BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Osservatorio Astronomico di Roma - ECPv6.15.18//NONSGML v1.0//EN
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:Osservatorio Astronomico di Roma
X-ORIGINAL-URL:https://www.oa-roma.inaf.it
X-WR-CALDESC:Eventi per Osservatorio Astronomico di Roma
REFRESH-INTERVAL;VALUE=DURATION:PT1H
X-Robots-Tag:noindex
X-PUBLISHED-TTL:PT1H
BEGIN:VTIMEZONE
TZID:Europe/Rome
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20170326T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20171029T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20180325T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20181028T010000
END:STANDARD
BEGIN:DAYLIGHT
TZOFFSETFROM:+0100
TZOFFSETTO:+0200
TZNAME:CEST
DTSTART:20190331T010000
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
DTSTART:20191027T010000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20181204T114400
DTEND;TZID=Europe/Rome:20181204T124500
DTSTAMP:20260404T181616
CREATED:20180804T134547Z
LAST-MODIFIED:20180804T134547Z
UID:4313-1543923840-1543927500@www.oa-roma.inaf.it
SUMMARY:Colloqium - Donatella Romano
DESCRIPTION:
URL:https://www.oa-roma.inaf.it/event/colloqium-donatella-romano/
LOCATION:Aula Gratton
CATEGORIES:Seminari
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20181204T114500
DTEND;TZID=Europe/Rome:20181204T124500
DTSTAMP:20260404T181616
CREATED:20180804T134547Z
LAST-MODIFIED:20181119T172935Z
UID:4763-1543923900-1543927500@www.oa-roma.inaf.it
SUMMARY:The evolution of CNO isotope ratios: a litmus test for stellar IMF variations in galaxies across cosmic time
DESCRIPTION:Determining the shape of the stellar initial mass function (IMF) and whether it is constant or varies in space and time is the Holy Grail of modern astrophysics\, with profound implications for all theories of star and galaxy formation. On a theoretical ground\, the extreme conditions for star formation (SF) encountered in the most powerful starbursts in the Universe are expected to favour the formation of massive stars. Direct methods of IMF determination\, however\, cannot probe such systems\, because of the severe dust obscuration affecting their starlight. The next best option is to observe CNO bearing molecules in the interstellar medium at millimetre/submillimetre wavelengths\, which\, in principle\, provides the best indirect evidence for IMF variations. In this talk\, I discuss some recent findings on this issue. First\, I reassess the roles of different types of stars in the production of CNO isotopes\, by using a proprietary chemical evolution code and up-to-date Milky Way data from the literature. The model is then extended to discuss extragalactic data. I show that\, though significant uncertainties still hamper our knowledge of the evolution of CNO isotopes in galaxies\, compelling evidence for an IMF skewed towards high-mass stars can be found for galaxy-wide starbursts. In particular\, I show the results for a sample of submillimetre galaxies observed by our team with the Atacama Large Millimetre Array at the peak of the SF activity of the Universe\, for which we measure a ratio 13C/18O of about 1. This isotope ratio is especially sensitive to IMF variations\, and little affected by observational uncertainties. At the end\, ongoing and future developments of our work are briefly outlined.
URL:https://www.oa-roma.inaf.it/event/colloqium-donatella-romano-2/
LOCATION:Aula Gratton
CATEGORIES:Seminari
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20181206T114500
DTEND;TZID=Europe/Rome:20181206T124500
DTSTAMP:20260404T181616
CREATED:20181106T172218Z
LAST-MODIFIED:20181106T172218Z
UID:4814-1544096700-1544100300@www.oa-roma.inaf.it
SUMMARY:Paolo Dal Pozzo Toscanelli\, Cosimo de’ Medici and the Sky of the Magi:  a new reading of the Florentine Celestial Hemispheres in the Sagrestia Vecchia at San Lorenzo and in the Pazzi Chapel at Santa Croce.
DESCRIPTION:After 30 years since the historical pubblication of the analysis\nconducted by Forti\, Lapi Ballerini\, Monsignori Fossi and Ranfagni (1987)\, I\noffer a careful re-examination of the two famous florentine starry vaults of\nthe early Renaissance\, taking into account the recent restoration of the\nhemisphere of the Pazzi Chapel and the almost coeval maps drawn by Paolo\nDal Pozzo Toscanelli for his studies of comets in 1456 (Halley) and 1457.\nThe authorship by the Tuscan cosmographer is confirmed in the Sagrestia\nVecchia on the basis of a comparison between a sample of stars from the\ndome\, Toscanelli’s maps and Ptolemy’s Catalogue. The Pazzi Chapel instead\,\nreveals on close inspection to be a clumsy\, derivative later work.\nWhile the double date proposed in 1987\, the enigmatic 4/5 july 1442\, still\nremains astronomically the most probable\, I will show that the exactness of\nthe planetary positions have been overestimated\, unfairly provoking a lack of\nattention for other candidate dates\, more astrologically meaningful if not\ndepicted with satisfying correctness. Relying indeed on the astrological\ntechniques and interests of the time\, I propose to assess the 1442 and the\n1439 most probable candidate horoscopes following the very appropriate line\nof reasoning introduced by Dieter Blume (2000)\, i.e. considering the\ncongruence of the sky charts with principles and rules of astral divination as\nwell as with the political situation in Florence and with the cultural needs of\nthe clients.\nFinally\, I single out as most probable the second date (even exhibiting a\nmarginal evidence for it on the basis of Lorenzo de’ Medici’s calendarial\nconcerns)\, and I offer a new hypothetical explanation for this preference\,\nlinking medicean interest in the magian narrative and the Star of Bethlehem\,\nastrological speculation and political propaganda.
URL:https://www.oa-roma.inaf.it/event/paolo-dal-pozzo-toscanelli-cosimo-de-medici-and-the-sky-of-the-magi-a-new-reading-of-the-florentine-celestial-hemispheres-in-the-sagrestia-vecchia-at-san-lorenzo-and-in-the-pazzi-chapel-at/
LOCATION:Aula Gratton
CATEGORIES:Seminari
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20181211T114500
DTEND;TZID=Europe/Rome:20181211T124500
DTSTAMP:20260404T181616
CREATED:20180910T113353Z
LAST-MODIFIED:20181203T092120Z
UID:4768-1544528700-1544532300@www.oa-roma.inaf.it
SUMMARY:The role of cosmic rays on physical and chemical processes of the interstellar medium
DESCRIPTION:The study of the interaction of cosmic rays with the interstellar matter is a multi-disciplinary investigation that involves the analysis of several physical and chemical processes: ionisation of atomic and molecular hydrogen\, energy loss by elastic and inelastic collisions\, energy deposition by primary and secondary electrons\, gamma-ray production by pion decay\, the production of light elements by spallation reactions\, and much more. Cosmic-ray ionisation activates the rich chemistry of dense molecular clouds and determines the degree of coupling of the gas with the local magnetic field\, which in turn controls the collapse timescale and the star-formation efficiency of a molecular cloud. In recent years a wealth of observations from the ground and from space has provided information and constraints that still need to be incorporated in a consistent global theoretical framework. My goal is to use the results of chemical models and state-of-the-art numerical simulations supplemented by dedicated observations to provide a unifying interpretation of the data with a model of cosmic-ray propagation specifically developed to make predictions that can be tested against the observations. Finally\, I will talk about my most recent study: a mechanism able to accelerate local thermal particles in protostars that can be used to explain the high ionisation rate as well as the synchrotron emission observed towards protostellar sources.
URL:https://www.oa-roma.inaf.it/event/colloquium-marco-padovani-2/
LOCATION:Aula Gratton
CATEGORIES:Seminari
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20181211T114500
DTEND;TZID=Europe/Rome:20181211T124500
DTSTAMP:20260404T181616
CREATED:20180910T113353Z
LAST-MODIFIED:20180910T113353Z
UID:4374-1544528700-1544532300@www.oa-roma.inaf.it
SUMMARY:colloquium - Marco Padovani
DESCRIPTION:
URL:https://www.oa-roma.inaf.it/event/colloquium-marco-padovani/
LOCATION:Aula Gratton
CATEGORIES:Seminari
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20181218T114500
DTEND;TZID=Europe/Rome:20181218T124500
DTSTAMP:20260404T181616
CREATED:20180725T070155Z
LAST-MODIFIED:20181210T123509Z
UID:4756-1545133500-1545137100@www.oa-roma.inaf.it
SUMMARY:How to tackle a giant Star: multi-wavelength studies of cool\, evolved stars\, using HST and VLTI
DESCRIPTION:The chemical enrichment of the Universe is considerably affected by the contributions of Giant stars. Giant and supergiant stars are surrounded by a hot layer called the chromosphere\, which could likely powers Magneto-Hydrodynamic Alfven waves that could initiate their mass loss. Toward the end of their life\, on the Asymptotic Giant Branch (AGB)\, stars produce heavy chemical elements\, molecules\, and dust\, which\, through the mass loss provided via their stellar winds\, are placed into the interstellar medium.\nThis talk will explore ongoing work modeling high-resolution spectroscopic observations with Hubble Space Telescope instruments (Rau et al. 2018)\, to reveal the role of the chromosphere in driving K-M giant and supergiant winds. Our results include estimates of wind and chromospheric parameters\, mass-loss rates\, and fundamental stellar parameters.\nIn addition\, ground-based interferometric measurements with high-angular resolution instruments from VLTI\, such as MIDI (Rau et al. 2015\, Rau et al. 2017)\, GRAVITY (Wittkowski\, Rau et al. 2018)\, help to test geometrical and dynamical models describing the behavior of the outer AGB atmospheres at various spatial scales. In this way we are able to unravel the role of molecules and dust in their extended atmospheres.\nFuture plans include the use of high-angular resolution instruments such as VEGA at CHARA\, and MATISSE at VLTI\, to better understand the behavior of cool stars outer atmospheres at various spatial scales.
URL:https://www.oa-roma.inaf.it/event/colloquium-gioia-rau-2/
LOCATION:Aula Gratton
CATEGORIES:Seminari
END:VEVENT
BEGIN:VEVENT
DTSTART;TZID=Europe/Rome:20181218T114500
DTEND;TZID=Europe/Rome:20181218T124500
DTSTAMP:20260404T181616
CREATED:20180725T070155Z
LAST-MODIFIED:20180725T070155Z
UID:4170-1545133500-1545137100@www.oa-roma.inaf.it
SUMMARY:colloquium - Gioia Rau
DESCRIPTION:
URL:https://www.oa-roma.inaf.it/event/colloquium-gioia-rau/
LOCATION:Aula Gratton
CATEGORIES:Seminari
END:VEVENT
END:VCALENDAR