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ICRANet Newsletter
April/May 2021



SUMMARY
1. International joint PhD programme in Relativistic Astrophysics USTC-UNIFE with the participation of ICRA and ICRANet, April 28, 2021
2. ICRANet scientists received the third Award for the Gravity Research Foundation Award for Essays Competition 2021
3. Marcel Grossmann Awards 2021
4. The Sixteenth Marcel Grossmann virtual Meeting (MG16), July 5 - 10, 2021
5. ICRA-ICRANet press release "The morphology of the X-ray afterglows and of the jetted GeV emission in long gamma-ray bursts", May 12, 2021
6. ICRA-ICRANet press release "The newborn black hole in GRB 191014C proves that it is alive", May 27, 2021
7. Renewal of the Cooperation Agreement ICRANet - University of Ferrara, Italy, May 28, 2021
8. New Cooperation protocol and specific Agreement ICRANet- Universidad Nacional de La Plata (UNLP), Argentina, March 18, 2021
9. Renewal of the Cooperation Protocol ICRANet - Sharif University of Technology, Iran, March 9, 2021
10. Renewal of the Cooperation Protocol ICRANet - Institute for Research in Fundamental Sciences (IPM), Iran, April 12, 2021
11. "Gerbertus 2021. Astrophysics and new technologies", online meeting, May 12, 2021
12. World Astronomy week virtual meeting, ICRANet Isfahan (Iran), May 11-12, 2021
13. Recent publications


1. International joint PhD programme in Relativistic Astrophysics USTC-UNIFE with the participation of ICRA and ICRANet, April 28, 2021

It is our pleasure to announce that on April 2021, a cooperation agreement has been signed concerning the establishment of an international joint PhD programme in Relativistic Astrophysics (JIRA PhD) by the University of Sciences and Technology of China (USTC) and the University of Ferrara (UNIFE), with the participation of ICRA and ICRANet.
Both USTC and UNIFE have ongoing cooperation agreements with ICRANet; moreover, USTC has also signed 2 agreements with ICRA, aiming at the development of scientific research and academic training at Ph.D. level in the field of Relativistic Astrophysics, with the support of the infrastructures and the scientists of all the institutions with signed cooperation agreements with ICRA and ICRANet. As a result, ICRA and ICRANet will be collaborating with both parties in the framework of this agreement.
The main intent of this programme is to ensure a high level of education and high quality academics research in the field of Relativistic Astrophysics. It is addressed to highly qualified candidates from all the European and non-European nations who meet the admission criteria established by regulations in force at the Partner Institutions. With regard to the mobility of the Ph.D. students, the Parties agree that the curriculum of the Programme will include at least 12 months of research activity at each of the Partner Institutions. The mobility program can take place in one of the ICRANet centers, including institutions with a signed collaboration agreement with ICRANet, when approved by the Joint Coordination Committee, as long as it is located in a country different from the Institution of first enrolment of the doctoral students. In this case, the Joint Coordination Committee will assign a research co-tutor identified among the researchers associated with ICRANet with the appropriate qualification in the field of interest.
More details about this PhD programme will be announced soon.



2. ICRANet scientists received the third Award for the Gravity Research Foundation Award for Essays Competition 2021

The article "The Quantum Emission of an Alive Black Hole" by Prof. J. A. Rueda (ICRANet Faculty Professor) and Prof. R. Ruffini (Director of ICRANet) received the Third Award by the Gravity Research Foundation (www.gravityresearchfoundation.org) in the 2021 Essay Competition. A long fifty-years march 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. The five award-winning essays of 2021 competition will be also posted on Gravity Research Foundation web site and will be published in the October 2021 SPECIAL ISSUE of the International Journal of Modern Physics D (IJMPD).
The paper can be downloaded here: https://arxiv.org/abs/2105.07890
For details see here



3. Marcel Grossmann Awards 2021

We are very happy to announce that the MG16 Individual Awards this year will go to:
• Prof. Gerard 't Hooft (Utrecht University) "for his persistent devotion to the study of the quantum field theory boundary conditions at the black hole horizon";
• Prof. Tsvi Piran (Hebrew University of Jerusalem) "for extending Relativistic Astrophysics across international frontiers, a true companion in the search for the deeper meaning of Einstein's great theory"; and
• Prof. Steven Weinberg (University of Texas at 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".
• 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)".

It is also our great pleasure to announce that the shared MG16 Institutional Award will be presented to:
• Prof. Alexander Shirshakov (on behalf of the S.A. Lavochkin Association);
• Prof. Peter Predehl (on behalf of the Max Planck Institute for Extraterrestrial Physics - MPE); and
• Prof. Rashid Sunyaev (on behalf of the 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. The Sixteenth Marcel Grossmann virtual Meeting (MG16), July 5 - 10, 2021

We are happy to present the official poster of the MG16 meeting http://www.icra.it/mg/mg16/MG16_official_poster.pdf with explanatory notes (http://www.icra.it/mg/mg16/MG16_official_poster_info.pdf), as well as the MG16 special poster, celebrating the 50th anniversary of the article "Introducing the Black Hole" and the Black Hole mass energy formula http://www.icra.it/mg/mg16/MG16_special_poster.pdf with explanatory text (http://www.icra.it/mg/mg16/MG16_special_poster_info.pdf).
The Sixteenth Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Relativity, Astrophysics and Relativistic Field Theories (MG16) will be organized in virtual format from July 5 to 10, 2021. During this six days online conference, a variety of topics will be discussed in the plenary and parallel sessions. Each day there will be three blocks of three hours with the plenary and the parallel sessions (Central European Summer Time):
First block: h 6:30 - h 9:30 (CEST)
Second block: h 9:30 - h 12:30 (CEST)
Third block: h 16:30 - h 19:30 (CEST)
Recordings of plenary session will be available next day on YouTube. Each block will have 10 sessions running in parallel, each parallel session will have 9 talks.
The deadline for registration has been postponed to June 15, 2021 with regular fee of 150 Euro and reduced fee of 50 Euro applicable to students, retired scientists and auditors. We recall that the abstract submission deadline is June 15, 2021.
The meeting program will include a set of plenary lectures, public lectures, round tables as well as parallel sessions. As soon as more information on plenary and parallel programs will be available, they will be posted on the MG16 meeting website (http://www.icra.it/mg/mg16) as well as on the associated Indico website (https://indico.icranet.org/event/1/) after June 15.
For any query, please contact mg16[AT]icranet.org



5. ICRA-ICRANet press release "The morphology of the X-ray afterglows and of the jetted GeV emission in long gamma-ray bursts", May 12, 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. ICRA-ICRANet press release "The newborn black hole in GRB 191014C proves that it is alive", May 27, 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. Renewal of the Cooperation Agreement ICRANet - University of Ferrara, Italy, May 28, 2021

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On May 28, 2021, the Cooperation Agreement between ICRANet and the University of Ferrara (UNIFE) has been renewed. The renewal was signed by Prof. Vincenzo Guidi (Director of the Physic Department of UNIFE) and by Prof. Remo Ruffini (Director of ICRANet). This agreement will be valid for further 5 years and the main joint activities to be developed under its framework include: the promotion of theoretical and observational activities within the field of Relativistic Astrophysics; the institutional exchange of faculty members, researchers, post-doctorate fellows and students; the promotion of technological developments; the development of Data Centers for Astrophysical data in all wavebands; the organization of training and teaching courses, seminars, conferences, workshops or short courses, the development of inter-institutional research areas associated to local graduate programs and joint publications.
For the text of the agreement see:
http://www.icranet.org/index.php?option=com_content&task=view&id=1097



8. New Cooperation protocol and specific Agreement ICRANet- Universidad Nacional de La Plata (UNLP), Argentina, March 18, 2021

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On May 2021, ICRANet has received the official confirmation that a new Cooperation protocol as well a specific agreement between ICRANet and the Universidad Nacional De La Plata (UNLP) in Argentina have been signed. The Cooperation Protocol has been signed on March 18, 2021 (both in English and in Spanish) by Dr Fernando Alfredo Tauber (President of UNLP) and by Prof. Remo Ruffini (Director of ICRANet), while the Specific Agreement has been signed by EngD Marcos Daniel Actis (UNLP Vice President for Institutional Affairs), by Lic. Raúl Anìbal Perdomo (UNLP Faculty of Astronomy and Geophysics) as well as by Prof. Remo Ruffini.
Both the agreements will be valid for 4 years and the main joint activities to be developed under their framework include: the promotion of theoretical and observational activities within the field of Relativistic Astrophysics; the institutional exchange of faculty members, researchers, post-doctorate fellows and students; the promotion of technological developments; the development of Data Centers for Astrophysical data in all wavebands; the organization of training and teaching courses, seminars, conferences, workshops or short courses, the development of inter-institutional research areas associated to local graduate programs and joint publications.
For the texts of the Cooperation Protocol as well as of the Specific Agreement:
http://www.icranet.org/index.php?option=com_content&task=view&id=1369



9. Renewal of the Cooperation Protocol ICRANet - Sharif University of Technology, Iran, March 9, 2021

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On April 2021, ICRANet has received the official confirmation that the Cooperation protocol between ICRANet and Sharif University of Technology (Iran) was renewed. The renewal was signed on March 9, 2021 by Prof. Mahmoud Fotouhi Firoozabad (President of Sharif University of Technology) and by Prof. Remo Ruffini (Director of ICRANet). This agreement will be valid for further 5 years and the main joint activities to be developed under its framework include: the promotion of theoretical and observational activities within the field of Relativistic Astrophysics; the institutional exchange of faculty members, researchers, post-doctorate fellows and students; the promotion of technological developments; the development of Data Centers for Astrophysical data in all wavebands; the organization of training and teaching courses, seminars, conferences, workshops or short courses, the development of inter-institutional research areas associated to local graduate programs and joint publications.
For the text of the agreement see:
http://www.icranet.org/index.php?option=com_content&task=view&id=1061



10. Renewal of the Cooperation Protocol ICRANet - Institute for Research in Fundamental Sciences (IPM), Iran, April 12, 2021

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On April 12, 2021 the Cooperation Protocol between ICRANet and the Institute for Research in Fundamental Sciences (IPM) has been renewed. The renewal has been signed by Prof. Mohammad Javad A. Larijani (Director of IPM) and by Prof. Remo Ruffini (Director of ICRANet). This agreement will be valid for further 5 years and the main joint activities to be developed under its framework include: the promotion of theoretical and observational activities within the field of Relativistic Astrophysics; the institutional exchange of faculty members, researchers, post-doctorate fellows and students; the promotion of technological developments; the development of Data Centers for Astrophysical data in all wavebands; the organization of training and teaching courses, seminars, conferences, workshops or short courses, the development of inter-institutional research areas associated to local graduate programs and joint publications.
For the text of the agreement see:
http://www.icranet.org/index.php?option=com_content&task=view&id=1060


11. "Gerbertus 2021. Astrophysics and new technologies", online meeting, May 12, 2021

The annual congress in honor of Gerbert of Aurillac, scientist, scholastic astronomer and Pope, took place virtually on May 12, 2021 and has been coordinated, as the previous ones, by and in the ICRANet center in Pescara at international level.
Gerbert d'Aurillac (circa 938-12.5.1003) was a Benedictine monk in his home town in France, he studied mathematics and astronomy in Vic (Catalonia) and was known for the music already by Pope Johannes XIII in 971 in Rome. From there, he left for Reims, where he served as a teacher at the cathedral school and as secretary of the Archbishop Adalberone until his death. He was elected Bishop of Reims in 991, after the deposition of Arnolfo, which the Pope didn't recognize as valid, and in 995 he withdrawn in Saasbach to be the tutor of the young Emperor Otto III. He wrote several treaties on the organ pipes (980), on the Astrolabe and on the Abaco, he introduced the indo-Arab digits (983, Carme Figurato a Ottone II) on the De Rationali et ratione uti (997 a Ottone III) and his epistolary was the richest we received in the X century. In 998, Pope Gregory V appointed him as Bishop of Ravenna and on April 9, 999, on the Easter day, he was crowned Pope in Rome "da R in R in R", assuming the name of Sylvester II. According to a legend, Gerbert, considered as the most duct man of his times, built an automaton in binary logic.
Astrophysics and new technologies is the title of the 2021 edition of the meeting and the idea is to maintain the contact with the historical tradition, also by using new technologies. The invited speakers included also undergraduate students, in order to be more efficient in hitting the audience of high school students and addressing them on the opportunities offered to them in computer science, electronics, automation, robotic, environment and territory in relation to the field of observational astronomy and/or theoretical astrophysics.
The virtual meeting started at 4:00 PM on May 12, with the opening remarks made by Prof. Remo Ruffini (Director of ICRANet) and by Prof. Cosimo Palagiano (Accademia nazionale dei Lincei). Those have been followed by presentations on "Science, astrophysics and new technologies" by Prof. Francesco Berrilli (Tor Vergata and Accademia nazionale dei Lincei - physicist of the Sun), on "Interferometry in astronomy: from the Hanbury Brown and Twiss interferometer to the global very long baseline array" by Prof. Paolo Ochner (Astrophysical Observatory of Asiago and University of Padua, astronomer), by Daniele Impellizzeri (ITA G. Garibaldi, IT specialist), on the "study of the photoluminescence of the hybrid Perovskiti" by Paolo De Vincenzi (University of Roma La Sapienza, Physics, student), on the "computer science in the study of the phenomena" by Andrea Brucato (University of Roma La Sapienza, Physics, student), on the "Computer science in the school" by Fabio Zaccagnini (University of Roma La Sapienza, Physics, student), on "The role of computer science in astronomy" by Lorenzo Ricciardi (University Roma Tre, Computer science, student), on the "total station" by Prof. Paola Spera (IIS Caffè, CAT instructor), on the "survey campaign for the sundial of Santa Maria degli Angeli" by Prof. Giuseppe Cultrera (IIS Caffè, CAT teacher), on "Technology for astrophysics" by Prof. Runa Briguglio (INAF - Astrophysical Observatory of Arcetri) and on the "comment to the digital edition of Lo Scontro della Cometa (G. Artom, 1910)" by Prof. Federico Manzini (Astronomical station IAU A12).
During the conference, 2 digitalized booklets were presented: "Lo Scontro della Cometa" (1911) and "Mars in 1896/97", the last one also with an experiment to see through a telescope a coin at 30 m far, with the same angular diameter of Mars in January 1897. It has been also presented by Prof. Sigismondi, the volume n. 14 of Gerbertus (2021) - http://www.icra.it/gerbertus/2021/Gerb-14-2021-totale.pdf.
Both the program of the event, as well the recording of the talks are available on the webpage of the meeting: http://www.icranet.org/index.php?option=com_content&task=view&id=1366
On that occasion, Prof. Sigismondi has also prepared a press release (in Italian) available at this link: http://www.icranet.org/scuola_lavoro/2020-2021/12052021/press_release.pdf
For the history of the previous meetings since 2003: http://www.icra.it/gerbertus



12. World Astronomy week virtual meeting, ICRANet Isfahan (Iran), May 11-12, 2021

International Astronomy Week is a public annual event, intended to inform students and general audience about Astronomy and Astrophysics, and to provide an active atmosphere for public scientific discussions about astronomy between professionals, scholars and students to interact and exchange new ideas in this field.
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This event has been organized by Dr. Soroush Shakeri, from ICRANet-Isfahan, and the Department of Physics at IUT on May 11-12, 2021 as a virtual meeting. In this meeting, several scientists from Germany and Iran have been brought together to discuss about different topics in astronomy. The meeting started on May 11 at 16:30 (IRST), with an interesting talk given by Dr. Behnam Javanmardi from University of Bonn, Germany, about "Cosmological inconsistencies and Hubble Constant", and continued with an extensive discussion by Dr. Javad Taghizadeh Firouzjaee from K.N. Toosi University of Technology, Tehran, about "The Mystery of Black Holes" and the recent Nobel Prize in physics. In the second day of the meeting, Dr. Sedighe Sajadian from the Department of Physics of IUT, Isfahan, talked about different methods of detecting extrasolar planets and about the possibility to have life beyond our solar system. At the end, Dr. Mahdi Kord Zangeneh from Shahid Chamran University of Ahvaz, presented an extensive overview about Cosmology and the recent achievements in astrophysics, where he had an interactive discussion with students about various ongoing researches in the field.
For the news on the IUT newsletter:
https://iscoweb.iut.ac.ir/sites/iscoweb/files/u758/nl-no.18-_may_2021.pdf



13. Recent publications

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
 
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