<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=""><br class=""><div 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 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 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 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 style="margin: 0px; font-stretch: normal; line-height: normal;" class="">Dear Colleagues,</div><div style="margin: 0px; font-stretch: normal; line-height: normal; min-height: 15px;" class=""><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">I apologize if you will receive this announcement multiple times.</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="-webkit-font-kerning: none;" class="">We are pleased to announce that the second colloquium of the program QUID ULTRA? Frontiers and Controversies in Astrophysics,</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">will be on <b class="">February 23 2021</b> <b class="">at 16:30 by </b></span><span style="-webkit-font-kerning: none;" class=""><b class="">Razmik Mirzoyan (Max-Planck-Institute for Physics, Munich)</b>. Title and abstract</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">are attached below. </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">The </span><span style="-webkit-font-kerning: none;" class="">program QUID ULTRA? Frontiers and Controversies in Astrophysics, a series of monthly prestigious colloquia that will be </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">running from early February till December 2021. This initiative has been funded by Sapienza University with the co-sponsorship </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">of INAF/Astronomical Observatory of Rome and of the joint PhD program in Astronomy, Astrophysics and Space Science of Sapienza, </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">Tor Vergata University and INAF.</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">Due to the pandemic situation, the first 6 colloquia will be held online via zoom. </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">The scientific program and all the information on how to attend the meeting can be found on the project website: <a href="http://www.quidultra.it" class="">www.quidultra.it</a>. </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">Looking forward to seeing you soon, </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">Raffaella Schneider (on behalf of the SOC)</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">————————————————</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">February 23 2021 at 16:30</b></span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">Razmik Mirzoyan (Max-Planck-Institute for Physics, Munich)</b></span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">Title: Gamma-Ray Astronomy: The Cross-Road Between Physics and Astrophysics</b></span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class=""><b class="">Abstract:</b></span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">Thirty-two years ago a report about the measurement of unusual, so-called teraelectronvolt signal from the Crab Nebula captured the attention of the world scientific community. </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">The authors reported a flux of so-called gamma-ray photons, where each carried an incredible amount of energy, exceeding that of the well-known X-rays by billion times. </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">How and in which processes the nature managed to pack such a huge energy content into single photons remained a mystery for the coming years. </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">Researchers used for observations a special technique and instrumentation dubbed as imaging atmospheric Cherenkov telescopes. In the following couple of years not much </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">has happened and the community started speculating about the new science of a single source. More researchers joined that effort and already ten years after the initial </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">discovery ~10 sources of teraelectronvolt gamma-rays were known. Today this discipline boasts to know more than 200 sources of very different origin, from supernova </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">remnants to pulsars, from supermassive active galactic nuclei with black holes in their centre to gamma-ray busts, from binary systems to pulsar wind nebulae. </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">A new discipline, the so-called astro-particle physics with diverse instrumentation appeared in the cross-roads between physics and astrophysics. In this lecture we </span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">will have a closer look to the details of this rapidly evolving, fascinating frontier science.</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class=""><span style="-webkit-font-kerning: none;" class="">Join Zoom Meeting</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; color: rgb(9, 79, 209); -webkit-text-stroke-color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class=""><span style="-webkit-font-kerning: none;" class=""><a href="https://uniroma1.zoom.us/j/89931306878?pwd=WG5RYlYyZzRSMzJsOFpSRHczWEFCZz09" class="">https://uniroma1.zoom.us/j/89931306878?pwd=WG5RYlYyZzRSMzJsOFpSRHczWEFCZz09</a></span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class=""><span style="-webkit-font-kerning: none;" class="">Meeting ID: 899 3130 6878</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none; background-color: rgb(255, 255, 255);" class="">Passcode: 419276</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0);" class=""><span style="-webkit-font-kerning: none;" class="">————————————————</span></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div style="-webkit-text-stroke-width: initial; margin: 0px; font-stretch: normal; line-height: normal; -webkit-text-stroke-color: rgb(0, 0, 0); min-height: 15px;" class=""><span style="-webkit-font-kerning: none;" class=""></span><br class=""></div><div class=""><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""></div><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><br class=""><br class=""><br class=""><br class=""><br class=""></div></div></div></div></div></div><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=""><br class=""><br class=""><br class=""><br class=""><br class=""><br class=""><br class=""><br class=""></div></div></div></div>
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