanks to its proper motions it is setting the Galaxy in motion for us. For the first time we are able to map in detail the stellar kinematics not only in the solar neighborhood, but also in other neighboring volumns to significant distances. I present some of the most recent surprises that this data set has revealed regarding the dynamics of the Milky Way, some remaining open questions, and how Gaia is allowing us to see our home galaxy in a new light and is forcing us to rethink our usual assumptions.
31-08-2018, 11:30, Aula IB09, ARTOV- IAPS Via Fosso del Cavaliere, 100
Multiple-scale analysis of effective transport in compressible magnetohydrodynamic turbulence
Nobumitsu Yokoi (Institute of Industrial Science (IIS), University of Tokyo, Japan)
Strongly compressible magnetohydrodynamic (MHD) turbulence is investigated with the aid of the multiple-scale direct-interaction approximation, a renormalised perturbation closure scheme for inhomogeneous turbulence at very high Reynolds numbers. Turbulence correlations in the mean-field equations are evaluated with analytical expressions of the turbulent transport coefficients. It is shown that, in addition to the usual solenoidal effects, genuine compressibility effects show up in the turbulence correlation expressions, which include the density variance effects in the turbulent electromotive force, the compressive cross-helicity effects in the turbulent mass and energy fluxes, etc. Turbulence modelling based on the theoretical results is also presented. Some possible applications to shock–turbulence interaction in the context of dynamo and magnetic reconnection are discussed.
References:
Yokoi, N. “Cross helicity and related dynamo,” Geophys. Astrophys. Fluid Dyn. 110, 114-184 (2013) doi.org/10.1080/03091929.2012.754022
Yokoi, N. “Electromotive force in strongly compressible magnetohydrodynamic turbulence,” J. Plasma Phys. 84, 1-26 (2018) doi:10.1017/S0022377818000727
27-08-2018, 11:30, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Electromotive force in space plasmas
Yasuhito Narita (Space Research Institute, Austrian Academy of Science, Graz, Austria)
Electromotive force is a cross product of fluctuations between the flow velocity and the magnetic field, and plays an important role in the dynamo mechanism.
Electromotive force is one of the second-order fluctuation quantities like fluctuation energies or elicity quantities, but has so far drawn only little attention in the observational studies in situ in the solar system plasmas. I focus on the use of electromotive force as an observational tool to study turbulence and dynamo mechanism. An analysis method is developed for the electromotive force and the transport coefficients such as those for the alpha effect and the turbulent diffusivity. A test against a magnetic cloud event in the inner heliosphere using the Helios spacecraft data is presented. The electromotive force is enhanced together with the magnetic cloud event by 1 or 2 orders of magnitude, suggesting that the magnetic field can instantly and locally be amplified in the heliosphere.
27-06-2018, 14:30, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
The OSIRIS-REx Mission: scientific outcomes from the sampling site selection
Maurizio Pajola (INAF – Osservatorio Astronomico di Padova)
The OSIRIS-REx mission is the third one in NASA’s New Frontiers Program, and its main goal is to carry home samples (2023) from the surface of 101955 Bennu, a ~500 m size B-type Near-Earth Asteroid. In December 2018, the OSIRIS-REx will finally rendezvous its target. Then, for more than 1.5 years, the entire instruments suite will be dedicated to select the best sampling site. We are deeply involved in the sampling site selection task, with the main aim of providing the boulder size-frequency distribution of the entire asteroid, the boulders localized surface densities and the boulders hazard maps of the sampling site. In addition, we will focus on the surface processes generating such sizes distributions, aiming to maximize the scientific return of the high-resolution observations. Within this talk we will first introduce the OSIRIS-REx mission, its main goals and the onboard instruments suite. Then, we will present both the expected engineering and scientific products we will prepare while riding around Bennu.
20-06-2018, 14:30, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Solar Orbiter and beyond: a new season of heliphysics studies, looking further
Daniele Spadaro (INAF – Osservatorio Astrofisico di Catania)
This is a great year for a new season of heliophysics studies, thanks to the creation of a group of Instruments, on board of space missions or steadily on earth, which will be put in operation in the next decade and will let us study our star and the heliosphere as never before.
In addition to ESA Solar Orbiter mission, whose scientific payload integration is underway and whose launch is planned in February 2020, soon (August 2018) NASA Parker Solar Probe (PSP) mission will be launched, a “mission to touch the Sun”, since the minimum distance perihelion is expected at less than 10 solar radii. On the other hand, the minimum perihelion of Solar Orbiter mission is expected at 0.28 AU, well inside Mercury orbit. The contemporary presence of both “in-situ” and “remote-sensing” instruments, in the two missions, will let us study in great details the solar processes that give birth and set the heliosphere, and then have important consequences on circumplanetary environments.
In the next decade, two big solar telescopes will be built (4 m class), the American DKIST, on the Hawaii islands, and the European EST, on the Canarian islands. They might both have the capacity to observe the solar atmosphere with a remarkable space, temporal and spectral resolution, with a great contribution to the detailed study of processes of emergence and evolution of solar magnetic fields, their role in the structure and dynamics of solar atmosphere, as well as eruptive phenomena that release great amounts of plasma in the interplanetary space. The main features of such instruments and their potential contribution to the progresses on heliophysics studies are going to be described, looking at the possibility of having new useful information concerning star physics and eso-planetary researches.
13-06-2018, 11:00. Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Preparandosi per SKA – Getting ready for the SKA
Grazia Umana (INAF – Osservatorio Astrofisico di Catania)
Lo Square Kilometre Array (SKA) è un ambizioso progetto globale di scienza e ingegneria finalizzato alla costruzione di una delle più imponenti infrastrutture astronomiche mai realizzate. Attualmente in avanzata fase di progettazione, lo SKA sarà un network di radiotelescopi, distribuito su due continenti, caratterizzato da una sensibilità mai raggiunta, da uno elevato potere risolutivo e dall’applicazione di tecnologie innovative allo sviluppo dei ricevitori, al trasporto ed elaborazione del segnale e del calcolo.
L’Italia, attraverso l’Istituto Nazionale di Astrofisica (INAF), è uno dei maggiori attori della fase di pre-costruzione, partecipando in prima linea alla progettazione, e contribuisce attivamente alla definizione dei casi scientifici attraverso gli SKA Science Working Group.
Dopo una breve illustrazione del progetto e del suo stato di avanzamento, presenterò alcune attività scientifiche preparatorie nel campo della scienza galattica che vedono alcuni team italiani protagonisti, con particolare riferimento all’Australian SKA Precursor ASKAP, attualmente in fase di Early Science.
30-05-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Research on exoplanets in Italy: current status and perspectivesGiusi Micela (INAF – Osservatorio Astronomico di Palermo)
In recent years the research on exoplanets has led to many discoveries that are allowing a better understanding of the place of the solar system in a broader astrophysical context.
The Italian scientific community has invested significantly in this field participating to the development of dedicated instruments operating both from ground and from space.
The HARPS-N spectrograph at the TNG is today the most efficient facility for the research of exoplanets through the radial velocity method. Today HARPS-N can work simultaneously with GIANO – in the GIARPS mode – observing from optical to near infrared wavelengths with performances currently unique in the world.
This, together with the participation with a leading role, to the design and exploitation of other instruments from ground and space, has allowed the development of an internationally recognized national community expert in the study of exoplanets. The future spatial missions CHEOPS, PLATO and ARIEL will give a further boost to this research for the next decades.
02-05-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Probing the innermost regions of blazar jets at tens of microarcseconds through space and millimeter VLBI observations
Jose Luis (Instituto de Astrofisica de Andalucia, Granada Spain)
Investigating how AGN jets originate, and what are the sites and mechanisms for the production of high energy emission, requires probing these jets at the highest angular resolution.
We present the results of our RadioAstron Key Science Program to study a sample of AGN jets in combination with the Event Horizon Telescope (EHT) and the GMVA. Among our earlier results,
we have successfully imaged the jet in BLLac at an angular resolution of 21 microarcseconds (uas), revealing a large scale helical magnetic field in the vicinity of the central black hole, and 0716+714 at 24 uas, showing a sharp inner bending that may be responsible for the characteristic intraday variability observed in this source. OJ287 is the best candidate for harboring a coalescing supermassive binary black hole (SMBBH) system, making it an excellent laboratory for studying strong-field relativistic effects and the future detection of nano- and mili-hertz gravitational waves. Our quasi-simultaneous RadioAstron, EHT, and GMVA observations of OJ287 reveal a highly twisted jet at an unprecedented angular resolution of 10 uas (26 Schwarzschild radii); these are analyzed in combination with our multiwavelength monitoring (optical to gamma-rays), to test the SMBBH scenario and jet formation models.
18-04-2018, 11:00, Aula Convegni, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
The realm of the first AGN in the Universe
Cristian Vignali (Dipartimento di Fisica e Astronomia – Università di Bologna)
Over the last decade, optical, near-infrared and X-ray observations have pushed the search for galaxies and AGN to very high redshifts and, coupled to mid-IR, far-IR and millimeter data, have enabled detailed studies on their physical properties and evolution.
I will present the state of the art concerning the observation and characterization of the first black holes in the Universe, including the obscured ones and the properties of their host galaxies, and the firm constraints on the low-rate mass accretion onto supermassive black holes at high redshifts as probed by the deepest X-ray exposure carried out in the Chandra Deep Field-South. I will also outline some open issues and promising prospects for the future.
04-04-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Climate models as a tool for quantifying the habitability of rocky planetsGiovanni Vladilo (INAF – Osservatorio Astronomico di Trieste)
One of the drivers of Solar System missions and exoplanet observations is the search for astronomical bodies showing signatures of life. This search poses several challenges, partly related to the definition and identification of life in the context of exobiology. In this talk I will emphasize the essential role of climate models in this type of investigation, showing how it is possible to define a quantitative index of surface habitability. I will then present a climate model developed for the study of the surface temperature of Earth-like exoplanets (Vladilo et al. 2015, ApJ 804, 50) and show an example of application of this model to a terrestrial-size exoplanet discovered with the Kepler mission (Silva et al. 2017, MNRAS, 470, 2270). Finally, I will briefly discuss the challenges that must be faced to extend the range of application of the climate-model approach to the wide spectrum of physical and chemical conditions expected to exist in rocky exoplanets.
28-03-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Astroinformatics, a data-driven Science
Massimo Brescia (INAF – Osservatorio Astronomico Capodimonte)
Astronomy has entered the big data era and Machine Learning based methods have found widespread use in a large variety of astronomical applications. This is demonstrated by the recent huge increase in the number of publications making use of this new approach. The usage of machine learning methods, however is still far from trivial and many problems still need to be solved. Through a series of astrophysical use case studies, we outline main problems and some ongoing efforts to solve them.
15-03-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Planet formation in the ALMA era
Davide Fedele (INAF – Osservatorio Astrofisico Arcetri)
Planet formation is one of the most fundamental process in modern astrophysics as it is tightly linked to the origin of life. With more than 3000 planets known so far we are learning that planetary systems are ubiquitous in the Galaxy and their architectures are highly heterogeneous. These findings challenge our understanding of the planet formation mechanism. Protoplanetary disks (a natural outcome of the star formation process) offer a unique laboratory to investigate the early phases of planet formation and evolution. A major contribution to this field is coming from the Atacama Large Millimeter Array (ALMA). For the first time indeed, we are now able to detect and spatially resolve the emission coming from the cold disk interior where planet formation takes place. I will present recent results based on ALMA observations of gas and dust in disks.
28-02-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Superfici di asteroidi: irraggiamento e micro-spettroscopia VIS-IR in laboratorio
Rosario Brunetto (Institute d’Astrophysique Spatiale, CNRS- Orsay Paris)
I materiali primitivi extraterrestri, come alcune meteoriti e le polveri di asteroidi e comete, sono caratterizzati da una grande eterogeneità di composizione a diverse scale. Questa eterogeneità è stata osservata in laboratorio con diverse tecniche. Tra queste, la micro-spettroscopia infrarossa ha il vantaggio di essere totalmente non distruttiva e consentire un confronto diretto con le osservazioni astronomiche dei corpi minori del Sistema Solare. Grazie ai recenti sviluppi dei rivelatori a matrice di tipo “Focal Plan Array”, la mappatura IR ad alta risoluzione spaziale e in tempi brevi di acquisizione e la tomografia IR sono ora possibili. In questa presentazione mostreremo alcune misure recenti di imaging spettrale FTIR su diversi materiali extraterrestri, ottenuti in collaborazione con la linea SMIS del sincrotrone SOLEIL (Francia).
Nella seconda parte presenteremo nuovi dati di imaging spettrale di meteoriti irraggiate in laboratorio con ioni a 40 keV. Questi esperimenti hanno come scopo di simulare l’irradiazione da parte del vento solare delle superfici degli asteroidi. Insieme agli evidenti effetti dell’irraggiamento misurati nelle particelle dell’asteroide Itokawa (raccolte dalla missione Hayabusa), questi risultati possono essere di supporto all’interpretazione spettrale delle osservazioni di asteroidi, per stabilire un collegamento tra asteroidi e meteoriti e per comprendere i processamenti energetici che modificano le superfici dei corpi minori. Nei campioni irraggiati in laboratorio osserviamo variazioni spettrali delle componenti organiche e minerali, nonché le variazioni dell’albedo. Questi effetti di irraggiamento in funzione della dose sono quindi confrontati su scala micrometrica con l’eterogeneità composizionale dei materiali originari, per determinare quali bande spettrali sono più sensibili agli effetti dell’alterazione energetica. I risultati saranno discussi nel contesto delle prossime missioni di raccolta di campioni asteroidali Hayabusa 2 (JAXA) e OSIRIS-REx (NASA).
25-01-2018, 11:00, Aula IB09, ARTOV – IAPS, Via Fosso Del Cavaliere, 100
Exoplanet characterisation from space and using stratospheric balloons
Enzo Pascale (Dipartimento di Fisica dell’Università di Roma, La Sapienza)
With more than 3700 exoplanets discovered to date, spectroscopic characterisation of their atmospheres is the next step. The exoplanetary science stands on an exciting threshold as remote-sensing of exo-atmospheres has now become possible, allowing us to study the thermodynamics and chemistry of planets orbiting stars other than our Sun, and to constrain models of planetary formation and evolution. For this, observations are needed from the visible to the mid-IR portion of the electromagnetic spectrum which are challenging to obtain from the ground. I will review the status of the ARIEL space mission, and discuss the early science it would be possible to obtain on a shorter time-scale using stratospheric balloon instrumentation.