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ICRANet Newsletter
Avril/Mai 2021



RÉSUMÉ
1. Programme de doctorat International conjoint en astrophysique relativiste entre USTC-UNIFE avec la participation de l'ICRA et de l'ICRANet, 28 Avril 2021
2. Les scientifiques de l'ICRANet ont reçu le 3ème prix pour la Gravity Research Foundation Award for Essays Competition 2021
3. Les Marcel Grossmann Awards 2021
4. Le Seizième Marcel Grossmann Meeting virtuel (MG16), 5-10 Juillet 2021
5. Communiqué de presse ICRA-ICRANet "The morphology of the X-ray afterglows and of the jetted GeV emission in long gamma-ray bursts", 12 Mai 2021
6. Communiqué de presse ICRA-ICRANet "The newborn black hole in GRB 191014C proves that it is alive", 27 Mai 2021
7. Renouvellement de l'accord de coopération ICRANet - Université de Ferrara, Italie, 28 Mai 2021
8. Nouveau protocole de coopération et accord spécifique ICRANet- Universidad Nacional de La Plata (UNLP), Argentine, 18 Mars 2021
9. Renouvellement du protocole de coopération ICRANet - Sharif University of Technology, Iran, 9 Mars 2021
10. Renouvellement du protocole de coopération ICRANet - Institute for Research in Fundamental Sciences (IPM), Iran, 12 Avril 2021
11. "Gerbertus 2021. Astrophysique et nouvelles technologies", meeting virtuel, 12 Mai 2021
12. Meeting virtuel à l'occasion de la semaine mondiale de l'astronomie, ICRANet Isfahan (Iran), 11-12 Mai 2021
13. Publications récentes


1. Programme de doctorat International conjoint en astrophysique relativiste entre USTC-UNIFE avec la participation de l'ICRA et de l'ICRANet, 28 Avril 2021

C'est notre plaisir d'annoncer que dans le mois d'Avril 2021 a été signé un accord de coopération pour l'établissement d'un programme de doctorat international conjoint en astrophysique relativiste (JIRA PhD) entre l'Université de Sciences et Technologie de la Chine (USTC) et l'Université de Ferrara (UNIFE), avec la participation de l'ICRA et de l'ICRANet.
Soit l'USTC que l'UNIFE ont des accords de coopération actifs avec l'ICRANet; en plus, l'USTC a récemment signé aussi 2 accords avec l'ICRA, qui aime au développement de la recherche scientifique et de la formation académique à niveau de doctorat, dans le domaine de l'astrophysique relativiste, avec le support des infrastructures et des scientifiques dès tous les instituts qui ont signé accords de collaboration avec l'ICRA e con l'ICRANet. Pour cette raison, l'ICRA et l'ICRANet collaboreront avec les deux parties (USTC et UNIFE) dans le cadre de ce nouveau programme de doctorat.
Le but principal de ce programme est d'assurer une formation et une recherche académique de haut niveau dans le domaine de l'astrophysique relativiste. Il s'adresse à des étudiants hautement qualifiés, provenant de pays d'Europe et on, qui remplissent les critères d'éligibilité établis par le règlement en vigueur entre les parties. Pour ce qui concerne la mobilité des doctorants, les partie établissent que le programme s'articulera en au moins 12 mois d'activité de recherche auprès de chacun des instituts partenaires. Le programme de mobilité pourra se dérouler dans un des centres ICRANet, y compris les instituts qui ont signé avec lui des accords de collaboration, alors que soient approuvés par le Comité conjoint, à condition qu'il soit dans un pays différent de celui de l'institution de premier enregistrement des doctorants. Dans ce cas, le Comité conjoint assignera un co-tuteur à la recherche, identifié entre les chercheurs associés à l'ICRANet, avec une formation approprié dans le domaine d'intérêt.
Plus d'informations sur ce programme seront annoncé dès que disponibles.



2. Les scientifiques de l'ICRANet ont reçu le 3ème prix pour la Gravity Research Foundation Award for Essays Competition 2021

L'article "The Quantum Emission of an Alive Black Hole" du Prof. J. A. Rueda (Professeur de la Faculté d'ICRANet) et du Prof. R. Ruffini (Directeur d'ICRANet) a reçu le troisième prix de la Gravity Research Foundation (www.gravityresearchfoundation.org) dans le cadre de l'Essay Competition pour le 2021. Une longue marche de 50 ans, fait de plusieurs progrès théoriques et de nouvelles découvertes faites en utilisant les observations de rayons gamma, ont mené à la formulation d'un mécanisme efficace capable d'extraire l'énergie rotationnelle d'un Trou noir de Kerr afin d'alimenter soit ces plus énergétiques sources astrophysiques que les noyaux galactiques actifs. Dans cet article sont présentées les principales caractéristiques de ce mécanisme, basé sur la gravito-électrodynamique, qui représente un changement de paradigme radical des Trous noirs en tant qu'objets astrophysiques toujours vivants.
Les 5 articles gagnants de la compétition 2021 seront aussi publiés sur le site web de la Gravity Research Foundation et seront publiés dans le mois d'Octobre 2021 dans le volume spécial de l'International Journal of Modern Physics D (IJMPD).
Pour télécharger l'article: https://arxiv.org/abs/2105.07890
Pour plus d'informations https://static1.squarespace.com/static/5852e579be659442a01f27b8/t/609d66c823a9a352bc3b24c3/1620928201758/2021-GRF-Abstracts.pdf



3. Les Marcel Grossmann Awards 2021

C'est notre plaisir annoncer que les prix individuels du meeting MG16 seront assigné, pour cet année:
• au Prof. Gerard 't Hooft (Université de Utrecht) "for his persistent devotion to the study of the quantum field theory boundary conditions at the black hole horizon";
• au Prof. Tsvi Piran (Hebrew University de Jérusalem) "for extending Relativistic Astrophysics across international frontiers, a true companion in the search for the deeper meaning of Einstein's great theory";
• au Prof. Steven Weinberg (Université du Texas à Austin) "for unwavering support for the MG meetings since their inception, a true companion in the search for the deeper meaning of Einstein's great theory"; et
• au Prof. Demetrios Christodoulou (ETH Zurich) "for the 50th anniversary of the discovery of the Mass Energy Formula of a Kerr Newmann Black Hole by Christodoulou, Ruffini and Hawking (see Christodoulou, Phys. Rev.Lett. 25 (1970) 1596 - Christodoulou-Ruffini, Phys. Rev. D,4 (1971)3552 - Hawking, Phys. Rev. Lett. 26 (1971) 1344)".

C'est aussi notre plaisir annoncer que les prix institutionnels du meeting MG16 seront assigné:
• au Prof. Alexander Shirshakov (en tant que représentant de la S.A. Lavochkin Association);
• au Prof. Peter Predehl (en tant que représentant du Max Planck Institute for Extraterrestrial Physics - MPE); et
• au Prof. Rashid Sunyaev (en tant que représentant du Space Research Institute IKI of the Russian Academy of Sciences)
"for the creation of the world's best X-ray map of the entire sky, for the discovery of millions of previously unknown accreting supermassive black holes at cosmological redshifts, for the detection of X-rays from tens of thousands of galaxy clusters, filled mainly with dark matter, and for permitting the detailed investigation of the growth of the large-scale structure of the universe during the era of dark energy dominance".



4. Le Seizième Marcel Grossmann Meeting virtuel (MG16), 5-10 Juillet 2021

C'est notre plaisir de présenter soit le poster officiel http://www.icra.it/mg/mg16/MG16_official_poster.pdf avec ses note explicatives (http://www.icra.it/mg/mg16/MG16_official_poster_info.pdf), que le poster spécial du meeting MG16, à l'occasion du 50ème anniversaire de l'article "Introducing the Black Hole" et de la formule d'énergie de masse du trou noir http://www.icra.it/mg/mg16/MG16_special_poster.pdf avec ses note explicatives (http://www.icra.it/mg/mg16/MG16_special_poster_info.pdf).
Le seizième Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories (MG16) aura lieu virtuellement de Lundi 5 à Vendredi 9 Juillet 2021. Pendant cette conférence online de 6 jours, seront adressés plusieurs sujets pendant des sessions plénières et parallèles. Chaque jour de meeting, il y auront 3 blocs de program de 3 heures chacun, dans lesquelles se tiendront les sessions plénières et celles parallèles (fuseau horaire: Heure d'été d'Europe centrale):
Bloc 1: h 6:30 - h 9:30 (CEST)
Bloc 2: h 9:30 - h 12:30 (CEST)
Bloc 3: h 16:30 - h 19:30 (CEST)
Les enregistrements des sessions plénières seront disponibles depuis le jour suivant sur YouTube. Chaque bloc aura 10 sessions qui se déroulent parallèlement et chaque session aura 9 exposés.
La date limite pour s'enregistrer a été reportée au 15 Juin 2021, avec une frais régulière d'inscription de 150 Euro et une frais réduite de 50 Euros (pour les étudiants, les scientifiques à la retraite et les observateurs). On aimerait aussi rappeler que la date limite pour soumettre des abstract c'est toujours le 15 Juin.
Le programme du meeting comprend une série de présentations plénières, de public lectures, round tables et sessions parallèles. Dès que disponibles, plus d'informations concernant les programmes des sessions plénières et parallèles seront visibles soit sur le site web officiel du meeting MG16 (http://www.icra.it/mg/mg16) que sur la plateforme associé Indico (https://indico.icranet.org/event/1/) après le 15 Juin.
Pour toute autre information ou requête, veuillez contacter mg16[AT]icranet.org



5. Communiqué de presse ICRA-ICRANet "The morphology of the X-ray afterglows and of the jetted GeV emission in long gamma-ray bursts", 12 Mai 2021

What is the fate of very massive binary stars, which kind of signatures/observables are associated with their stepwise evolution, which kind of new physical laws are revealed, represent the most relevant questions at the heart of relativistic astrophysics. The answer to these questions is intimately related to the explanation of the most powerful transients in the Universe, supernovae (SNe) and gamma-ray bursts (GRBs), and with the formation of neutron star-black hole (NS-BH), of neutron star-neutron star (NS-NS), and possibly BH-BH binaries. A crucial question then arises: how large are the mass and how fast are the rotational spin of those astrophysical BHs and NSs?
A clue to this answer comes out from decades of electromagnetic observations of X-ray binaries in which a BH accretes mass from a stellar companion. From their continuous monitoring, it has turned out that these BHs have masses ranging ~5-20 M, where the upper edge is given by the very recently updated mass of the BH harbored by the X-ray binary Cygnus X-1 [1]. While the origin of X-ray binaries is well established, focus is needed to identify the evolutionary channels leading to the onset of GRBs, to their time evolution, as well as to the new physical laws and astrophysical regimes envisaged for their description.
In a new article published in the Monthly Notices of the Royal Astronomical Society [2], an ICRA-ICRANet research team (some of them INAF associates) sheds light on the mass and spin of stellar-mass BHs from an extensive analysis of long-duration GRBs. This has been allowed by fifty years of exponential growth of multiwavelength observations of GRBs and theoretical progress, from which it has been possible to identify the \inner engine" of the GRB, and verify the validity of the BH mass-energy formula established fifty years ago. The subject of study are 380 energetic long GRBs with energy release above 1052 erg in gamma-rays, all with a measured cosmological redshift, and an X-ray afterglow. These systems are accompanied by an SN of type Ic, namely an SN produced by a star which has lost its hydrogen and helium layers. The binary-driven hypernova (BdHN) scenario of long GRBs bridges what we know from binary evolution, with high-energy relativistic astrophysics to explain these extreme systems.
The GRB progenitor system is a binary composed of a carbon-oxygen (CO) star and a companion NS. During their long lifetime, a very massive binary experiences several stages, each one characterized by specific physical phenomena and observables (see left side of Figure 1). The more massive of the two stellar components evolves faster through the nuclear burning phases, leading it to make a first SN explosion, with consequent formation of a NS. Mass-transfer from the ordinary stellar component to the NS leads to an X-ray binary stage. Further binary interactions lead to multiple common envelope phases in which mass loss is enhanced and the ordinary star gets rid of its outer low-density envelope, forming a CO star. The binary orbit shrinks while thermonuclear evolution of the CO star proceeds until its iron core becomes unstable against gravitational collapse, forming a new NS (vNS) at its center, and driving an SN explosion. At this point, a powerful transient starts and its ultimate fate depends crucially on the distance separating the exploding CO star and the NS companion. The SN ejected material triggers a massive accretion process onto the NS companion as well as onto the vNS by matter fallback (see Figure 2).
For compact binaries with orbital periods of the order of 5 minutes (see right side of Figure 1), the companion NS accretes sufficient matter to trigger its gravitational collapse, forming a BH which emanates a distinct, associated emission at high-energies (GeV) characterized by a luminosity as a function of time that follows a power-law. The fallback accretion onto the vNS and its pulsar emission power the GRB X-ray and optical afterglow, characterized by power-law luminosities, different from the one of the GeV emission. BdHNe forming a BH have been called of type I.
From the statistics of the GeV emission, it has been inferred the morphology of the GRB emission process: it occurs within a conical region of 60° measured from the normal to the orbital plane. No GeV radiation is observable outside such a conical region. The X-ray afterglow is instead present in all the BdHN I, independently of the inclination angle of the GRB with respect to the orbital plane. This detailed understanding have allowed the team to infer, from the analysis of the X-ray afterglow, the spin and magnetic field of the vNS. The analysis of the GeV emission have led, for the first time in about fifty years of GRB observations, to directly evaluate the precise mass and spin of the BHs formed in these powerful transients. The specific mass and spin of 11 BHs have been obtained and they range 2.3- 8.9 M and 0.27- 0.87, respectively.
This treatment of long GRBs, originating from the very massive binary stars, makes ample use of a description based on the four fundamental interactions: relativistic gravity and electrodynamics describe the "inner engine", weak interactions drive the neutrino emission in the accretion process, and the strong interactions shape the inner structure of the NSs responsible of the X-ray afterglow.
Since the pioneering observations of BATSE instrument on board the Compton satellite [3], we know that GRBs are isotropically distributed when mapped in galactic coordinates. Similarly, following the discovery of their cosmological redshift thanks to BeppoSAX [4], observations of BdHN I have occurred all the way to z = 8.2 (e.g. GRB 090423 [5, 6]). We can safely assert that GRBs, also thanks to their outstanding energetic, have a fundamental role in relativistic astrophysics processes in the 95.5% of our known Universe. Their prolonged emission of polarized synchrotron radiation in the X-rays and in the GeV regime may well have a fundamental role in the life in and of our Universe.
Having said all the above, it comes as a surprise the vision carried forward by the LIGO-Virgo observatories that very massive binary stars should rapidly gravitationally collapse, evolve into two BHs, crossing the space time of our Universe, finally merging into a larger BH. Such a vision avoids the role of any fundamental interactions with the sole exception of gravity, which seems at odds with the field of relativistic astrophysics.

[1] J. C. A. Miller-Jones, A. Bahramian, J. A. Orosz, I. Mandel, L. Gou, T. J. Maccarone, C. J. Neijssel, X. Zhao, J. Ziolkowski, M. J. Reid, et al., Science 371, 1046 (2021), 2102.09091.
[2] R. Ruffini, R. Moradi, J. A. Rueda, L. Li, N. Sahakyan, Y. C. Chen, Y. Wang, Y. Aimuratov, L. Becerra, C. L. Bianco, et al., MNRAS (2021), Volume 504, Issue 4, pp.5301-5326, arxiv:2103.09142.
[3] W. S. Paciesas, C. A. Meegan, G. N. Pendleton, M. S. Briggs, C. Kouveliotou, T. M. Koshut, J. P. Lestrade, M. L. McCollough, J. J. Brainerd, J. Hakkila, et al., Astroph. J. Supp. 122, 465 (1999), astro-ph/9903205.
[4] M. R. Metzger, S. G. Djorgovski, S. R. Kulkarni, C. C. Steidel, K. L. Adelberger, D. A. Frail, E. Costa, and F. Frontera, Nature (London) 387, 878 (1997).
[5] N. R. Tanvir, D. B. Fox, A. J. Levan, E. Berger, K. Wiersema, J. P. U. Fynbo, A. Cucchiara, T. Krühler, N. Gehrels, J. S. Bloom, et al., Nature (London) 461, 1254 (2009), 0906.1577.
[6] R. Ruffini, L. Izzo, M. Muccino, G. B. Pisani, J. A. Rueda, Y. Wang, C. Barbarino, C. L. Bianco, M. Enderli, and M. Kovacevic, Astron. Astroph. 569, A39 (2014), 1404.1840.
[7] J. A. Rueda, R. Ruffini, M. Karlica, R. Moradi, and Y. Wang, Astroph. J. 893, 148 (2020), 1905.11339.
[8] L. Becerra, C. L. Ellinger, C. L. Fryer, J. A. Rueda, and R. Ruffini, Astroph. J. 871, 14 (2019), 1803.04356.

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FIG. 1. Taken from [7]. Schematic evolutionary path of a massive binary up to the emission of a BdHN. (a) Binary system composed of two main-sequence stars, say 15 and 12 M, respectively. (b) At a given time, the more massive star undergoes the core-collapse SN and forms a NS (which might have a magnetic field B~1013 G). (c) The system enters the X-ray binary phase. (d) The core of the remaining evolved star, rich in carbon and oxygen, for short CO star, is left exposed since the hydrogen and helium envelope have been striped by binary interactions and possibly multiple common-envelope phases (not shown in this diagram). The system is, at this stage, a CO-NS binary, which is taken as the initial configuration of the BdHN model [8]. (e) The CO star explodes as SN when the binary period is of the order of few minutes, the SN ejecta of a few solar masses start to expand and a fast rotating, newborn NS, for short vNS, is left in the center. (f) The SN ejecta accrete onto the NS companion, forming a massive NS (BdHN II) or a BH (BdHN I; this example), depending on the initial NS mass and the binary separation. Conservation of magnetic flux and possibly additional MHD processes amplify the magnetic field from the NS value to B~1014 G around the newborn BH. At this stage the system is a vNS-BH binary surrounded by ionized matter of the expanding ejecta. (g) The accretion, the formation and the activities of the BH contribute to the GRB prompt gamma-ray emission and GeV emission. (h) X-ray afterglow powered by the fallback accretion and pulsar-like emission of the vNS. (i) Optical emission of the SN due to nickel decay in the ejecta.


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FIG. 2. A SPH simulation from Becerra et al. [8] of the exploding CO-star as the SN in the presence of a companion NS. The CO-star is obtained from the evolution of a 25 Mzero-age main-sequence (ZAMS) progenitor which leads to a pre-SN CO-star mass MCO= 6.85 M. The initial mass of the vNS (formed at the center of the SN) is 1.85 Mand the one of the NS companion is MNS = 2 M. The initial orbital period is 4.8 min. The panels show the mass density on the binary equatorial plane at two selected times from the SN explosion (t = 0 of the simulation), 159 s and 259 s. The reference system is rotated and translated so that the x-axis is along the line that joins the vNS and the NS, and the axis origin (0, 0) is located at the NS position. In this simulation, the NS collapses when it reaches 2.26 Mand angular momentum 1.24 G M2/c, while the vNS is stable with mass and angular momentum, respectively, 2.04 Mand 1.24 G M2/c. Up to the final simulation time, the binary system kept bound although the binary orbit widens, reaching an orbital period of 16.5 min and an eccentricity of є = 0.6. The collapse of the NS to the newly-formed BH, characteristic of a BdHN I, occurs at t = 21.6 min.

Link to the press release on ICRANet website: http://www.icranet.org/communication/
Link to the press release on INAF website: http://www.inaf.it/it/notizie-inaf/morphology-afterglows-jetted-ge-emission-long-grb



6. Communiqué de presse ICRA-ICRANet "The newborn black hole in GRB 191014C proves that it is alive", 27 Mai 2021

A new theory explains the high-energy (photon energies of gigaelectronvolts — GeV) observed in the energetic long-duration gamma-ray bursts (GRBs) as originated in the vicinity of the black hole horizon. The theory, published today in Astronomy & Astrophysics [1], led by an ICRA-ICRANet research team (INAF associates), is based on the "inner engine" previously introduced by the team [2, 3]. The theory, which is also shown to work in active galactic nuclei (AGN), proofs that the rotational energy of a black hole can indeed be extracted from the horizon of the black hole, and efficiently used to power the most energetic and powerful objects in the Universe.
Rotating black holes were initially conceptualized either as "dead" objects or as sinks of energy. Subsequently, it was realized that much as the thermodynamical systems, black holes may interact with their surroundings exchanging energy [4, 5]. This result led to one of the most important concepts in black hole physics and astrophysics: the Christodoulou-Ruffini-Hawking black hole mass-energy formula [4 -6]. In its most general form, for a rotating charged black hole, it relates the black hole mass-energy to three independent pieces: its "irreducible mass, its charge, and its angular momentum. It led to a corollary of paramount importance in astrophysics: up to 50% of the mass-energy of a charged black hole, and up to 29% of the one of a rotating black hole, could be in principle extracted!. This extraordinary result led to the alternative view of "alive" black holes, and since then it has permeated, for fifty years as of this writing, relativistic astrophysics both theoretically and experimentally.
The most energetic astrophysical sources, GRBs and AGN, were soon identified as primary candidates to be powered by black holes. GRBs, the most powerful transient objects in the sky, release energies of up to a few 1054 erg in just a few seconds! Their luminosity in the gamma-rays, in the time interval of the event, is as large as the luminosity of all the stars of the observable Universe! GRBs have been thought to be powered, by an up-to-now unknown mechanism, by stellar-mass black holes. AGN, releasing 1046 erg s−1 for billion years, must be powered by supermassive black holes of up to a few billion solar masses. However, every theoretical effort to find a mechanism to extract the black hole energy has been vanified by the implausibility of their realization in nature (see, e.g. [7]).
There was the urgency of new physics!. The novel engine presented in the new publication makes the job through a purely general relativistic, gravito-electrodynamical process: a rotating black hole, interacting with a surrounding magnetic field, creates an electric field (see Fig. 1) that accelerates ambient electrons to ultrahigh-energies leading to high-energy radiation (see Fig. 2) and ultrahigh-energy cosmic rays (UHECRs). Aspects of this novel machine worth to be outlined are: (1) the nature of the emission results from the physical process leading to the electric and magnetic fields and the black hole formation. (2) The emission process is not continuous but discrete, it repeats over and over, releasing in every characteristic time a well-established "blackholic quantum" of energy [2], extracted from the black hole horizon thanks to the presence of a surrounding magnetic field. (3) Such a timescale, for GRBs, is as short as femtoseconds, making it difficult to be probed directly by current observational facilities. Direct evidence of the process discreteness might come out, instead, from AGN. In the case of M87*, the authors have predicted a high-energy (GeV) luminosity of a few 1043 erg s−1, released in a timescale of up to tenths of seconds, while the timescale for UHECRs emission is of the order of half a day!
All the above results are important. The proof that we can use the extractable rotational energy of a black hole to explain the high-energy jetted emissions of GRBs and AGN stands alone. The jetted emission does not originate from an ultra-relativistic acceleration of matter in bulk (massive jets), but from very special energy-saving general relativistic and electrodynamical processes leading to the emission of blackholic quanta of energy [2]. A long march of successive theoretical progress and new physics discovered using observations of GRBs has brought to this result which has been waited for about fifty years of relativistic astrophysics.

[1] R. Moradi, J. A. Rueda, R. Ruffini, and Y. Wang, A&A, 649 (2021) A75, https://www.aanda.org/10.1051/0004-6361/201937135.
[2] J. A. Rueda and R. Ruffini, European Physical Journal C 80, 300 (2020), 1907.08066.
[3] R. Ruffini, R. Moradi, J. A. Rueda, L. Becerra, C. L. Bianco, C. Cherubini, S. Filippi, Y. C. Chen, M. Karlica, N. Sahakyan, et al., Astroph. J. 886, 82 (2019), 1812.00354.
[4] D. Christodoulou, Phys. Rev. Lett. 25, 1596 (1970).
[5] D. Christodoulou and R. Ruffini, Phys. Rev. D 4, 3552 (1971).
[6] S. W. Hawking, Physical Review Letters 26, 1344 (1971).
[7] R. Penrose and R. M. Floyd, Nature Physical Science 229, 177 (1971).
[8] R. Ruffini, R. Moradi, J. A. Rueda, L. Li, N. Sahakyan, Y. C. Chen, Y. Wang, Y. Aimuratov, L. Becerra, C. L. Bianco, et al., MNRAS (2021), 2103.09142.

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FIG. 1. Figure taken from [1] with the kind permission of the authors. Electric (blue lines) and magnetic (golden lines) field lines surrounding the rotating black hole. Electrons located in these northern and southern hemisphere cones of semi-aperture angle of ≈ 60° are outwardly accelerated leading to GeV photons (see Fig. 2).


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FIG. 2. Figure taken from [1] with the kind permission of the authors. Electrons are accelerated and emit GeV photons in the conical region with a semi-aperture angle θ± ≈ 60° (dark boundary). This "jetted" emission is essential to infer the BdHN I morphology from the GeV emission data of long GRBs [8].

Link to the press release on ICRANet website: http://www.icranet.org/communication/
Link to the press release on A&A website: https://www.aanda.org/component/content/article/190-press-releases/2021-press-releases/2191-the-newborn-black-hole-in-grb-191014c-proves-that-it-isalive



7. Renouvellement de l'accord de coopération ICRANet - Université de Ferrara, Italie, 28 Mai 2021

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Le 28 Mai 2021 a été renouvelé l'accord de coopération entre l'ICRANet et l'Université de Ferrara (UNIFE). Le renouvellement a été signé par le Prof. Vincenzo Guidi (Directeur du Département de physique UNIFE) et par le Prof. Remo Ruffini (Directeur ICRANet). Cet accord demeurera valide pour 5 années et les principales activités conjointes qui seront développées dans le cadre de cet accord comptent: la promotion des activités de recherche et d'observation dans le champ de l'astrophysique relativiste; la collaboration entre des membres de la Faculté, des chercheurs, des post-doctorat fellows et des étudiants; l'organisation de séminaires, conférences, workshops, cours de formations et de recherche, et publications conjointes.
Pour consulter le texte de l'accord:
http://www.icranet.org/index.php?option=com_content&task=view&id=1097



8. Nouveau protocole de coopération et accord spécifique ICRANet- Universidad Nacional de La Plata (UNLP), Argentine, 18 Mars 2021

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Dans le mois de Mai 2021, l'ICRANet a reçu la confirmation officielle de la signature d'un nouveau protocole de coopération et d'un accord spécifique entre l'ICRANet et l'Universidad Nacional De La Plata (UNLP) en Argentine. Le Protocole de coopération a été signé le 18 Mai 2021 (soit en anglais qu'en espagnol) par le Dr Fernando Alfredo Tauber (Président de la UNLP) et par le Prof. Remo Ruffini (Directeur d'ICRANet), tandis que l'accord spécifique a été signé par l'EngD Marcos Daniel Actis (Vice Président pour les affaires institutionnels UNLP), par le Lic. Raúl Anìbal Perdomo (Département d'astronomie et géophysique UNLP) et par le Prof. Remo Ruffini.
Les deux accords demeureront valides pour 4 années et les principales activités conjointes qui seront développées dans le cadre de ces accords comptent: la promotion des activités de recherche et d'observation dans le champ de l'astrophysique relativiste; la collaboration entre des membres de la Faculté, des chercheurs, des post-doctorat fellows et des étudiants; l'organisation de séminaires, conférences, workshops, cours de formations et de recherche, et publications conjointes.
Pour consulter le texte des 2 accords:
http://www.icranet.org/index.php?option=com_content&task=view&id=1369



9. Renouvellement du protocole de coopération ICRANet - Sharif University of Technology, Iran, 9 Mars 2021

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Dans le mois de Avril 2021, l'ICRANet a reçu la confirmation officielle du renouvellement su protocole de coopération entre l'ICRANet et la Sharif University of Technology (Iran). Le renouvellement a été signé le 9 Mars 2021 par le Prof. Mahmoud Fotouhi Firoozabad (Président de la Sharif University of Technology) et par le Prof. Remo Ruffini (Directeur d'ICRANet). Cet accord demeurera valide pour 5 années et les principales activités conjointes qui seront développées dans le cadre de cet accord comptent: la promotion des activités de recherche et d'observation dans le champ de l'astrophysique relativiste; la collaboration entre des membres de la Faculté, des chercheurs, des post-doctorat fellows et des étudiants; l'organisation de séminaires, conférences, workshops, cours de formations et de recherche, et publications conjointes.
Pour consulter le texte de l'accord:
http://www.icranet.org/index.php?option=com_content&task=view&id=1061



10. Renouvellement du protocole de coopération ICRANet - Institute for Research in Fundamental Sciences (IPM), Iran, 12 Avril 2021

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Le 12 Avril 2021 a été renouvelé le protocol de coopération entre l'ICRANet et l'Institute for Research in Fundamental Sciences (IPM). Le renouvellement a été signé par le Prof. Mohammad Javad A. Larijani (Directeur de l'IPM) et par le Prof. Remo Ruffini (Directeur d'ICRANet). Cet accord demeurera valide pour 5 années et les principales activités conjointes qui seront développées dans le cadre de cet accord comptent: la promotion des activités de recherche et d'observation dans le champ de l'astrophysique relativiste; la collaboration entre des membres de la Faculté, des chercheurs, des post-doctorat fellows et des étudiants; l'organisation de séminaires, conférences, workshops, cours de formations et de recherche, et publications conjointes.
Pour consulter le texte de l'accord:
http://www.icranet.org/index.php?option=com_content&task=view&id=1060


11. "Gerbertus 2021. Astrophysique et nouvelles technologies", meeting virtuel, 12 Mai 2021

Le congres annuel en l'honneur de Gerbert d'Aurillac, scientifique, astronome et Pape, a eu lieu virtuellement le 12 Mai 2021 et, comme les meetings précédents, a été coordonné par le centre ICRANet de Pescara au niveau international.
Gerbert d'Aurillac (938 a.c. 12.5.1003) était un moine bénédictin dans son village d'origine en France, il a étudié la mathématique et l'astronomie à Vic (Catalogne) et était connu pour sa musique déjà par le Pape Jean XIII en 971 à Rome. De là il partait pour Rome, ou il a travaillé comme enseignant dans l'école cathédrale et comme secrétaire de l'Archevêque Adalberone jusqu'à sa mort. Il a été élu Evêque de Reims en 991, après la déposition de Arnolfo, qui le Pape ne considérait pas valide, et en 995 il s'est retiré à Saasbach pour travailler comme tuteur du jeune Empereur Otto III. Il a écrit plusieurs traités concernant les tuyaux d'orgue (980), sur l'astrolabe et sur l'abaque, il a introduit les caractères indo-arabes (983, Carme Figurato a Ottone II) dans le De Rationali et ratione uti (997 à Ottone III) et son épistolaire a été le plus riche qu'on a reçu dans le X siècle. En 998, le Pape Grégoire V lui a nommé Evêque de Ravenna et le 9 Avril 999, dans le jour de Pâque, il a été couronné Pape à Rome "da R in R in R", avec le nome de Silvestre II. Selon une légende, Gerbert, considéré l'homme le plus savant de son temps, a aussi construit une loque binaire autonome.
Astrophysique et nouvelles technologies est le titre de l'édition 2021 du meeting et l'idée de base est maintenir le contact avec la tradition historique, même à travers l'utilise des nouvelles technologies. Les orateurs qui ont été invités incluent aussi des étudiants non gradués, pour pouvoir mieux rejoindre, comme public, les étudiants des lycées et pour leur illustrer les opportunités que leurs sont offertes dans le domaine de la science des computers, de l'électronique, de l'automation, de la robotique, de l'environnement et du territoire en relation au domaine de l'astronomie d'observation et/ou de l'astrophysique théorique.
Le meeting virtuel est commencé à 16 h du 12 Mia, avec les salutation d'ouverture par le Prof. Remo Ruffini (Directeur d'ICRANet) et par le Prof. Cosimo Palagiano (Accademia nazionale dei Lincei). Après, on a eu des présentations "Science, astrophysique et nouvelles technologies" par le Prof. Francesco Berrilli (Tor Vergata et Accademia nazionale dei Lincei), "Interferometry in astronomy: from the Hanbury Brown and Twiss interferometer to the global very long baseline array" par le Prof. Paolo Ochner (Observatoire astrophysique d'Asiago et Université de Padova) et par Daniele Impellizzeri (ITA G. Garibaldi), "study of the photoluminescence of the hybrid Perovskiti" par Paolo De Vincenzi (Université de Rome La Sapienza), "computer science in the study of the phenomena" par Andrea Brucato (Université de Rome La Sapienza), "Computer science in the school" par Fabio Zaccagnini (Université de Rome La Sapienza), "The role of computer science in astronomy" par Lorenzo Ricciardi (Université Roma Tre), "total station" par la Prof. Paola Spera (IIS Caffè), "survey campaign for the sundial of Santa Maria degli Angeli" par le Prof. Giuseppe Cultrera (IIS Caffè), "Technology for astrophysics" par le Prof. Runa Briguglio (INAF - Observatoire astrophysique de Arcetri) et "comment to the digital edition of Lo Scontro della Cometa (G. Artom, 1910)" par le Prof. Federico Manzini (Station astronomique IAU A12).
Pendant cette conférence ont été aussi présentés 2 livres, récemment digitalisés: "Lo Scontro della Cometa" (1911) et "Mars in 1896/97". Ce dernier parle aussi d'un expérimente pour regarder, à travers le télescope, une pièce à 30 mt de distance, avec le même diamètre angulaire de Mars au mois de Janvier 1897. Le Prof. Sigismondi a aussi présenté le volume n. 14 de Gerbertus (2021) - http://www.icra.it/gerbertus/2021/Gerb-14-2021-totale.pdf.
Soit le programme de la conférence que l'enregistrement des présentations se trouvent sur la page web: http://www.icranet.org/index.php?option=com_content&task=view&id=1366
Dans cette occasion, le Prof. Sigismondi a préparé aussi un communiqué de presse (en Italien), disponible ici: http://www.icranet.org/scuola_lavoro/2020-2021/12052021/press_release.pdf
Pour la liste des meeting précédents à partir de 2003: http://www.icra.it/gerbertus



12. Meeting virtuel à l'occasion de la semaine mondiale de l'astronomie, ICRANet Isfahan (Iran), 11-12 Mai 2021

La semaine mondiale de l'astronomie est un événement public annuel, qui aime à l'information des étudiants et le public sur l'astronomie est l'astrophysique ainsi que à la création d'une atmosphère dynamique pour des discussions scientifiques publiques sur l'astronomie entre académiques, scientifiques et étudiants afin d'interagir et s'échanger des nouvelles idées dans ce domaine.
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Cette conférence à été organisée virtuellement par le Dr. Soroush Shakeri (ICRANet-Isfahan) et par le Département de Physique de l'IUT dans les journées du 11 et 12 Mai 2021. Au cours de ce meeting, plusieurs scientifiques de l'Allemagne et de l'Iran se sont réunis pour discuter les différentes sujets liés à l'astronomie. Le meeting est commencé le 11 Mai à 16:30 h (IRST), avec une intéressante présentation par le Dr. Behnam Javanmardi de l'Université de Bonn (Allemagne), titré "Cosmological inconsistencies and Hubble Constant", et est continué avec un débat entre le Dr. Javad Taghizadeh Firouzjaee (K.N. Toosi University of Technology, Tehran), sur "The Mystery of Black Holes" et le récent Prix Nobel pour la Physique. Dans la deuxième journée de meeting, la Dr Sedighe Sajadian (Département de Physique IUT, Isfahan) a présenté des différents méthodes pour découvrir des planètes extrasolaires et de la possibilité qu'il existe de la vie au-delà de notre système solaire. Enfin, le Dr. Mahdi Kord Zangeneh (Shahid Chamran University, Ahvaz) a présenté une illustration de la cosmologie et des récentes objectifs en astrophysique et il a eu un débat interactif avec les étudiants concernant les différent recherches actives dans ce domaine.
Pour lire cette nouvelle sur la newsletter de l'IUT:
https://iscoweb.iut.ac.ir/sites/iscoweb/files/u758/nl-no.18-_may_2021.pdf



13. Publications récentes

Becerra-Vergara, E. A.; Argüelles, C. R.; Krut, A.; Rueda, J. A.; Ruffini, R., Hinting a dark matter nature of Sgr A* via the S-stars, to be published in Monthly Notices of the Royal Astronomical Society Letters.
The motion data of the S-stars around the Galactic center gathered in the last 28 yr imply that Sgr A* hosts a supermassive compact object of about 4×106 M, a result awarded with the Nobel Prize in Physics 2020. A non-rotating black hole (BH) nature of Sgr A* has been uncritically adopted since the S-star orbits agree with Schwarzschild geometry geodesics. The orbit of S2 has served as a test of General Relativity predictions such as the gravitational redshift and the relativistic precession. The central BH model is, however, challenged by the G2 post-peripassage motion and by the lack of observations on event-horizon-scale distances robustly pointing to its univocal presence. We have recently shown that the S2 and G2 astrometry data are better fitted by geodesics in the spacetime of a self-gravitating dark matter (DM) core - halo distribution of 56 keV-fermions, "darkinos", which also explains the outer halo Galactic rotation curves. This Letter confirms and extends this conclusion using the astrometry data of the 17 best-resolved S-stars, thereby strengthening the alternative nature of Sgr A* as a dense core of darkinos.
ArXiv: https://arxiv.org/abs/2105.06301


J. A. Rueda and R. Ruffini, The Quantum Emission of an Alive Black Hole, Third Award-Winning Essay of the "Gravity Research Foundation 2021 awards for essays on Gravitation", to be published in a special issue of IJMPD in October 2021.
A long march of fifty years of successive theoretical progress and new physics discovered using observations of gamma-ray bursts, has finally led to the formulation of an efficient mechanism able to extract the rotational energy of a Kerr black hole to power these most energetic astrophysical sources and active galactic nuclei. We here present the salient features of this long-sought mechanism, based on gravito-electrodynamics, and which represents an authentic shift of paradigm of black holes as forever "alive" astrophysical objects.
GRF Award Announcement website: https://www.gravityresearchfoundation.org/announcement
ArXiv: https://arxiv.org/abs/2105.07890


Moradi, R.; Rueda, J. A.; Ruffini, R.; Wang, Y., The newborn black hole in GRB 191014C proves that it is alive, to be published in A&A on May 27, 2021.
A multi-decade theoretical effort has been devoted to finding an efficient mechanism to use the rotational and electrodynamical extractable energy of a Kerr-Newman black hole (BH), to power the most energetic astrophysical sources such as gamma-ray bursts (GRBs) and active galactic nuclei (AGN). We show an efficient general relativistic electrodynamical process which occurs in the "inner engine" of a binary driven hypernova (BdHN). The inner engine is composed of a rotating Kerr BH of mass M and dimensionless spin parameter α, a magnetic field of strength B0 aligned and parallel to the rotation axis, and a very low-density ionized plasma. Here, we show that the gravitomagnetic interaction between the BH and the magnetic field induces an electric field that accelerates electrons and protons from the environment to ultrarelativistic energies emitting synchrotron radiation. We show that in GRB 190114C the BH of mass M=4.4 M, α=0.4, and B0≈4×1010 G can lead to a high-energy (≳GeV) luminosity of 1051 erg s−1. The inner engine parameters are determined by requiring 1) that the BH extractable energy explains the GeV and ultrahigh-energy emission energetics, 2) that the emitted photons are not subjected to magnetic-pair production, and 3) that the synchrotron radiation timescale agrees with the observed high-energy timescale. We find for GRB 190114C a clear jetted emission of GeV energies with a semi-aperture angle of approximately 60° with respect to the BH rotation axis.
A&A forthcoming article: https://doi.org/10.1051/0004-6361/201937135
ArXiv: https://arxiv.org/abs/1911.07552


Sahakyan, N., Modeling the broadband emission of 3C 454.3, published in Monthly Notices of the Royal Astronomical Society on April 22, 2021.
The results of a long-term multiwavelength study of the powerful flat spectrum radio quasar 3C 454.3 using Fermi-LAT and Swift XRT/UVOT data are reported. In the γ-ray band, Fermi-LAT observations show several major flares when the source flux was >10−5 photon cm−2 s−1; the peak γ-ray flux above 141.6 MeV, (9.22±1.96) × 10−5 photon cm−2 s−1 observed on MJD 55519.33, corresponds to 2.15×1050 erg s−1 isotropic γ-ray luminosity. The analysis of Swift XRT and UVOT data revealed a flux increase, although with smaller amplitudes, also in the X-ray and optical/UV bands. The X-ray emission of 3C 454.3 is with a hard spectral index of ΓX = 1.16 -1.75, and the flux in the flaring states increased up to (1.80±0.18) × 10−10erg cm−2 s−1. Through combining the analysed data, it was possible to assemble 362 high-quality and quasi-simultaneous spectral energy distributions of 3C 454.3 in 2008 -2018, which all were modelled within a one-zone leptonic scenario assuming the emission region is within the broad-line region, involving synchrotron, synchrotron self-Compton, and external Compton mechanisms. Such an extensive modelling is the key for constraining the underlying emission mechanisms in the 3C 454.3 jet and allows to derive the physical parameters of the jet and investigate their evolution in time. The modelling suggests that during the flares, along with the variation of emitting electron parameters, the Doppler boosting factor increased substantially, implying that the emission in these periods has most likely originated in a faster moving region.
DOI: https://doi.org/10.1093/mnras/stab1135


MAGIC collaboration, H.E.S.S. and MAGIC observations of a sudden cessation of a very-high-energy γ-ray flare in PKS 1510‒089 in May 2016, Astronomy & Astrophysics, Volume 648, id.A23, 22 pp.
The flat spectrum radio quasar (FSRQ) PKS 1510−089 is known for its complex multiwavelength behaviour and it is one of only a few FSRQs detected in very-high-energy (VHE, E > 100 GeV) γ rays. The VHE γ-ray observations with H.E.S.S. and MAGIC in late May and early June 2016 resulted in the detection of an unprecedented flare, which revealed, for the first time, VHE γ-ray intranight variability for this source. While a common variability timescale of 1.5 h has been found, there is a significant deviation near the end of the flare, with a timescale of ∼20 min marking the cessation of the event. The peak flux is nearly two orders of magnitude above the low-level emission. For the first time, a curvature was detected in the VHE γ-ray spectrum of PKS 1510 -089, which can be fully explained by the absorption on the part of the extragalactic background light. Optical R-band observations with ATOM revealed a counterpart of the γ-ray flare, even though the detailed flux evolution differs from the VHE γ-ray light curve. Interestingly, a steep flux decrease was observed at the same time as the cessation of the VHE γ-ray flare. In the high-energy (HE, E >  100 MeV) γ-ray band, only a moderate flux increase was observed with Fermi-LAT, while the HE γ-ray spectrum significantly hardens up to a photon index of 1.6. A search for broad-line region (BLR) absorption features in the γ-ray spectrum indicates that the emission region is located outside of the BLR. Radio very-long-baseline interferometry observations reveal a fast-moving knot interacting with a standing jet feature around the time of the flare. As the standing feature is located ∼50 pc from the black hole, the emission region of the flare may have been located at a significant distance from the black hole. If this is indeed a true correlation, the VHE γ rays must have been produced far down in the jet, where turbulent plasma crosses a standing shock.
DOI: https://doi.org/10.1051/0004-6361/202038949


MAGIC collaboration, Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign, The Astrophysical Journal Letters, Volume 911, Issue 1, id.L11, 43 pp.
In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ~6.5 × 109 M. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.
DOI: https://doi.org/10.3847/2041-8213/abef71


Li-Yang Gao, Ze-Wei Zhao, She-Sheng Xue, Xin Zhang, Relieving the H0 tension with a new interacting dark energy model, accepted for publication in JCAP.
We investigate an extended cosmological model motivated by the asymptotic safety of gravitational field theory, in which the matter and radiation densities and the cosmological constant receive a correction parametrized by the parameters δG and δΛ, leading to that both the evolutions of the matter and radiation densities and the cosmological constant slightly deviate from the standard forms. Here we explain this model as a scenario of vacuum energy interacting with matter and radiation. We consider two cases of the model: {(i) ΛCDM with one additional free parameter δG, with δG and δΛ related by a low-redshift limit relation and (ii) e ΛCDM with two additional free parameters δG and δΛ that are independent of each other.} We use two data combinations, CMB+BAO+SN (CBS) and CMB+BAO+SN+H0 (CBSH), to constrain the models. We find that, in the case of using the CBS data, neither Λ˜CDM nor eΛCDM can effectively alleviate the H0 tension. However, it is found that using the CBSH data the H0 tension can be greatly relieved by the models. In particular, in the case of eΛCDM, the H0 tension can be resolved to 0.71σ. We conclude that as an interacting dark energy model, Λ˜CDM is much better than Λ(t)CDM in the sense of both relieving the H0 tension and fitting to the current observational data.
ArXiv: https://arxiv.org/abs/2101.10714