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:20220327T010000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:20221030T010000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:20230326T010000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:20231029T010000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:20240331T010000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:20241027T010000 END:STANDARD BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:20250330T010000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:20251026T010000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230221T113000 DTEND;TZID=Europe/Rome:20230221T123000 DTSTAMP:20260405T014646 CREATED:20230210T063356Z LAST-MODIFIED:20230211T123928Z UID:11269-1676979000-1676982600@www.oa-roma.inaf.it SUMMARY:The most extreme phase of black holes growth and feedback DESCRIPTION:Deep surveys have revealed fully-grown supermassive black holes powering active galactic nuclei at very high redshifts\, when the Universe was a few hundred Myr old\, less than 10% of its current age. This challenges the theories of black holes growth\, requiring long periods of high accretion\, most likely above the Eddington limit. These objects will be difficult to study in detail\, even with future advanced observatories. However\, in the nearby Universe\, there are several objects that shine beyond Eddington\, can be studied in great detail and used as proxy for primordial black holes. In the supermassive regime we have some narrow line Seyfert 1 galaxies and tidal disruption events\, whilst hundreds of stellar-mass black holes and neutron stars are known to power ultraluminous X-ray sources (ULXs). A common denominator to these stellar-mass and supermassive objects is the presence of extreme winds which confirm the predictions by theoretical models of super-Eddington accretion. These winds carry a huge amount of power owing to their mildly-relativistic speeds (~0.2c) and are able to significantly affect the surrounding medium and limit the amount of matter that can reach the central accretor. In this seminar I will discuss the state-of-art of super-Eddington accretion in different mass regimes and highlight future missions that will decisively boost this research field. URL:https://www.oa-roma.inaf.it/event/colloquium-ciro-pinto/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230228T113000 DTEND;TZID=Europe/Rome:20230228T123000 DTSTAMP:20260405T014646 CREATED:20230210T063549Z LAST-MODIFIED:20230217T063652Z UID:11272-1677583800-1677587400@www.oa-roma.inaf.it SUMMARY:Connecting AGN and massive gas reservoir in protoclusters: the Chandra view of the Jackpot nebula at z=2 DESCRIPTION:High-redshift\, gas-rich galaxy protoclusters represent excellent laboratories\nfor investigating the effects of the environment on SMBH growth\, nuclear\nactivity and onset of AGN feedback in overdense regions.\nThe detection of enormous (>200 kpc) Ly_alpha nebulae (ELANe) in some of these\nsystems\, coupled with the presence of multiple AGN\, has called for an extensive\nfollow-up observational campaign\, including X-rays to properly census\nthe AGN population in these protocluster and\, hence\, determine their role in\npowering ELANe.\nIn this talk\, I will present an ongoing large Chandra program targeting some\nhigh-redshift ELANe; in particular\, I will focus on the properties of the\nJackpot nebula at z=2\, showing four X-ray detected AGN in the inner part and\nsome additional AGN associated with Lyman alpha emitters on larger scales.\nI will also report on the detection of diffuse X-ray emission in the inner\nregion of the nebula. URL:https://www.oa-roma.inaf.it/event/colloquium-cristian-vignali/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230307T113000 DTEND;TZID=Europe/Rome:20230307T123000 DTSTAMP:20260405T014646 CREATED:20230217T061831Z LAST-MODIFIED:20230223T160230Z UID:11309-1678188600-1678192200@www.oa-roma.inaf.it SUMMARY:VVV Microlensing events as tracers of Galactic structure and kinematics DESCRIPTION:We report the discovery of ~1\,000 microlensing events within an area covering 20.68 deg^2 between 2010 and 2015 in the zero-latitude region of the Galactic bulge using the VVV Survey near-IR data. We used the near-IR Color-Magnitude and Color-Color Diagram to analyze the extinction properties of the sample in the central region of the Galactic plane. We study the Einstein ring crossing time distribution as a strong dark mass indicator and study features of the Galactic structure. We found 20 distant microlensing events probably located in the far disk of the Galaxy. This is the first time a population of events has been discovered\, allowing us to study the other side of the Milky Way. We also examine specific events\, such as the long timescale events showing parallax that favor the presence of dark stellar remnants such as black holes and neutron stars\, which are essential ingredients in our understanding of stellar evolution and mass distribution\, galaxy evolution and structure\, dark matter balance\, etc. URL:https://www.oa-roma.inaf.it/event/colloquium-gabriela-navarro/ LOCATION:Aula Gratton CATEGORIES:Seminari ORGANIZER;CN="Flavia Dell'Agli":MAILTO:flavia.dellagli@inaf.it END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230321T113000 DTEND;TZID=Europe/Rome:20230321T123000 DTSTAMP:20260405T014646 CREATED:20230210T063937Z LAST-MODIFIED:20230313T064314Z UID:11276-1679398200-1679401800@www.oa-roma.inaf.it SUMMARY:colloquium - Sonia Fornasier: Latest results on 67P/Churyumov-Gerasimenko comet from the OSIRIS instrument onboard the ROSETTA mission DESCRIPTION:The Rosetta space mission of the European Space Agency Rosetta has observed comet 67P/Churyumov-Gerasimenko for about 2 years\, delivering the lander Philae on the comet surface for the first time in the history of the space exploration.  Ended in September 2016\, the Rosetta/Philae mission\, acquired an incredible amount of unique data of comet 67P\, allowing the most detailed study ever attempted of a comet.\nRosetta had a large complement of scientific experiments including the OSIRIS imaging system which consists of a Wide Angle Camera (WAC) and a Narrow Angle Camera (NAC). More than 80000 images were acquired with the OSIRIS imaging system with spatial resolution ranging from several meters to a few centimeters per pixel during Rosetta’s descent to the comet in late September 2016.  In particular\, the high dynamics of the cameras detectors permitted to distinguish morphological structures on shadowed areas as well as frost layers\, and to monitor at the same time the very dark surface\, faint jets (with lifetimes shorter than a few minutes)\, and ices exposures.\nAn extensive catalogue of volatiles exposure was recently created permitting to investigate the link between composition\, morphology and activity. It also indicates that ices exposures are typically sub-meter sized\, information which is relevant for cometary models.\nDetailed analysis of highly active regions revealed that the small lobe has different physical and mechanical properties than the big one and a lower volatile content\, at least in its uppermost layers. These findings support the hypothesis that comet 67P originated from the merging of two distinct bodies in the early Solar System\, as previously suggested by the geomorphological analyses of the comet terrains.\nFinally\, the reconstructed Philae orbit revealed that it had a second landing site located only 30 m apart from the final one. Philae stamped within a boulder for 25 cm depth\, indicating that the cometary material is extremely soft and highly porous. This collision exposed the primordial water ice embedded within the boulder\, providing an accurate measurement of the refractory to volatile ratio in comet 67P. URL:https://www.oa-roma.inaf.it/event/colloquium-sonia-fornasier-3/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230328T113000 DTEND;TZID=Europe/Rome:20230328T123000 DTSTAMP:20260405T014646 CREATED:20230210T064046Z LAST-MODIFIED:20230325T095723Z UID:11279-1680003000-1680006600@www.oa-roma.inaf.it SUMMARY:colloquium - Giulia De Somma: The classical Cepheids modelling in the Gaia Era DESCRIPTION:Classical Cepheids are the most used primary distance indicators to calibrate\nthe cosmic distance ladder and reliable stellar population tracers. These stars\nhave been adopted to probe galactic evolution and star formation\, thanks to\ntheir intrinsic variability and the link between pulsation properties and\nevolutionary parameters. A theoretical approach to the study of these objects\nis crucial to interpret observed behaviors and fully exploiting the accuracy of\nobserved oscillation characteristics in terms of stellar properties and distances.\nBy using the Stellingwerf hydrodynamical code\, we recently provided detailed\nhomogeneous nonlinear Classical Cepheid pulsation models. We take into\naccount variations of chemical composition\, mass-luminosity (ML) relation\, and\nefficiency of super-adiabatic convection.\nThe predicted pulsation observables included the instability strips\, multi-filter\nlight curves\, and the corresponding mean magnitudes and colors.\nWe used these quantities to derive metal-dependent period-luminosity-color\n(PLC) and period-Wesenheit (PW) relations. The latter were applied to a\nsample of Gaia Early Data Release 3 (DR3) Galactic Cepheids. The inferred\ntheoretical parallaxes were tested against Gaia astrometric results. By\ncombining this pulsational scenario with updated stellar evolution\npredictions and using the BASTI code\, we derived new and accurate metal-\ndependent Period-Age and Period-Age-Color relations\, which were applied to\nthe same sample of Galactic Cepheids in the Gaia DR3 to constrain their age\ndistribution. These results are all discussed in view of the incoming SPECTRUM\nproject that will represent the first attempt to systematically compute\nnonlinear convective pulsation models along stellar evolutionary tracks. URL:https://www.oa-roma.inaf.it/event/colloquium-giulia-de-somma/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230404T113000 DTEND;TZID=Europe/Rome:20230404T123000 DTSTAMP:20260405T014646 CREATED:20230210T064348Z LAST-MODIFIED:20230322T075149Z UID:11283-1680607800-1680611400@www.oa-roma.inaf.it SUMMARY:Colloquium - Gianluca Castignani: Processing of gas in galaxies within the cosmic web DESCRIPTION:Galaxies are distributed in a complex filamentary network of matter called the cosmic web. Several studies showed that galaxy properties can be influenced by their large scale environments: spiral galaxies may interact and merge into an elliptical galaxy\, they can be stripped from their gas by ram pressure and see their star formation quenched\, they can be harassed in small groups\, even before entering into clusters. However\, it remains debated which is the overall impact of the cosmic web in processing cold gas of galaxies\, as they move through large-scale filaments around the clusters down to the densest regions of the cluster cores. To evaluate the degree of such processing it is essential to study the reservoirs of molecular gas as it is the raw material from which stars form. I will present the results of a large observational campaign\, mainly exploiting IRAM millimeter facilities\, with the goal of quantifying the processing of galaxies’ gas in the cosmic web and with cosmic time. I will discuss the degree of such processing in a variety of dense megaparsec-scale environments for: i) galaxies in the cosmological filaments around Virgo\, the nearest cluster in the Universe\, ii) galaxies in and around clusters at intermediate redshifts\, iii) distant brightest cluster galaxies (BCGs) at the center of clusters. Finally\, I will discuss the potential of such studies for next generation multi-wavelength facilities. Thousands of distant clusters and BCGs will be detected with Euclid\, enabling an unprecedented leverage to constrain galaxy evolution in clusters. URL:https://www.oa-roma.inaf.it/event/colloquium-gianluca-castignani/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230418T113000 DTEND;TZID=Europe/Rome:20230418T123000 DTSTAMP:20260405T014646 CREATED:20230210T064525Z LAST-MODIFIED:20230417T042938Z UID:11285-1681817400-1681821000@www.oa-roma.inaf.it SUMMARY:colloquium - Eilat Glikman: Understanding the role of Quasar feedback and Radio emission in red Quasars DESCRIPTION:Observational evidence suggests that quasar activity plays an important role in regulating how \ngalaxies and their nuclear supermassive black holes grow and co-evolve\, despite their \norders-of-magnitude difference in scale. In this talk\, I will present a population of highly \nluminous dust-reddened quasars that may be the key to understanding this co-evolution. Red \nquasars are among the most intrinsically-luminous quasars in the Universe representing a \nshort-lived phase in the lifetime of a quasar\, during which their energy output (feedback) \nirrevocably impacts their host galaxy. Recent evidence has also shown that red quasars have \nenhanced radio emission\, possibly linking the formation of jets to the merger phenomenon or \nexposing a different form of feedback in these systems\, such as dusty radiation-driven winds. \nRed quasars are thus ideal laboratories for addressing fundamental questions on the co-evolution \nof black holes and their host galaxies as well as the physics of feedback. I will present \nfindings from several surveys that are uncovering this elusive population of quasars using \nvarious selection methods across the electromagnetic spectrum to probe a broad range of redshift \nand luminosity regimes. URL:https://www.oa-roma.inaf.it/event/colloquium-eliat-glikman/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;VALUE=DATE:20230509 DTEND;VALUE=DATE:20230510 DTSTAMP:20260405T014646 CREATED:20230210T064205Z LAST-MODIFIED:20230210T064205Z UID:11281-1683590400-1683676799@www.oa-roma.inaf.it SUMMARY:OAR student's day DESCRIPTION: URL:https://www.oa-roma.inaf.it/event/oar-students-day/ LOCATION:Aula Gratton CATEGORIES:Congressi END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230517T143000 DTEND;TZID=Europe/Rome:20230517T153000 DTSTAMP:20260405T014646 CREATED:20230210T065013Z LAST-MODIFIED:20230210T065013Z UID:11291-1684333800-1684337400@www.oa-roma.inaf.it SUMMARY:JAC Colloquium: Bertrand Lamasle DESCRIPTION: URL:https://www.oa-roma.inaf.it/event/jac-colloquium-bertrand-lamasle/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230523T113000 DTEND;TZID=Europe/Rome:20230523T123000 DTSTAMP:20260405T014646 CREATED:20230325T095954Z LAST-MODIFIED:20230515T153733Z UID:11370-1684841400-1684845000@www.oa-roma.inaf.it SUMMARY:colloquium - Alessandra De Rosa: The quest for dual and binary supermassive black holes DESCRIPTION:Hierarchical models of galaxy formation predict that galaxy mergers represent a key transitional stage of rapid SMBH growth; however\, the lack of a census of AGN pairs over cosmic time prevents us from firmly connecting AGN triggering and merging processes.\nThe quest for pairs of SMBHs at the dawn of the multi-messenger era is compelling. These systems represent the natural precursor to coalescing SMBHs that are among the loudest sources of gravitational waves.  Detecting dual AGN – active SMBHs at projected separations larger than several parsecs – and binary AGN – active SMBHs  bound in a Keplerian binary – is an observational challenge.\nThe talk will review the observational efforts\, across the electromagnetic spectrum\, on the detection and study of dual and binary SMBHs and will reflect on broader implications of these findings when considering the current simulations of merging BH. URL:https://www.oa-roma.inaf.it/event/colloquium-alessandra-de-rosa/ LOCATION:Aula Gratton CATEGORIES:Seminari ORGANIZER;CN="Flavia Dell'Agli":MAILTO:flavia.dellagli@inaf.it END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230530T113000 DTEND;TZID=Europe/Rome:20230530T123000 DTSTAMP:20260405T014646 CREATED:20230210T064708Z LAST-MODIFIED:20230520T105901Z UID:11287-1685446200-1685449800@www.oa-roma.inaf.it SUMMARY:colloquium - Michele Perna: First results from the JWST GTO programme 'Galaxy Assembly with NIRSpec IFS’ (GA-NIFS): The gaseous environment and ISM properties of quasars at z = 3-7 DESCRIPTION:The JWST/NIRSpec GTO programme ‘Galaxy Assembly with NIRSpec IFS’ (GA-NIFS) is an ambitious project aimed at characterising the internal structure of >40 distant galaxies and active galactic nuclei (AGN) and quasars (QSOs) at z=3-9\, and\, therefore\, to investigate the primary physical processes driving galaxy evolution across cosmic time. In this talk I will present an overview of the very first results obtained from a subsample of QSOs\, as well as the analysis and the knowledge on optimising the QSO-host decomposition in NIRSpec IFS data (Perna et al. 2023\, Marshall et al. 2023\, Übler et al. 2023).\nI will discuss the interacting environment of two QSOs at z~6.8 and one at z~5.5\, as well as the ultra-dense environment of a dual AGN at z~3.3. I will also present their interstellar medium properties\, in terms of dynamical conditions\, ionisation\, metallicity\, and outflows energetics. In particular\, I will discuss the limitations of classical emission line diagnostics to distinguish between AGN and star formation ionisation source\, and the relation between black hole masses and host galaxy properties in the context of other recent JWST results on high-z QSOs. URL:https://www.oa-roma.inaf.it/event/colloquium-michele-perna/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230606T113000 DTEND;TZID=Europe/Rome:20230606T123000 DTSTAMP:20260405T014646 CREATED:20230210T064844Z LAST-MODIFIED:20230530T062309Z UID:11289-1686051000-1686054600@www.oa-roma.inaf.it SUMMARY:colloquium - Shuowen Jin: Massive galaxies and clusters in the making: Multi-wavelength study of optically-dark SMGs and galaxy overdensities at z>2.5 DESCRIPTION:Recent studies have revealed an important population of submillimeter galaxies (SMGs) that dropped out in deep optical surveys\, however their nature is still largely unknown. On the other hand\, high-z protoclusters are often suspected to be forming the local massive clusters\, while the evolutionary path is still elusive. Thus discovering more SMGs and galaxy overdensities towards high redshift are key to pushing our understanding of the formation of massive galaxies and structures. Here I report recent discoveries and study on the two topics from our team\, including (1) spectroscopic confirmation of a sample of optically-dark SMGs at z~4–6 using ALMA\, NOEMA and JWST; (2) detailed insight into a z=2.58 HST-dark SMG by synergy of JWST and ALMA data; (3) discovery of protoclusters and compact galaxy groups at z~3–5 using NOEMA\, ALMA and JWST. We found that most of the optically-dark SMGs have optically thick dust in FIR\, and they consist of s significant fraction of star-forming galaxies at z~4. By comparison with simulations\, we revealed that low-mass and compact galaxy groups most likely merge into single massive galaxies at lower-z\, i.e.\, “proto-massive galaxy”\, while only the most massive protoclusters are likely to evolve to local clusters. URL:https://www.oa-roma.inaf.it/event/colloquium-showen-jin/ LOCATION:RM CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230615T113000 DTEND;TZID=Europe/Rome:20230615T123000 DTSTAMP:20260405T014646 CREATED:20230523T071652Z LAST-MODIFIED:20230529T084702Z UID:11567-1686828600-1686832200@www.oa-roma.inaf.it SUMMARY:colloquium - Stephane Courteau: Puzzles in Galaxy Structure DESCRIPTION:Galaxies like our Milky Way can be described in terms of their structure\,\ndynamics\, and stellar populations. Some robust correlations between\ngalaxy structural properties such as stellar mass\, circular velocity\, and \nsize display surprisingly small scatter over many orders of magnitude\, \nhinting at well-regulated galaxy formation processes. A major challenge \nto understanding these scaling relations\, their tight scatter\, and ultimately \ngalaxy formation and evolution\, is the elusive interplay between visible \nand dark matter.  Among others\, the radial acceleration relation\, concept \nof “galaxy diversity”\, intrinsic scatter in galaxy scaling relations\, impact\nof supermassive black hole on galaxies\, and comparisons with numerical \nsimulations of galaxy formation are presented in this context. URL:https://www.oa-roma.inaf.it/event/colloquium-stephane-courteau/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230620T113000 DTEND;TZID=Europe/Rome:20230620T123000 DTSTAMP:20260405T014646 CREATED:20230325T100149Z LAST-MODIFIED:20230607T112933Z UID:11372-1687260600-1687264200@www.oa-roma.inaf.it SUMMARY:colloquium - Gabriele Cescutti: First results of the MINCE survey DESCRIPTION:The struggle to find the most metal port stars in our Galaxy has produced an important bias in the observations and the intermediate metal-poor stars (-2.5<[Fe/H]< -1.5)\nhave been frequently overlooked. The missing information has consequences for the precise study of the chemical enrichment of our Galaxy\, in particular for\nwhat concerns neutron capture elements. Measuring at intermediate metallicity neutron capture elements (MINCE) aims to cover this gap\, gathering\nhigh quality spectra (high signal to noise and high resolution) of several hundred bright and metal poor stars\, manly from of our Galactic halo.\nIn this talk\, I show the results of the first sample of 42 stellar spectra for 40 different stars with the abundances of the elements up to europium. I also present\n the results for the hyperfine splitting effects in two metal-poor halo stars: the profiles of the barium lines in HD 4306 agree with an s-process composition whereas\nthose in HD 6268 have a different profile\, most likely linked to the presence of an r-process isotopic pattern. Therefore\, the lines of barium of HD 6268 and HD 4306\nseem to confirm the expectation that both r-process events and s-process contribution by rotating massive stars have polluted the ancient halo of our Galaxy. URL:https://www.oa-roma.inaf.it/event/colloquium-gabriele-cescutti-2/ LOCATION:Aula Gratton CATEGORIES:Seminari ORGANIZER;CN="Flavia Dell'Agli":MAILTO:flavia.dellagli@inaf.it END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230627T113000 DTEND;TZID=Europe/Rome:20230627T123000 DTSTAMP:20260405T014646 CREATED:20230405T135705Z LAST-MODIFIED:20230615T073616Z UID:11379-1687865400-1687869000@www.oa-roma.inaf.it SUMMARY:Colloquium - Kenneth Wong: An Independent Measurement of H0 from Lensed Quasars DESCRIPTION:Strong gravitational lens systems with time delays between the multiple images are a powerful probe of cosmology\, particularly of the Hubble constant (H0).  This independent method is an important test of the recent tension between early-Universe and late-Universe measurements of H0.  The TDCOSMO project has measured H0 from lensed quasars using deep Hubble Space Telescope and AO imaging\, precise time delay measurements from dedicated monitoring observations\, a measurement of the velocity dispersion of the lens galaxies\, and a characterization of the mass distribution along the line of sight.  Assuming well-motivated physical profiles for the lens galaxies\, our latest results constrain H0 to be ~74 km/s/Mpc for a flat Lambda CDM cosmology\, with a precision of ~2%.  These results are consistent with independent determinations of H0 using type Ia supernovae calibrated by the distance ladder method\, and are in >4-sigma tension with the results of Planck CMB measurements\, hinting at possible new physics beyond the standard LCDM model and highlighting the importance of this independent probe.  Relaxing our assumptions on the form of the lens galaxy mass profiles and only allowing kinematic constraints\, we can constrain H0 to ~8% precision.  Including information from external data sets can improve the precision to ~5%.  Future observations to increase the sample size and control systematic uncertainties will be key to resolving the current tension in H0. URL:https://www.oa-roma.inaf.it/event/colloquium-kenneth-wong/ LOCATION:Aula Gratton CATEGORIES:Seminari ORGANIZER;CN="Flavia Dell'Agli":MAILTO:flavia.dellagli@inaf.it END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230704T113000 DTEND;TZID=Europe/Rome:20230704T123000 DTSTAMP:20260405T014646 CREATED:20230417T134921Z LAST-MODIFIED:20230523T071854Z UID:11405-1688470200-1688473800@www.oa-roma.inaf.it SUMMARY:colloquium - Steven Finkelstein: Unveiling the Earliest Galaxies and Super-massive Black Holes with JWST DESCRIPTION:Pushing the Hubble Space Telescope to its limits at the end of the last decade has allowed astronomers to view the tip of the cosmic iceberg at a time only 500 Myr after the Big Bang.  While a few candidate galaxies were found\, significant questions about the onset and evolution of the earliest galaxies persisted.  The launch of JWST has opened up this epoch to direct and detailed observation by providing a significant leap in our ability to study the entire epoch of reionization due to its redder sensitivity and spectroscopic capabilities.  The Cosmic Evolution Early Release Science (CEERS) and Next Generation Deep Extragalactic Exploratory Probe (NGDEEP) programs have enabled one of our first looks into this epoch\, finding that galaxies at z > 9 are more abundant than predicted by most simulations.  This hints at not only an early onset of galaxy formation\, but that stars are forming differently at these early times (at higher efficiency and/or with different initial mass functions).  The CEERS spectroscopic program has shown that photometric redshifts *work*\, with a high fraction of spectroscopic confirmations\, and only one (interesting\, yet rare) case of contamination.  These data have also significantly improve our ability to identify early growing supermassive black holes\, showing that they appear (relatively) frequently at high-redshift\, including a remarkable AGN at z=8.7.  These observations pushing models of early black hole growth\, implying that massive seeds and/or super-Eddington accretion are needed at early times. URL:https://www.oa-roma.inaf.it/event/colloquium-steven-finkelstein/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230920T143000 DTEND;TZID=Europe/Rome:20230920T153000 DTSTAMP:20260405T014646 CREATED:20230419T114639Z LAST-MODIFIED:20230911T123635Z UID:11411-1695220200-1695223800@www.oa-roma.inaf.it SUMMARY:Quasars and the intergalactic medium at cosmic dawn DESCRIPTION:High-redshift quasars provide direct probes to the formation of the earliest supermassive black holes\, their connections to early galaxy formation\, and the history of cosmic reionization. More than 200 quasars have now been discovered in the first billion years of the cosmic history\, with the highest redshift currently at z=7.6\, indicating that billion solar mass black holes have already fully formed merely half billion years after the first star formation in the universe. I will (1) review the current state of high-redshift quasar surveys and discoveries\, as a result of the new generations of wide-field sky surveys and developments in data mining and machine learning; (2) discuss using high-redshift quasars as probes to the history of supermassive black hole growth in the early universe\, using measurements of quasar luminosity function and black hole masses; (3) present the latest observations of the the co-evolution of early SMBH growth and galaxy formation\, and the roles quasar played in early galaxy formation and structure formation; and (4) review the progress of using IGM absorption in quasar sightlines and properties of quasar proximity zones\, which is unveiling a rapid and highly inhomogeneous reionization process at z~5.5 – 7.5. In particular\, I will highlight new results from early JWST observations on early supermassive black hole growth\, the environment of early quasars and the IGM and galaxy connection. URL:https://www.oa-roma.inaf.it/event/jac-colloquium-xiaohui-fan/ LOCATION:Aula Gratton CATEGORIES:Seminari ORGANIZER;CN="Flavia Dell'Agli":MAILTO:flavia.dellagli@inaf.it END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20230926T113000 DTEND;TZID=Europe/Rome:20230926T123000 DTSTAMP:20260405T014646 CREATED:20230627T145117Z LAST-MODIFIED:20230921T052613Z UID:11853-1695727800-1695731400@www.oa-roma.inaf.it SUMMARY:Colloquium - Riccardo La Placa: FRBs from neutron star magnetospheres: a unified model DESCRIPTION:Fast Radio Bursts (FRBs) have\, since their first detection\, ranked among the most puzzling events in the sky owing to the extreme energies involved and the presence of both repeating and non-repeating sources: 15 years and thousands of bursts later\, their emission mechanism still eludes us. I will present a new unified model for FRBs as magnetospheric events from neutron stars which naturally accounts for both types of behaviours\, and show some predictions (and first applications) of the model on the expected energy and redshift distributions\, both for the population at large and individual\, well-studied sources. \n  URL:https://www.oa-roma.inaf.it/event/colloquium-riccardo-la-placa/ LOCATION:Aula Gratton END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20231010T113000 DTEND;TZID=Europe/Rome:20231010T123000 DTSTAMP:20260405T014646 CREATED:20230911T123832Z LAST-MODIFIED:20230920T101623Z UID:12154-1696937400-1696941000@www.oa-roma.inaf.it SUMMARY:Alessia Tortosa: Deep broad-band X-ray investigation of extreme accretion onto supermassive black holes DESCRIPTION:Super-Eddington accretion periods are expected to be extremely important to explain the fast growth of the first supermassive black holes (SMBHs). While standard optically thick\, geometrically thin accretion discs explain the observed spectral energy distribution (SED) of many AGN with low Eddington ratios\, at higher accretion rates the disc becomes thin or slim and the nature of the accretion changes dramatically. Slim accretion disks are thought to have SEDs that are different from thick accretion disks\, with strong anisotropy of the emitted radiation and a large fraction of the output carried out in the form of outflows and jets capable of controlling the growth and evolution of the host galaxy\, and affecting the gas reservoir available for both star formation and SMBH accretion.\nAmong all accretion modes\, accretion close or above the Eddington limit is still the least understood ones\, and it is still largely debated what are the physical properties of the X-ray emitting plasma and of the accretion flow coming from the direct relativistic environment of the SMBH.\nI will present the first systematic broad-band X-ray study of extreme accretion onto SMBHs of a sample of Hyper and Super Eddington accreting AGN with 1 < λEdd < 426. These sources belong to the Super-Eddington Accreting Massive Black Holes sample\, which contains exclusively objects with black hole masses estimated via reverberation mapping. This analysis allowed us to investigate the properties of the X-ray corona and the behaviour of the reprocessed radiation in this regime of extreme accretion\, as well as the structure of the iron complex and the properties of outflows. URL:https://www.oa-roma.inaf.it/event/colloquium-alessia-tortosa/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20231017T113000 DTEND;TZID=Europe/Rome:20231017T123000 DTSTAMP:20260405T014646 CREATED:20230911T124006Z LAST-MODIFIED:20230920T134649Z UID:12156-1697542200-1697545800@www.oa-roma.inaf.it SUMMARY:colloquium Chris Sneden: Lithium-rich Red Giants: the helium and rotation connections DESCRIPTION: URL:https://www.oa-roma.inaf.it/event/lithium-rich-red-giants-the-helium-and-rotation-connections/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20231024T113000 DTEND;TZID=Europe/Rome:20231024T123000 DTSTAMP:20260405T014646 CREATED:20230725T141858Z LAST-MODIFIED:20231011T053804Z UID:12050-1698147000-1698150600@www.oa-roma.inaf.it SUMMARY:Tiziana Macaluso\, Francesco Poppi: Le prime osservazioni astronomiche in fotografia e le immagini conservate nell'archivio INAF-OAR. Studio a supporto del recupero conservativo. DESCRIPTION:Le prime immagini astronomiche\, conservate presso l’archivio INAF-OAR\, sono tre dagherrotipi\nottenuti da Angelo Secchi nel 1851 presso l’Osservatorio del Collegio Romano\, in occasione\ndell’eclissi totale di Sole.\nNel 1857 fotografò anche le fasi lunari\, acquisite con il telescopio equatoriale Merz. Queste\nimmagini rappresentano il primo atlante fotografico della Luna presentato il 28 agosto 1858\nall’Académie des Sciences di Parigi\, e poi all’Osservatorio londinese di Greenwich.\nSuccessivamente\, nel 1860 Angelo Secchi osservò e stampò su carta salata l’eclissi solare\,\npartecipando alla spedizione internazionale a Las Palmas de Gran Canaria. L’osservazione\ndell’eclissi evidenziò le protuberanze solari e fu la prima prova della loro esistenza. Si dimostrò\nanche che la corona appartiene al Sole e non alla Luna.\nQueste pregevoli fotografie costituiscono anche le prime tecniche fotografiche delle origini\,\nnonché le prime osservazioni astronomiche per mezzo della fotografia.\nLo studio storico e le analisi diagnostiche di questi beni\, utile a caratterizzare la natura dei\ncomponenti e lo stato di degrado\, arricchiranno le conoscenze sia in campo storico che scientifico\,\ne supporteranno il futuro restauro conservativo\, che avverrà in collaborazione con corsi\nuniversitari sul restauro e la conservazione di beni culturali. URL:https://www.oa-roma.inaf.it/event/colloquium-tiziana-macaluso-francesco-poppi/ LOCATION:Aula Gratton CATEGORIES:Seminari ORGANIZER;CN="Flavia Dell'Agli":MAILTO:flavia.dellagli@inaf.it END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20231107T113000 DTEND;TZID=Europe/Rome:20231107T123000 DTSTAMP:20260405T014646 CREATED:20230725T142148Z LAST-MODIFIED:20231027T055053Z UID:12052-1699356600-1699360200@www.oa-roma.inaf.it SUMMARY:colloquium Gregory Sloan: Carbon stars and dust in the Universe DESCRIPTION:Intermediate-mass stars become carbon-rich in the final phases of their\nlives as stars.  As they die\, carbon stars produce significant\nquantities of carbon-rich dust\, and they dominate the dust production in nearby\nmetal-poor galaxies like the Magellanic Clouds.  Infrared spectroscopy\nof carbon stars in these galaxies and our own reveals that (1) the\ninitial metallicity of a carbon star has little influence on how much\ndust it will produce\, and (2) the transition to strong pulsations in the\natmospheres of these stars leads to high rates of mass loss and dust\nproduction\, which will end the life of the star and eject most of its\nmass back into its host galaxy.  Stellar modeling shows that at lower\nmetallicity\, stars evolve more quickly\, and higher-mass stars can\nbecome carbon stars.  Carbon-rich dust has now been detected in\ngalaxies with redshifts up to 7\, or only 800 million years after the\nBig Bang.  While carbon stars can evolve in this time\, higher-mass\nobjects such as core-collapse supernovae or Wolf-Rayet stars are often\ninvoked as the likely source of that dust.  Nonetheless\, the available\nevidence points to carbon stars as the most likely culprit. URL:https://www.oa-roma.inaf.it/event/colloquium-greg-sloan/ LOCATION:Aula Gratton CATEGORIES:Seminari ORGANIZER;CN="Flavia Dell'Agli":MAILTO:flavia.dellagli@inaf.it END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20231113T113000 DTEND;TZID=Europe/Rome:20231113T123000 DTSTAMP:20260405T014646 CREATED:20231027T042658Z LAST-MODIFIED:20231027T042715Z UID:12389-1699875000-1699878600@www.oa-roma.inaf.it SUMMARY:colloquium - Richard de Grijs: Unveiling the complexities of massive star clusters DESCRIPTION:Around the turn of the last century\, star clusters of all kinds were considered ‘simple’ stellar populations. Over the past decades\, this situation has changed dramatically. At the same time\, star clusters are among the brightest stellar population components and\, as such\, they are visible out to much greater distances than individual stars\, even the brightest\, so that understanding the intricacies of star cluster composition and their evolution is imperative for understanding stellar populations and the evolution of galaxies as a whole. In this brief review of where the field has moved to in recent years\, we place particular emphasis on the properties and importance of the effects of rapid stellar rotation\, and the presence of multiplicity among the red-giant-branch populations in Magellanic Cloud star clusters with ages up to a few billion years. URL:https://www.oa-roma.inaf.it/event/colloqium-richard-de-grijs-unveiling-the-complexities-of-massive-star-clusters/ LOCATION:Aula Gratton CATEGORIES:Seminari END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20231114T113000 DTEND;TZID=Europe/Rome:20231114T123000 DTSTAMP:20260405T014646 CREATED:20230619T141534Z LAST-MODIFIED:20231018T153147Z UID:11813-1699961400-1699965000@www.oa-roma.inaf.it SUMMARY:colloquium - Davide Massari: Globular clusters as tracers of the Milky Way assembly history DESCRIPTION:The combination of stellar proper motions measured by the Gaia mission with spectroscopic radial velocities has recently enabled the precise determination of the orbits of Milky Way stars and globular clusters. The information on their dynamics\, coupled with existing chemical information\, has allowed us to unravel many unknowns on their origin and evolution\, as well as on the assembly history of the Milky Way itself. In this talk I will present the most recent results on this topic\, focusing on how globular clusters can be superior tracers of the Milky Way build-up\, and introducing a project\, named CARMA\, that aims at using globular cluster ages to characterise the most important merger events experienced by our Galaxy URL:https://www.oa-roma.inaf.it/event/colloquium-davide-massari/ LOCATION:Aula Gratton CATEGORIES:Seminari ORGANIZER;CN="Flavia Dell'Agli":MAILTO:flavia.dellagli@inaf.it END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Rome:20231121T113000 DTEND;TZID=Europe/Rome:20231121T123000 DTSTAMP:20260405T014646 CREATED:20231109T090747Z LAST-MODIFIED:20231109T091233Z UID:12500-1700566200-1700569800@www.oa-roma.inaf.it SUMMARY:colloquium - Mario Llerena: Probing the extreme ISM of extreme emission line galaxies at z~4-9 DESCRIPTION:Over the past decades\, several studies have discovered a population of galaxies that undergo very strong star formation events. They are called extreme emission line galaxies (EELGs) and are characterized by typically high EWs which are driven by elevated specific star formation rates in low mass galaxies with subsolar metallicities and little dust. Such extreme systems are rare in the local universe\, but the number density of EELGs increases with increasing redshift. Such starburst galaxies are currently presumed strongly to be the main drivers of Hydrogen reionization over 5.5 < z < 15\, which serves to motivate many of the searches for high-z EELGs as well. I will present the physical properties of a sample of ~1000 EELGs at 4