Title: High Resolution X-ray Spectroscopy as a powerful tool of diagnostics of the hot and energetic Universe: Missing Baryons and Time-Resolved Photo-Ionization

Speaker: Fabrizio Nicastro

Institute:  Istituto Nazionale di Astrofisica 意大利国家天体物理研究所

Host: 方陶陶

Time: 11.2 周四 16:00-17:30

Location: 物理楼552

Abstract:

High resolution X-ray spectroscopy has first become available in the late 90s, with the advent of the two X-ray grating spectrometers onboard the two NASA and ESA satellites Chandra and XMM-Newton, and is now receiving a new strong momentum with the launch of the JAXA-NASA satellite XRISM and that of several other medium-size or large X-ray spectroscopic mission that will be launched over the next two decades.

Among the many fields of research that X-ray spectroscopy opened, two of the most important are those of the Universe and galaxy’s missing baryons and of AGN outflows and their energy impact on their host galaxy and surrounding CGM (feedback). The thorough investigation of both fields also need adequate modelling, and AGN outflows can only be fully assessed through time-resolved X-ray spectroscopy.

In this informal seminar I will present a quick overview of my research in these two fields over the past two decades and show the most recent results that my collaborators and I have reached in these fields.

Bio：

Dr. Fabrizio NIcastro is a researcher at the Italian National Institute of Astrophysics, at the Astronomical Observatory of Roma (INAF- OAR), in Italy, where is currently leading the group of extragalactic high-energy astrophysics, supervising a number of students and post-docs. Dr. Nicastro scientific interests span a wide range of both observational and theoretical astrophysical (and not only) fields, from the physics of accretion in AGNs to AGN-outflows and feedback with the host galaxy, to the Universe and galaxy’s Missing Barons, to the mathematical modeling of time-evolving phenomena (an astronomical-based variant of which, he also applied to epidemiology, during the Covid-19 pandemics). He is also currently involved, within leading roles, in a number of national and international projects and space-programs, from the Athena Ground-Segment Innovation Center, to the Athena-XIFU Science Advisory Committee, to a national program for high-resolution X-ray spectroscopy and a laboratory-astrophysics program at a national synchrotron facility, to a program for the development of a public Time-Evolving Photo-Ionization Device (TEPID) for the analysis of UV and X-ray spectra.

In 1996, Dr. Nicastro entered a PhD program in astrophysics at the first University of Rome “La Sapienza” and shortly after moved to the Harvard-Smithsonian Center for Astrophysics where he earned his PhD degree in astrophysics in 2000, on a thesis focused on the theoretical development of time-evolving photo-ionization models. From 2000 to 2003 he worked in the Chandra X-Ray Center and his scientific interests broadened from high-resolution X-ray spectroscopy of ionized gas in astrophysics and the search for the Universe missing baryons to the physics of black-hole acretion and related models for the existence of Broad Emission Line Regions in AGN. He left the Harvard-Smithsonian Center for Astrophysics in 2007, to move back to Italy at the Italian National Institute of Astrophysics. In years 2004-2005 Dr. Nicastro also worked as an associate-Professor at the Institute of Astronomy of the Autonomous University of Mexico (UNAM), in Mexico City, and in years 2008-2011 spent three sabbatical years at the University of Crete, in Greece. In recent years Dr. Nicastro developed fruitful scientific collaborations with Chinese colleagues at the University of Xiamen and the Purple Mountain Observatory of Nanjing, and is currently involved in one of the working groups of the Chinese HUBS spectroscopic space mission.