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2022  -   2023

NGC 2992 (right) and NGC 2993 (left). Credit Line and Copyright Adam Block/ Mount Lemmon SkyCenter/University of Arizona.

Fig. 1: H.E. Amb. Federico Failla (Ambasciatore dell'Italia in Corea) durante la cerimonia ufficiale di aperture del meeting IK17, 2 Agosto 2021.

Fig. 2: Prof. Remo Ruffini, Prof. Rahim Moradi and Prof. Soroush Shakeri durante il loro intervento al meeting IK17.

Fig. 3: il Prof. Remo Ruffini durante il suo intervento al 23esimo meeting RAGtime ad Opava, 7 Settembre 2021.

Fig. 4: Prof. Jorge Rueda durante il suo intervento al 23esimo meeting RAGtime ad Opava, 7 Settembre 2021.

È con nostro grande piacere che annunciamo l'"ICRANet - Isfahan Astronomy Meeting. From the Ancient Persian Astronomy to Recent Developments in Theoretical and Experimental Physics, Astrophysics and General Relativity". Isfahan, in quanto sito storico nel cuore dell'Iran e una delle città più belle del mondo, ospiterà il primo di questa serie di meeting, che si terrà dal 3 al 5 Novembre 2021 presso l'Isfahan University of Technology (IUT - Iran) e online.
Questo meeting, co-organizzato dall'ICRANet e IUT, rappresenterà una grande occasione di discussione su svariati temi, dall'antica astronomia persiana ai recenti sviluppi astronomici, tra cui i fenomeni ad alta energia come i Gamma-Ray Bursts (GRBs) e Nuclei Galattici Attivi (AGNs), Teoria della Gravità, Relatività Generale e le sue basi matematiche, i Buchi Neri, la Materia Oscura e la Cosmologia del Primo Universo. Durante il meeting, si terrà anche un workshop sulla Scienza dei Dati applicata all'astrofisica.
I membri del comitato scientifico del meeting sono il Presidente, Prof. Remo Ruffini (ICRANet/ICRA), e co-Presidente, Prof. Yousef Sobouti (ISABS, Iran), Prof. Hassan Firouzjahi (IPM, Iran), Prof. Shahram Khosravi (KHU, Iran), Prof. Habib Khosroshahi (IPM), Prof. Kourosh Nozari (UMZ, Iran), Prof. Sohrab Rahvar (SUT, Iran), Prof. Soroush Shakeri (IUT), Prof. Shadi Tahvildar-Zadeh (Rutgers, USA) and Prof. She-Sheng Xue (ICRANet). I membri del comitato organizzativo sono il Presidente, Prof. Soroush Shakeri (IUT), Prof. Amin Farhang (IPM and IUT), Prof. Fazlollah Hajkarim (UNIPD, Italy), Prof. Rahim Moradi (ICRANet), Prof. Sedigheh Sajadian (IUT), Prof. Shahab Shahidi (DU, Iran), Prof. Wang Yu (ICRANet) and Prof. M. H. Zhollideh Haghighi (IPM,KNTU, Iran).
Il programma scientifico è in fase di preparazione, maggiori dettagli sull'evento saranno forniti sul sito web: https://indico.icranet.org/event/2/. Vi invitiamo a registrarvi al meeting attraverso il seguente link: https://indico.icranet.org/event/2/registrations/4/.
Per maggiori informazioni sulla collaborazione ICRANet-Isfahan, vi invitiamo a visitare i seguenti siti web: http://www.icranet.org/index.php?option=com_content&task=view&id=1059 - https://indico.icranet.org/event/2/page/9-icranet-isfahan.

6. Prossimi eventi: Damour Fest meeting, IHES Parigi, 12-15 Ottobre 2021

Annunciamo con grande piacere l'evento "Damour Fest: Adventures in Gravitation", che si svolgerà dal 12 al 15 Ottobre 2021 presso l' Institut des Hautes Études Scientifiques (IHES, France) ed online. L'evento, dunque, si terrà in modalità mista, con alcuni interventi presentati in sede presso l'IHES ed altri da remoto via Zoom.
Questa conferenza, organizzata da Nathalie Deruelle (APC, Université de Paris), Alessandro Nagar (INFN Torino), e Slava Rychkov (IHES), è un omaggio per il 70esimo compleanno del Prof. Thibault Damour, professore presso l'IHES dal 1989. Il Prof. Prof. Thibault Damour è un fisico teorico specializzato nella relatività generale e teoria delle stringhe. È conosciuto in tutto il mondo per il suo lavoro innovativo sui buchi neri, onde gravitazionali, e cosmologia quantistica. Durante tutta la sua carriera, ha ricevuto diversi premi internazionali, come la prestigiosa Einstein Medal e la CNRS Gold Medal, e più di recente (nel 2021) la Galileo Galilei Medal, la ICTP Dirac medal, ed il Balzan Prize.
I relatori confermati sono: Prof. Leor Barack (University of Southampton), Prof. Sebastiano Bernuzzi (University of Jena), Prof. Lydia Bieri (Michigan University), Prof. Luc Blanchet (IAP, Paris), Prof. Alessandra Buonanno (AEI, MPI, Potsdam), Prof. Sophie De Buyl (Vrije Universiteit Brussel), Prof. Stanley Deser (Brandeis University), Prof. Marc Henneaux (Collège de France & ULB Bruxelles), Prof. Bala Iyer (ICTS, Tata institute, Bangalore), Prof. Piotr Jaranowski (University of Białystok), Prof. Sergiu Klainerman (Princeton University), Prof. Michael Kramer (MPI, Bonn), Prof. Juan Maldacena (IAS, Princeton), Prof. Viatcheslav Mukhanov (Ludwig Maximilian University, Munich), Prof. Hermann Nicolai (AEI, MPI, Potsdam), Prof. Adam Pound (University of Southampton), Prof. Giuseppe Policastro (ENS Paris), Prof. Alexander Polyakov (Princeton University), Prof. Manuel Rodrigues (ONERA, Université Paris-Saclay), Prof. Remo Ruffini (ICRA, ICRANet), Prof. David Shoemaker (MIT), Prof. Sergey Solodukhin (University of Tours), Prof. Alexei Starobinski (Landau Institute, Moscow), Prof. Gabriele Veneziano (CERN & Collège de France), Prof. Alex Vilenkin (Tufts University) e Prof. Edward Witten (IAS, Princeton).
Il programma è in fase di preparazione e sarà disponibile sul sito della conferenza al seguente link: https://indico.math.cnrs.fr/event/6802/
Vi invitiamo a registrarvi tramite il seguente link: https://indico.math.cnrs.fr/event/6802/registrations/557/
Per maggiori informazioni, si prega di contattare Elisabeth Jasserand, la coordinatrice delle attività scientifiche presso l'IHES: jasserand@ihes.fr (email), +33 (0)160926604 (telefono).

7. Seminario del Prof. Ivan Rybak presso il centro ICRANet, 22 Settembre 2021

Mercoledì, 22 Settembre 2021, il Dr. Ivan Rybak (Centro de Astrofísica da Universidade do Porto - Portugal) ha presentato il suo seminario intitolato "Cosmic (super/superconducting) strings as a probe of high energy physics". Si riporta di seguito l'abstract:
The theoretical possibility of cosmic strings existence was suggested in the 1970s. Since that time, these hypothetical objects have passed through the ups and downs of scientific community attention. Cosmic strings evoked particular interest in the 2000s, whereby implementing superstring theory to the early universe description, we "have discovered cosmic strings lurking everywhere in the undergrowth", as was expressed by Tom Kibble. Nowadays, many scenarios that extend the Standard Model of particles physics suggest the production of cosmic string. Future missions, such as LISA, with improved observational facilities, will probe models where cosmic strings occur, thereby shedding light on possible early universe scenarios. In this talk, I will make a short overview of models where cosmic strings take place. I will provide state of the art methods to study the evolution of cosmic strings and explain why we should pay attention to cosmic superconducting and (super)strings. I will conclude with current and future observational constraints on cosmic strings.
La notizia del seminario è stata pubblicata sul sito dell'ICRANet: http://www.icranet.org/index.php?option=com_content&task=blogcategory&id=89&Itemid=781
Il video del seminario è disponibile sul canale YouTube dell'ICRANet al seguente link: https://youtu.be/sZr1LKzDIvw

Fig. 5 and 6: Dr Ivan Rybak durante il suo seminario presso la sede ICRANet a Pescara, 22 Settembre 2021.

8. Visita del Prof. Vladimír Karas, Direttore dell'Istituto Astronomico dell'Accademia delle Scienze della Repubblica Ceca, presso la sede ICRA di Roma, 27 Settembre 2021

Il 27 Settembre 2021, il Prof. Vladimír Karas, Direttore dell'Istituto Astronomico dell'Accademia delle Scienze della Repubblica Ceca, è venuto in Italia ed ha visitato la sede ICRA presso l'Università Sapienza di Roma. Durante la visita, il Professore ha apposto la sua firma su una parete dell'ICRA, così come è stato fatto in precedenza da scienziati illustri e premi Nobel che hanno collaborato con l'ICRA, fornendo un contributo significativo alle varie attività. In questa occasione, il Prof. Ruffini ha discusso di svariate questioni con il Prof. Karas ed ha, inoltre, avuto l'occasione di proporgli un possibile accordo di collaborazione tra l'ICRANet ed il suo Istituto a Praga.

Fig. 7: il Prof. Vladimír Karas, Direttore dell'Istituto Astronomico dell'Accademia delle Scienze della Repubblica Ceca, mentre firma la parete dell'ICRA presso l'Università Sapienza di Roma, 27 Settembre 2021.	Fig. 8: la parete dell'ICRA presso l'Università Sapienza di Roma.

9. Visite scientifiche presso l'ICRANet

	• Dr. Ivan Rybak (Centro de Astrofísica da Universidade do Porto - Portugal), 22-23 Settembre 2021
	• Prof. Narek Sahakyan (Director of ICRANet Armenia), 24-25 Settembre 2021

Durante le loro visite, questi scienziati hanno avuto l'opportunità di presentare le loro ricerche e di confrontarsi con altri ricercatori dell'ICRANet provenienti da diverse parti del mondo.

10. Pubblicazioni recenti

Yen Chen Chen, Classifying Seyfert Galaxies with Deep Learning ApJS 256 34. The traditional classification for a subclass of the Seyfert galaxies is visual inspection or using a quantity defined as a flux ratio between the Balmer line and forbidden line. One algorithm of deep learning is the convolution neural network (CNN), which has shown successful classification results. We build a one-dimensional CNN model to distinguish Seyfert 1.9 spectra from Seyfert 2 galaxies. We find that our model can recognize Seyfert 1.9 and Seyfert 2 spectra with an accuracy of over 80% and pick out an additional Seyfert 1.9 sample that was missed by visual inspection. We use the new Seyfert 1.9 sample to improve the performance of our model and obtain a 91% precision of Seyfert 1.9. These results indicate that our model can pick out Seyfert 1.9 spectra among Seyfert 2 spectra. We decompose the Hα emission line of our Seyfert 1.9 galaxies by fitting two Gaussian components and derive the line width and flux. We find that the velocity distribution of the broad Hα component of the new Seyfert 1.9 sample has an extending tail toward the higher end, and the luminosity of the new Seyfert 1.9 sample is slightly weaker than the original Seyfert 1.9 sample. This result indicates that our model can pick out the sources that have a relatively weak broad Hα component. In addition, we check the distributions of the host galaxy morphology of our Seyfert 1.9 samples and find that the distribution of the host galaxy morphology is dominated by a large bulge galaxy. In the end, we present an online catalog of 1297 Seyfert 1.9 galaxies with measurements of the Hα emission line.
DOI: 10.3847/1538-4365/ac13aa


Giommi P., Perri M., Capalbi M., D'Elia V., Barres de Almeida U., Brandt C.H., Pollock A.M.T., et al., X-ray spectra, light curves and SEDs of blazars frequently observed by Swift, MNRAS, Volume 507, Issue 4, November 2021, Pages 5690-5702.
Blazars research is one of the hot topics of contemporary extragalactic astrophysics. That is because these sources are the most abundant type of extragalactic γ-ray sources and are suspected to play a central role in multimessenger astrophysics. We have used Swift_xrtproc, a tool to carry out an accurate spectral and photometric analysis of the Swift-XRT data of all blazars observed by Swift at least 50 times between December 2004 and the end of 2020. We present a database of X-ray spectra, best-fit parameter values, count rates and flux estimations in several energy bands of over 31 000 X-ray observations and single snapshots of 65 blazars. The results of the X-ray analysis have been combined with other multifrequency archival data to assemble the broad-band Spectral Energy Distributions (SEDs) and the long-term light curves of all sources in the sample. Our study shows that large X-ray luminosity variability on different time-scales is present in all objects. Spectral changes are also frequently observed with a ‘harder-when-brighter’ or ‘softer-when-brighter’ behaviour depending on the SED type of the blazars. The peak energy of the synchrotron component (ν_peak) in the SED of HBL blazars, estimated from the log-parabolic shape of their X-ray spectra, also exhibits very large changes in the same source, spanning a range of over two orders of magnitude in Mrk421 and Mrk501, the objects with the best data sets in our sample.
DOI: https://doi.org/10.1093/mnras/stab2425


Fraga B.M.O., Barres de Almeida U., Bom C.R., Brandt C.H., Giommi P., Schubert P., de Albuquerque M.P., Deep learning Blazar classification based on multifrequency spectral energy distribution data, MNRAS, Volume 505, Issue 1, July 2021, Pages 1268-1279.
Blazars are among the most studied sources in high-energy astrophysics as they form the largest fraction of extragalactic gamma-ray sources and are considered prime candidates for being the counterparts of high-energy astrophysical neutrinos. Their reliable identification amid the many faint radio sources is a crucial step for multimessenger counterpart associations. As the astronomical community prepares for the coming of a number of new facilities able to survey the non-thermal sky at unprecedented depths, from radio to gamma-rays, machine-learning techniques for fast and reliable source identification are ever more relevant. The purpose of this work was to develop a deep learning architecture to identify Blazar within a population of active galactic nucleus (AGN) based solely on non-contemporaneous spectral energy distribution information, collected from publicly available multifrequency catalogues. This study uses an unprecedented amount of data, with spectral energy distributions (SEDs) for ≈14 000 sources collected with the Open Universe VOU-Blazars tool. It uses a convolutional long short-term memory neural network purposefully built for the problem of SED classification, which we describe in detail and validate. The network was able to distinguish Blazars from other types of active galactic nuclei (AGNs) to a satisfying degree (achieving a receiver operating characteristic area under curve of 0.98), even when trained on a reduced subset of the whole sample. This initial study does not attempt to classify Blazars among their different sub-classes, or quantify the likelihood of any multifrequency or multimessenger association, but is presented as a step towards these more practically oriented applications.
DOI: https://doi.org/10.1093/mnras/stab1349


S. Campion, J.A. Rueda, R. Ruffini, S.S. Xue, Magnetic field screening in strong crossed electromagnetic fields, Physics Letters B, Volume 820, 10 September 2021, 136562.
We consider crossed electric and a magnetic fields , with E/B <1, in presence of some initial number of e^± pairs. We do not discuss here the mechanism of generation of these initial pairs. The electric field accelerates the pairs to high-energies thereby radiating high-energy synchrotron photons. These photons interact with the magnetic field via magnetic pair production process (MPP), i.e. γ+B→e⁺+e⁻, producing additional pairs. We here show that the motion of all the pairs around the magnetic field lines generates a current that induces a magnetic field that shields the initial one. For instance, for an initial number of pairs N_±,0=10¹⁰, an initial magnetic field of 10¹²G can be reduced of a few percent. The screening occurs in the short timescales 10⁻²¹ ≤ t ≤ 10−¹⁵s, i.e. before the particle acceleration timescale equals the synchrotron cooling timescale. The present simplified model indicates the physical conditions leading to the screening of strong magnetic fields. To assess the occurrence of this phenomenon in specific astrophysical sources, e.g. pulsars or gamma-ray bursts, the model can be extended to evaluate different geometries of the electric and magnetic fields, quantum effects in overcritical fields, and specific mechanisms for the production, distribution, and multiplicity of the e⁻e⁺ pairs.
DOI: https://doi.org/10.1016/j.physletb.2021.136562