<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Please accept my apologies if you receive this more than once.<div class=""><br class=""><div class="">
<meta charset="UTF-8" class=""><div dir="auto" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><br class=""></div></div></div><div class=""><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Dear Students and Colleagues,</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">this is to gently remind you that the next online colloquium of the series: </span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Quid Ultra? Frontiers and Controversies in Astrophysics </span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">will be tomorrow, <b class="">March 2 at 16:30 by </b></span><span style="-webkit-font-kerning: none;" class=""><b class="">Felix Aharonian (Dublin Institute for Advanced Studies and Max-Planck-Institute for Nuclear Physics Heidelberg) </b></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">in aula Conversi, Dipartimento di Fisica, Sapienza Università di Roma</b></span><span style="-webkit-font-kerning: none;" class=""><b class="">.</b> Title and abstract are attached below. </span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">It will be possible to follow the seminar remotely via the zoom link:</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; color: rgb(107, 0, 109);" class=""><span style="text-decoration: underline; -webkit-font-kerning: none;" class=""><a href="https://uniroma1.zoom.us/j/81122901013?pwd=M1hnRHRXZkEyeW1QMFlPQ2FXa0dNZz09" class="">https://uniroma1.zoom.us/j/81122901013?pwd=M1hnRHRXZkEyeW1QMFlPQ2FXa0dNZz09</a></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""> </span><br class="webkit-block-placeholder"></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">ID riunione: 811 2290 1013</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Passcode: 686688</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">For people coming from outside the Campus, please make sure </span><span style="-webkit-font-kerning: none;" class="">to fill the google form for guests and visitors that you will need to show at the main campus gate:</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; color: rgb(9, 79, 209);" class=""><span style="text-decoration: underline; -webkit-font-kerning: none;" class=""><a href="https://www.uniroma1.it/en/notizia/covid-19-phase-2-procedures-students-staff-and-guests" class="">https://www.uniroma1.it/en/notizia/covid-19-phase-2-procedures-students-staff-and-guests<span style="-webkit-font-kerning: none; color: rgb(9, 79, 209);" class=""></span></a></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">and to be ready to show your green pass.</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">You can find all the details below and the link: <a href="https://www.quidultra.it/" class=""><span style="-webkit-font-kerning: none; color: rgb(9, 79, 209);" class="">https://www.quidultra.it</span></a></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Looking forward to seeing you soon, </span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Raffaella Schneider (on behalf of the SOC)</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""> </span><br class="webkit-block-placeholder"></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Prof. Raffaella Schneider</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Dipartimento di Fisica "G. Marconi”</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Senior Fellow, Scuola Superiore di Studi Avanzati Sapienza</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Sapienza, Università di Roma</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">P.le A. Moro 2, 00185 Roma, Italy</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; color: rgb(9, 79, 209);" class=""><span style="text-decoration: underline; -webkit-font-kerning: none;" class=""><a href="mailto:raffaella.schneider@roma1.infn.it" class="">raffaella.schneider@roma1.infn.it<span style="-webkit-font-kerning: none; color: rgb(9, 79, 209);" class=""></span></a></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">2nd QUID ULTRA colloquium 2022</b></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">March 2 2022 at 16:30, aula Conversi, Dipartimento di Fisica, Sapienza Università di Roma</b></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">Speaker: </b></span><span style="-webkit-font-kerning: none;" class=""><b class="">Felix Aharonian (Dublin Institute for Advanced Studies and Max-Planck-Institute for Nuclear Physics Heidelberg)</b></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""><b class=""></b></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">Title:</b> </span><span style="-webkit-font-kerning: none;" class=""><b class="">PeVatrons and the "Century-old-Mistery" of Galactic Cosmic Rays</b></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">Abstract:</b></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Despite the recent advances in Cosmic Ray studies, the origin of Galactic Cosmic Rays (CRs) is still considered a "century-old mystery" - we do not know yet which sources contribute to CR fluxes measured in the Earth's vicinity. Identifying the major CR contributors with astronomical source populations is one of the highest priorities of the field. The best carriers of information about CR factories are gamma-rays and neutrinos - the only stable and neutral secondary products of CR interactions pointing to the CR production sites. The recent years' outstanding achievement of gamma-ray astronomy was the discovery of TeV gamma-radiation from SNRs generally supporting the SNR paradigm of the origin of Galactic CRs. On the other hand, the lack of the extension of gamma-ray spectra of young SNRs well beyond 10 TeV raises doubts about their ability to contribute to the highest energy galactic CR spectrum in the so-called "knee" region above 1 PeV. Meanwhile, the ultra-high-energy (UHE; E> 100 TeV) gamma-ray observations of the clusters of young massive stars demonstrate mounting evidence of these objects (and related superbubbles) being prime contributors to Galactic CRs at PeV energies. I will discuss these observations in the context of the concept of "Young Stars versus Dead Stars". The hunt for CR PeVatrons cannot be reduced merely to the identification of the sources contributing to the local "CR fog". The term 'cosmic rays' has broader implications; after matter, radiation and magnetic fields, the relativistic nonthermal plasma constitutes the fourth substance of the observable Universe. The localisation and exploration of physical conditions and processes in these extreme CR factories, independent of their relative contributions to the 'CR fog', is a fundamental issue in its own right. I will highlight the recent exciting achievements of UHE gamma-ray astronomy in elucidating the cites of extreme CR accelerators in the Milky Way and discuss the implications of the discovery of a large number of CR PeVatrons by the LHAASO collaboration.</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none; background-color: rgb(255, 255, 255);" class="">Join Zoom Meeting</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; color: rgb(107, 0, 109);" class=""><span style="text-decoration: underline; -webkit-font-kerning: none;" class=""><a href="https://uniroma1.zoom.us/j/81122901013?pwd=M1hnRHRXZkEyeW1QMFlPQ2FXa0dNZz09" class="">https://uniroma1.zoom.us/j/81122901013?pwd=M1hnRHRXZkEyeW1QMFlPQ2FXa0dNZz09</a></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 16px;" class=""><span style="-webkit-font-kerning: none;" class=""> </span><br class="webkit-block-placeholder"></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">ID riunione: 811 2290 1013</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">Passcode: 686688</span></div></div></div><div class=""><span style="-webkit-font-kerning: none;" class=""><br class=""></span></div></div></div></body></html>